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Let Γ be a finite graph and let A ( Γ ) be the corresponding right-angled Artin group. We characterize the Hamiltonicity of Γ via the structure of the cohomology algebra of A ( Γ ) . In doing so, we define and develop a new canonical graph associated to a matrix, which as a consequence provides a novel perspective on the matrix determinant.

The Goldbach conjecture, one of the oldest problems in mathematics, has fascinated and inspired many mathematicians for ages. In 1742 a German mathematician Christian Goldbach, in a letter addressed to Leonhard Euler proposed a conjecture. The modern day version of the Binary/Strong Goldbach conjecture asserts that: Every even integer greater than 2 can be written as the sum of two primes. The conjecture had been empirically verified up to 4× 10 18​​​​​, its proof however remains elusive, which seems to confirm that: Some problems in mathematics remain buried deep in the catacombs of slow progress ... mind stretching mysteries await to be discovered beyond the boundaries of former thought. Avery Carr (2013) The research was aimed at exposition, of the intricate structure of the fabric of the Goldbach Conjecture problem. The research methodogy explores a number of topics, before the definite proof of the Goldbach Conjecture can be presented. The Ternary Goldbach Conjecture Corollary follows the proof of the Binary Goldbach Conjecture as well as the Representation of even numbers by the difference of two primes Corollary. The research demonstrates that the Goldbach Conjecture is a genuine arithmetical question. ​​​

The structure of the bone is very complex and heterogeneous; this causes different mechanical and biological properties in its longitudinal and transverse directions. For example, the modulus of elasticity and the permeability of the trabecular bone in a longitudinal and radial direction can vary up to several times. Therefore, implant design that matches these differences is necessary to maximize compliance with the host bone. Given that, in this study, a gyroid structure that generally is used in bone scaffolds was modified to design anisotropic scaffolds. Therefore, the gyroid triply periodic minimal surface trigonometric function was manipulated, and five different architectures were denoted as G(-50), G(-25), G(0), G(+25), and G(+50) with a constant porosity of 80% were developed. The effective elastic moduli of the models were calculated using finite element analysis. The results showed an anisotropicity rate of 0.21, 0.62, 1.50 and 2.23 in elastic moduli for G(-50), G(-25), G(+25) and G(+50) models respectively. As well, the permeability of the models was calculated using computational fluid dynamics (CFD) analysis. Anisotropic models showed different permeability in longitudinal and transverse directions. Longitudinal permeability to lateral direction rate were 0.67, 0.80, 1.25 and 1.47 for G(-50), G(-25), G(+25) and G(+50) models respectively., Kemiğin yapısı karmaşık ve heterojendir, bu da boylamasına ve enine yönlerinde farklı mekanik ve biyolojik özelliklere neden olur. Örneğin, trabeküler kemiğin uzunlamasına ve enine yönde elastik modülü ve geçirgenliği birkaç kata kadar değişebilir. Dolaysıyla, implantların tasarımında konuk kemikle uyum sağlaması için bu farklılıkları dikkate almak gerekir. Bu çalışmada, yaygın olarak kemik iskeleleri tasarımında kullanılan gyroid yapısı, izotropik olmayan iskeleler modellemek için modifiye edilmiştir. Bu nedenle, gyroid üçlü periyodik minimal yüzey trigonometrik fonksiyonu manipüle edilerek ve %80 sabit bir gözenekliliğe sahip beş farklı iskele G (-50), G (-25), G (0), G (+25) ve G (+50) modeli elde edilmiştir. Modellerin etkili elastik modülleri sonlu elemanlar analizi kullanılarak hesaplanmıştır. Analiz sonuçları G (-50), G (-25), G (+25) ve G (+50) modellerin boylarınca elastisite modülünün enlerine göre sırasıyla 0.21, 0.62, 1.50 ve 2.23 oranda olduğunu göstermiştir. Ayrıca modellerin geçirgenliği hesaplamalı akışkanlar dinamiği (CFD) analizi kullanılarak hesaplanmıştır. İzotropik olmayan modeller boyuna ve enine yönlerde farklı geçirgenlik göstermiştir. G (-50), G (-25), G (+25) ve G (+50) modellerin geçirgenliği boylarınca enlerine göre oranı sırasıyla 0.67, 0.80, 1.25 ve 1.47 olarak hesaplanmıştır.

