Elements Of Various Sizes Research Articles

Ген sua как диагностическая мишень при детектировании S. uberis у крупного рогатого скота методом ПЦР

The bacterial genome is of high interest for understanding the many mechanisms that occur inside bacteria, as well as during their interaction with the environment under the influence of many factors. The genome of each species retains a clear structure, i.e. remains conservative in most cases. The internal structure of genes may differ due to mutations, deletions, and insertions. Inserts of migrating DNA elements of various sizes, these structures introduce polymorphism into genes. Like any system, bacteria cannot exist in isolation and are forced to change under environmental conditions. Existing mechanisms of adaptation such as: regulation of genome transcription to fluctuations in temperature, pressure and concentration of metal ions; communication links between individuals of the bacterial population, providing modulation of the expression of protein factors depending on the density of the bacterial focus in the focus of infection. In understanding the essence of the mechanism of «quorum sensing» – the ability to regulate the expression of microorganism genes in response to fluctuations in the density of the cell population, the materials accumulated on the regulation of gene transcription and the expression of their products that change the virulence of the pathogen help to understand.

Discussion on “Effect of soil spatial variability on failure mechanisms and undrained capacities of strip foundations under uniaxial loading”

It is a widely accepted practice to use finer meshes at soil domains of stronger interest and coarser meshes at other domains of less interest on a finite element model (FEM) to simultaneously save computational resources and achieve accuracy. But when the random field modeling is implemented into FEM consisting of unequal element sizes, the local averaging of soil property across the elements needs to be consistently applied on elements of various sizes. The mesh-dependent variance reduction factors are required in the statistics of a random field. Otherwise, the generated random field will not be stationary as desired, and the actual statistics of soil property mapped onto the FEM mesh will no longer be constant.

Lagrangian Data Assimilation and Parameter Estimation of an Idealized Sea Ice Discrete Element Model

AbstractSea ice is a complex media composed of discrete interacting elements of various sizes and thicknesses (floes), and at sufficiently small lengthscales it can not be approximated as a continuous media as routinely done at large scales. While the Eulerian data assimilation is a relatively mature field, techniques for assimilation of satellite‐derived Lagrangian trajectories of sea ice floes remain poorly explored. Here, an idealized discrete element sea ice model is developed and used as a testbed to quantify the efficacy of the minimum approximation for the Lagrangian data assimilation in an one‐way coupled ice‐ocean system. First, it is shown that observations of O(100) floes in a 50 km by 50 km domain are needed to achieve a high data assimilation accuracy, with a large observational timestep of 1 day being sufficient to recover the geophysically balanced part of the unobserved ocean flow, while about a 2‐h timestep is necessary to recover the unbalanced flows. Second, a simple stochastic parameterization is shown to improve the assimilation accuracy when only a small subset of floes is observed or there is a significant model error resulting for example from simplifying the collision laws between floes. Finally, an efficient expectation‐maximization algorithm is developed that succeeds in assimilating the ocean flow and simultaneously estimating individual floe thicknesses and the overall thickness distribution function. Our study implies that the minimum approximation with its closed analytical formulae could potentially provide an efficient data assimilation scheme for satellite observations of sea ice floes.

Modeling of Ice Impacts Using Cohesive Element Method: Influence of Element Size

The use of numerical methods is a promising way to solve the problem of assessing ice impacts on structures. Among such methods the finite element method is the most prevalent. In its framework the cohesive element method was used in last years for modeling the destruction of ice and good results were obtained. However, a more thorough study of this approach is required. This article is part of numerical experiments performed to study the cohesive element method for solving ice problems. In this paper, the effect of element size on the result is studied. The principles of creating a numerical model are described and several conclusions and recommendations are made on the discretization of the model into finite elements of various sizes.

경관단위 유형분류 및 가치평가에 기초한 경관 개선방안 설정 및 적용

The greatest significance in this study is to explore the methodology of establishing quantitative basic data for establishing landscape plans by creating type classification drawings and valuation drawings based on the concept of landscapetope type classification for district unit planning sites in Shindong district in Daejeon, Korea. Put. The summary of the research results is as follows. As a result of the landscapetope type classification, a total of 9 landscapetope types (large classification), a total of 24 landscapetope types (medium classification), and a total of 56 detailed landscapetope types (small classification). As a result of the primary evaluation, a total of 12 landscapetope types corresponding to the I-grade with the highest value were found. As a result of the secondary evaluation, targeting the types of landscapetopes rated as intermediate grade or higher in the first evaluation, 39 landscapetopes (1a, 1b) with special meaning in the microscopic aspect, and landscapetopes with meaning in the microvisual aspect. (2a, 2b, 2c) were analyzed to be 56. In addition, as a result of a comparative analysis between the current laws and systems related to landscape planning and the contents of landscape plans suggested in previous studies, most of the current laws and systems focus on improving artifacts in the microscopic aspect, within the spatial scope of the district unit development plan. It was found that the legal and institutional support for effectively preserving elements of various sizes and shapes, such as the microscopically high value of the belt-shaped forests and old trees, from the development plan was insufficient. The results of this study are considered to play an important role as basic data that can guide the district unit plan established for non-urban areas in a sustainable direction from a microscopic perspective.

