complex transformation
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Mathematics ◽  
2021 ◽  
Vol 9 (24) ◽  
pp. 3253
Author(s):  
Abdulmohsen D. Alruwaili ◽  
Aly R. Seadawy ◽  
Asghar Ali ◽  
Sid Ahmed O. Beinane

The aim of this work is to build novel analytical wave solutions of the nonlinear space-time fractional (2+1)-dimensional breaking soliton equations, with regards to the modified Riemann–Liouville derivative, by employing mathematical schemes, namely, the improved simple equation and modified F-expansion methods. We used the fractional complex transformation of the concern fractional differential equation to convert it for the solvable integer order differential equation. After the successful implementation of the presented methods, a comprehensive class of novel and broad-ranging exact and solitary travelling wave solutions were discovered, in terms of trigonometric, rational and hyperbolic functions. Hence, the present methods are reliable and efficient for solving nonlinear fractional problems in mathematics physics.


2021 ◽  
Vol 11 (3) ◽  
pp. 138-144
Author(s):  
Tatiana A. MEDVEDEVA

The preservation of the historical, urban planning and architectural heritage of historical cities requires a special approach to the environment modernization. The modern period is characterized by the search for new safe waste management algorithms. It often leads to the construction of large-scale discordant objects. This process puts forward new requirements for the preservation of the visual protection zones of cultural heritage objects. The article is devoted to a promising strategy for optimizing of devastated territories. It includes the creation of overpass pedestrian links, which can be an additional source of landscaping, as well as open up new opportunities for the transit of engineering networks. The article analyzes the possibility of using such architectural and spatial solutions to modernize the waste management infrastructure of urban devastated.


2021 ◽  
Vol 9 (3) ◽  
pp. 26-30
Author(s):  
Nadezhda Zhilina

The oil and gas industry is becoming one of the key priorities of the state policy of the Russian Federation. Ensuring energy and economic security, sustainable development, and innovative development in the context of the digitalization of the economy requires a qualitatively new approach to regulating the oil and gas industry. The tasks of rational use of oil and gas resources, increasing productivity, and environmental friendliness of production processes are set not only for companies in the oil and gas sector, but also increase the responsibility of the state for achieving them. The solution of the above-mentioned tasks requires an integrated approach based on a theoretical and methodological basis, economic research, systematization of world experience, taking into account the use of modern management and regulation mechanisms of oil and gas complex enterprises.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Min Jin ◽  
Congyun Tang ◽  
Yingying Li ◽  
Shuai Yang ◽  
Ying-Tao Yang ◽  
...  

AbstractInverse-electron-demand-hetero-Diels-Alder reactions of alkenes with α,β-unsaturated keto compounds allow rapid access to the tetrahydropyran ring found in numerous natural products and bioactive molecules. Despite its synthetic interest, catalytic asymmetric versions of this process remain underdeveloped, especially regarding the use of non-activated alkenes reacting with α,β-unsaturated ketone or aldehyde, for which no report can be found in the literature. Herein, we describe the catalytic inverse-electron-demand-hetero-Diels-Alder reactions between neutral alkenes and an α,β-unsaturated ketones or aldehydes to produce a variety of trans-fused [5,6,8] tricyclic structures containing a central, chiral tetrahydropyran ring. This complex transformation, which is achieved using a chiral phosphoric acid, allows for the formation of four stereogenic centers in a single step with high regio-, diastereo- and enantioselectivity (up to 99% ee). Such level of stereocontrol could be achieved by a key remote double hydrogen atom bonding interaction between the linear substrate and the catalyst.


2021 ◽  
Author(s):  
Alberto Hernández-Escobar ◽  
Elena Abdo-Sánchez ◽  
Jaime Esteban ◽  
Teresa María Martín-Guerrero ◽  
Carlos Camacho-Peñalosa

The use of an eigenstate based equivalent circuit topology is proposed for the analysis and modeling of lossless and lossy bi-periodic scatterers. It can significantly simplify the design of this kind of surfaces, since it reduces the number of elements with respect to other general circuits. It contains at most only two admittances and two transformers depending on one unique transformation ratio. The real parts of these admittances can be assured to be non-negative, an interesting aspect in the modeling of lossy surfaces such as those present in asorbers. Moreover, due to the capability of decomposition into the eigenexcitations of the structure, the circuit provides important physical insight. Different cases of scatterers have been analyzed: symmetric and asymmetric, lossy and lossless. In all these cases, the modeling of the circuit admittances has been successfully achieved with a few RLC elements, positive and frequency independent. In the case of structures with symmetries, the transformation ratio directly reflects the physical orientation of the eigenexcitations of the scatterer. Furthermore, in the case of lossy scatterers but without symmetries, the resulting equivalent circuit reveals that their eigenexcitations are not linear polarizations, but elliptic polarizations whose properties are described by the complex transformation ratio.