Seismic isolation is a significant useful technology to protect various infrastructures from earthquake hazards. This manuscript employs the incremental dynamic analysis (IDA) and multiple strip (MSA) analysis methods to study the effectiveness of isolation devices on reducing the damage risk of the isolated nuclear power plant structure. Seismic fragility functions for different performance levels are derived using nonlinear time history analyses of isolated nuclear power plant structures under a series of earthquake ground motions. Four limit states, five performance levels, and the intensity measure are proposed to conduct the seismic fragility of isolated nuclear power plant structures. The results indicate that the deformation coefficient of the isolators is a suitable damage index for evaluating the seismic fragility of the isolated nuclear power plant structure, which has a higher safety compared to the non-isolated structure. The maximum error of the exceeding probabilities obtained by IDA and MSA is about 10%, and the fragility curves of MSA are more conservative than the results of IDA. The results can provide a practical guide for the design of an isolated nuclear power plant structure.

The structural confirmation of the 1-(4-Bromophenyl)-3-(2-chloro-6-fluorophenyl) prop-2-en-1-one compound is done by experimental techniques. Experimental techniques FTIR, proton NMR, UV-Visible, performed for the compound. The experimentally obtained results are compared with density functional theory obtained results. The decomposition and melting point of the compound is obtained by TGA & DTA. Density functional theory is performed for the 1-(4-Bromophenyl)-3-(2- chloro-6-fluorophenyl) prop-2-en-1-one compound B3LYP/6-311G++(d,p) basis set. Time dependent density functional theory calculated for three different methods B3LYP, Hartree-Fock and CAMB3LYP also employed for the 2C6FBC at 6-311G++(d,p) basis set. Keywords: DFT Study, HOMO-LUMO, FTIR, 1H NMR, TGA/DTA, chalcone

When the truss structure is reinforced in operating state the additional force is given to it.We propose the method for determining the reasonable magnitude of additional force to reduce the internal force by minimum condition strain energy of truss

We show that the weak monadic second order theory of the structure $({\mathbb Q}

In a recent paper, Kishi and Komatsu have shown that the complex quadratic fields of discriminant $$\begin{aligned} \Delta _{18} = 4 - 3^{18n+3} \end{aligned}$$ have a class group whose 3-Sylow subgroup is of rank at least three for all integers n. The Kishi and Komatsu paper proves this by looking at the structure of the algebraic fields involved. Our purpose in this paper is to show that the class groups for the order whose discriminant is $$\Delta _{18}$$ have a 3-SSG of rank at least three, to show this using elementary means that would have been available to Gauss, and to elucidate further the group structure of the subgroup of classes of order 3. More generally, we shall show that $$\Delta _{18}$$ is actually a special case of a more general sequence of discriminants, all of which can be shown parametrically to have a class group whose 3-Sylow subgroup has rank at least three.

We show that the weak disorder phase for the directed polymer model in a random environment is characterized by the integrability of the running supremum $$\sup _{n\in \mathbb N}W_n^\beta $$ of the associated martingale $$(W_n^\beta )_{n\in \mathbb N}$$ . If the environment is bounded, we also show that $$(W_n^\beta )_{n\in \mathbb N}$$ is $$L^p$$ -bounded in the whole weak disorder phase, for some $$p>1$$ . The argument generalizes to non-negative martingales with a certain product structure.

