Types Of Structural Elements Research Articles

Detection and identification of transgenic events by next generation sequencing combined with enrichment technologies

Next generation sequencing (NGS) is a promising tool for analysing the quality and safety of food and feed products. The detection and identification of genetically modified organisms (GMOs) is complex, as the diversity of transgenic events and types of structural elements introduced in plants continue to increase. In this paper, we show how a strategy that combines enrichment technologies with NGS can be used to detect a large panel of structural elements and partially or completely reconstruct the new sequence inserted into the plant genome in a single analysis, even at low GMO percentages. The strategy of enriching sequences of interest makes the approach applicable even to mixed products, which was not possible before due to insufficient coverage of the different genomes present. This approach is also the first step towards a more complete characterisation of agrifood products in a single analysis.

ИССЛЕДОВАНИЕ ПРОЧНОСТИ КОНТАКТА ПЛАСТИКОВОЙ ТРУБЫ И БЕТОНА ПРИ РАСЧЕТЕ ПЛАСТИКОТРУБОБЕТОННЫХ КОНСТРУКЦИЙ

This article presents numerical studies of the stress-strain state of centrally compressed short plastic-tube-concrete (PTC) cylindrical cores, having experimentally obtained and analyzed the influence of the tangential friction forces at the boundary of the concrete core and plastic shell layers on the stress-strain state of the PTC core under the assumption of elastic work of the core materials and shell. The need for these studies is associated with a lack of theoretical and numerical studies of the influence of tangential friction forces on the stress-strain state of this type of structural elements, including the classical solution with a steel shell. In this regard, mathematical modeling and the creation of engineering methods for calculating the PTC based on the study of the actual joint work of the concrete core and the cylindrical plastic shell has significant scientific potential. The performed calculations demonstrated the relevance with engineering accuracy of using the mathematical model of a short PTC rack for engineering calculations and structural analysis of the structure. It has been established that the use of an analytical model allows us to study the effect of variations in the physical and mechanical characteristics of the materials of the core and shell of the PTC on the parameters of the stress-strain state of the structure and to rationally design the PTC elements in the construction of civil and industrial buildings with reference to the widely used materials market.

Forced vibration analysis of Timoshenko double-beam system under compressive axial load by means of Green's functions

As typical and significant structural elements, double-beam systems widely exist in practical engineering applications such as some subgrades and highway bridges. This paper focuses on presenting the closed-form solutions of the forced transverse vibration of a coupled Timoshenko double-beam system under compressive axial load. The solutions are generalized and can be suitable for any boundary conditions. The present model is generalized and can be reduced to any existing double-beam systems. Timoshenko model is employed to express the two beams of the double-beam system. Using the Laplace transform, the steady-state Green's functions of the coupled double-beam system can be derived. Since the Green's functions are fundamental solutions of the system, the steady-state forced vibration solutions can be obtained with the help of the superposition principle. In the numerical section, the present solutions are compared with the other known results along with FEM solutions for verification. In addition to the influences of the stiffness modulus of Winkler elastic layer and axial force on the present solutions that should be discussed, the influences of some physical parameters, such as the height-to-length ratio, external frequency, shearing effect, rotational inertia, on the closed-form solutions will also be presented. The effect of the compressive axial load is studied in this work.

Membrane systems as a means of forming interior design

The article identifies specific features of the interior spaces’ structural morphology that utilizes membrane systems defined as types of structures that combine flexible insulation material and load-bearing construction elements. The article describes (the) factors that predated the emergence of the currently utilized membrane structures. It discusses the origins of membrane architecture and the properties that determine its successful application in various regions of the globe without interfering with the character of a specific region. The article describes the relevance of the development of membrane structures for Ukraine, where the rate of tent construction has been gradually declining after reaching its peak in the mid-90s. The article provides the definition of the term “membrane structures” and outlines general technical and aesthetic characteristics of these structures as well as their advantages and inherent adaptability. It also describes the systems’ individual adaptability aspects such as transformability, mobility and modularity in greater detail. The article provides an overview of three main types of membrane structures – tensile membrane structures, stretched meshes and pneumatic structures. The article explains how by combining the three types of structural elements – membranes, rigid structures (poles, masts), and cables – the system’s particular form is built; what determines the choice of a particular membrane material; how the system’s construction elements work together by using supports and tie-rods and what the systems’ benefits are in their interior application. The article discusses the applicability, purposes and uses of interior membrane systems, their additional capability for creating various free-form designs that potentially can be used in art installations or as set elements in exhibition displays. The article concludes that Ukraine has every potential and all resources for using membrane structures and reversing the declining trend that began in the 90s. In this regard, the article recommends reevaluating the construction utility of membrane structures and their uses in specific locations.