Levels of the Hierarchical Organization of Protein Sequences: An Analysis of Entropy Characteristics

A set of 24 647 nonhomologous protein sequences was examined. A pentapeptide occurrence profile was constructed for each sequence and hierarchically organized elements of various sizes were detected in each profile by a special mathematical method. Correlations between the hierarchical elements were studied. A total of 11 levels of protein organization with elements ranging from 7 to 56 amino-acid residues were found in the protein sequence set. The organization levels were assumed to correspond to super-secondary structure elements of different topologies.

Fiber End‐Capping and Splicing of High‐Power Fiber Arrays

AbstractWell‐established splicer devices for fiber‐to‐fiber splices have been on the market for many years. The availability of CO2 laser‐based fiber splicing systems that can control the position and size of the heating zone has opened up new possibilities in the splicing of single and multiple fibers to optical elements of various sizes and shapes. The ability to control the splicing temperature in real time (ms range) enables precise and repeatable splicing results on a new level – especially for complex fiber structures such as large mode area (LMA) and hollow core fibers. Temperature‐controlled splicing also opens up the possibility of splicing different glass types (e.g. soft glass fibers).

УРОВНИ ИЕРАРХИЧЕСКОЙ ОРГАНИЗАЦИИ БЕЛКОВЫХ ПОСЛЕДОВАТЕЛЬНОСТЕЙ. АНАЛИЗ ЭНТРОПИЙНЫХ ХАРАКТЕРИСТИК

This research investigates 24 647 non-homologous protein sequences. The occurrence profile of peptapeptides was constructed for every sequence and hierarchically organized elements of various sizes were revealed by a special mathematical method in each profile. The correlations between these hierarchical elements were analyzed and it was shown that in a tested set of protein sequences there are 11 levels of protein organization with elements ranging in length from 7 to 56 amino acid residues. It was suggested that the identified levels of organization correspond to elements of a super-secondary structure with different topology.

Polar Activity of the Sun and Latitudinal Activity Drifts in Cycles 15–24

The solar activity at different latitudes is analyzed based on daily observations at Kodaikanal, Mount Wilson, Sacramento Peak, and Meudon observatories in the CaIIK line. Activity elements of various sizes, from the elements of the chromospheric network to the flocculi, are identified. A joint database of observation results that provides information on solar activity for 1905–2018 is created. Bright elements at middle and high latitudes are distinguished in the CaIIK line in daily images, in addition to the low-latitude activity that accompanies the appearance of sunspots. The activity can be represented as a single process that begins at high latitudes during the decline phase of the previous solar cycle and continues at low latitudes as sunspot activity. The activity-drift pattern is studied for Cycles 14–24. It is more consistent with the hypothesis of an extended solar cycle than the concept of two activity waves from the midlatitudes to poles and equator obtained from the processing of faculae in white light.

Generating dual-polarized orbital angular momentum radio beams with dual-bowtie cell

In this paper, we propose a reflectarray metasurface to generate two modes of orbital angular momentum (OAM) in two orthogonal directions of polarization. The metasurface comprises dual-bowtie elements of various sizes. By varying the size of the geometry, the element can simultaneously alter the phases of reflection of both polarizations. In the design, equivalent circuit models of the unit cell in both the orthogonal direction and the direction of excitation are built and discussed. These models are used to explain the results of the simulation and can help accelerate the optimization process when designing other reflective metasurfaces. Both the first- and second-order metasurface reflectarrays were simulated and measured at 10 GHz, and the results confirmed that different OAM modes can be generated in two orthogonal directions of polarization. Compared with the prevalent design, the proposed one is more compact as it has only one layer and does not require active components. We also simulated and measured the first-order metasurface reflectarray at multiple frequencies, and the results from 9.2 to 10.5 GHz show that it can generate the two polarized OAMs independently in broadband.