Research background: The analysis of the genesis and the way of defining clinical hospitals allows us to conclude that the evaluation of their activities should consider many criteria, not only the treatment process in itself. Activities characteristic for a clinical hospital include, apart from the medical, also prophylaxis and preventative measures, preceded by the identification of health risks, soliciting research and creating new directions of medical research, as well as implementing new medical technologies and treatment methods (Article 3, paragraph 2, points 1–2, Journal of Laws of 2020, items 295, 567, 1493, 2112, i.e.) combined with the training of medical personnel. Which all makes those units unique among hospitals. Purpose: The article aims to confirm the thesis that, despite significant organizational and functional differences, due to the specific nature of their activities, clinical hospitals do not differ significantly in the structure of generated costs. Research methodology: The article proposes using the taxonomic method as a tool for a comparative analysis of Polish clinical hospitals between the years 2012–2016. The study was conducted from a space-time perspective and concerned 20 hospitals. The use of the hierarchical agglomeration method to assess the cost structure of clinical hospitals is, according to the author, a tool that should be used, in addition to standard methods, by both external and internal decision-makers, in the process of assessing the coherence of the activities of units. Results: The conducted research confirmed that despite the differences between the analyzed units, they are characterized by the same structure of prime costs. Novelty: These studies should form the basis for further, a more detailed, cause-and-effect analysis of the cost structure to identify the main determinants shaping total operating costs.

In this paper, the robust minimum norm partial eigenstructure assignment problems (PESAPs) are studied in a singular vibrating structure via acceleration-velocity-displacement active control. The solvability and stabilization conditions are given by using the singular value decomposition method and no spill-over property of eigenvalues and corresponding eigenvectors. A new parametric method is proposed for solving the PESAPs using the imposed modal constraints technique. Based on the derived condition number of closed-loop eigenvalues, the robust and minimum norm PESAPs are considered by setting appropriate weight factors. Algorithms are presented for solving the corresponding problems. Two numerical examples are reported to verify the effectiveness of algorithms.

Most of the current 3D reservoir porosity estimation methods are based on analyzing the elastic parameters inverted from seismic data. It is well-known that elastic parameters vary with the pore structure parameters such as the pore aspect ratio, consolidation coefficient, and critical porosity. Thus, we may obtain inaccurate 3D porosity estimation if the chosen rock-physics model fails to properly address the effects of the pore structure parameters on the elastic parameters. However, most of the current rock-physics models only consider one pore structure parameter such as the pore aspect ratio or the consolidation coefficient. To consider the effect of multiple pore structure parameters on the elastic parameters, we have developed a comprehensive pore structure (CPS) parameter set that is generalized from current popular rock-physics models. The new CPS set is based on the first-order approximation of current rock-physics models that consider the effect of the pore aspect ratio on the elastic parameters. The new CPS set can accurately simulate the behavior of current rock-physics models that consider the effect of pore structure parameters on the elastic parameters. To demonstrate the effectiveness of the proposed parameters in porosity estimation, we use a theoretical model to demonstrate that our CPS parameter set properly addresses the effect of pore aspect ratio on elastic parameters such as velocity and porosity. Then, we obtain a 3D porosity estimation for a tight sand reservoir by applying it seismic data. We also predict the porosity of the tight sand reservoir using a neural network algorithm and a rock-physics model that is commonly used in porosity estimation. The comparison demonstrates that the predicted porosity has a higher correlation with the porosity logs at blind well locations.

Duck down, as a natural keratin material, has been widely used as a filling material. The multilevel bifurcation structure of down has been observed and characterized through scanning electron microscopy. The structure is a complex fractal structure composed of four-level self-similar structures including five units, that is, the calamus, main barb, barb, barbule, and node or prong. The differential friction effect of the dynamic friction coefficients of the barb was reduced from 0.4 (dry state) to 0.23 (wet state), namely a decrease of 42.5%. The friction locking effect decreases due to the swelling of the fiber diameter. The down is zero gravity in water, and under the action of vibration and internal stress, down that has been subjected to friction or heat setting treatment can quickly return to its original shape in water. This shape memory mechanism was further confirmed, in which down after heat setting can restore its shape to the natural state by shaking it quickly and vigorously. This research provides inspiration to investigate more complicated functions of natural materials and encourages the creation of very intelligent synthetic polymers.

