bluuebunny/crossref_metadata_2025 huggingface dataset:
Healthier Energy Balance Behaviors Most Important for Health-Related Quality of Life in Rural Cancer Survivors in Central Pennsylvania
Authors: Olson Jenny L. , Robertson Michael , Chen Minxing , Conroy David E. , Schmitz Kathryn H. , Mama Scherezade K.
Published: May 2023

Background: Rural cancer survivors face a greater number of health disparities, including poorer health-related quality of life (HRQoL), than urban cancer survivors. Engagement in healthy lifestyle behaviors also varies between rural and urban cancer survivors. Lifestyle behaviors can improve HRQoL; however, the combination of behaviors most important for HRQoL in rural survivors is unclear. This study examined clusters of lifestyle behaviors in rural cancer survivors, and differences in HRQoL between behavioral clusters. Methods: Rural cancer survivors in the United States (N = 219) completed a cross-sectional survey. Lifestyle behaviors were classified into unhealthy/healthy binary categories (inactive/active, longer/shorter sedentary time, excessive/acceptable fat intake, very low/higher fruit and vegetable intake, some/no alcohol consumption, and poor/good sleep quality). Behavioral clusters were identified by latent class analysis. HRQoL differences between behavioral clusters were assessed by ordinary least squares regression. Results: The 2-class model demonstrated the best fit and interpretability. The “mostly unhealthy behaviors” class (38.5% of sample) had higher probabilities of all unhealthy behaviors, except alcohol consumption. The “healthier energy balance” class (61.5% of sample) had higher probabilities of active, shorter sedentary, higher fruit and vegetable consumption, excessive fat intake, some alcohol consumption, and poor sleep categories, and reported better HRQoL. Conclusions: Healthier energy balance behaviors were particularly relevant for HRQoL in rural cancer survivors. Multiple behavior change interventions to improve HRQoL in rural cancer survivors should focus on supporting energy balance behaviors. Many rural cancer survivors may lead very unhealthy lifestyles, placing them at high risk of adverse outcomes. This subpopulation should be prioritized to help alleviate cancer health disparities.
The K League and the Duality of Glocality: Men’s Professional Football in South Korea, 1983–2017
Authors: Hong Eunah
Published: May 2023

What happens when modern sports systems in noncore sports nations have undergone extended globalization? In this article, I draw on glocalization theory, particularly Roland Robertson and Richard Giulianotti’s “duality of glocality” to explore the historical developments of the K League, South Korea’s men’s professional football league, launched in 1983. There are many reasons the K League has not yet firmly established its status: (a) the league imposed continuous rule changes on foreign field players while banning foreign goalkeepers, (b) the league introduced a distinct competition structure partially adopted from its Western counterparts, (c) a supporter culture was established which has a similar outlook to that of other supporter cultures but it had a different internal structure, and (d) the league produced media content reflecting local viewer needs while maintaining a structure similar to Western media formats. The notion of a two-step glocalization, the process of heterogenization followed by homogenization with other cultures based on the things that were already heterogenized for a lengthy period, is used to advance the debate on glocalization and to better understand the reasons for the failure to attract K League spectators since its establishment in 1983.
Vertical Distribution of Dust Aerosol Under Conditions of Weak and Moderate Winds
Authors: Malinovskaya E. A. , Chhetiani O. G. , Golitsyn G. S. , Lebedev V. A.
Published: May 2023

The height distribution of dust aerosol in the surface layer based on the measurements made in the summer of 2020–2021 under arid conditions on the territory of the Republic of Kalmykia is considered. For the profiles of the aerosol concentration under conditions of weak winds, a characteristic gradual slope with an index close to the value of –0.5 is recorded. When the wind strengthens, the profile slope takes on values closer to the degrees known for the conditions of saltation –0.7…–1.0 (and steeper). The observed patterns can be explained by the character of motion of dust particles rising from the hot surface together with the surrounding heated air volume that differs for the fine (<1 μm) and coarse (>1 μm) particle fractions.
New Data on Late Cretaceous Theropods from the Bostobe Formation of Northeastern Aral Sea Region (Kazakhstan)
Authors: Averianov A. O. , Lopatin A.V.
Published: May 2023

Two isolated metatarsals (III and IV) of theropod dinosaurs from the Bostobe Formation (Upper Cretaceous, Santonian–Campanian) of the Shakh-Shakh locality in Kazakhstan are assigned to the representatives of the families Caenagnathidae and Dromaeosauridae, respectively. The metatarsal III of Caena-gnathidae indet. confirms the presence of oviraptorosaurs in the dinosaur assemblage from the Bostobe Formation. This bone is very similar morphologically with the metatarsal III of Elmisaurus rarus Osmólska, 1981 from the Maastrichtian of Mongolia. The metatarsal IV of Dromaeosauridae indet. is characterized by a lateral crest, which among dromaeosaurids is known only for Velociraptor mongoliensis Osborn, 1924 from the Campanian of Mongolia.
The Dimensional Effect and Crystal Morphological Peculiarities of Gibbsite in a Bauxite-Bearing Weathering Crust
Authors: Boeva N. M. , Bortnikov N. S.
Published: May 2023