Energy and strength in brittle materials

A study concerning the strength of brittle materials is presented in this paper. The failure behavior was investigated examining the plane of the crack after the failure and comparing the results obtained with those deriving from the fracture mechanics theory. Although the proposed methods are valid in general for brittle materials, the experiment was performed on glass because the results are more significant for this. Glass elements of various sizes and different edge finishes were subjected to bending tests until collapsing. The bending results were studied in terms of failure load and energy dissipation, and the fracture surfaces were examined by means of microscopic analysis, in which the depth of the flaw and the mirror radius of the fracture were measured and the strength was calculated. These results agreed with those obtained from the fracture mechanics analysis.

Improving the Reliability of Permanent Pipeline Connections by Using the Shape Memory Effect in Thermomechanical Couplings

This paper considers a method of forming the inner element (coupling) contour, which makes it possible to obtain relief elements of various sizes from shape memory alloys due to the stresses generated by thermomechanical recovery and specified shaping that meets the requirements for the finished element.

Fractal dimension of roughness: Influence of grain size and granular class

The soil structure can be described as an assembly of elements of various sizes separated by a complex system of cracks and fractures, since the grains of the soil are differentiated by their shape, size and orientation. They are thus differently associated and related, their masses can form complex and irregular configurations which are in general extremely difficult to characterize in exact geometric terms. To understand the mechanical behavior of granular materials, it is then necessary to characterize the grains using the fractal dimension which is a characteristic that indicates the degree of irregularity and fragmentation of the latter.
 This experimental work consists in studying the influence of the parameters variation: granular class, grain size and normal stress applied during Casagrande's direct shear tests on the roughness fractal dimension calculated with the method of Box counting. The analysis of the results obtained at the end of a granulometric variation which caused a variation of the fractal dimension of grain roughness. This variation made it possible to analyze the level of fragmentation suffered by the sandstone grains during the various shear tests. This fragmentation produces fines that are the source of variations in the mechanical properties of the sandstone material.

Testing and modelling of stiffened aluminium panels subjected to quasi-static and low-velocity impact loading

The behaviour and failure of stiffened panels made of the aluminium alloy AA6082-T6 is investigated under quasi-static and low-velocity impact loading conditions. The strain rate and inertia effects are found to be negligible suggesting that quasi-static tests might be representative for low-velocity impacts where a large mass is placed on the impactor. A simplified approach to the finite element modelling of aluminium panels under impact loading, including a regularised failure criterion, is proposed and validated against the experimental data. The effect of mesh size is investigated with shell elements of various sizes in the range from 1 to 5 times the thickness. A good correlation is obtained between experiments and simulations for fine meshes, while large shell elements have difficulties to initiate and propagate properly the observed cracks.

Hunter-Gatherer Earth Ovens in the Archaeological Record: Fundamental Concepts

AbstractRemains of earth ovens with rock heating elements of various sizes and configurations are common at hunter-gatherer sites around the world. They span the last 30,000 years in the Old World and some 10,000 years in the New World. Although various foods were baked in these ovens, plants predominate. Earth ovens are ethnographically well documented as family-size and bulk cooking facilities, but related technology and its archaeological signatures remain poorly understood and understudied. These ubiquitous features are often mischaracterized as generic cooking facilities termed hearths. It is proposed that, in fact, most rock “hearths” are heating elements of earth ovens. Reliable identification and interpretation of earth ovens requires documentation of heating elements, pit structure, rock linings, and various remnants thereof. Fundamental technological concepts for investigating their archaeological signatures include thermodynamics, construction designs, and life cycles in systemic context, as informed by ethnographic, archaeological, and experimental data. Earth oven technology explains well the primary purpose of labor-intensive thermal storage for long-term cooking and conserving fuel. Information from the extensive archaeological record of earth ovens on the Edwards Plateau of south-central North America illustrates these points.

Equilibrium Finite Elements of Spherical Shells in Analysis Problems

In this paper, the problems of analysis of flat spherical shells modelled by equilibrium finite elements are formulated and solved. A new second-order equilibrium finite element developed by the method of Bubnov-Galerkin is suggested. Equilibrium and geometrical equations are created for this element and, based on these equations, the mathematical models of the analysis problem of internal forces and displacements, as well as the limit external load optimization problem for the shell structures are constructed. These are nonlinear mathematical programming problems. The methodology is illustrated by the numerical examples. The solution results are obtained for the finite elements of various sizes and show very high accuracy of the suggested element and convergence of the results.

