bluuebunny/crossref_metadata_2025 huggingface dataset:
Laclos après Laclos
Authors: Thil Éric
Published: September 2021

Un des textes de jeunesse de Marguerite Yourcenar, Alexis ou Le Traité du vain combat , un roman de 1929, acquiert une profondeur nouvelle si on le voit comme un dialogue littéraire avec Les Liaisons dangereuses de Laclos : sa forme (il s’agit d’une confession épistolaire monodique) et la subversion de celle-ci vont main dans la main pour livrer un message qu’il s’agit de lire entre les lignes.
Laclos après Laclos
Authors: Matar Imen
Published: September 2021

Dans le roman épistolaire Nous sommes cruels , Camille de Peretti relève le défi de récrire, deux-cent- vingt-quatre ans après leur parution, Les Liaisons dangereuses de Choderlos de Laclos. L’œuvre nouvelle est une création par dérivation, ce qui lui donne son statut. Le propos de cet article est d’analyser l’un des aspects du travail accompli par le récrivain sur l’hypotexte. Entre le respect total des énoncés originels intégrés au sein du texte second sans la moindre indexation et la dénaturation des propos des Liaisons via les citations intégrées, C. de Peretti écrit un nouveau roman original basé sur le palimpseste originel.
Laclos après Laclos
Authors: Sebbah Alain
Published: September 2021

Il y a eu du roman de Laclos un nombre d’adaptations considérable, depuis Les Liaisons dangereuses 1960 , jusqu’à de récents films américains ou coréens. Ils dialoguent avec l’œuvre en offrant à l’occasion des ouvertures sur des scènes suggérées par l’auteur ou en en rajoutant. On peut se demander si toute version cinématographique n’est pas, à sa façon, une trahison du romancier.
Les femmes sur l’Île de La Réunion fortement exposées aux violences pendant l’enfance et l’adolescence
Authors: Condon Stéphanie , Dauphin Sandrine , Dupuis Justine , l’équipe de l’enquête Virage dans l
Published: September 2021

À La Réunion, d’après l’enquête Virage dans les Outre-mer, 30 % des femmes et 25 % des hommes déclarent des faits de violence avant 18 ans dans les différentes sphères de vie (études, loisirs, cercle amical, famille, proches). Ces faits sont nettement plus fréquents que dans l’Hexagone. Au sein de la famille, les femmes déclarent davantage de violences subies, et cela de tout type (psychologique, physique, sexuel). Les auteurs de violences sexuelles subies par les mineures de moins de 18 ans sont majoritairement des hommes de la famille et de l’entourage proche.
The Brinkman-Fourier system with ideal gas equilibrium
Authors: Liu Chun , Sulzbach Jan-Eric
Published: September 2021

In this work, we will introduce a general framework to derive the thermodynamics of a fluid mechanical system, which guarantees the consistence between the energetic variational approaches with the laws of thermodynamics. In particular, we will focus on the coupling between the thermal and mechanical forces. We follow the framework for a classical gas with ideal gas equilibrium and present the existences of weak solutions to this thermodynamic system coupled with the Brinkman-type equation to govern the velocity field.
A computable formula for the class number of the imaginary quadratic field $ \mathbb Q(\sqrt{-p}), \ p = 4n-1 $
Authors: Villeda Jorge Garcia
Published: September 2021

Using elementary methods, we count the quadratic residues of a prime number of the form $ p = 4n-1 $ in a manner that has not been explored before. The simplicity of the pattern found leads to a novel formula for the class number $ h $ of the imaginary quadratic field $ \mathbb Q(\sqrt{-p}). $ Such formula is computable and does not rely on the Dirichlet character or the Kronecker symbol at all. Examples are provided and formulas for the sum of the quadratic residues are also found.
A class of fourth-order hyperbolic equations with strongly damped and nonlinear logarithmic terms
Authors: Cheng Yi , Chu Ying
Published: September 2021

In this paper, we study a class of hyperbolic equations of the fourth order with strong damping and logarithmic source terms. Firstly, we prove the local existence of the weak solution by using the contraction mapping principle. Secondly, in the potential well framework, the global existence of weak solutions and the energy decay estimate are obtained. Finally, we give the blow up result of the solution at a finite time under the subcritical initial energy.
The algebraic classification of nilpotent commutative algebras
Authors: Jumaniyozov Doston , Kaygorodov Ivan , Khudoyberdiyev Abror
Published: September 2021

This paper is devoted to the complete algebraic classification of complex $ 5 $-dimensional nilpotent commutative algebras. Our method of classification is based on the standard method of classification of central extensions of smaller nilpotent commutative algebras and the recently obtained classification of complex $ 5 $-dimensional nilpotent commutative $ \mathfrak{CD} $-algebras.
Stabilizing effect of elasticity on the motion of viscoelastic/elastic fluids
Authors: Jiang Fei
Published: September 2021

It is well-known that viscoelasticity is a material property that exhibits both viscous and elastic characteristics with deformation. In particular, an elastic fluid strains when it is stretched and quickly returns to its original state once the stress is removed. In this review, we first introduce some mathematical results, which exhibit the stabilizing effect of elasticity on the motion of viscoelastic fluids. Then we further briefly introduce similar stabilizing effect in the elastic fluids.
Semi-analytic pricing of double barrier options with time-dependent barriers and rebates at hit
Authors: Itkin Andrey , Muravey Dmitry
Published: September 2021