The correlation between the crystal morphological peculiarities of gibbsite and its position in a bauxite-bearing weathering profile is revealed from the example of the Tsentral’noe deposit of the Chadobets Uplift. The free space favorable for the growth of gibbsite increases from bottom to top in various parts of the profile as a result of infiltration metasomatosis and various physicochemical conditions. The higher the position of the rock, the higher its porosity. The size of the gibbsite crystals thus increases, and their morphology becomes more complex upward through the section. The results of thermal analysis showed that the higher the sizes of the gibbsite crystals, the higher the amount of boehmite forms upon its heating. These conclusions will help the technologists to choose the most feasible reworking scheme of bauxites.
Anomalous Absorption of Smoke Aerosol in the Visible and Near-Infrared Regions of the Spectrum
Authors: Gorchakov G. I. , Gushchin R. A. , Kopeikin V. M. , Karpov A. V. , Semoutnikova E. G. , Datsenko O. I. , Ponomareva T. Ya.
Published: May 2023

Anomalous absorption of finely dispersed smoke aerosol was recorded in large-scale smoke haze during mass fires in the boreal forests of Alaska in July 2019 in the visible and near-infrared regions of the spectrum (440‒1020 nm) according to the data of monitoring of the spectral dependences in the refractive index imaginary part on the network of AERONET stations. The variations in the spectral dependences of the aerosol optical depths (extinction and absorption), as well as the size distribution function of aerosol particles, are analyzed. During the anomalous absorption, the imaginary part of the refractive index increased by a factor of 1.8‒7.2 with an increasing optical wavelength from 440 to 1020 nm, reaching a value of 0.315 for the wavelength of 1020 nm. A power approximation is proposed for the spectral dependence of the imaginary part of the refractive index with indices of power approximately from 0.7 to 2.3.
First Evidence of the Precambrian Diamond Source of the Siberian Platform: U–Pb LA-ICP-MS Geochronological Studies of Detrital Zircon from Sedimentary Rocks of the Moti Group
Authors: Gladkochub D. P. , Ivanov A. V. , Donskaya T. V. , Motova Z. L. , Brianskiy N. V. , Reshetov E. V.
Published: May 2023

The U–Pb LA-ICP-MS age is analyzed for detrital zircons from diamondiferous sandstones of the Khuzhir Formation of the Moti Group of a sedimentary cover of the south Siberian Platform. Similar ages are determined for two samples with the most representative maxima at 620, 780, 1860, and 2550 Ma and single data within the ranges of 985–1000, 1400–1500, 1150–1190, 2700–2880, and 3225–3230 Ma. The maximum age of sedimentation is 605 ± 6 Ma, which corresponds to the Ediacaran and is close to a period of carbonatite and alkali-silicate magmatism of the region. The Neoproterozoic ages correspond to the age of rocks of the Tuva–Mongolian Terrane of the Central Asian Orogenic Belt, and the most ancient maxima are typical of the basement rock complexes of the south Siberian Platform. Our result allows the first substantiation of the Precambrian age of diamondiferous sedimentary rocks of the Khuzhir Formation and therefore indicates the presence of Precambrian diamondiferous rocks within the Siberian Platform.
Impact of nonlinear thermal radiation on three-dimensional unsteady flow of carbon nanotube-suspended nanofluid with different length and radius over a stretching surface
Authors: Ganie Abdul Hamid , Mahmood Zafar , Khan Umar , Almusawa Musawa Yahya
Published: May 2023

Carbon nanotubes (CNTs) influenced nanofluid is gaining popularity in the industry for solar energy and scratch heat exchanger applications. Consequently, this research focuses on evaluating the impact of nonlinear thermal radiation from a CNT-based nanofluid on an unsteady three-dimensional nonasymmetric Homann stagnant flux as a function of length and radius. CNTs have remarkable thermal physical properties that appear to be critical for nonlinear thermal transport. As a result, the nonlinear heat transfer properties of H2O composed of single or multiple wall CNTs are studied. The nanomaterial has a length and radius of approximately [Formula: see text] and [Formula: see text]. Partially differential equations with appropriate similarity transformations serve as a mathematical model for the process. The numerical solution of the simplified system of equations is achieved via the use of the well-known Runge–Kutta (RK) method in conjunction with the shooting approach. An effective way to show how a component affects velocity and temperature, skin frictions in both direction and Nusselt number are utilized in graphical representations. Increasing the unsteadiness parameter causes a reduction in the temperature profile and the velocity profile in both directions. As [Formula: see text] grows larger with [Formula: see text], the skin friction in both directions decreases, while the Nusselt number profile grows larger. In addition, the variation in the Nusselt number is included in the tables, along with a comparison of the model without radiation to the model with radiation.
Explicit Chebyshev–Galerkin scheme for the time-fractional diffusion equation
Authors: Moustafa M. , Youssri Y. H. , Atta A. G.
Published: May 2023