2021 ◽  
Author(s):  
Alberto Hernández-Escobar ◽  
Elena Abdo-Sánchez ◽  
Jaime Esteban ◽  
Teresa María Martín-Guerrero ◽  
Carlos Camacho-Peñalosa

The use of an eigenstate based equivalent circuit topology is proposed for the analysis and modeling of lossless and lossy bi-periodic scatterers. It can significantly simplify the design of this kind of surfaces, since it reduces the number of elements with respect to other general circuits. It contains at most only two admittances and two transformers depending on one unique transformation ratio. The real parts of these admittances can be assured to be non-negative, an interesting aspect in the modeling of lossy surfaces such as those present in asorbers. Moreover, due to the capability of decomposition into the eigenexcitations of the structure, the circuit provides important physical insight. Different cases of scatterers have been analyzed: symmetric and asymmetric, lossy and lossless. In all these cases, the modeling of the circuit admittances has been successfully achieved with a few RLC elements, positive and frequency independent. In the case of structures with symmetries, the transformation ratio directly reflects the physical orientation of the eigenexcitations of the scatterer. Furthermore, in the case of lossy scatterers but without symmetries, the resulting equivalent circuit reveals that their eigenexcitations are not linear polarizations, but elliptic polarizations whose properties are described by the complex transformation ratio.


2021 ◽  
Vol 12 (2) ◽  
pp. 221-233 ◽  
Author(s):  
Carl H. Sederholm

Although Stephen King’s most famous use of the pronoun ‘It’ comes from his 1986 novel It, he nevertheless uses ‘It’ in highly distinctive ways well before then. These uses of ‘It’ before It need to be discussed because they signify a complex transformation of human characters into monstrous creatures. Focusing on texts ranging from Carrie to The Shining, this article explores how King developed these distinctive ‘Its’ from a somewhat vague sense of unease or twisted desires into complex signifiers of the ways human characteristics can transform into monstrous actions. But King’s focus is never solely on the spectacle or the general horror of this transformation from human to monster. Instead, he explores the unsettling problem of the ways even the most positive human desires and actions can turn characters into ‘It’ creatures. Thus, the real tragedy of becoming an ‘It’, this article argues, comes from recognizing that these ‘It’ creatures are never just simple variations on a monstrous theme; instead, they represent the ways ordinary people can become monstrous as they lose themselves to their own alluring, but ultimately empty, actions.


2021 ◽  
Author(s):  
K. Hosseini ◽  
Mohammad Mirzazadeh ◽  
L. Akinyemi ◽  
D. Baleanu ◽  
S. Salahshour

Abstract The major goal of the present paper is to construct optical solitons of the Ginzburg–Landau (GL) equation including the parabolic nonlinearity. Such an ultimate goal is formally achieved with the aid of symbolic computation, a complex transformation, and Kudryashov and exponential methods. Several numerical simulations are given to explore the influence of the coefficients of nonlinear terms on the dynamical features of the obtained optical solitons. To the best of the authors’ knowledge, the results reported in the current study, classified as bright and kink solitons, are new and have been acquired for the first time.


Mathematics ◽  
2021 ◽  
Vol 9 (16) ◽  
pp. 1854
Author(s):  
Nina S. T. Hirata ◽  
George A. Papakostas

Morphological operators are nonlinear transformations commonly used in image processing. Their theoretical foundation is based on lattice theory, and it is a well-known result that a large class of image operators can be expressed in terms of two basic ones, the erosions and the dilations. In practice, useful operators can be built by combining these two operators, and the new operators can be further combined to implement more complex transformations. The possibility of implementing a compact combination that performs a complex transformation of images is particularly appealing in resource-constrained hardware scenarios. However, finding a proper combination may require a considerable trial-and-error effort. This difficulty has motivated the development of machine-learning-based approaches for designing morphological image operators. In this work, we present an overview of this topic, divided in three parts. First, we review and discuss the representation structure of morphological image operators. Then we address the problem of learning morphological image operators from data, and how representation manifests in the formulation of this problem as well as in the learned operators. In the last part we focus on recent morphological image operator learning methods that take advantage of deep-learning frameworks. We close with discussions and a list of prospective future research directions.


2021 ◽  
Vol 376 (1834) ◽  
pp. 20200177 ◽  
Author(s):  
Binoy Sarkar ◽  
Raj Mukhopadhyay ◽  
Sammani Ramanayaka ◽  
Nanthi Bolan ◽  
Yong Sik Ok

Soil serves as both a ‘source’ and ‘sink’ for contaminants. As a source, contaminants are derived from both ‘geogenic’ and ‘anthropogenic’ origins. Typically, while some of the inorganic contaminants including potentially toxic elements are derived from geogenic origin (e.g. arsenic and selenium) through weathering of parent materials, the majority of organic (e.g. pesticides and microplastics) as well as inorganic (e.g. lead, cadmium) contaminants are derived from anthropogenic origin. As a sink, soil plays a critical role in the transformation of these contaminants and their subsequent transfer to environmental compartments, including groundwater (e.g. pesticides), surface water (phosphate and nitrate), ocean (e.g. microplastics) and atmosphere (e.g. nitrous oxide emission). A complex transformation process of contaminants in soil involving adsorption, precipitation, redox reactions and biodegradation control the mobility, bioavailability and environmental toxicity of these contaminants. Soil also plays a major role in the decontamination of contaminants, and the ‘cleaning’ action of soil is controlled primarily by the physico-chemical interactions of contaminants with various soil components, and the biochemical transformations facilitated by soil microorganisms. In this article, we examine the geogenic and anthropogenic sources of contaminants reaching the soil, and discuss the role of soil in the sequestration and decontamination of contaminants in relation to various physico-chemical and microbial transformation reactions of contaminants with various soil components. Finally, we propose future actions that would help to maintain the role of soils in protecting the environment from contaminants and delivering sustainable development goals. This article is part of the theme issue ‘The role of soils in delivering Nature's Contributions to People’.


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