We continue a series of papers devoted to construction of semi-analytic solutions for barrier options. These options are written on underlying following some simple one-factor diffusion model, but all the parameters of the model as well as the barriers are time-dependent. We managed to show that these solutions are systematically more efficient for pricing and calibration than, e.g., the corresponding finite-difference solvers. In this paper we extend this technique to pricing double barrier options and present two approaches to solving it: the General Integral transform method and the Heat Potential method. Our results confirm that for double barrier options these semi-analytic techniques are also more efficient than the traditional numerical methods used to solve this type of problems.
Option pricing under a discrete-time Markov switching stochastic volatility with co-jump model
Authors: Fu Michael C. , Li Bingqing , Wu Rongwen , Zhang Tianqi
Published: September 2021

We consider option pricing using a discrete-time Markov switching stochastic volatility with co-jump model, which can capture asset price features such as leptokurtosis, skewness, volatility clustering, and varying mean-reversion speed of volatility. For pricing European options, we develop a computationally efficient method for obtaining the probability distribution of average integrated variance (AIV), which is key to option pricing under stochastic-volatility-type models. Building upon the efficiency of the European option pricing approach, we are able to price an American-style option, by converting its pricing into the pricing of a portfolio of European options. Our work also provides constructive guidance for analyzing derivatives based on variance, e.g., the variance swap. Numerical results indicate our methods can be implemented very efficiently and accurately.
Asset price bubbles: Invariance theorems
Authors: Jarrow Robert , Protter Philip , Martin Jaime San
Published: September 2021

This paper provides invariance theorems that facilitate testing for the existence of an asset price bubble in a market where the price evolves as a Markov diffusion process. The test involves only the properties of the price process' quadratic variation under the statistical probability. It does not require an estimate of either the equivalent local martingale measure or the asset's drift. To augment its use, a new family of stochastic volatility price processes is also provided where the processes' strict local martingale behavior can be characterized.
Small defects reconstruction in waveguides from multifrequency one-side scattering data
Authors: Bonnetier Éric , Niclas Angèle , Seppecher Laurent , Vial Grégory
Published: September 2021

Localization and reconstruction of small defects in acoustic or electromagnetic waveguides is of crucial interest in nondestructive evaluation of structures. The aim of this work is to present a new multi-frequency inversion method to reconstruct small defects in a 2D waveguide. Given one-side multi-frequency wave field measurements of propagating modes, we use a Born approximation to provide a \begin{document}$ \text{L}^2 $\end{document}-stable reconstruction of three types of defects: a local perturbation inside the waveguide, a bending of the waveguide, and a localized defect in the geometry of the waveguide. This method is based on a mode-by-mode spacial Fourier inversion from the available partial data in the Fourier domain. Indeed, in the available data, some high and low spatial frequency information on the defect are missing. We overcome this issue using both a compact support hypothesis and a minimal smoothness hypothesis on the defects. We also provide a suitable numerical method for efficient reconstruction of such defects and we discuss its applications and limits.
The evolution mechanism of the multi-value chain network ecosystem supported by the third-party platform
Authors: Zhang Xumei , Yuan Jiafeng , Dan Bin , Sui Ronghua , Li Wenbo
Published: September 2021

This paper aims to study the evolution mechanism of the third-party platform ecosystem. A multi-value chain network ecosystem composed of multiple manufacturers, multiple suppliers, several logistics providers and a third-party platform for manufacturing is considered. The system dynamics method is used to build the model, and this paper collects relevant industry and platform data to simulate the evolution of user scale and participants' revenues. Furthermore, the influence of platform subsidy and matching service level on the evolution is studied. The results show that the platform's evolution can be divided into four stages: emergence, growth, maturity and upgrade. This paper also finds that, at the emergence stage and the growth stage, the augmentation of the subsidies to manufacturers makes the manufacturers' scale expand but let their revenues decline. Meanwhile, the platform's revenues reduce at the emergence stage while increase at the growth stage. When the subsidy amount is high and continues to augment, its positive effect on the user scale is weakened while its negative effect on manufacturers' revenues is enhanced. Besides, improving the matching service level is not conducive to the platform's revenues at the emergence stage, but after entering the growth stage, it can increase user scale and the platform's revenues simultaneously.
Human resources optimization with MARS and ANN: Innovation geolocation model for generation Z
Authors: Graczyk-Kucharska Magdalena , Olszewski Robert , Golinski Marek , Spychala Malgorzata , Szafranski Maciej , Wilhelm Weber Gerhard , Miadowicz Marek
Published: September 2021