Pure stainless steel (SUS 316L) powders with both a nano-grain and micro-structure were prepared using a mechanical milling process. The bimodal microstructure consists of a nano-grain with a size of 50 nm in the surface region and microstructure in the core of the particle. The nano-grain with a bcc structure at the surface and the microstructure of fcc in the core of the particles were prepared by milling at 150rpm for 9h, and those compositions were 14.39% for the nano structure and 85.61% for the micro structure, respectively. Spark plasma sintering (SPS) was carried out for the compaction of the powders. The compacts forming powders with a bi-modal structure have a mesoscopic structure.

For a continuous multi-objective optimization problem, it is usually not a practical approach to compute all its nondominated points because there are infinitely many of them. For this reason, a typical approach is to compute an approximation of the nondominated set. A common technique for this approach is to generate a polyhedron which contains the nondominated set. However, often these approximations are used for further evaluations. For those applications a polyhedron is a structure that is not easy to handle. In this paper, we introduce an approximation with a simpler structure respecting the natural ordering. In particular, we compute a box-coverage of the nondominated set. To do so, we use an approach that, in general, allows us to update not only one but several boxes whenever a new nondominated point is found. The algorithm is guaranteed to stop with a finite number of boxes, each being sufficiently thin.

Generally, the surrounding rock at the entrance of a mountain tunnel is loose, and the entrance has more slopes due to topography, which causes the tunnel entrance section to be easily destroyed under an earthquake. Based on the established slope model with a single free surface, this paper adopted the elastic wave theory to derive the analytical solution of the strain at the entrance of the mountain tunnel when the SH wave is incident perpendicularly to the bottom of the tunnel; besides, the factors affecting strain were also analyzed. The tangential strain curve at each point of the entrance section takes the centre of the elliptical tunnel as the centre of symmetry, forming symmetry between the left and right sides and mirror symmetry between the top and bottom sides. Then, large-scale shaking table model experiments were conducted to model the actual working conditions, and the correctness of the analytical solution was verified. The research can provide a theoretical reference for the seismic design of the entrance section of the high-speed railway tunnel and greatly improve the understanding of its seismic response.

In this study, we discuss the structure and properties of high-entropy AlCoCrFeNi alloy after casting, cold deformation, and heat treatment. Ingots of the investigated alloys were obtained by arc melting method in argon atmosphere. In order to ensure a homogeneous chemical composition, ingots were remelted several times. Cylindrical samples of 5 mm in diameter and 8 mm in height were cut from ingots by electrospark method for mechanical tests. Subsequently, samples were subjected to uniaxial compression by 5, 11, and 23 %. During the tests, compression curves were recorded, and limit of proportionality of the analyzed alloys was calculated. High-temperature annealing and thermal studies were performed using thermogravimetric analyzer. Thermal studies were carried out in a cyclic mode (3 cycles, including heating up to 1200 °C at a rate of 20 °C/min and cooling at a rate of 20 °C/min). High-temperature annealing was carried out at a temperature of 1200 °C for 5 hours. Such annealing of cast alloys promotes material homogenization and eliminates dendritic structure. The alloy presents limited plasticity. Grain boundaries are effective barriers preventing crack propagation. The studies indicate that plastic deformation has a significant effect on development of relaxation processes during subsequent heat treatment. An increase in strain during the compression leads to a higher rate of healing processes of defects in crystal structure.

In this study, a time-series analysis is applied to the daily accidents between the periods January 1, 2019 and December 31, 2019 of Turkey. The most important feature of the data used in the study is the official daily traffic accident records kept by the law enforcement units. Regarding these data, the most appropriate time series model is determined and it is examined whether there are periodic components in traffic accidents or not. It is observed that the data is first-order integrated. In this case, the difference of the series from the first order should be taken in terms of statistical conclusion. When the graphs of the series are examined, the stationarity of the series has been also tested with the periodogram-based unit root test proposed by Akdi and Dickey (1998) with the assumption that possible periodicity can be found in the series, and it has been observed that the series is stationary at the 10% significance level. According to the results 33, 36.5 and 73-day periods are significant in the number of daily traffic accidents in 2019. It has been demonstrated that the 73-day period corresponds to the period between Ramadan Feast and Feast of Sacrifice (there is a 70-day interval between the two religious holidays).