The time-fractional diffusion equation is applied to a wide range of practical applications. We suggest using a potent spectral approach to solve this equation. These techniques’ main objective is to efficiently solve the linear time-fractional problem by transforming it into a system of linear algebraic equations in the expansion coefficients, together with the problem’s initial and boundary conditions. The main advantage of our technique is that the resulting linear systems have special structures which facilitate their computational solution. The numerical methods are supported by a thorough convergence study for the suggested Chebyshev expansion. Some test problems are offered to demonstrate the suggested methods’ broad applicability and a high degree of accuracy.
Range changeable local structural information of nodes in complex networks
Authors: Li Meizhu , Zhou Minghao , Feng Deyue , Zhang Qi
Published: May 2023

In the research of complex networks, structural analysis can be explained as finding the information hidden in the network’s topological structure. Thus, the way and the range of the structural information collection decide what kinds of information can be found in the structural analysis. In this work, based on the definition of Shannon entropy and the changeable range of structural information collecting (changeable local network for each node), the local structural information (LSI) of nodes in complex networks is proposed. According to the definition, when the range of the local network converges to the node itself, the LSI is their original structural properties, e.g. node’s degree, betweenness and clustering coefficient, but when the range of the local network extends to the whole network (order of the local network equal to the diameter of networks), the LSI is equivalent to the structural entropy of the entire static network, e.g. degree structural entropy, betweenness structural entropy. We also find that the local degree structural information can be used to classify the nodes in the network, and the proportion of the “bridge” nodes in the network is a new indicator of the network’s robustness, the bigger this proportion of bridge nodes in the network, the more robust the network. This finding also explains why the regular networks or the lattice is so stable, as almost all the nodes in those systems are the “bridge” nodes that are identified by the local degree structural information.
Accelerating aerodynamic design optimization based on graph convolutional neural network
Authors: Li Tiejun , Yan Junjun , Chen Xinhai , Wang Zhichao , Zhang Qingyang , Zhou Enqiang , Gong Chunye , Liu Jie
Published: May 2023

Computational fluid dynamics (CFD) plays a critical role in many scientific and engineering applications, with aerodynamic design optimization being a primary area of interest. Recently, there has been much interest in using artificial intelligence approaches to accelerate this process. One promising method is the graph convolutional neural network (GCN), a deep learning method based on artificial neural networks (ANNs). In this paper, we propose a novel GCN-based aerodynamic design optimization acceleration framework, GCN-based aerodynamic design optimization acceleration framework. The framework significantly improves processing efficiency by optimizing data flow and data representation. We also introduce a network model called GCN4CFD that uses the GCF framework to create a compact data representation of the flow field and an encoder–decoder structure to extract features. This approach enables the model to learn underlying physical laws in a space-time efficient manner. We then evaluate the proposed method on an airfoil aerodynamic design optimization task and show that GCN4CFD provides a significant speedup compared to traditional CFD solvers while maintaining accuracy. Our experimental results demonstrate the robustness of the proposed framework and network model, achieving a speedup average of [Formula: see text].
Effect of relative opening on the moving thin plate under the action of ocean wave in the surging direction: A numerical simulation approach
Authors: Singh Deepak Kumar , Patil Naveen G. , Gurani Rajesh
Published: May 2023

This paper aims to develop the simulated numerical methodology for sloping beach with nonlinear free-surface waves of sloshing water in a 2D rectangular tank. The current computational tool would be the first step in accurately modeling wave energy converters. The 2D tank model was developed by ANSYS FLUENT software, and Navier–Stokes equations are discretized on a regular structured grid based on the finite volume method (FVM). The model is validated for nonlinear sloshing cases. In addition, tank flexibility is analyzed for its impact on liquid sloshing. The test was conducted in five different wave steepness conditions. There were five conditions of wave steepness used in the test. This study looked at fluid–structure interaction around moving plates. The output power of the plate wave energy converter for different plate heights and streamline motion around the plate are important studies in the flow field. Variations of drag coefficient with the wave steepness are the important study in this paper. It shows that the drag coefficient increases with the increase in wave steepness and plate length. In particular, the new structure can give a new, highly accurate formula for determining the wave power of the ocean structures. Its application is seen in wave energy converter (WEC), where the interaction of solid objects, such as wind turbines with water waves, extracts renewable wave energy from the ocean. A highly efficient CFD approach method is introduced to capture the interaction of solid object with a two-phase flow. The effect of wave steepness using second-order stokes wave theory on a moving thin plate in intermediate water is a new discussion. This research is a highly relevant source of information in the development of many practical systems and has direct employment in the design of WEC in order to extract ocean energy.
Classical and quantum cosmology in Einstein–æther scalar–tensor gravity: Noether symmetry analysis
Authors: Laya Dipankar , Bhaumik Roshni , Dutta Sourav , Chakraborty Subenoy
Published: May 2023

This work deals with Einstein–æther scalar–tensor gravity in the background of homogeneous and isotropic flat FLRW space–time model. The Noether symmetry vector identifies a transformation in the augmented space so that the field equations become solvable. The cosmological solutions are analyzed from the observational point of view. Finally, for quantum cosmology, the Wheeler–DeWitt (WD) equation has been formulated and solutions have been determined by identifying the periodic nature of the wave function using conserved (Noether) charge.
Strong CP violation: Problem or blessing?
Authors: Senjanović Goran , Tello Vladimir
Published: May 2023