Human resources (HR) have a key impact on the creation and implementation of modern products, solutions and concepts. Relatively new and rarely undertaken research challenge in enterprise is optimization of HR in the context of their location and requirements for working conditions. A great challenge here is the transparency and reliability of the collected data. In the article, we present a modern approach to knowledge extraction based on Artificial Intelligence (AI) and Multivariate Adaptive Regression Splines optimizing the availability of HR with a high innovation rate, taking into account their availability time and location. This study was conducted on a group of 5095 young people from the Z generation. A total of 11 variables were analyzed in the context of innovation and presented in this article. The effect of research using machine learning methods is the analysis of the characteristics of generation Z representatives, whose desire is to work in innovative companies. Research results indicate that some regions offer candidates with a higher level and commitment to innovation, and thus make HR more available for the development of innovative products. Chosen models designed by using AI and Operational Research Analytics were presented in the graphic visualization, which is a novelty in the presentation of similar issues in relation to HR.
Analysis of 2D heat conduction in nonlinear functionally graded materials using a local semi-analytical meshless method
Authors: Wang Chao ,   College of Mechanical and Electrical Engineering, National Engineering Research Center for Intelligent Electrical Vehicle Power System, Qingdao University, Qingdao 266071, China, Wang Fajie , Gong Yanpeng ,   Institute of Mechanics for Multifunctional Materials and Structures, Qingdao University, Qingdao 266071, China,   Institute of Electronics Packaging Technology and Reliability, Faculty of Materials and Manufacturing, Beijing University of Technology, Beijing 100124, China
Published: September 2021

This paper proposes a local semi-analytical meshless method for simulating heat conduction in nonlinear functionally graded materials. The governing equation of heat conduction problem in nonlinear functionally graded material is first transformed to an anisotropic modified Helmholtz equation by using the Kirchhoff transformation. Then, the local knot method (LKM) is employed to approximate the solution of the transformed equation. After that, the solution of the original nonlinear equation can be obtained by the inverse Kirchhoff transformation. The LKM is a recently proposed meshless approach. As a local semi-analytical meshless approach, it uses the non-singular general solution as the basis function and has the merits of simplicity, high accuracy, and easy-to-program. Compared with the traditional boundary knot method, the present scheme avoids an ill-conditioned system of equations, and is more suitable for large-scale simulations associated with complicated structures. Three benchmark numerical examples are provided to confirm the accuracy and validity of the proposed approach.
Optimal control of transverse vibration of a moving string with time-varying lengths
Authors: Sun Bing
Published: September 2021

In this article, we are concerned with optimal control for the transverse vibration of a moving string with time-varying lengths. In the fixed final time horizon case, the Pontryagin maximum principle is established for the investigational system with a moving boundary, owing to the Dubovitskii and Milyutin functional analytical approach. A remark then follows for discussing the utilization of obtained necessary optimality condition.
Convergence of coprime factor perturbations for robust stabilization of Oseen systems
Authors: Heiland Jan
Published: September 2021

Linearization based controllers for incompressible flows have been proven to work in theory and in simulations. To realize such a controller numerically, the infinite dimensional system has to be linearized and discretized. The unavoidable consistency errors add a small but critical uncertainty to the controller model which will likely make it fail, especially when an observer is involved. Standard robust controller designs can compensate small uncertainties if they can be qualified as a coprime factor perturbation of the plant. We show that for the linearized Navier-Stokes equations, a linearization error can be expressed as a coprime factor perturbation and that this perturbation smoothly depends on the size of the linearization error. In particular, improving the linearization makes the perturbation smaller so that, eventually, standard robust controller will stabilize the system.
An explicit finite volume algorithm for vanishing viscosity solutions on a network
Authors: Towers John D.
Published: September 2021

In [Andreianov, Coclite, Donadello, Discrete Contin. Dyn. Syst. A, 2017], a finite volume scheme was introduced for computing vanishing viscosity solutions on a single-junction network, and convergence to the vanishing viscosity solution was proven. This problem models \begin{document}$ m $\end{document} incoming and \begin{document}$ n $\end{document} outgoing roads that meet at a single junction. On each road the vehicle density evolves according to a scalar conservation law, and the requirements for joining the solutions at the junction are defined via the so-called vanishing viscosity germ. The algorithm mentioned above processes the junction in an implicit manner. We propose an explicit version of the algorithm. It differs only in the way that the junction is processed. We prove that the approximations converge to the unique entropy solution of the associated Cauchy problem.
Overview, Framework, and Research Propositions of Secondhand Exchange in the Platform Economy
Authors: Armstrong Soule Catherine Anne , Hanson Sara
Published: September 2021

This chapter describes secondhand exchange in the context of the platform economy. Consumers have long engaged in reselling and buying used items as an alternative to purchasing firsthand items, but researchers have little understanding of how these exchanges are different theoretically from traditional consumption patterns. This chapter presents a clear definition of secondhand exchange and separates it from related concepts, including lateral exchange markets, the sharing economy, access-based consumption, and collaborative consumption. It is suggested that secondhand exchange and related consumer behavior in the platform economy can be understood by considering platform differences related to 1) when and how product ownership is transferred (i.e., direct and indirect), 2) the level of platform intermediation (i.e., low, moderate, or high), and 3) buyers' knowledge of reseller identity (i.e., unknown, obscured, and known). Research propositions are presented for these dimensions for each facet of the consumption process (i.e., buying, owning, and disposal).
A Look at the New Online Consumer Behavior on Social Media Platforms
Authors: Rosário Albérico Travassos
Published: September 2021