Bi-infinite geodesics are fundamental objects of interest in planar first passage percolation. A longstanding conjecture states that under mild conditions there are almost surely no bigeodesics; however, the result has not been proved in any case. For the exactly solvable model of directed last passage percolation on $$\mathbb {Z}^2$$ with i.i.d. exponential passage times, we study the corresponding question and show that almost surely the only bigeodesics are the trivial ones, i.e., the horizontal and vertical lines. The proof makes use of estimates for last passage time available from the integrable probability literature to study coalescence structure of finite geodesics, thereby making rigorous a heuristic argument due to Newman (Auffinger et al., 50 Years of First-passage Percolation, American Mathematical Soc., 2017).

Two-dimensional material MoS2 has excellent optical and electrical characteristics and a controllable energy band structure, leading to a high potential value for designing photodetectors. In this ...

In this research, the plate embedded parts and grooved embedded parts reinforced concrete structures were investigated. Two types of plate embedded parts and three types of grooved embedded parts experienced coating treatment to enable sustainable function. Later, the ultimate failure capacity by bending experiments was conducted and compared with the theoretically calculated results. Moreover, three grooved embedded parts were simulated by ABAQUS to compare the results with the experimental exploration results, which was in close agreement with the theoretically calculated results and finite element analysis results. The result indicated that the failure modes of the embedded specimens under the five working conditions are all concrete vertebral failure. The plate-type embedded components were proved to exhibit higher ultimate bearing capacity than the grooved embedded parts. Moreover, the flexural and shear capacity of these five types of embedded parts has not been fully developed. The ultimate flexural and shear capacity of these five types of embedded parts could be further explored by adjusting the higher concrete grade.

In this paper, some stochastic comparison results are developed for the class of multivariate normal variance-mean mixture (NVM) distributions. These comparisons are done based on Hessian and increasing Hessian orderings as well as several of their special cases. Necessary and/or sufficient conditions of the orderings are provided simply based on a comparison of the underlying model parameters. Furthermore, some linear stochastic orderings are expressed as equivalent to some multivariate orderings. The adequacy region of correlation-based ordering for the dependence structure ordering is extended from multivariate normal to NVM family by expressing supermodular order as equivalent to pairwise correlation order in NVM distributions. Some interpretations and applications of the results to actuarial science, finance and reliability are also provided. The results are finally illustrated with two real data sets.

Metric-related parameters in graph theory have several applications in robotics, navigation, and chemical strata. An important such parameter is the partition dimension of graphs that plays an important role in engineering, computer science, and chemistry. In the context of chemical and pharmaceutical engineering, these parameters are used for unique representation of chemical compounds and their structural analysis. The structure of benzenoid hydrocarbon molecules is represented in the form of caterpillar trees and studied for various attributes including UV absorption spectrum, molecular susceptibility, anisotropy, and heat of atomization. Several classes of trees have been studied for partition dimension; however, in this regard, the advanced variant, the fault-tolerant partition dimension, remains to be explored. In this paper, we computed fault-tolerant partition dimension for homogeneous caterpillars C p ; 1 , C p ; 2 , and C p ; 3 for p ≥ 5 , p ≥ 3 , and p ≥ 4 , respectively, and it is found to be constant. Further numerical examples and an application are furnished to elaborate the accuracy and significance of the work.

Peterzil and Steinhorn proved that if a group $G$ definable in an $o$-minimal structure is not definably compact, then $G$ contains a definable torsion-free subgroup of dimension one. We prove here a $p$-adic analogue of the Peterzil-Steinhorn theorem, in the special case of abelian groups. Let $G$ be an abelian group definable in a $p$-adically closed field $M$. If $G$ is not definably compact then there is a definable subgroup $H$ of dimension one which is not definably compact. In a future paper we will generalize this to non-abelian $G$., Comment: 28 pages; typos corrected, proofs cleaned up, numbering changed