Assessment and Restoration of an Earthquake-Damaged Historical Masonry Building

This paper presents an assessment of the capacity and enhancement of the seismic performance of a historical masonry structure in Plomari, a town on the south coast of Lesbos island in Greece. Owing to uncertainties regarding the properties of the material and the effectiveness of the members in providing lateral resistance, the study was particularly challenging. In addition, the fact that the structure consisted of a variety of structural element types, e.g., unreinforced masonry from natural stones, timber-framed masonry (with burned clay masonry units) and timber girders, while lacking horizontal diaphragms, introduced complexities to the response of the structure in both directions. In the design of the retrofit, the need to preserve the building’s architectural and historical value by minimizing interventions posed several problems. To solve them, conventional as well as state-of-the-art strengthening methods are proposed. Moreover, the procedures of these methods are in accordance with the Greek seismic design code of 1959 and European standards (Eurocodes) related to earthquake-resistant masonry as well as guidelines for the design of timber and reinforced concrete. Seismic analyses of the structure were carried out with two different methods (statically applied load and time history analysis) for comparison. The results verify the improvement in its behavior in response to earthquakes as a result of the proposed strengthening methods.

Damage assessment of squat, thin and lightly-reinforced concrete walls by the Park & Ang damage index

Damage progression indexes are widely used to evaluate the performance of structural elements in buildings and bridges subjected to seismic actions. Although the Park & Ang damage index is currently implemented in several computational tools, the index has not been calibrated for squat and thin reinforced concrete (RC) elements controlled by shear deformations. It has been observed that the equations originally proposed for the Park & Ang damage index are unsuited for these types of structural elements, which are characterized by a failure mode dominated by shear instead of flexural deformations. The index was evaluated in this study for squat, thin and lightly-reinforced concrete walls using experimental data from a program comprising monotonic and reversed-cyclic load testing of 25 RC squat cantilever walls. The experimental program included walls, with and without openings, having height-to-length ratios equal to 0.5, 1.0 and 2.0. Full-scale wall thickness and clear height were 100 mm and 2.4 m, respectively. The specimens were built using three different types of concrete (normal-weight, light-weight and self-consolidating) with nominal compressive strength of 15 MPa. A novel formulation for the parameter β included in the Park & Ang damage index was proposed in this study using key variables of the wall specimens such as web reinforcement ratio and cumulative ductility. Comparison between the computed damage index and crack pattern evolution observed in wall specimens at different damage states demonstrated the ability of the model to numerically assess the damage of the wall specimens. Hence, this new formulation proposed for parameter β leads to a better estimation of damage for this particular type of elements when applying the broadly used Park & Ang damage index.

Performance of Self-Compacted Reactive Powder Concrete Slab Under Harmonic Dynamic Loading

Many types of loading the structure must sustain in addition to dead and live loads according to the function of structural element type that must be taken in analysis. Dynamic resistance to loading of reinforced concrete slabs using self-compact reactive powder concrete, with different boundary conditions at the sides in addition of static loading was studied. The reinforced concrete slabs were designed under static load according to ACI-318R-2014 and then the adequacy was checked under harmonic dynamic loading. The static loading consists of dead load and residential live load considering according to ASCE-07-2010. Modeling analysis was performed to determine the eigenvalues and eigenvectors values and then frequency response analyses of the slab by finite elements method that adopted for analysis. The results indicated that in case of self-compacted reactive powder concrete rather than normal concrete gave deflection less and also there was a different result of deflection according the type of slab boundary condition supports.