A parallel direct solver for the self-adaptive hp Finite Element Method

In this paper we present a new parallel multi-frontal direct solver, dedicated for the hp Finite Element Method (hp-FEM). The self-adaptive hp-FEM generates in a fully automatic mode, a sequence of hp-meshes delivering exponential convergence of the error with respect to the number of degrees of freedom (d.o.f.) as well as the CPU time, by performing a sequence of hp refinements starting from an arbitrary initial mesh. The solver constructs an initial elimination tree for an arbitrary initial mesh, and expands the elimination tree each time the mesh is refined. This allows us to keep track of the order of elimination for the solver. The solver also minimizes the memory usage, by de-allocating partial LU factorizations computed during the elimination stage of the solver, and recomputes them for the backward substitution stage, by utilizing only about 10% of the computational time necessary for the original computations. The solver has been tested on 3D Direct Current (DC) borehole resistivity measurement simulations problems. We measure the execution time and memory usage of the solver over a large regular mesh with 1.5 million degrees of freedom as well as on the highly non-regular mesh, generated by the self-adaptive h p -FEM, with finite elements of various sizes and polynomial orders of approximation varying from p = 1 to p = 9 . From the presented experiments it follows that the parallel solver scales well up to the maximum number of utilized processors. The limit for the solver scalability is the maximum sequential part of the algorithm: the computations of the partial LU factorizations over the longest path, coming from the root of the elimination tree down to the deepest leaf.

Mesoscopic modeling of Acoustic Emission through an energetic approach

The aim of the present work is to present a simple model for damage progression and Acoustic Emission that correctly accounts for energy dissipation due to the formation of micro-cracks and the creation of surfaces in a material undergoing external loading, and thus to derive the scaling behaviour observed in experiments. To do this, energy balance considerations are included in a Fibre Bundle Model approach. The model predictions are first illustrated in a uniaxial test under quasistatic loading conditions. Numerical results are then compared to experimental data relative to tests on masonry elements of various sizes subjected compression. The scaling properties of Acoustic Emission under the chosen energy balance assumptions is analyzed and compared to previous numerical and experimental results in the literature. Power-law scaling behaviour is found with respect to specimen dimensions.

Effect of element size on stereoscopic apparent motion.

Spatial displacement limits in stereoscopic (cyclopean) apparent motion were measured from sequentially presented two-frame random-depth configurations. Each depth configuration was defined by stereoscopically near or far elements of various sizes. The limits were compared with those in luminance-defined apparent motion. The subject's task was 2-alternative forced-choice of the perceived motion direction of the sequentially presented two-frame random-dot stereograms. The spatial displacement limit below which correct motion perception arose with stereoscopic configurations was larger in proportion to increases in size of elements. The values were almost consistent with those measured by luminance-defined configurations with the same element sizes. This result suggests that the strategy for discrimination of motion direction of random configurations is similar in both stereoscopic and luminance-defined apparent motion.

Physical mesomechanics of materials

The basic principles of the physical mesomechanics of materials are formulated. This new scientific discipline relates the physics of plasticity (the micro level), the mechanics of a deformable solid (the macro level), and physical materials science. Plastic deformation and subsequent failure of a loaded solid develops as the successive evolution of shear-stability loss at the micro, meso, and macro levels. The deformation laws at the different scale levels are scale-invariant. To study the deformation mechanisms at the meso level, engineering viewing methods may be used. It is shown that, in deformable materials, a basic stress concentrator always appears at the point of application of an external load; this plays the fundamental role in the meso-level development of deformation. The basic carriers of plastic flow at the meso level are volume elements of various sizes; their motion occurs by a shear+rotation mechanism. In a structurally inhomogeneous medium, stress mesoconcentrators arise at internal boundaries; these form dissipative substructures and result in fragmentation of the material at the meso level. Electron-microscopic data on the basic types of meso-level substructures for high-strength materials indicate that, at the substructure boundaries, high-energy states that are in structural disequilibrium are formed at the substructure boundaries; these states are characterized by crystal-lattice curvature of up to 1 deg/μm and a high disclination density. A new structural state is observed: a substructure with a continuum disclination density, characterized by crystal-lattice curvature of up to 40 deg/μm. The methodological aspects of a unified theory of a deformable solid are discussed, and a theoretical approach that may be used to model the deformation and failure of materials with a complex internal structure at different scale levels, on the basis of continuum-mechanics methods, is proposed. This approach allows defining equations for the description of plastic deformation at the micro, meso, and macro levels to be written, taking account of the contribution of the accumulated strain at the lower levels to the strain at the upper levels. The theoretical results are in good agreement with experimental data.