Technological advances have caused great business changes. In this new business environment, the internet has become an indispensable technology tool in the creation of new business models, based on the exchange relations between customers/suppliers/distributors/partners, with a significant increase in online purchasing transactions. This virtual environment has provided the development of e-commerce and efficiency gains and influences changes in consumer habits, thus changing consumer behavior. The online purchase presents an important change in consumer behavior; thus, the understanding of online consumer behavior is essential to understand the impact of this behavior on business. This chapter follows a systematic analysis of the literature with a qualitative approach to online consumer behavior in the last 5 years (2015-2020) in order to verify research topics and development patterns. The aim is to identify trends in online consumer behavior and recognize research gaps by providing avenues for further research into online consumer behavior.
The Landscape of Social Commerce in Indonesia
Authors: Anggraeni Adilla , Felix Derian
Published: September 2021

Social commerce is a growing research field. However, there is still limited discussion on how social commerce companies can thrive in the emerging market such as Indonesia given some differences in terms of customer and other supporting infrastructure characteristics. The chapter covers the growth of social commerce, Indonesian social commerce landscape, and different elements of social commerce including customer engagement, customer interaction, and digital influencers. It is expected that this chapter can provide better insights into social commerce in Indonesia.
Creative Solutions for Today's Students
Authors: Thomas Tyan , Scaletta Alice Lim , Park Sharon K.
Published: September 2021

This chapter will explore the connection between diversifying health profession student demographics, diversifying challenges these students face, and the new obstacles presented by shifting curriculum delivery to remote and hybrid learning during the coronavirus disease 2019 (COVID-19) pandemic. The chapter will explore challenges that may seem especially difficult to address in a remote learning model: the desire to develop community among fellow learners when in a hybrid or fully remote program and when learners are from varied backgrounds; cultivating in students coping mechanisms to manage anxiety from the economic uncertainty of today's world, balancing commitments between educational pursuits and other responsibilities (e.g., child or parent care, etc.); and facilitating learning for students with physical and/or mental disabilities or chronic medical conditions.
Innovative Adaptation of Training and Technical Assistance
Authors: Hagle Holly N. , Liu Yifei , Murphy Deena M. , Krom Laurie
Published: September 2021

The behavioral health workforce is pivotal to provide evidence-based services (EBPs) for patients with mental illnesses or substance use disorders. The COVID-19 pandemic has exacerbated existing healthcare issues for these patients and highlighted the need for a well-trained workforce. The stay-at-home orders compelled a rapid transition to delivering behavioral health services from traditional face-to-face encounters to telehealth/telecommunication services. Training and technical assistance (TTA) networks supporting the behavioral health workforce's educational needs quickly moved to virtual delivery. This shift has resulted in innovations and adaptations categorized into four areas: adapting is crucial, convening stakeholders is essential, resources (human and technological) are needed, and community involvement is integral. Future TTA efforts should focus on sharing the successful virtual adaptations to EBPs.
Exposing Learners to Practice
Authors: Shewmaker Jennifer Wade , Austin Lynette , Garcia M. Monica
Published: September 2021

Clinical education is the center of professional preparation in healthcare fields, linking theoretical knowledge with clinical practice in the minds and behaviors of student clinicians. Clinical education, supervised by educators who are licensed professionals, is essential in the process of creating new professionals. What does a professional training program do about clinical education when the world shuts down? This chapter addresses the context of a private, not for profit university's response to the COVID-19 public healthcare crisis in spring of 2019 and the process by which a graduate training program in speech-language pathology re-organized, and re-visioned, clinical education in that context. The process allowed an upper cohort of students to graduate successfully and on time, engaged a lower cohort of brand-new clinicians in meaningful clinical learning, and taught the program new lessons about what is important in designing clinical education.
Challenges in Pharmacy Education With Limited Resources During COVID-19
Authors: Olson Phayom Sookaneknum , Leelathanalerk Areerut , Hung Nguyen Van , Tan Bee Kim , Nacabu-an Shiela May Jayme , Setiawan Christianus Heru , Sibounheuang Phoutsathaphone , Srimongkon Pornchanok , Sungthong Bunleu , Jungnickel Paul W.
Published: September 2021

The rapidly emerging COVID-19 pandemic resulted in the need for rapid and extensive changes in the education programs of universities. This chapter reviews the changes in teaching and learning made by pharmaceutical faculties in six universities located in the Association of Southeast Asian Nations (ASEAN): Mahasarakham University (Thailand), Taylor's University (Malaysia), University of the Philippines-Manilla (Philippines), Hai Phong University of Medicine and Pharmacy (Vietnam), University of Health Sciences (Lao PDR), and Sanata Dharma University (Indonesia). The authors discuss adjustments that were made based on educational contexts, planning and infrastructure, educational processes, and products and outcomes. Each university provides a specific story concerning lessons learned in responding to the pandemic. The chapter concludes with changes that will be employed in future emergency situations, as well as those that will continue to be incorporated with the resumption of normal operations.
Artificial Neural Network (ANN) Model for Shear Strength of Soil Prediction
Authors: Richard Jacqueline A. , Sa’don Norazzlina M. , Karim Abdul Razak Abdul
Published: September 2021