Artistic and stylistic peculiarities of the graphic work of Petro Lapyn, illustrator of the children's books in the first third of the 20th century

The beginning of the 20th century is a period of creative and printing experiments in the Ukrainian art. New generation of Ukrainian books was born in this period. The illustration of the children's books was a significant part of this process. Famous Ukrainian graphic artists, such as H. Narbut, M. Zhuk, O. Sudomora, V. Kononchuk, took part in the creation of a new Ukrainian children's book. Some little-known artists also worked with them, and their creativity was an important part of the artistic process. Petro Lapyn was one of those artists. From 1917 to 1929, he worked with the famous publishing houses, such as Vernyhora, Derzhavne Vydavnytstvo, Proliski, Knyhospilka and Rukh. Children's books, illustrated by P. Lapyn, are kept in the funds of the Pedagogical Museum of Ukraine, the National Library of Ukraine for Children, Ivan Fedorov Book Chamber of Ukraine and private collections. We have found about 30 of his projects. But the information about the artist himself and his life is quite limited. One of the first books he illustrated was the poem of S. Rudanskyi «Vovk, Sobaka ta Kit» («The Wolf, the Dog, and the Cat»), published in black and white in 1918. This early Petro Lapyn's work revealed his artistic outstanding peculiarities: vibrant linear drawing, harmonious combination of text and illustrations, variety of graphic techniques and skills in the representation of characteristic features. The high point of the artist's career is the illustration of «Crows and Owls», I. Franko’s fairy tale, printed in 1926 (Kharkiv, Rukh). It demonstrates the animalistic works of the artist. There are typical structural elements in fairy tale books: vignettes, drop caps. P. Lapyn uses decorative handwritten fonts and silhouette drawings for them. His graphic creations are full of emotions. Specific features of his work are: humour, emotionality, anthropomorphism, careful attitude towards literary material, and consistently high level of drawing.

Performance of connection system used in lightweight glubam shear wall

Abstract Industrial-produced laminated bamboo panel is a new type of eco-friendly material used for glubam structures in construction industry. This type of panel can be further cold-glued with different orientation combinations to form various types of glubam structural elements and to meet different structural and architectural requirements. The lightweight glubam frame structure is one of the popular forms of glubam structures which can be produced in factory and installed on site with few labor forces and transportation equipment, making it potentially possible to be widely used in urban or rural areas. Like the lightweight wood-frame structures, the governing structural element determining the lateral resistance capacity of lightweight glubam structures is the frame shear wall, as well as that the shear wall’s lateral resistance strength is determined through the metal connections used. Thus, this study is focused on the performance of connection system used in lightweight glubam shear walls made with thick strip ply-bamboo boards, the connection system includes panel-frame nail connections, frame-frame connections and hold-down devices, respectively. Yield moment and curves of nails used in lightweight glubam structures were experimentally obtained according to ASTM F1575 standard. The monotonic and cyclic loading tests of panel-frame connections and frame-frame connections with different nail connectors were performed following ASTM D1761 standard. Mechanical parameters (such as elastic stiffness ke, maximum force Fmax, ultimate displacement Δu) are obtained. Tests of hold-down connection with two different capacities under monotonic and cyclic loading are also presented in this research. A finite element model of lightweight shear wall based on metal connections information is validated through previous research in literature, and is used to predict the performance of lightweight frame shear walls with various combination of connections and studs, to find a suitable type of glubam or timber-glubam hybrid shear wall corresponding to certain load bearing and deformation requirements.

Strut-and-tie models for linear and nonlinear behavior of concrete based on topological evolutionary structure optimization (ESO)

Abstract The search for representative resistant systems for a concrete structure requires deep knowledge about its mechanical behavior. Strut-and-tie models are classic analysis procedures to the design of reinforced concrete regions where there are stress concentrations, the so-called discontinuous regions of the structure. However, this model is strongly dependent of designer’s experience regarding the compatibility between the internal flow of loads, the material’s behavior, the geometry and boundary conditions. In this context, the present work has the objective of presenting the application of the strut-and-tie method in linear and non-linear on some typical structural elements, using the Evolutionary Topological Optimization Method (ESO). This optimization method considers the progressive reduction of stiffness with the removal of elements with low values of stresses. The equivalent truss system resulting from the analysis may provide greater safety and reliability.