Gravity inversion, as a static potential field inversion, has inherent ambiguity with low vertical resolution. To reduce the nonuniqueness of the inversion, it is necessary to impose the a priori constraints derived by other geophysical inversions, drilling, or geologic modeling. Based on the a priori normalized gradients derived from seismic imaging or reference models, a structure-guided gravity inversion method with a few known point constraints is developed for mapping density with multiple layers. The cubic B-spline interpolation is used to parameterize the forward modeling calculation of the gravity response to smooth density fields. A recently adopted summative gradient is used to maximize the structural similarity between the a priori and inverted models. First, we have determined the methodology, followed by a synthetic fault model example to confirm its validity. Monte Carlo tests and uncertainty tests further examine the stability and practicality of the method. This method is easy to implement; consequently, it produces an interpretable density model with geologic consistency. Finally, we apply this method to the density modeling of the Chezhen Depression in the Bohai Bay Basin. Our work determines the distribution of deep Lower Paleozoic carbonate rocks and Archean buried hills with high-density characteristics. Our results are consistent with the existing formation mechanism of the “upper source-lower reservoir” type oil-gas targets.

Esta pesquisa investiga e analisa a estrutura e recursos de planos de aula sobre sistema circulatório, disponíveis no Portal do Professor – Ministério da Educação. Foram coletados no Portal todos os planos de aula que citavam o sistema circulatório (141 planos), e selecionados apenas os que e desenvolviam o conteúdo (15 planos) para a análise da problematização, recursos didáticos e avaliação. A análise e discussão da estrutura dos planos foi alicerçada em duas propostas de metodologia de organização, denominadas: Três Momentos Pedagógicos e Modelo Instrucional BSCS 5E. Os resultados indicam que: a problematização predomina como atividades e questionamentos sobre conhecimentos prévios na introdução da unidade ou assunto; os recursos de Tecnologias Digitais e Informação e Comunicação são frequentes, especialmente os vídeos; o processo avaliativo é pouco enfatizado e sem detalhamento ou indicado ao final sob forma de lista de questões. Os planos utilizam alguns elementos das metodologias analisadas, mas são organizações próprias decorrentes da prática docente. Identificar e compreender o que é valorizado pelos professores na construção do plano de aula cria possibilidades para ampliar as discussões e a aplicação de propostas que contribuem para as práticas docentes com reflexos no processo de ensino e aprendizagem.

It has been known that the Hosoya index of caterpillar graph can be calculated as the numerator of the simple continued fraction. Recently in [MATCH Commun. Math. Comput. Chem. 2020, 84 (2), 399-428], the author introduces a more general graph called caterpillar-bond graph and shows that its Hosoya index can be calculated as the numerator of the general continued fraction. In this paper, we show how the Hosoya index of the graph with non-uniform ring structure can be calculated from the negative continued fraction. We also give the relation between some radial graphs and multidimensional continued fractions in the sense of the Hosoya index.

Aims: The aim of this study was to develop the mathematical models of the linear elasticity theory of biomaterials by taking into account their fractal structure. This study further aimed to construct a variational formulation of the problem, obtain the main relationships of the finite element method to calculate the rheological characteristics of a biomaterial with a fractal structure, and develop application software for calculating the components of the stress-strain state of biomaterials while considering their fractal structure. The obtained results were analyzed. Background: The development of adequate mathematical models of the linear elasticity theory for biomaterials with a fractal structure is an urgent scientific task. Finding its solution will make it possible to analyze the rheological behavior of biomaterials exposed to external loads by taking into account the existing effects of memory, spatial non-locality, self-organization, and deterministic chaos in the material. Objective: The objective of this study was the deformation process of biomaterials with a fractal structure under external load. Methods: The equations of the linear elasticity theory for the construction of the mathematical models of the deformation process of biomaterials under external load were used. Mathematical apparatus of integro-differentiation of fractional order to take into account the fractal structure of the biomaterial was used. A variational formulation of the linear elasticity problem while taking into account the fractal structure of the biomaterial was formulated. The finite element method with a piecewise linear basis for finding an approximate solution to the problem was used. Results: The main relations of the linear elasticity problem, which takes into account the fractal structure of the biomaterial, were obtained. A variational formulation of the problem was constructed. The main relations of the finite-element calculation of the linear elasticity problem of a biomaterial with a fractal structure using a piecewise-linear basis are found. The main components of the stress-strain state of the biomaterial exposed to external loads are found. Conclusion: Using the mathematical apparatus of integro-differentiation of fractional order in the construction of the mathematical models of the deformation process of biomaterials with a fractal structure makes it possible to take into account the existing effects of memory, spatial non-locality, self-organization, and deterministic chaos in the material. Also, this approach makes it possible to determine the residual stresses in the biomaterial, which play an important role in the appearance of stresses during repeated loads.