Geotechnical structures, design of embankment, earth and rock fill dam, tunnels, and slope stability require further attention in determining the shear strength of soil and other parameters that govern the result. The shear strength of soil commonly obtained by conducting laboratory testing such as Unconfined Compression Strength (UCS) Test and Unconsolidated Undrained (UU) Test. However, random errors and systematic errors can occur during experimental works and caused the findings imprecise. Besides, the laboratory test also consuming a lot of time and some of them are quite costly. Therefore, soft computational tools are developed to improve the accuracy of the results and time effectively when compared to conventional method. In this study, Artificial Neural Network (ANN) was employed to develop a predictive model to correlate the moisture content (MC), liquid limit (LL), plastic limit (PL), and liquidity index (LI) of cohesive soil with the undrained shear strength of soil. A total of 10 databases was developed by using MATLAB 7.0 - matrix laboratory with 318 of UCS tests and 451 of UU tests which are collected from the verified site investigation (SI) report, respectively. All the SI reports collected were conducted in Sarawak, Malaysia. The datasets were split into ratio of 3:1:1 which is 60:20:20 (training: validation: testing) with one hidden layer and eight hidden neurons. The input parameter of Liquidity index (LI) has shown the highest R-value (regression coefficient) which are 0.926 and 0.904 for UCS and UU model, respectively. In addition, the predictive models were tested and compare with the predicted and observed cohesion obtained from the collected experimental results. In summary, the ANN has the feasibility to be used as a predictive tool in estimating the shear strength of the soil.
Sorption of Coated and Uncoated Nanocrystalline Zinc Oxide from Aqueous Solutions onto Raw and Acetylated Cellulose Sago Hampas: Equilibrium, Kinetic and Thermodynamic Studies
Authors: Droepenu Eric Kwabena , Wee Boon Siong , Chin Suk Fun , Kok Kuan Ying
Published: September 2021

In this study, sorption efficiency of coated (C-) and uncoated (U-) zinc oxide nanoparticles (ZnO-NPs) in aqueous solution onto raw sago hampas (RSH) and acetylated sago hampas (ACSH) was studied. Physical and chemical characteristics of both the sorbate and sorbents were analysed using various characterization techniques. The mechanism of the sorption process was evaluated using equilibrium isotherms, kinetic and thermodynamic studies. From the study, maximum percentage removal of both sorbate ions were achieved at an equilibration time of 100 minutes with an optimum sorbate mass of 2.0 g per 50 ml. The study recorded a maximum % removal of 85.1% & 87.6% for C-and U-ZnO-NPs (< 50 nm) onto RSH and 90.0% & 91.1% onto ACSH. Langmuir isotherm fitted well for the sorption process with the highest efficiency of 0.793 mg/g recorded for C-ZnO-NPs onto RSH. Pseudo-second model best described the sorption process. An exothermic and non-spontaneous sorption process was realised in all the sorption studies except that of U-ZnO-NPs (< 50 nm) onto ACSH which became spontaneous as temperature increased. Based on the findings from the multiple approaches employed, both sorbents could be proposed as viable alternatives to act as a green sorbent in the removal of ZnO-NPs from water and wastewater.
Chemically Modified Coconut Shell Biochar for Removal of Heavy Metals from Aqueous Solution
Authors: Imran-Shaukat Muhammad , binti Rosli Nur Rafikah , Wahi Rafeah , Abdullah Sharifah Mona Abd Aziz , Ngaini Zainab
Published: September 2021

In this study, coconut shells were converted into biochar via pyrolysis and chemically modified via an acid-base treatment to enrich its adsorption capabilities. Batch experiments were carried out to analyze the adsorption potential of the modified coconut shell (MCSC) or removal of chromium, nickel, and copper from aqueous solution. The chemical modification increased the surface area of MCSC to 185.712 m2/g. Batch adsorption study using MCSC resulted in 99% removal of copper, 95% (nickel), and 39% (chromium). The adsorption of studied metal ions fitted well with Langmuir isotherm, showing a monolayer adsorption process. A kinetic analysis showed that all the samples match a strong correlation coefficient in pseudo-second-order (R2>0.95), indicating the occurrence of a chemical adsorption process.
Effect of the Type of Adhesives on the Properties of Multilayer Packaging Material Based on PET/AlOx Film with Acrylic Coating before and after the Sterilization Process
Authors: Muratov Iskander , Garipov Ruslan , Efremova Anna
Published: September 2021

In this work the properties of multilayer packaging materials based on PET/AlOx film with acrylic coating were studied. Multilayer packaging materials were produced on industrial laminators using three different adhesive compositions with different content of reactive groups. It is shown that the peculiarity of the chemical nature of adhesive components affects the bond strength and the seal strength of multilayer packaging materials.
Study of the Aging of Cold-Cured SKU-PFL Type Polyurethane Filled with Waste Products
Authors: Safiullina Tatyana R. , Nurieva Elvira N. , Zenitova Lyubov A.
Published: September 2021

The article describes the results of aging of samples of cold-cured molded polyurethanes of SKU-PFL brand filled with zeolite and silica gel - wastes of petrochemical production. The samples were aged under normal climatic conditions for 5 years. Filling of the samples varied from 10 to 50 %wt. Investigations of physical and mechanical properties of the samples before and after aging were carried out, the basic indicators of material quality were calculated using Microsoft Office Excel package. As a result of researches it was established that after aging the basic physical and mechanical properties of cast polyurethanes of SKU-PFL brand of cold curing filled with zeolite and silica gel change insignificantly, however the best resistance to aging are in samples with 20 %wt. zeolite and 10 %wt. silica gel filling both before and after aging that allowed to recommend them for long-term use of articles.
The Influence of Technological Parameters on Morphology of Electrospun Nanofibers Based on Hyaluronic Acid
Authors: Snetkov Petr P. , Morozkina Svetlana N. , Olekhnovich Roman O. , Uspenskaya Mayya Valerievna
Published: September 2021