PROFESSIONAL ROLES OF THE HIGHER SCHOOL TEACHER IN THE FUTURE SPECIALISTS TRAINING

The article discusses the features of professional roles of a higher education teacher in the training of future specialists (using the example of a teacher of biology and human health). The features of the individual work of a teacher-tutor with a student are given; the functions of the moderator and the facilitator in the group work; working with future specialists of the teacher-curator during extracurricular time. Types of tutoring and structural elements of tutor support, moderation, facilitation, and curator functions are proposed. It is emphasized that the teacher-tutor is responsible for the level of knowledge of the student, and for the formation of his personality. The teacher-moderator carries out the process of managing the interaction in a group of students, combines the solution of issues of development of the educational group as a team, and organizes the interaction and cooperation of all participants. The teacher-facilitator stimulates the independence and responsibility of students when choosing courses, goals, and ways to achieve them when evaluating the results of their work. The teacher-curator creates external conditions and accompanies the actualization of the student’s internal reserves for full-fledged creative self-realization in all spheres of life. For the effective work of the curator it is proposed to combine the informative, organizational, communicative, administrative, creative functions. The survey data on the effectiveness of the use of new professional roles by a teacher among future specialists is indicated.

A cysteine protease–like domain enhances the cytotoxic effects of the Photorhabdus asymbiotica toxin PaTox

The nematode mutualistic bacterium Photorhabdus asymbiotica produces a large virulence-associated multifunctional protein toxin named PaTox. A glycosyltransferase domain and a deamidase domain of this large toxin function as effectors that specifically target host Rho GTPases and heterotrimeric G proteins, respectively. Modification of these intracellular regulators results in toxicity toward insects and mammalian cells. In this study, we identified a cysteine protease-like domain spanning PaTox residues 1844-2114 (PaToxP), upstream of these two effector domains and characterized by three conserved amino acid residues (Cys-1865, His-1955, and Asp-1975). We determined the crystal structure of the PaToxP C1865A variant by native single-wavelength anomalous diffraction of sulfur atoms (sulfur-SAD). At 2.0 Å resolution, this structure revealed a catalytic site typical for papain-like cysteine proteases, comprising a catalytic triad, oxyanion hole, and typical secondary structural elements. The PaToxP structure had highest similarity to that of the AvrPphB protease from Pseudomonas syringae classified as a C58-protease. Furthermore, we observed that PaToxP shares structural homology also with non-C58-cysteine proteases, deubiquitinases, and deamidases. Upon delivery into insect larvae, PaToxP alone without full-length PaTox had no toxic effects. Yet, PaToxP expression in mammalian cells was toxic and enhanced the apoptotic phenotype induced by PaTox in HeLa cells. We propose that PaToxP is a C58-like cysteine protease module that is essential for full PaTox activity.

Cтруктура и оптические свойства халькогенидных стеклообразных полупроводников системы As-Ge-Se

AbstractThe types of structural elements and chemical bonds forming an amorphous matrix of chalcogenide glassy semiconductors of the As–Ge–Se system and changes occurring in them depending on the chemical composition are determined using a method for studying the Raman and transmission spectra and density measurements. It is shown that a transition from the elastic to isostatic state and then to the stressed-rigid state occurs in the system under study with increasing arsenic and germanium contents. The observed changes in the Raman spectra and the features of the dependences of optical and other parameters on the chemical composition are explained within the chemical-ordering model, taking into account the existence of local states near the allowed band boundaries.