We readdress the issue of strong CP violation both in the Standard Model (SM) and in the Minimal Left–Right (LR) Symmetric Model and try to clear the confusion that seems to still pervade the field. We argue that the smallness of strong CP violation, while harmless and basically decoupled from the rest of the physics in the SM, in the context of LR symmetry provides a blessing by helping to narrow down the parameter space of the theory and connecting apparently the uncorrelated physical quantities. In particular, in the context of left–right symmetry being parity, it either points to the suppression of leptonic CP violation noticed before, or leads to relatively light right-handed neutrinos, potentially accessible at the next hadron collider. The latter, more natural in view of complex quark Yukawa couplings, goes hand in hand with the smallness of lepton flavor violation and enhances the possibility of observing neutrinoless double-beta decay.
A Fast-Warning Method of Financial Risk Behavior Based on BP Neural Network
Authors: Yang Qun , Xi Zhengyan
Published: May 2023

With the speedy development of economy, there are many issues in business enterprise finance, and organization finance is going through large risks. With more and more complicated market environment, the uncertainty danger of business enterprise operation intensifies, and economic crises happen frequently. The monetary disaster of a company regularly shows that there can also be a complete crisis. Once the organization is deeply in economic crisis, it can also now not be capable to make certain the ordinary capital chain of the enterprise, and in serious cases, it may also have an effect on the sustainable operation of the agency or even make the employer bankrupt and liquidate. Therefore, we have to set up a best financial catastrophe early warning model to prevent and control the occurrence of economic disaster risk. BP neural network can, quite in shape nonlinear feature relationship, have true gaining knowledge of adaptability, excessive parallel computing and statistics processing ability. In view of the actual state of affairs of commercial enterprise, business enterprise and economic risk, the BP neural community algorithm is used to predict agency financial risk and a hazard prediction model in particular primarily based on BP neural community is established. The simulation consequences exhibit that the accuracy and correctness of economic hazard conduct early warning primarily based on BP neural network are 91.51% and 95.28%, respectively. It is proved that the fast-warning approach of economic threat that is conducted primarily based on BP neural network has excessively taken a look at the accuracy and robust cognizance ability.
A Mental Stress Classification Method Based on Feature Fusion Using Physiological Signals
Authors: Sun Ming , Cao Xuanmeng
Published: May 2023

Mental stress can cause a range of mental health issues, which makes it challenging to develop a stress classification method especially based on physiological signals. Although cutting-edge deep learning models are currently popular for recognizing mental stress, most frameworks rely solely on deep features, which may not provide a comprehensive understanding of physiological signals. In response to this concern, we propose a mental stress classification method that uses feature fusion. We integrate the squeeze-excitation attention mechanism and voting classifier technique to learn detailed and typical information about mental stress. To be more precise, the feature fusion segment consists of two steps: we first extract shallow statistic features and deep features separately from raw signal recordings, and the deep features are dimensionally reduced using principal component analysis to enable better integration with the shallow features. We then flatten both kinds of features and concatenate them by column to create a combined set that contains more salient information about physiological signals. Our experiments show that the attention mechanism and voting classifier technique improve the accuracy of stress classification. Furthermore, our proposed model based on feature fusion achieves remarkable performance compared to state-of-the-art methods.
An introduction to Thompson knot theory and to Jones subgroups
Authors: Aiello Valeriano
Published: May 2023

We review a constructions of knots from elements of the Thompson groups due to Vaughan Jones, which comes in two flavors: oriented and unoriented.
Over then under tangles
Authors: Bar-Natan Dror , Dancso Zsuzsanna , van der Veen Roland
Published: May 2023

Over-then-Under (OU) tangles are oriented tangles whose strands travel through all of their over crossings before any under crossings. In this paper, we discuss the idea of gliding: an algorithm by which tangle diagrams could be brought to OU form. By analyzing cases in which the algorithm converges, we obtain a braid classification result, which we also extend to virtual braids, and provide a Mathematica implementation. We discuss other instances of successful “gliding ideas” in the literature — sometimes in disguise — such as the Drinfel’d double construction, Enriquez’s work on quantization of Lie bialgebras, and Audoux and Meilhan’s classification of welded homotopy links.
Algebra, topology and the discoveries of Vaughan Jones
Authors: Birman Joan S.
Published: May 2023

In this paper, the discovery of the Jones polynomial will be discussed, emphasizing the way in which it illustrated the remarkable unity between distinct parts of mathematics, each with its own language, but initially without a dictionary.
B-type Catalan states of lattice crossing
Authors: Dabkowski Mieczyslaw K. , Rakotomalala Mihaja
Published: May 2023

We show which crossingless connections between [Formula: see text] outer boundary points of an annulus can be realized as Kauffman states of the B-type lattice crossing [Formula: see text]. Furthermore, we give a closed-form formula for the number of realizable B-type Catalan states, and we find coefficients of those obtained as Kauffman states of [Formula: see text] and [Formula: see text].
Petal number of torus knots of type (r,r + 2)
Authors: Lee Hwa Jeong , Jin Gyo Taek
Published: May 2023

Let [Formula: see text] be an odd integer, [Formula: see text]. Then the petal number of the torus knot of type [Formula: see text] is equal to [Formula: see text].
Knot invariants for rail knotoids
Authors: Kodokostas Dimitrios , Lambropoulou Sofia
Published: May 2023

