Pair Of Elements Research Articles

Criteria for solubility and nilpotency of finite groups with automorphisms

AbstractLet be a finite group admitting a coprime automorphism . Let denote the set of all commutators , where belongs to an ‐invariant Sylow subgroup of . We show that is soluble or nilpotent if and only if any subgroup generated by a pair of elements of coprime orders from the set is soluble or nilpotent, respectively.

GEOCHEMICAL CHARACTERISTICS OF THE MAIN ORE COMPONENTS IN THE GOSHGARCHAY PORPHYRY-EPITHERMAL SYSTEM (LESSER CAUCASUS, AZERBAIJAN)

The article deals with the determining characteristics of ore elements in the Goshgarchay porphyry-epithermal system. The genetic and geochemical characteristics of the main ore components were studied, and close positive and negative relationships between pairs of elements were determined by correlation analysis on the selected elements. According to the results of the cluster analysis, the geochemical associations that allow the localization of the development area of mineralization at different stages of formation of the porphyry-epithermal system were analyzed. The following series of stable elements, which are typical for hydrothermal deposits, are distinguished among the ore elements of the host and ore-bearing intrusive rocks: Cu, Mo, Pb, Zn, Ag, Ni, Co, Mn, Ti, Cr, V, Sr, etc. This group of elements is considered to be the indicator elements of the copper-porphyry deposit within the porphyry-epithermal system. It has been determined that correlations between elements in copper-porphyry mineralization are characterized by a wide range of element impurities. It includes both chalcophile (As, Sb, Cu, Bi, Cd, Ga, In, Ge, Au, Ag, Te) and siderophile (Co, Ni, Mo, Fe, Cr) elements. The range of values of vertical geochemical zonality on individual sections of the deposit allows to assess the level of the erosion truncation of occurrences in the porphyry-epithermal system.

Explaining or Guiding Legal System: Hohfeld’s Approach of Rights

In the early twentieth century, an American jurist, Wesley Newcomb Hohfeld, proposed an analytical scheme of jural relations. He put forward four pairs of basic legal elements to justify the nature of the entire legal relations in reality, which however incurs a large number of criticisms from various perspectives in academic literatures. This essay will analyse and respond certain main criticisms on the basis of appropriate interpretation of Hohfeld’s framework and explore one of primary flaws of his theory.

The possibility of predicting the performance of advanced ski elements based on the performance of basic ski elements

The aim of this research was to predict the success of the performance of advanced ski elements based on the level of performance of basic ski elements, with the ultimate purpose of improving training programmes for alpine ski beginners. The sample of participants consisted of 250 students of the Faculty of Kinesiology University of Zagreb who attended their mandatory classes of the university study subject of Skiing in the academic year 2021/22. The sample of variables consisted of the grades the students earned for their performance of four exam elements, two basic ski elements and the other two belonging to the advanced ski elements group. The basic ski elements were uphill turn (UT), for which the mean of two grades was taken for further analysis due to its performance to both sides – left and right, and snowplough turn (SPT). Advanced ski elements were parallel turn (PT) and short turn (ST). Besides descriptive statistics for each variable, two ordinal logistic regression models were constructed for determining the relationship between the performance of short turn based on the level of performance of snowplough turn, on the one hand, and on the other, between the performance of parallel turn based on the performance of uphill turn. The results of the first ordinal logistic regression analysis (short turn performance based on snowplough performance) showed the existence of a statistically significant linear association of the two ski elements performance (b=2.15, SE=0.72, p=.03). Similar results were obtained in the second ordinal logistic regression analysis for the other pair of ski elements (parallel turn performance based on uphill turn performance): b=2.36, SE=0.24, p<.001. Well acquired dynamic motor stereotypes, reflected in good performance of basic ski elements, are the basis for good performance of advanced ski elements, therefore skipping any step in the teaching process based on progression could have a negative impact on achieving the desired goals.