Flexural behaviour of filigree slab elements made of carbon reinforced UHPC

In a research programme at TU Wien, the combination of ultra-high performance concrete (UHPC) reinforced with carbon fibre-reinforced polymers (CFRP) has been investigated. Experimental investigations of a filigree slab element made of these high-performance materials are presented in this paper. The focus here is on the flexural behaviour of this innovative structural elements. The performance of this material combination in the serviceability limit state was very good. However, the analytical moment capacity of the slab elements was not reached in the tests due to a bond failure between the textile reinforcement and the surrounding concrete, which led to premature failure of the specimens. Nevertheless this does not indicate a bad suitability for this type of structural element in practice, but rather shows that the bond behaviour of textile reinforced concrete is not fully understood yet.

Analysis of the ideal gas flow over body of basic geometrical shape

An approximate mathematical model of the heat transfer processes in the laminar and turbulent boundary layers, which occur near the surface of an aircraft moving at the hypersonic speed in the Earth’s atmosphere, is derived. This mathematical model makes it possible to calculate the convective heat transfer on the surface of typical structural elements of modern perspective aircrafts. 2D versions of the calculations of convective heat fluxes for bodies of simple geometric shapes are performed.

Procedure for the synthesis of models of electrotechnical complexes

A procedure for developing visual mathematical models of multichannel electrotechnical complexes which reduces time of synthesis of mathematical models and error likelihood was developed. The procedure includes two stages: representation of an electrotechnical complex in a form of a structure of the energy path and its transformation into a visual-block model. Representation of the system in a form of a structure of energy paths is based on the principle of system decomposition proposed by the authors which involves definition of six types of structural elements in the power conversion structure: source and receiver, distributor and consolidator, converter and energy storage. The principle of decomposition allows one to create a library of models of subblock, components of the visual-block model and introduce unification of the subblock designation. To illustrate the proposed procedure, an example of building a visual model of a DC drive for a rolling mill roll and its implementation on a personal computer were considered. A fragment of the library of components of the visual-block model with a mathematical description of the components included in the considered example was given. The introduced unification creates conditions for effective work of developers in elaboration of this procedure of model synthesis in terms of formation of a library of subblocs. In addition, unification of the form of representation of the library of components creates conditions for effective communication of researchers and developers within the frames of complex integrated projects. The model at the stage of developing structure of energy paths is a convenient tool for visualizing system operation and contributes to understanding of its functioning. The form of the obtained mathematical model is convenient for its further transformation into a model in variables of state which, in turn, is the starting point for synthesis of control systems

Behaviour and design of spiral-welded stainless steel tubes subjected to axial compression

Spiral welded stainless steel tubes are produced by helical welding of a continuous stainless steel strip. Recently, spiral welded stainless steel tubes have found increasing application in the construction industry due to their ease of fabrication and aesthetic appeal. However, an in-depth understanding of the behaviour of these types of structural elements is still needed due to the insufficient experimental evidence and lack of rational design guidance. In the present paper, an extensive experimental program was carried out to investigate the behaviour of axially loaded hollow and concrete-filled spiral welded stainless steel tubes. The effects of various design parameters were investigated throughout the test program. In addition to the experiments, this paper presents a finite element model for the prediction of these columns. Specifically, the proposed finite element models take into account the effects of material and geometric nonlinearities. The helical welding is modelled as an independent part that is further tied to the stainless steel tube. Moreover, the initial imperfections of the stainless steel tube and the residual stresses resulting from helical welding are included. Enhancement of the understanding of the experimental results can be achieved by extending the parametric studies based on the developed finite element model. Furthermore, a comparison of the ultimate strength between the experimental results and those obtained from existing codes of practice is conducted.

Kinetics of Grain Boundary Networks Controlled by Triple Junction and Grain Boundary Mobility

The kinetics of a triple junction of grain boundaries with distinct specific energies and mobilities and a finite mobility of the triple junction is investigated. The microstructure is approximated by different 2D settings consisting of typical structural elements. First, the migration of the triple point together with the adjacent grain boundaries, is simulated, assuming that the grains are infinitely large. Secondly, growth or shrinkage of finite n-sided grains is simulated by altering the boundary conditions and the results are compared to the already published analytical solution. The numerical results coincide with the corrected analytical solution. This solution can be derived either by applying the principle of maximum dissipation, or by applying the force balance at the triple junction within the framework of linear irreversible thermodynamics. The change of the area of infinite and finite grains is investigated analytically and numerically. By comparing the results of both approaches, the influence of the initial topology of the structural elements on the kinetics of grain growth can be estimated. Furthermore, the kinetics of grain growth of different idealized grain boundary networks is investigated. It is shown that square shaped grains surrounded by hexagons and dodecagons result in a more realistic grain growth scenarios than squares surrounded by octagons. A deviation from idealized grain boundary arrangements is e.g., observed, due to different triple junction mobilities, and the initially n-sided regular grain deforms in a complex manner.