To each rail knotoid we associate two unoriented knots along with their oriented counterparts, thus deriving invariants for rail knotoids based on these associations. We then translate them to invariants of rail isotopy for rail arcs.
Jones rational coincidences
Authors: Lawrence Ruth , Rosenstein Ori
Published: May 2023

We investigate coincidences of the (one-variable) Jones polynomial amongst rational knots, what we call “Jones rational coincidences”. We provide moves on the continued fraction expansion of the associated rational which we prove do not change the Jones polynomial and conjecture (based on experimental evidence from all rational knots with determinant [Formula: see text]) that these moves are sufficient to generate all Jones rational coincidences. In the process we give a new formula for the Jones polynomial of a rational knot based on a continued fraction expansion of the associated rational, which has significantly fewer terms than other formulae known to us. The paper is based on the second author’s Ph.D. thesis and gives an essentially self-contained account.
HOMFLY-PT polynomials of open links
Authors: Millett Kenneth C. , Panagiotou Eleni
Published: May 2023

We numerically estimate the superposition of the HOMFLY-PT polynomial of an open two-component link, define its spread, and describe how this quantity may be employed to quantify the degree of entanglement of confined two component open links.
Tangles in affine Hecke algebras
Authors: Morton Hugh
Published: May 2023

Framed oriented [Formula: see text]-tangle diagrams in the annulus, subject to the Homfly skein relations, are used to produce an algebra isomorphic to the affine Hecke algebras [Formula: see text] of type [Formula: see text]. The use of closed curves and braids gives neat pictures for central elements in the algebras.
The colored Jones polynomial of a cable of the figure-eight knot
Authors: Murakami Hitoshi , Tran Anh T.
Published: May 2023

We study the asymptotic behavior of the [Formula: see text]-dimensional colored Jones polynomial of a cable of the figure-eight knot, evaluated at [Formula: see text] for a real number [Formula: see text]. We show that if [Formula: see text] is sufficiently large, the colored Jones polynomial grows exponentially when [Formula: see text] goes to the infinity. Moreover the growth rate is related to the Chern–Simons invariant of the knot exterior associated with an [Formula: see text] representation.
Biquandle bracket quivers
Authors: Falkenburg Pia Cosma , Nelson Sam
Published: May 2023

Biquandle brackets define invariants of classical and virtual knots and links using skein invariants of biquandle-colored knots and links. Biquandle coloring quivers categorify the biquandle counting invariant in the sense of defining quiver-valued enhancements which decategorify to the counting invariant. In this paper, we unite the two ideas to define biquandle bracket quivers, providing new categorifications of biquandle brackets. In particular, our construction provides an infinite family of categorifications of the Jones polynomial and other classical skein invariants.
Set-theoretic Yang–Baxter (co)homology theory of involutive non-degenerate solutions
Authors: Przytycki Józef H. , Vojtěchovský Petr , Yang Seung Yeop
Published: May 2023

W. Rump showed that there exists a one-to-one correspondence between involutive right non-degenerate solutions of the Yang–Baxter equation and cycle sets. J. S. Carter, M. Elhamdadi, and M. Saito, meanwhile, introduced a homology theory of set-theoretic solutions of the Yang–Baxter equation in order to define cocycle invariants of classical knots. In this paper, we introduce the normalized homology theory of an involutive right non-degenerate solution of the Yang–Baxter equation and compute the normalized set-theoretic Yang–Baxter homology of cyclic racks. Moreover, we explicitly calculate some two-cocycles, which can be used to classify certain families of torus links.
Personal recollection of Vaughan F. R. Jones (1952–2020)
Authors: Przytycki Józef H.
Published: May 2023

Vaughan Jones was my mentor and friend. I provide here a few personal recollections including the “knotted antennas” project which brought me to Berkeley.
Regular isotopy classes of link diagrams from Thompson’s groups
Authors: Raghavan Rushil , Sweeney Dennis
Published: May 2023

In 2014, Vaughan Jones developed a method to produce links from elements of Thompson’s group [Formula: see text], and showed that all links arise this way. He also introduced a subgroup [Formula: see text] of [Formula: see text] and a method to produce oriented links from elements of this subgroup. In 2018, Valeriano Aiello showed that all oriented links arise from this construction. We classify exactly those regular isotopy classes of links that arise from [Formula: see text], as well as exactly those regular isotopy classes of oriented links that arise from [Formula: see text], answering a question asked by Jones in 2018.
An alternate approach to Habiro and Lê’s universal invariant of homology three-spheres
Authors: Sawin Stephen F.
Published: May 2023

An alternative construction of the invariant of homology three spheres valued in a completion of an integral polynomial ring associated to each quantized complex simple Lie algebra by Habiro and Lê [Unified quantum invariants for integral homology spheres associated with simple Lie algebras, Geom. Topol. 20 (2016) 2687–2835, doi:10.2140/gt.2016.20.2687, arXiv:1503:03549v1] is given.
Linking number of monotonic cycles in random book embeddings of complete graphs
Authors: Aguillon Yasmin , Burkholder Eric , Cheng Xingyu , Eddins Spencer , Harrell Emma , Kozai Kenji , Leake Elijah , Morales Pedro
Published: May 2023