Разработка программного модуля построения карт распределения вероятностей встречи с морским льдом для изучения дальневосточных морей

The article presents a description of the developed software module for creating maps of the probability distribution of encountering sea ice. The module allows to process collections of raster map files based on satellite data and obtain vector maps of the probability distribution of encountering sea ice. Source data is Japan Meteorological Agency (JMA) maps provided in raster format without georeferencing, and National Snow and Ice Data Center (NSIDC) maps provided in GeoTIFF format with georeferencing. The module implements an algorithm that allows to calculate the probability of ice occurrence of a given concentration interval at each point (pixel) of a raster map, and then build polygonal vector maps in SHP-format based on the array of probabilities. The algorithm for constructing polygonal objects provides for a sequential enumeration of all horizontal adjacent pairs of elements of the array of probabilities, followed by determining the boundaries of the polygon. Detection of the first points of the polygon boundary allows to start a cyclic search for adjacent points that meet the boundary condition and creating a complete list of points of a closed polygon. Similarly, all other polygons are searched within the water area specified by the color mask. At the last stage, the lists of Cartesian coordinates of points are converted into geographical coordinates. Based on them, polygonal objects are formed in the SHP-file format. Polygon features define areas of probability of encountering ice that belong to the same interval, and include numeric attributes with values for the boundaries of the probability intervals. The generated vector maps allow further data analysis in GIS applications. The developed software was used to build maps of the probability distribution of encountering ice in the waters of the Far Eastern seas.

Unconditional stability and convergence analysis of fully discrete stabilized finite volume method for the time-dependent incompressible MHD flow

In this paper, we consider the stability and convergence of fully discrete stabilized finite volume method for the unsteady incompressible magnetohydrodynamics (MHD) equations on the quasi-uniform and regular triangulations. The spatial discretization is based on the lowest equal-order mixed finite element pair for the velocity, pressure and the magnetic fields, while the time discretization is based on the backward Euler semi-implicit scheme. In order to overcome the restriction of the discrete inf-sup condition, the local pressure projection stabilized method on the element is employed. This stabilized method has the advantages of parameter-free, no need to calculate the high-order derivatives or the edge-based data structures and it can be implemented at the element level. The unconditional stability of numerical scheme is established by using the Gronwall lemma, mathematical induction and choosing different test functions. Optimal error estimates of numerical approximations in various norms are also presented by constructing the corresponding dual problem. Finally, some numerical results are proposed to verify the established theoretical findings and show the performances of the considered numerical method.

MODERNIZATION OF THE EXTRUDER WORM WITH THE PURPOSE OF IMPROVING THE EFFICIENCY OF MATERIAL MIXING IN THE MANUFACTURE OF POLYMER PRODUCTS

The study selected a technical solution to improve the mixing of polymeric materials in the extruder with the modernization of the worm based on the execution of a detachable mixing and dispersing section. It is formed by a pair of elements, each in the form of a cylinder with coots evenly made along the side surface inclined towards one of its bases, converging to nothing. This design of the extruder worm eliminates the formation of stagnant zones, but also due to the alternation in the circular direction of each element of the specified section of the annular sections and sections in the form of circular segments, it provides a high mixing and dispersing effect of the machine as a whole.

Flexible integrated sensor with asymmetric structure for simultaneously 3D tactile and thermal sensing

The human body detects tactile stimuli through a combination of pressure force and temperature signals via various cutaneous receptors. The development of a multifunctional artificial tactile perception system has potential benefits for future robotic technologies, human-machine interfaces, artificial intelligence, and health monitoring devices. However, constructing systems beyond simple pressure sensing capabilities remains challenging. Here, we propose an artificial flexible and ultra-thin (50 μ m) skin system to simultaneously capture 3D tactile and thermal signals, which mimics the human tactile recognition process using customized sensor pairs and compact peripheral signal-converting circuits. The 3D tactile sensors have a flower-like asymmetric structure with 5-ports and 4 capacitive elements in pairs. Differential and average signals would reveal the curl and amplitude values of the fore field with a resolution of 0.18/mm. The resistive thermal sensors are fabricated with serpentine lines and possess stable heat-sensing performance (165 mV/°C) under shape deformation conditions. Real-time monitoring of the skin stimuli is displayed on the user interface and stored on mobile clients. This work offers broad capabilities relevant to practical applications ranging from assistant prosthetics to artificial electronic skins.