Petrographic and structural analysis of exposed rocks of Musawa Sheet 56, Northwestern Nigeria

This work is among the few studies conducted in Musawa sheet 56 NE, which is part of the basement complex rocks of TudunWulli - Kankia area. The study area lies between Latitude 12º 19ʹ 00ʹʹ to 12º 23ʹ 00ʹʹN and longitude 7º 42ʹ 00ʹʹ to 7º 46ʹ 00ʹʹN. Due to the continuous play of geologic processes on the earth, there is the need to continuously update the geology of the Nigeria basement complex as this has a very important economic implication especially in areas like mineral and groundwater exploration. Equally, less attention has been given to this sheet unlike other sheets within the zone. The study done in this area has revealed the various rock types and their geological characteristics: field relation, macroscopic and microscopic features as well as structural elements. Results from the study shows that the area consists of granite, migmatite- gneiss and quartzite which all display a variety of colors, textures and mineralogy. Careful analysis of the distinctive mineralogy, textures, optical and structural characteristics led to the nomenclature of the rocks. The migmatite-gneiss display two petrographic varieties base on their foliation: one with linear foliation of alternating light and dark color minerals, and the other with wave like foliation. While granite is generally fine to medium grained in texture. The dominant structural trend of joints and faults in the study area are NNE-SSW and NW-SE. All these trends are consistent with the general trends of the Nigeria basement rocks. A study of thin sections of the rocks under a petrological microscope reveals optical properties peculiar to each rock type. The type and nature of structural elements associated with the rocks together with their geometry reveal that the rocks have undergone more than one deformational event. The occurrence of numerous brittle and ductile structures shows that the area has a great potential for groundwater and mineralization. But the area still experience shortage of water for domestic purposes.Keywords: basement complex, brittle structures, foliation, petrographic varieties, thin sections

Topology optimization of a novel fuselage structure in the conceptual design phase

PurposeIn recent years, innovative aircraft designs have been investigated by researchers to address the environmental and economic issues for the purpose of green aviation. To keep air transport competitive and safe, it is necessary to maximize design efficiencies of the aircrafts in terms of weight and cost. The purpose of this paper is to focus on the research which has led to the development of a novel lattice fuselage design of a forward-swept wing aircraft in the conceptual phase by topology optimization technique.Design/methodology/approachIn this paper, the fuselage structure is modelled with two different types of elements – 1D beam and 2D shell – for the validation purpose. Then, the finite element analysis coupled with topology optimization is performed to determine the structural layouts indicating the efficient distributed reinforcements. Following that, the optimal fuselage designs are obtained by comparison of the results of 1D and 2D models.FindingsThe topological results reveal the need for horizontal stiffeners to be concentrated near the upper and lower extremities of the fuselage cross section and a lattice pattern of criss-cross stiffeners should be well-placed along the sides of the fuselage and near the regions of window locations. The slight influence of windows on the optimal reinforcement layout is observed. To form clear criss-cross stiffeners, modelling the fuselage with 1D beam elements is suggested, whereas the less computational time is required for the optimization of the fuselage modelled using 2D shell elements.Originality/valueThe authors propose a novel lattice fuselage design in use of topology optimization technique as a powerful design tool. Two types of structural elements are examined to obtain the clear reinforcement detailing, which is also in agreement with the design of the DLR (German Aerospace Center) demonstrator. The optimal lattice layout of the stiffeners is distinctive to the conventional semi-monocoque fuselage design and this definitely provides valuable insights into the more efficient utilization of composite materials for novel aircraft designs.