Recently, the dual isolation system has been verified to be effective in decreasing the floor acceleration of superstructure and base overturning moments compared with the traditional base isolation system. However, a significant drawback of the dual isolation system is the amplification of the relative displacement of the superstructure. This study proposes an enhanced dual isolation configuration combined with supplemental inerters. By simplifying the dual-isolated structure with supplemental inerters as three degrees-of-freedom (3DOF) model, parametric studies on the modal characteristics of the simplified model have revealed that the transitions of the dual-isolated structure with supplemental inerters to base-isolated structure or fixed-base structure would emerge. Within a probabilistic framework, the optimal inertance values of supplemental inerters have been determined numerically by solving the constrained optimization problem accounting for displacement and acceleration variances of the structural responses. Finally, compared with the original dual-isolated structure and corresponding base-isolated structure, the advantages of the dual-isolated structure with optimal supplemental inerters over the original dual-isolated structure and the corresponding base-isolated structure have been demonstrated by time-history analysis. Consequently, the drawback of the dual-isolated structure has been addressed because the relative displacements of superstructure of the proposed dual-isolated structure with optimal supplemental inerters are considerably decreased compared with those of the original dual-isolated structure and to some extent reduced as well compared with those of the corresponding base-isolated structure.

Purpose Pulsating torques cause a number of problems in electrical machines, including mechanical vibrations, acoustic noise and the depreciation of mechanical equipment. In induction motors, the slot skewing method is an effective way to solve these issues; however, it has some drawbacks such as output torque drop, stray loss intensification due to inter-bar currents and iron loss increment. Besides, slot skewing may not be practical in higher-rated induction motors. In this regard, this paper introduces a modified non-skewed rotor (MNSR) structure as a possible alternative to the skewed designs. Design/methodology/approach The proposed structure includes a two-segmented rotor with an intermediate ring between the rotor parts that are mounted on the shaft with a relative shift angle. Detailed information about the idea and structure of the MNSR as well as its manufacturing aspects will be presented in the second section of the paper. First, the working principle of the proposed design is described via analytical equations to provide an insight into the concept. The shifting angle will then be calculated by analyzing the harmonic contents of the electromagnetic torque. Finally, the validity of the analytical method will be verified by developing three-dimensional finite element models. Findings It is demonstrated that by using the proposed rotor structure, the torque ripple has been reduced to a satisfactory level without significantly affecting the mean torque, unlike the skewing method. Furthermore, the new method could avoid the disadvantages of the skewing method while enhancing other motor characteristics such as iron loss. Also, the total volume of the MNSR is equal to the initial design, and the mass and material differences are also negligible. Originality/value In this paper, a MNSR is introduced as a possible alternative to the skewed patterns. The study mainly focused on electromagnetic torque profile characteristics, i.e. the mean torque enhancement and the ripple reduction. The MNSR structure can be used for general purposes and high-performance applications, especially where excellent torque characteristics are required.

Based on measurements of rubber hysteresis curves, the relationship between the network structure of elastomers and their mechanical behavior is analyzed. On the basis of the classical theory of ru...

Two-level fractional factorial designs are often used in screening scenarios to identify active factors. This article investigates the block diagonal structure of the information matrix of nonregul...