Evaluation of coastal wetland ecosystem services based on modified choice experimental model: A case study of mangrove wetland in Beibu Gulf, Guangxi

The evaluation of the service value of coastal wetland ecosystem is of great significance for the scientific development and effective utilization of coastal wetland resources. It has been proved that the addition of attribute cut-offs in the choice experiment (CE) evaluation framework improves the validity of evaluation results. However, whether this improvement is due to the improvement of the questionnaire or the improvement of the utility equation cannot be distinguished with this framework. In this study, the modified selection model with cut-off is used to assess the two key elements of the modified selection model that differ from the traditional model. These are the CE questionnaire that leads to cut-off and the CE utility equation that incorporates cut-off. Each element pair is analyzed separately. Both are utilized to evaluate the impact of the validity of the results, and quantitatively evaluate the service value of the mangrove wetland ecosystem in the Beibu Gulf region, Guangxi, China. The results showed that: In 2021, the total value of mangrove wetland ecosystem services in the Beibu Gulf region was 1.181 billion yuan. In the modified CE model, both the improvement of the questionnaire and the improvement of the utility equation contribute to the improvement of the validity of the evaluation results; their contribution degree is equal. Regarding the choice model, based on the correction, the public's willingness to pay per capita values for strengthening the protection of mangroves are (in order): the improvement of biodiversity, mangrove forest coverage, water quality, and the appreciation of the landscape. Related values are 53.89 yuan, 47.00 yuan, 35.46 yuan, and 17.29 yuan, respectively. The results provide a scientific basis for the formulation of ecological management policies of coastal wetlands by the government.

Machine learning guided discovery of ternary compounds involving La and immiscible Co and Pb elements

Ternary compounds with an immiscible pair of elements are relatively unexplored but promising for novel quantum materials discovery. Exploring what third element and its ratio that can be added to make stable ternary compounds out of an immiscible pair of elements remains a great challenge. In this work, we combine a machine learning (ML) method with ab initio calculations to efficiently search for the energetically favorable ternary La-Co-Pb compounds containing immiscible elements Co and Pb. Three previously reported structures are correctly captured by our approach. Moreover, we predict a ground state La3CoPb compound and 57 low-energy La-Co-Pb ternary compounds. Attempts to synthesize La3CoPb via multiple techniques produce mixed or multi-phases samples with, at best, ambiguous signals of the predicted lowest-energy La3CoPb and the second lowest-energy La18Co28Pb3 phases. The calculated results of Gibbs free energy are consistent with experiments, and will provide very useful guidance for further experimental synthesis.

The effect of channel dimensions and configuration of thermoelectric elements on the performance of thermoelectric generator module for waste heat recovery

The use of thermoelectric modules can be effective in recovering waste heat in combustion gasses due to their special properties. In this study, due to the low efficiency of thermoelectric generators, the effects of channel dimensions and configuration of thermoelectric element pairs on heat transfer between a working fluid and a pair of PN elements were studied horizontally and vertically. To develop the simulation of the present model, temperature dependence of generator properties, variations in the convective heat transfer coefficient, temperature gradient, and pressure drop in both hot and cold working fluids along the channel were considered simultaneously. Additionally, it was found that geometric dimensions of rectangular channels affected the four main factors of temperature difference between the two sides of generators, pumped power, number of generators, and type of flow regime. Besides, the findings revealed that the increase in each dimension of the channel reduced the temperature difference between the two sides of elements. This factor was found to play a major role in the efficiency of the thermoelectric generator device, production of power peak, optimal module, channel area, and optimal channel height. In addition, the flow regime changed from turbulent to laminar at cold channel widths greater than 0.11 m. As a result, the total power dropped. Furthermore, the configuration model of PN elements affected the dimensions of the channel. At the length of 1.275 m of the channel, the power generation capacity of the vertical model was by 2.138 times greater than that of the horizontal model per 100 thermoelectric generators.

Compact groups with probabilistically central monothetic subgroups

If K is a closed subgroup of a compact group G, the probability that a randomly chosen pair of elements from K and G commute is denoted by Pr(K, G). Say that a subgroup K ≤ G is ϵ-central in G if Pr(〈g〉, G) ≥ ϵ for any g in K. Here 〈g〉 denotes the monothetic subgroup generated by g ∈ G. Our main result is that if K is ϵ-central in G, then there is an ϵ-bounded number e and a normal subgroup T ≤ G such that both the index [G:T] and the order of the commutator subgroup [Ke, T] are finite and ϵ-bounded. In particular, if G is a compact group for which there is ϵ > 0 such that Pr(〈g〉, G) ≥ ϵ for any g ∈ G, then there is an ϵ-bounded number e and a normal subgroup T such that both the index [G:T] and the order of [Ge, T] are finite and ϵ-bounded.