A book embedding of a complete graph is a spatial embedding whose planar projection has the vertices located along a circle, consecutive vertices are connected by arcs of the circle, and the projections of the remaining “interior” edges in the graph are straight line segments between the points on the circle representing the appropriate vertices. A random embedding of a complete graph can be generated by randomly assigning relative heights to these interior edges. We study a family of two-component links that arise as the realizations of pairs of disjoint cycles in these random embeddings of graphs. In particular, we show that the distribution of linking numbers of disjoint monotonic cycles can be described in terms of Eulerian numbers. Consequently, the mean of the squared linking number over all random embeddings is [Formula: see text], where [Formula: see text] is the number of interior edges in the cycles. We also show that the mean of the squared linking number over all pairs of disjoint monotonic [Formula: see text]-cycles in [Formula: see text] grows linearly in [Formula: see text].
An improvement of the lower bound for the minimum number of link colorings by quandles
Authors: Abchir H. , Lamsifer S.
Published: May 2023

We improve the lower bound for the minimum number of colors for linear Alexander quandle colorings of a knot given in Theorem 1.2 of [L. H. Kauffman and P. Lopes, Colorings beyond Fox: The other linear Alexander quandles, Linear Algebra Appl. 548 (2018) 221–258]. We express this lower bound in terms of the degree [Formula: see text] of the reduced Alexander polynomial of the knot. We show that it is exactly [Formula: see text] for L-space knots. Then we apply these results to torus knots and Pretzel knots [Formula: see text], [Formula: see text]. We note that this lower bound can be attained for some particular knots. Furthermore, we show that Theorem 1.2 quoted above can be extended to links with more than one component.
Dark matter in a bi-metric universe
Authors: Maldonado Carlos , Méndez Fernando
Published: May 2023

We study the possibility to describe dark matter in a model of the universe with two-scale factors and a nonstandard Poisson bracket structure characterized by the deformation parameter [Formula: see text]. The dark matter evolution is analyzed in the early stages of the universe, and its relic density is obtained via the Freeze-In and Freeze-Out mechanism. We show that by fixing [Formula: see text] and the initial ratio of energy densities present in the different sectors of the universe, the space of thermal average annihilation cross-sections and dark matter masses compatible with the standard cosmology prior to Big Bang Nucleosynthesis (BBN), is enlarged. This feature of the model is compatible with nonstandard cosmology.
A RESPONSE SURFACE STUDY ON THE GROWN BEHAVIOR AND SOME MECHANICAL PROPERTIES OF NIOBIUM CARBIDE COATINGS
Authors: GÜNEN ALİ , AÇIKGÖZ HASAN HÜSEYİN , ÇAVDAR FARUK , KARAHAN İSMAİL HAKKİ
Published: May 2023

In this study, response surface methodology was used to examine the effects of temperature and time on the development of niobium carbide coatings on AISI D3 steel. The effect of niobizing temperature (900–1100∘C) and period (2–6 hours) on coating thickness, hardness, fracture toughness, coefficient of friction and wear rates was investigated. ANOVA was conducted to analyze the experimental data, and it was observed that the coating thickness and microhardness increased with temperature and time. The response surfaces developed for fracture toughness, coefficient of friction and wear rates were found to exhibit a complex structure that is significantly influenced by temperature, time and their interactions. The correlation coefficients of the developed regression models range between 0.82 and 0.99. Using the empirical formulas obtained with these mathematical models, it is predicted that niobium carbide coatings can be obtained with the targeted properties more economically and practically with the thermochemical method.
INVESTIGATION IN UFV-μ WEDM PARAMETERS OF Ni-Cr SPACE ALLOY USING RSM TECHNIQUE
Authors: KARTHIKEYAN M. , MUTHU VIJAYA PANDIAN S. , VIJAYAKUMAR R.
Published: May 2023

Ultrasonic frequency vibration coupled micro-wire electrical discharge machining (UFV-[Formula: see text] WEDM) has received enormous consideration due to its zero-tolerance machining. Nickel chromium (Ni–Cr) space alloys are a natural choice within the aerospace industry, which are exposed to high temperatures and high pressure, such as turbine seals and exhaust liners. This study reveals the impact of the UFV-[Formula: see text] WEDM influencing machining parameters like ultrasonic frequency vibration (UFV), servo voltage ([Formula: see text]), time on ([Formula: see text]), cutting angle ([Formula: see text]), time off ([Formula: see text]), and current (I) on the Ni–Cr space alloy in terms of minimum surface undulation (Ra) with maximum material removal rate ([Formula: see text]). The cutting trials are carried out by central composite design (CCD). Analysis of variance (ANOVA) is used to find out the proportionate contribution of several factors, and it discloses that [Formula: see text] was the significant parameter impacting Ra (64.57%) and [Formula: see text] (61.86%). The performance sequence of significant influencing parameters is [Formula: see text]. According to desirability analysis (DA), optimum parameters for numerous solutions are [Formula: see text][Formula: see text][Formula: see text]s, [Formula: see text][Formula: see text]V, [Formula: see text][Formula: see text][Formula: see text]s, [Formula: see text][Formula: see text]A, and [Formula: see text]. The optimum conditions lead to the highest [Formula: see text] (5.72[Formula: see text]mm3/min) and the lowest Ra (3.42[Formula: see text][Formula: see text]m). Scanning electron, 3D topography, and atomic force microscope images are used to analyze the machined surface.
INVESTIGATION OF THE EFFECTS OF DEEP CRYOGENIC TREATMENT ON THE MICROSTRUCTURE, HARDNESS, STRENGTH AND WEAR RESISTANCE OF X17CrNi16-2 MARTENSITIC STAINLESS STEEL
Authors: YILDIZ EMRE , ÖZBEK NURSEL ALTAN
Published: May 2023