Electrospinning as a high-functioning, multi-operated, and advanced method of nanofiber production allowing to obtain fibrous materials based on different polymers for a wide range of biomedical and bioengineering applications. Hyaluronic acid is one of the most promising polymers for nanofiber formation due to its unique biological and biochemical properties. In spite of the difficulties and special features of the electrospinning from hyaluronic acid solutions, the amount of studies in this field is ever-growing. Unfortunately, there is a significant shortage of fundamental data describing the relations between the technological parameters and the nanofiber morphology. This study considers the key technological parameters of the electrospinning process such as applied voltage and flow volume rate and evaluates their influence on the morphology, mean diameter, and diameter distribution width of nanofibers based on native hyaluronic acid. The optimal range of the defined parameters has been established, at which the stability of the fiber formation is ensured. It is shown that by varying of the applied voltage and the flow volume rate of the polymer spinning solution, it is possible to control the properties of nanofibers.
Polymerization of Styrene in the Presence of Polybutadiene as a Stabilizer
Authors: Lobanova Nadezhda
Published: September 2021

The problem of synthesis of polymer suspensions with a narrow particle size distribution is relevant, since the field of their practical application is extremely wide. They are used as calibration standards in electron and optical microscopy and light scattering, for determining the pore size of filters and biological membranes, as model colloids, for studying the kinetics and mechanism of film formation from latex, as well as as polymer carriers of biological ligands in immunochemical studies [1].
Influence of Vulcanizing System on the Properties of Rubbers Based on Ethylenepropylene Rubber
Authors: Zakirova Larisa Yuryevna
Published: September 2021

The article investigates the effect of vulcanizing systems of different activity on the vulcanization and elastic-strength properties of rubber compounds based on ethylene-propylene rubber Keltan . Were taken vulcanizing systems: a mixture of organic peroxide, sulfur and sulfenamide accelerator (1); a mixture of organic peroxide, sulfur and dithiodimorpholine (2); a mixture of organic peroxide, sulfur and thiuram accelerator (3); sulfur and sulfenamide accelerator (4). The vulcanization characteristics (maximum and minimum torques; times of onset, optimum and reaching the maximum speed of vulcanization) were evaluated. Elastic-strength (conditional tensile strength, elongation at break, hardness) properties of rubber compounds and operational (changes in conditional tensile strength, elongation at break after aging in air) were determined. It was found that the vulcanizing system (3) containing sulfur, peroxide in an amount of 7.0 parts by weight and thiuram accelerator imparts the best elastic and strength properties to rubber compounds and leads to their resistance to high temperatures.
Self-Voluntary Polymerization with Formation of Quaternary Ammonium Groups
Authors: Malkanduev Yusuf A. , Begieva Madina B. , Kokoeva Aneta A. , Dzhalilov Аblulakhat T.
Published: September 2021

The reaction of spontaneous polymerization in the N, N-dialkylaminoethyl methacrylate - alkyl halide system in organic solvent solutions is considered. It is shown that polymerization in the system under study begins only after the formation of quaternary ammonium salt in the reaction medium (at a concentration of about 0.2 mol/L) by the Menshutkin reaction, as a result of quaternization of the unsaturated amine with an alkyl halide. For the explanation of the aggregate of the obtained experimental data, fundamental considerations were formulated, kinetic schemes were developed, and the corresponding mechanism of polymerization processes was proposed.
Peculiar Properties of Spontaneous Methacrylate Derivatives Polymerization with Haloidallyl Compounds
Authors: Malkanduev Yusuf A. , Kokoeva Aneta A. , Dzhalilov Аblulakhat T.
Published: September 2021

The reaction of spontaneous polymerization in the system of N, N-diethylaminoethyl methacrylate with allyl chloride and bromide, orthophosphoric acid in ethanol and dimethyl sulfoxide solutions is considered. Spontaneous polymerization proceeds, consisting of two stages: the quaternization reaction and the polymerization reaction. It was shown that the accompanying reaction of quaternization, spontaneous polymerization, takes place both in a mixture of reagents and in the presence of a solvent, in other words, and by mixing an unsaturated amine and an alkyl halide.
The Magneto-Dimensional Transformation Properties of the Ultradispersed Metallic Media as a Mechanism for Managing the Macrodynamic Features of Crystallizing Thermoplastic Nanocomposites
Authors: Mashukov N.I. , Altueva Albina M. , Danilova-Volkovskaya Galina M. , Shustov Gennady B.
Published: September 2021