Evolutionary assembly and disassembly of the mammalian sternum

Evolutionary transitions are frequently associated with novel anatomical structures,1 but the origins of the structures themselves are often poorly known. We use developmental, genetic, and paleontological data to demonstrate that the therian sternum was assembled from pre-existing elements. Imaging of the perinatal mouse reveals two paired sternal elements, both composed primarily of cells with lateral plate mesoderm origin. Location, articulations, and development identify them as homologs of the interclavicle and the sternal bands of synapsid outgroups. The interclavicle, not previously recognized in therians,2 articulates with the clavicle and differs from the sternal bands in both embryonic HOX expression and pattern of skeletal maturation. The sternal bands articulate with the ribs in two styles, most clearly differentiated by their association with sternebrae. Evolutionary trait mapping indicates that the interclavicle and sternal bands were independent elements throughout most of synapsid history. The differentiation of rib articulation styles and the subdivision of the sternal bands into sternebrae were key innovations likely associated with transitions in locomotor and respiratory mechanics.3,4 Fusion of the interclavicle and the anterior sternal bands to form a presternum anterior to the first sternebra was a historically recent innovation unique to therians. Subsequent disassembly of the radically reduced sternum of mysticete cetaceans was element specific, reflecting the constraints that conserved developmental programs exert on composite structures.

Quadratic fields admitting elliptic curves with rational j-invariant and good reduction everywhere

Clemm and Trebat-Leder (2014) proved that the number of quadratic number fields with absolute discriminant bounded by x over which there exist elliptic curves with good reduction everywhere and rational j-invariant is ≫xlog−12⁡(x). In this paper, we assume the abc-conjecture to show the sharp asymptotic ∼cxlog−12⁡(x) for this number, obtaining formulae for c in both the real and imaginary cases. Our method has three ingredients:(1)We make progress towards a conjecture of Granville: Given a fixed elliptic curve E/Q with short Weierstrass equation y2=f(x) for reducible f∈Z[x], we show that the number of integers d, |d|≤D, for which the quadratic twist dy2=f(x) has an integral non-2-torsion point is at most D23+o(1), assuming the abc-conjecture.(2)We apply the Selberg–Delange method to obtain a Tauberian theorem which allows us to count integers satisfying certain congruences while also being divisible only by certain primes.(3)We show that for a polynomially sparse subset of the natural numbers, the number of pairs of elements with least common multiple at most x is O(x1−ϵ) for some ϵ>0. We also exhibit a matching lower bound. If instead of the abc-conjecture we assume a particular tail bound, we can prove all the aforementioned results and that the coefficient c above is greater in the real quadratic case than in the imaginary quadratic case, in agreement with an experimentally observed bias.

Skeletal ontogeny of the Plainfin Midshipman, Porichthys notatus (Percomorphacea: Batrachoidiformes).

Batrachoidiformes are benthic fishes that utilize the undersides of rocks as spawning nests. Their larvae are attached to the nest and nourished by a large yolk sac. The evolutionary shift from feeding, free-swimming larvae to sedentary larvae that are reliant on their yolk sac for nutrition can lead to changes in skeletal development. Batrachoidiformes also have many morphological specializations, such as five pectoral-fin radials (versus four in other acanthomorphs) that are of uncertain homology, the determination of which may have phylogenetic implications. A larval series of Porichthys notatus was collected and its skeletal ontogeny is described. In P. notatus the ossification of the pharyngeal toothplates occurs relatively later than in percomorphs with free-swimming larvae. The posterior basibranchial copula cartilage (= fourth basibranchial) in Porichthys notatus has a unique development among fishes: it initially develops as a paired element at 6.8-7.1 mm NL before fusing posteriorly and forming single median cartilage at 7.4 mm SL. Cartilages of hypobranchial four are transitory, being observed in two specimens of 6.8 and 7.3 mm NL before fusing with ceratobranchial four. The previously identified dorsalmost pectoral radial is a bone formed by a hypertrophied propterygium that ossifies later in development. The earliest stages of P. notatus have three dorsal spines, but during late larval development, the growth of the third dorsal spine is interrupted. The development of P. notatus is compared and discussed in context to that of other acanthomorph.

Imaging stretching and displacement using gradient-index elements during the lens design process.

In this study, we propose an approach to stretch or translate images using gradient-index (GRIN) elements with a rotationally symmetric shape in lens systems. In this method, the GRIN material, instead of optical surfaces, are utilized to enable a breaking of rotational symmetry for the two image translations. GRIN expression with anamorphic and tilting terms is introduced. A pair of GRIN elements in front of the given system alters the magnification in two orthogonal directions using the anamorphic terms in the expression, which realizes image stretching. A pair of GRIN elements with tilting terms is used after the given system tilts the optical path to achieve a transverse displacement of the image. The structure of the given system remains unchanged when these translations are performed. A design method for the GRIN elements is presented. Additionally, a design example is presented whose image is stretched by 1.33 times in one direction and displaced to one side of its axis to demonstrate the feasibility of the proposed approach. The approach in this study may enable novel imaging GRIN lens system designs with flexible image positions or special optical functions.