In this paper, we consider the concentration property of solutions to the dispersive Ginzburg-Landau (or Gross-Pitaevskii) equation in three dimensions. On a spatial domain, it has long been conjectured that such a solution concentrates near some curve evolving according to the binormal curvature flow, and conversely, that a curve moving this way can be realized in a suitable sense by some solution to the dispersive Ginzburg-Landau equation. Some partial results are known with rather strong symmetry assumptions. Our main theorems here provide affirmative answer to both conjectures under certain small curvature assumption. The results are valid for small but fixed material parameter in the equation, in contrast to the general practice to take this parameter to its zero limit. The advantage is that we can retain precise description of the vortex filament structure. The results hold on a long but finite time interval, depending on the curvature assumption., Comment: 26 pp

Land surface heterogeneity exerts a strong control on atmospheric boundary-layer (ABL) evolution by spatially varying the distribution and partitioning of surface energy fluxes and triggering secondary circulations. The representation of this physical process in numerical weather prediction (NWP) models is especially affected in the terra incognita as the model grid resolution approaches the length-scale of the largest eddies in the boundary layer. We explore these effects for a mesoscale strip-like land surface inhomogeneity in land cover, soil moisture or a superposition of both embedded in an elsewhere homogeneous landscape. The study is conducted with the numerical weather prediction model ICON (ICOsahedral Nonhydrostatic), using the default operational level 2.5 Mellor–Yamada turbulence closure (MY) and a large-eddy simulation (LES) configuration as a benchmark. While simulations with the default ABL scheme approach the LES reference when refining the spatial grid towards finer resolution, the model generates artificial circulations leading to ABL height oscillations when the horizontal grid resolution (∆𝑥) approaches the ABL height (𝑧𝑖). The effect of these model-induced circulations on the state of the boundary layer is even present with weak thermal heterogeneity (∆𝐻) under low background wind speed (𝑣𝑥) but diminishes with increasing background wind speed. The tuning of the asymptotic turbulent mixing length-scale (𝑙∞) in the operational ABL scheme helps in reducing the amplitude of the oscillations, thereby reducing the artificially induced circulations due to thermal heterogeneity which might act as unintentional trigger for clouds and precipitation. Based on the tuned synthetic model data from sensitivity runs, we propose a new parametrization for a 2-D 𝑙∞ as a function of ∆𝐻, 𝑧𝑖/∆𝑥 and 𝑣𝑥, which is otherwise held as a constant in the ABL scheme.

The article presents the results of internal consistency and internal structure analysis on a sampleof 184 subjects of the four most widely used questionnaires of tolerance / intolerance to ambiguity: the Intolerance to Ambiguity Scale (IAS) by S. Badner, Multiple Stimulus Types Ambiguity Tolerance Scale (MSTAT-I and MSTAT-II) D. McLane and the Tolerance-intolerance of ambiguity new questionnaire (TAN) by T. V. Kornilova. The IAS subscales showed low internal consistency, the Tolerance-intolerance of ambiguity new questionnaire scale showed satisfactory internal consistency and the MSTAT-I and MSTAT-II scales showed high internal consistency. Confirmatory factor analysis confirmed the five-factor model of MSTAT-I, the other models were not confirmed on our data. Exploratory factor analysis revealed unsatisfactory internal structure of the IAS, TAN, MSTAT-II. The results of the study are discussed.

Among the inorganic compounds, there are many influential crystalline structures, and magnesium iodide is the most selective. In the making of medicine and its development, magnesium iodide is considered a multipurpose and rich compound. Chemical structures and networks can be studied by given tools of molecular graph theory. Given tools of molecular graph theory can be studied for chemical structures and networks, which are considered economical with simple methodology. Edge weight-based entropy is a recent advent tool of molecular graph theory to study chemical networks and structures. It provides the structural information of chemical networks or their related build-up graphs and highlights the molecular properties in the form of a polynomial function. In this work, we provide the edge weight-based entropy of magnesium iodide structure and compute different entropies, such as Zagreb and atom bond connectivity entropies.

In this paper we give a description of the structure of compact global attractor (Levinson center) for monotone Bohr/Levitan almost periodic dynamical system $x'=f(t,x)$ (*) with the strictly monotone first integral. It is shown that Levinson center of equation (*) consists of the Bohr/Levitan almost periodic (respectively, almost automorphic, recurrent or Poisson stable) solutions. We establish the main results in the framework of general non-autonomous (cocycle) dynamical systems. We also give some applications of theses results to different classes of differential/difference equations.