The work considers the main elements of the magneto-dimensional transformation properties in the ultradispersed metallic media (UDM) as a nanomodifier in the process of the formation of nanocompositional polymeric materials (NCPM) based on polyolefins () from a melt. It has been shown that UDM nanoparticles in a melt under the influence and interaction with a thermoplastic matrix are capable of transforming their magnetic properties (to the level of superparamagnetic), structural-dimensional parameters, and chemical potential. With this mutual influence, the nanomodifier has an active effect on the thermoplastic melt at all stages of the formation of the structure-property relationship: structureless ensembles of macromolecules → formation of clusters (domains), lamellas, crystallites → formation of a network of intermolecular entanglements → crystallization of the thermoplastic matrix → transition to a condensed state. An important component of the formation of a fine-crystalline anisotropic NCPM structure is the intramatrix orientation of the structural elements of the thermoplastic in the melt under the influence of the magneto-dimensional transformable manifestations of the nanomodifier. A consequence of the formation of a fine-crystalline anisotropic structure of the NCPM is an increased level of a complex of physicochemical properties (such as deformation-strength, rheological, etc.). An assumption is made about the possibility of the formation of coherent wave packets from clusters (domains) and lamellas of crystallites of matrix thermoplastic with a minimum three-dimensional geometry under the action of superparamagnetic forces of nanoparticles of the nanomodifier.
Novel Amphiphilic Star-Shaped Poly(2-Oxazoline)s with Calix[4]Arene Branching Center
Authors: Blokhin Aleksei N. , Razina Alla B. , Tenkovtsev Andrey V.
Published: September 2021

Novel amphiphlic four-arm star-shaped poly (2-alkyl-2-oxazoline) s with calix [4] arene core were synthesized using the “grafting from” approach. The chlorosulfonated calix [4] arene derivative was synthesized and successfully applied as a multifunctional initiator for the cationic ring-opening polymerization of 2-alkyl-2-oxazolines. Obtained star-shaped poly (2-alkyl-2-oxazoline) s were characterized by means of NMR, UV-Vis spectroscopy and gel-permeation chromatography. It was shown that star-shaped poly (2-isopropyl-2-oxazoline) perform thermosensitivity in aqueous solutions.
Study of the Residual Length of Discrete Carbon Fibers in Polyetherimide Based Composites for 3D-Printing
Authors: Musov Ismel V. , Slonov Azamat L. , Zhansitov Azamat A. , Kurdanova Zhanna I. , Khashirova Svetlana Yu.
Published: September 2021

The influence of the multiplicity of extrusion and melt viscosity on the residual length of discrete carbon fibers in composites based on polyetherimide for 3D-printing is estimated. A technique for measuring the residual length of carbon fibers in composites is proposed. The residual length of carbon fibers in composites containing from 10 to 40% fibrous filler with different initial linear dimensions has been determined. It was found that the addition of a melt viscosity modifier to a carbon-filled composite helps to maintain the linear dimensions of the fiber filler particles, thereby increasing the physical and mechanical properties of the material.
The Effect of Various Oligoether Additives on the Formation of the Physicomechanical Properties of Polysulfone
Authors: Kharaev Arsen , Bazheva Rima , Bazhev A.Z. , Salamov A.Kh. , Kongapshev Asker
Published: September 2021

New halogen-containing oligoethers based on 1,1-hydroxy-2,2-di (4-hydroxyphenyl) ethylene and 1,1-dichloro-2,2-di (4-hydroxyphenyl) ethylene of various degrees of condensation were synthesized by the method of high-temperature polycondensation. Features are investigated and optimal conditions of synthesis of new oligoethers are defined. On the basis of polysulfone compositions with various maintenance of oligoethers are prepared. With usage of the modern methods of researches, it is shown that new composites surpass industrial polysulfone in the main physical and chemical and production characteristics.
Preparation of a Composite Material by Graft Copolymerization of Methylmethacrylate and Fish Gelatin Using a Photocatalyst - Complex Oxide RbTe1.5W0.5O6
Authors: Chasova Victoria O. , Fukina Diana G. , Koryagin Andrey V.
Published: September 2021

A new composite material based on fish gelatin (FG) was obtained by graft copolymerization of methylmethacrylate (MMA) onto fish gelatin. The process was initiated by radicals formed by the RbTe1.5W0.5O6 photocatalyst under visible light (λ=400-700 nm) irradiation at room temperature. The characteristics of the new polymer material were obtained by the methods of elemental and physico-chemical analyses.
Study of Copolymerization Reaction N,N-Dialylaminocarbonic Acids with Vinyl Acetate
Authors: Begieva Madina B. , Pshikova Olga V. , Begieva Milana Kh. , Shaov Mukhamed T. , Malkanduev Yusuf A.
Published: September 2021

The reaction of radical copolymerization of N, N-diallylaminocarboxylic acids with vinyl acetate in an aqueous and aqueous-organic medium (a mixture of methanol-water in a ratio of 70:30 mol.%) Obtained copolymers of a statistical nature. It was found that vinyl acetate under these conditions is more reactive than N, N-diallylaminocarboxylic acids. The kinetic laws of the reactions have been investigated and the structures of the copolymers have been established.
The Obtainment Process of Biopolymer Coated NPK Fertilizer and its Comparison with Analog on Berry Plants
Authors: Bamatov Ibragim M. , Arsanov Magomed M. , Sapaev Khusein Kh.
Published: September 2021

