structural elements
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10.29007/s1rd ◽  
2022 ◽  
Minh Duc Nguyen ◽  
Thai Hien Nguyen

Nowadays in the construction of modem buildings, it is necessary to accommodate pipes and ducts necessary services, such as air conditioning, water supply, sewerage, electricity, computer networks, and telephone networks. Cellular members – steel I‐ shaped structural elements with circular web openings at regular intervals – have been used as beams for more than 35 years now. Although in the past already a large deal of research was performed into the subject of the behavior of cellular beams, almost no attention has been paid to the application of cellular members as columns. The column will be analyzed using the finite element method to calculate the critical load and compared with the Eurocode3 standard, web-post buckling, and frame using cellular member by FEM.

2022 ◽  
Vol 15 ◽  
Lavinia Floreani ◽  
Federico Ansaloni ◽  
Damiano Mangoni ◽  
Elena Agostoni ◽  
Remo Sanges ◽  

Transposable elements (TEs) are mobile genetic elements that made up about half the human genome. Among them, the autonomous non-LTR retrotransposon long interspersed nuclear element-1 (L1) is the only currently active TE in mammals and covers about 17% of the mammalian genome. L1s exert their function as structural elements in the genome, as transcribed RNAs to influence chromatin structure and as retrotransposed elements to shape genomic variation in somatic cells. L1s activity has been shown altered in several diseases of the nervous system. Huntington disease (HD) is a dominantly inherited neurodegenerative disorder caused by an expansion of a CAG repeat in the HTT gene which leads to a gradual loss of neurons most prominently in the striatum and, to a lesser extent, in cortical brain regions. The length of the expanded CAG tract is related to age at disease onset, with longer repeats leading to earlier onset. Here we carried out bioinformatic analysis of public RNA-seq data of a panel of HD mouse models showing that a decrease of L1 RNA expression recapitulates two hallmarks of the disease: it correlates to CAG repeat length and it occurs in the striatum, the site of neurodegeneration. Results were then experimentally validated in HttQ111 knock-in mice. The expression of L1-encoded proteins was independent from L1 RNA levels and differentially regulated in time and tissues. The pattern of expression L1 RNAs in human HD post-mortem brains showed similarity to mouse models of the disease. This work suggests the need for further study of L1s in HD and adds support to the current hypothesis that dysregulation of TEs may be involved in neurodegenerative diseases.

2022 ◽  
Diana Antoci ◽  

The implemented theoretical study has revealed various scientific positions aimed at: interpreting the concepts of value and value orientation; finding controversial positions and affinities in the use of “value” and “value orientation” concepts; identifyingambiguous positions on structural elements of value orientation and value formation mechanism. The purpose of undertakenresearch was theoretical, experimental and methodological in nature, outlining formation of value orientations in adolescence and youth ages.The developed definitions and determined structural components of value orientations allowed initiation of an experimental investigation of value orientations in adolescents and young people through which interrelation between the constitutive components of value orientation was confirmed, the specifics of values in adolescents and young people was emphasized. Outlining the specifics of value orientation structure led to identification of criteria, indicators and descriptors and to development and validation of a Questionnaire for Value Orientation Assessment. The results of experimental study laid the basis for development and recognition of a Pedagogical Model for formation of value orientations in adolescents and young people. The previously identified mechanism for formation of values and functioning of value orientations was transposed into the nucleus of the Pedagogical Model, which included the following components: behaviour, emotional states, attitudes, convictions, and values. In order to identify the methodology for forming value orientations in the formal, informal and non-formal educational environment, the principles of humanistic, constructivist and cognitivist education, strategies, conditions were highlighted, which ensure a dynamic progress in general development of the personality, implicitly of value orientations, and which is taken into account in framework ofa formative experiment.The data obtained from the validation of the developed Pedagogical Model confirmed its effectiveness and proved that it was a multidimensional one, which could be of great benefit to specialists in the field of Education Sciences and teachers from schools and higher educationalinstitutions.