This study investigates the effects of deep cryogenic treatment on the hardness, tensile strength, yield strength, and wear resistance of X17CrNi16-2 martensitic stainless steel. Steel samples were applied to deep cryogenic treatment at [Formula: see text]C for 12, 18 and 36[Formula: see text]h after conventional heat treatment. After these processes, the steel samples were examined microstructurally, and martensite structure and carbides were observed. Mechanical properties increased after the cryogenic treatment was applied at all soaking times. It has been observed that the cryogenic treatment soaking time is directly proportional to the improvement in mechanical properties. The highest mechanical properties were obtained after the cryogenic treatment was applied for 36[Formula: see text]h, which is the longest soaking time. Compared to the CHT sample, the DCT36 sample has a higher microhardness, tensile strength and yield strength of approximately 5.87%, 1.87% and 8.17%, respectively, and has 88% less wear rate.
EFFECT OF QUENCHING HOLDING TIME ON MICROSTRUCTURE AND PROPERTIES OF HIGH SILICON HYPEREUTECTIC HIGH CHROMIUM CAST IRON
Authors: CHENG XIAOLE , ZHANG DONG , WU XIAOJUN , FU HANGUANG
Published: May 2023

In this paper, the effects of different quenching holding times on the microstructure and properties of high-silicon hypereutectic high-chromium cast iron (Fe–4.0C–35.0Cr–1.9Si) were investigated. The effect of quenching holding time on the microstructure of high silicon hypereutectic high chromium cast iron was analyzed by optical microscope, scanning electron microscope and X-ray diffractometer. The hardness and wear resistance of high-silicon hypereutectic high-chromium cast iron quenched at 1150∘C for different time were tested by Rockwell hardness tester, microhardness tester and wear tester. The results show that the microstructure of as-cast high-silicon hypereutectic high-chromium cast iron is mainly composed of pearlite matrix and M7C3 carbide. Quenching heat treatment makes part of the matrix transform from pearlite to martensite, and precipitate a small amount of M[Formula: see text]C6 type secondary carbide. With the increase of quenching holding time from 1[Formula: see text]h to 6[Formula: see text]h, the amount of martensite transformation gradually increases, the primary carbide has no obvious change, the eutectic carbide tip dissolves, and the morphology gradually becomes smooth. The hardness and wear resistance both increase first and then decrease. After 4 hours of insulation, the hardness reaches the highest 60.5HRC, which is increased by 3 HRC compared to 1 hour of insulation. The wear resistance increases by 22.1% compared to 1 hour of insulation. At this time, the wear resistance is the best.
EFFECT OF PROCESS PARAMETERS ON THE MECHANICAL AND WEAR PROPERTIES OF AA6061/B4Cp COMPOSITES FABRICATED USING FRICTION STIR PROCESSING
Authors: PUVIYARASAN M. , RATHINASURIYAN C. , KARTHIKEYAN L. , SENTHIL KUMAR V. S.
Published: May 2023

The improved mechanical properties of AA6061 make it ideal for a wide range of industries, including aerospace, nuclear, defense, and marine. The development of empirical relationships for optimizing the parameters that influence the fabrication of AA6061/B4Cp composite is vital for using this composite in the above applications. In this study, the composites are fabricated using FSP by reinforcing B4C particles in AA6061 plates. In order to optimize the experimental conditions, a central composite rotatable design (CCRD) matrix with four factors and five levels was used. The response surface methodology (RSM) has been used to develop empirical relationships between process parameters such as tool rotational speed, traverse feed, tool tilt angle, penetration depth, and output factors such as yield strength, ultimate tensile strength (UTS), % of elongation, microhardness, and wear rate. Microstructural characterization of AA6061/B4Cp composites has been done in order to examine the effect of process parameters on the composite properties. The fabricated composites showed a maximum yield strength of 135[Formula: see text]MPa, a UTS of 172[Formula: see text]MPa, % elongation of 8.1, a microhardness of 179 VHN, and a minimum wear rate of 0.001185[Formula: see text]mm3/m. Upon analyzing the wear surface and wear debris of the composites, it was found that abrasion is the predominant wear mechanism. These experiments result in increased wear resistance for nuclear, defense and aerospace parts.
Vibration Suppression for an Elastically Supported Nonlinear Beam Coupled to an Inertial Nonlinear Energy Sink
Authors: Chang Zhi-Yong , Chen Jie , Li Qiu-Sheng
Published: May 2023