The transition to a highly productive and environmentally friendly agricultural sector, the development and implementation of systems for the rational use of mineral fertilizers for obtaining safe and high-quality, including functional, food products is one of the main tasks allocated by the President of the Russian Federation V. V. Putin. Due to this decree, the theory of mineral nutrition has received rapid development in recent decades within scientific and technological progress in the field of analytical chemistry and physics, molecular biology, and genetics. Information on various physiological and biochemical functions of plant nutrients has been obtained, and the regularities of the distribution of elements in various parts of plants and fruits (berries) have been also generalized. The main forms of nutrients in the soil and the factors determining the bioavailability of macro and micronutrients have been identified. The aim of this research paper is to produce a biodegradable fertilizer where Azofoska Universal (N16: P16: K16) was uniformly coated within layer size by water-soluble biopolymer through continuous flow reactor V-star. The obtained samples were further tested and compared to well-known American analog slow-released fertilizer TAGROW on berry plants under greenhouse conditions within, berry root plant volume, stress resistance of plants, yield, the resulting fruits were studied for sugar levels using an RHB-32ATC refractometer. Moreover, infrared spectroscopy data for obtained biopolymer coated Azafoska Universal is illustrated in this research.
Development of a Method for Determining the Main Parameters of the Percolation Process in Antistatic Composite Polymer Materials
Authors: Volnova Diana V. , Tsobkallo Ekaterina S. , Meshcheryakova Galina P. , Moskalyuk Olga A.
Published: September 2021

Polymer composite materials based on thermoplastic polymer and carbon nanoparticles with different axial ratio were obtained by melt technology. The values of the electrical resistance of polymer composites have been determined. Development of a methodology for assessing the parameters of the percolation process: the percolation threshold and the required resistance values of the polymer, to obtain a material with antistatic properties.
Influence of Heat Treatment Conditions on the Structure and Phisicochemical Properties of Polyphenylene Sulfide
Authors: Murzakanova Marina M. , Mamkhegov Rustam M. , Aloev Vladimir Z.
Published: September 2021

The effect of heat treatment on the structural changes and properties of the synthesized PPS samples was studied. The optimum temperature and the exposure time of the heat treatment of PPS were established, which allow to increase thermal stability, improve rheological and mechanical characteristics.
Possible Ways to Improve Interphase Adhesion between Fiberglass and Polyphenylenesulfide
Authors: Shakhmurzova Kamila T. , Kurdanova Zhanna I. , Zhansitov Azamat A. , Baikaziev Artyr E. , Khashirova Svetlana Yu.
Published: September 2021

The article presents a scientific review on the development of composite materials based on polyphenylene sulfide and glass fillers. The main ways (finishing of the filler surface, synthesis of a polymer matrix with functional groups, treatment of the filler and polymer matrix surface with a plasma flow) of increasing interfacial adhesion at the glass fiber-polyphenylene sulfide interface are considered.
Polymer 3D-Printing for Fabrication of Ceramic Parts with Complex Shape
Authors: Balabanov Sergey V. , Perevislov Sergei N. , Sychov Maxim М.
Published: September 2021

In this work, using polymer 3D printing, we obtained ceramic parts of complex shape with the topology of a triple periodic minimal surface (TPMS), of the “Schwarz primitive” type. The technology of manufacturing ceramic products from a diamond-silicon carbide composite ("Ideal") with the geometry of TPMS by pressing is described. The properties of 3D ceramics are similar to those of a monolithic material.
Vulcanization of Elastomers with Quinol Ethers of P-Benzoquinone Dioxime
Authors: Klyuchnikov Oleg R. , Klyuchnikov Yaroslav O.
Published: September 2021

The article discusses the synthesis and development of the direction of vulcanization of elastomers with quinol esters of p-benzoquinone dioxime. The concept of a critical temperature Tcr which denotes noticeability of the vulcanization process of unsaturated rubbers (with k=1×10-6, s-1) is introduced. Noted the increased vulcanizational activity of quinol esters of p-quinone dioxime after nitrosoarenes addition. The reactional ability of nitrosoarenes is proportional to estimated charge value on the oxygen of the nitroso group, with lgk= 11,3+49,7 qO. Quinol esters of p-quinone dioxime are proposed to create three-dimensional rubber paintings and prints.
RAFT Polymerization of 2,2,3,3-Tetrafluoropropyl Methacrylate in the Presence of Lewis Acids
Authors: Lebedev Oleg A. , Grigoreva Alexandra O. , Zaitsev Sergey D.
Published: September 2021

The influence of various tacticity regulators on the reversible addition-fragmentation (RAFT) polymerization of 2,2,3,3-tetrafluoropropyl methacrylate in the presence of 2-cyano-2-propyldodecyltritiocarbonate as an chain transfer agent was investigated. Among Lewis acids considered, the polymerization of TFPMA in dioxane with ZnBr2 turned out to be the most effective from the point of view of tacticity; the polymer with the highest isotacticity is formed. The addition of hexafluoroisopropanol leads to an increase in the heterotacticity and a decrease in the isotacticity of the polymer chain.
Influence of Copolycondensation Conditions on the Synthesis and Properties of Aromatic Copolyesulphonketones
Authors: Beev Aues A. , Khashirov Azamat A. , Beeva Dzhul’etta A. , Shokumova M.U. , Khasanov V.V.
Published: September 2021

The paper investigates the dependence of the reduced viscosity and some properties of aromatic copolyethersulfone ketones on the chemical structure of diphenols and activated dihaloid compounds on the conditions of copolycondensation processes. It is shown that the course of copolycondensation processes and important performance characteristics of products are significantly influenced by the chemical structures of the starting monomers and the order of their introduction into the reaction.