Numerical-analytical method in reinforced concrete mechanics

A variant of the numerical-analytical method in the nonlinear mechanics of reinforced concrete is proposed. Calculation models make it possible to take into account a number of important factors, such as discrete cracks, the effect of concrete discontinuity, and reinforcement reactions in a crack. When solving the inverse problem of determining the width of the crack opening, the deformation effect is not set, but is modeled using the “joining” of the assigned minimum possible width, its opening under the appropriate loading. In the calculation scheme, pairs of finite elements are distinguished, adjacent to such a crack from opposite special sides, called a two-element cantilever model. Pairs are considered in two states: before their jointing of cracks and after their jointing, taking into account the deformation effect and the effect of concrete discontinuity. The calculation algorithm is based on combinations of an analytical model for calculating the stiffness of complexly stressed structures and the intelligence of the “LIRA-SAPR” software package.

On the square of the antipode in a connected filtered Hopf algebra

It is well-known that the antipode $S$ of a commutative or cocommutative Hopf algebra satisfies $S^{2}=\operatorname*{id}$ (where $S^{2}=S\circ S$). Recently, similar results have been obtained by Aguiar, Lauve and Mahajan for connected graded Hopf algebras: Namely, if $H$ is a connected graded Hopf algebra with grading $H=\bigoplus_{n\geq0}H_n$, then each positive integer $n$ satisfies $\left( \operatorname*{id}-S^2\right)^n \left( H_n\right) =0$ and (even stronger) \[ \left( \left( \operatorname{id}+S\right) \circ\left( \operatorname{id}-S^2\right)^{n-1}\right) \left( H_n\right) = 0. \] For some specific $H$'s such as the Malvenuto--Reutenauer Hopf algebra $\operatorname{FQSym}$, the exponents can be lowered. In this note, we generalize these results in several directions: We replace the base field by a commutative ring, replace the Hopf algebra by a coalgebra (actually, a slightly more general object, with no coassociativity required), and replace both $\operatorname{id}$ and $S^2$ by "coalgebra homomorphisms" (of sorts). Specializing back to connected graded Hopf algebras, we show that the exponent $n$ in the identity $\left( \operatorname{id}-S^2\right) ^n \left( H_n\right) =0$ can be lowered to $n-1$ (for $n>1$) if and only if $\left( \operatorname{id} - S^2\right) \left( H_2\right) =0$. (A sufficient condition for this is that every pair of elements of $H_1$ commutes; this is satisfied, e.g., for $\operatorname{FQSym}$.)

Conjugator length in Thompson's groups

AbstractWe prove that Thompson's group has quadratic conjugator length function. That is, for any two conjugate elements of of length or less, there exists an element of of length that conjugates one to the other. Moreover, there exist conjugate pairs of elements of of length at most such that the shortest conjugator between them has length . This latter statement holds for and as well.

Mixed convection of ferrofluids in a square enclosure with obstacles: Effect of iso‐perimetric shapes

AbstractMixed convection of ferrofluid in square configurations having various iso‐perimetric shaped obstacles has been investigated for fluid flow and heat transfer characteristics. The iso‐perimetric shapes are allowed to vary in size and tested at three different vertical positions subject to adiabatic and isothermal conditions. Simulations have been carried out for various choices of controlling parameters using the higher order mixed finite element method. In particular, the higher order and stable finite element pair of cubic and quadratic () approximations on the hybrid grid is utilized to achieve the discretization of the governing non‐dimensional equations of mass, momentum and energy. The adaptive Newtons method is chosen to solve the discrete system of nonlinear equations. The present solver has been tested against a well‐known open source finite element analysis tool (FEAT2) and published results in the literature. The impact of governing parameters is investigated in the ranges as nanoparticles volume fraction ), the Richardson number , the perimeter of the obstacle , and positions of the obstacles . It is concluded that an increase in the perimeter of the inner obstacles causes a weakness in the fluid flow while a good thermal enclosure is obtained. Moreover, the isothermal obstacles enhance the average Nusselt number more than the adiabatic obstacles in all cases.