This paper investigates the vibration suppression of an elastically supported nonlinear cantilever beam attached to an inertial nonlinear energy sink (NES). The nonlinear terms introduced by the NES are transferred as the external excitations acting on the beam. The governing equations of the nonlinear beam with an inertial NES are derived according to the Lagrange equations and the assumed mode method. The linear and nonlinear frequencies of the beam are numerically obtained by the Rayleigh–Ritz method and the direct iteration method, respectively. The frequencies are verified by the results of the finite element analysis and literature. The responses of the beam under shock excitations and harmonic excitations are numerically solved by the fourth-order Runge–Kutta method. The suppression effect of the inertial NES on the transverse vibration of the beam is evaluated through the values of amplitude reduction and energy dissipation. In addition, a parametric analysis of the inertial NES is conducted to improve the vibration reduction effect of the NES on the beam.
Generalized Damped Outrigger Systems for Suppressing Multimode Vibrations of Tall Buildings
Authors: Wen Yongkui , Chen Lin , Nagarajaiah Satish
Published: May 2023

Damped outrigger is a viable means for reducing dynamic responses of tall buildings. This study focuses on generalized damped outrigger (GDO) systems. A GDO is composed of a damper for energy dissipation, a negative stiffness device and an inerter for damping enhancement. The GDO system incorporates GDOs at different floors of the tall building optimized to varied structural modes. Frequency equation of a tall building simplified as a cantilever beam with multiple GDOs is first derived by complex modal analysis. A finite different model of such a system is used for verification. Parametric analyses are then performed to compare damping effects of different GDO systems. It is found that a negative stiffness damped outrigger (NSDO) or inerter damped outrigger (IDO) needs to be optimized for maximizing damping of a specific mode. GDOs, respectively, tuned to different modes can largely improve the multimode damping effects. The optimal parameters of the GDOs are slightly different from those in the case when they are installed separately. With both negative stiffness and nonzero inertance, a GDO still needs to be tuned to a specific mode because multimode damping is sensitive to the damper coefficient. The combination of an NSDO optimized to the first mode and an IDO tuned to a higher mode seems the best solution. The IDO additionally improves the first mode damping provided by the NSDO and the two-mode damping is not sensitive to the damper coefficient of the NSDO. The findings are confirmed through seismic response analyses of a tall building with different GDO systems.
A Practical Method for Determining Dynamic Characteristics of Buildings Under the Effect of Foundation Rotations
Authors: Bozdogan Kanat Burak , Keskin Erdinc , Ozturk Duygu
Published: May 2023

In multi-storey buildings, unforeseen foundation rotations can change the building’s behavior. Therefore, these effects should be taken into account in the analysis. In the studies conducted in the literature, the impact of the rotation of the foundation on the building behavior under static loads has been investigated. In this study, an approach is proposed to determine the dynamic behavior of buildings under the effect of foundation rotation, regardless of the type of bearing system. The multi-storey building was modeled as an equivalent flexural-shear beam in the study. In the study, the axial displacements of the columns, which are neglected in the flexural-shear beam model, are also considered, which is different from the literature. The equation of motion representing the dynamic analysis of the equivalent flexural-shear beam was solved with the help of the Differential Transform Method. The period coefficients, effective mass ratio and peak displacement coefficient for five cases were determined and plotted. A code was prepared using Matlab for the analysis with the Differential Transform Method. As a result of the study, the dynamic characteristics obtained depending on the dimensionless building behavior coefficient have been graphed. Using the given graphs, the dynamic characteristics of the buildings under the effect of foundation rotation can be determined quickly and practically. The method presented in this study can be used for Response spectrum analysis of all systems with pure shear beam, pure bending beam and bending-shear beam behavior. In addition, an approach has been proposed to consider [Formula: see text] effects within the scope of the study. The results obtained in the study were interpreted, and the impact of rotation on dynamic characteristics was discussed. At the end of the study, for the convenience of the presented method, two examples, one for wall-frame and the other for frame systems, were solved with the proposed method, and the results were compared with the SAP2000 program.
Buckling and Postbuckling of Laterally Pressured Sandwich FG-GRC Laminated Toroidal Shell Segments with Corrugated Core in Thermal Environment
Authors: My Do Thi Kieu , Duc Vu Minh , Giang Nguyen Huu , Phuong Nguyen Thi , Nam Vu Hoai
Published: May 2023

The nonlinear buckling behaviors of sandwich functionally graded graphene reinforced composite (FG-GRC) laminated toroidal shell segments with corrugated core under lateral pressure in thermal environment are reported in this study. Three distributed types of the FG-GRC face sheets and two forms of corrugation including the trapezoidal and round corrugations are considered. By adding the thermal forces into an existing equivalent technique, the behavior of the corrugated core is modelled. The nonlinear formulations can be obtained by using the nonlinear Donnell shell theory taking into account the shell-foundation interaction. The Ritz energy procedure is used for three states of deflection to obtain the postbuckling curve expressions of the load-maximal deflection. The bifurcation buckling type of critical buckling pressure is obtained in the explicit form. The numerical examinations present the significant effects of corrugated core and FG-GRC laminated face sheets on nonlinear buckling behaviors of shells.