2022 ◽  
Vol 8 (1) ◽  
pp. 10
Taşkın Özkan ◽  
Norbert Pfeifer ◽  
Gudrun Styhler-Aydın ◽  
Georg Hochreiner ◽  
Ulrike Herbig ◽  

We present a set of methods to improve the automation of the parametric 3D modeling of historic roof structures using terrestrial laser scanning (TLS) point clouds. The final product of the TLS point clouds consist of 3D representation of all objects, which were visible during the scanning, including structural elements, wooden walking ways and rails, roof cover and the ground; thus, a new method was applied to detect and exclude the roof cover points. On the interior roof points, a region-growing segmentation-based beam side face searching approach was extended with an additional method that splits complex segments into linear sub-segments. The presented workflow was conducted on an entire historic roof structure. The main target is to increase the automation of the modeling in the context of completeness. The number of manually counted beams served as reference to define a completeness ratio for results of automatically modeling beams. The analysis shows that this approach could increase the quantitative completeness of the full automatically generated 3D model of the roof structure from 29% to 63%.

2022 ◽  
Vol 21 (4) ◽  
pp. 308-311
K. A. Molokov ◽  
V. V. Novikov

Introduction. Welded joints in large-sized metal structures (e.g., in the structures of ship hulls) subject to low-cycle fatigue are considered. The characteristic appearance of soft interlayers, which are significantly plastically deformed under working loads, was noted. Deformation of the metal structure with damage, especially in the form of cracks, reduces the strength and reliability of structural elements and joints. Pre-deformation negatively affects plasticity; therefore, much depends on the residual plasticity of the cracking material. At the same time, with a decrease in residual plasticity, such an important reliability indicator as the resistance of the material to crack propagation — the fracture toughness – decreases. The paper is devoted to the development of a model that includes analytical dependences for assessing the crack resistance of metal structures and their welded joints with soft interlayers according to the crack resistance limit for all crack sizes.Materials and Methods. The theory and methods of linear mechanics of materials destruction, structural-mechanical approach are used. The calculation results were analyzed and compared to the experimental data and other analytical solutions. The numerical experiment was performed for the ferrite-perlite steel grades of 10, 50, 22K, St3sp, etc., widely used in industry, as well as for alloy steels hardened to medium and high strength of 30KhGSA, 37KhN3A, etc. Results. Analytical dependences are obtained for calculating the relative crack resistance limit according to three main known mechanical characteristics of the state of the material of the soft interlayer of the welded joint.Discussion and Conclusions. The results obtained can be used to assess the crack resistance of pre-deformed structural elements and welded joints (including those with soft interlayers) operating under a transverse load. The results of experimental data and analytical calculations are shown in dimensionless form, which enables to obtain invariant results with respect to the fracture toughness limit.

Metals ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 124
Tomasz Trzepieciński ◽  
Sherwan Mohammed Najm ◽  
Valentin Oleksik ◽  
Delia Vasilca ◽  
Imre Paniti ◽  

Due to a favourable strength-to-density ratio, aluminium and its alloys are increasingly used in the automotive, aviation and space industries for the fabrication of skins and other structural elements. This article explores the opportunities for and limitations of using Single- and Two Point Incremental Sheet Forming techniques to form sheets from aluminium and its alloys. Incremental Sheet Forming (ISF) methods are designed to increase the efficiency of processing in low- and medium-batch production because (i) it does not require the production of a matrix and (ii) the forming time is much higher than in conventional methods of sheet metal forming. The tool in the form of a rotating mandrel gradually sinks into the sheet, thus leading to an increase in the degree of deformation of the material. This article provides an overview of the published results of research on the influence of the parameters of the ISF process (feed rate, tool rotational speed, step size), tool path strategy, friction conditions and process temperature on the formability and surface quality of the workpieces. This study summarises the latest development trends in experimental research on, and computer simulation using, the finite element method of ISF processes conducted in cold forming conditions and at elevated temperature. Possible directions for further research are also identified.

Belén González Sánchez ◽  
Antonia Navarro ◽  
Judith Ramírez-Casas ◽  
Joan Ramon Rosell

In traditional architecture, the construction systems used have always been linked to the material resources of the environment. In the areas of extraction of gypsum in the Iberian Peninsula, the use of this material as a conglomerant was not limited to the interior lining of vertical and/or horizontal walls or to interior decorations, as is the case today, but proved to be a very versatile material, which could be used both in structural elements and in finishing elements and decorations. This study shows the preliminary results of an ongoing research on the recovery of traditional gypsum pavements, where three types of traditional gypsum plasters with natural products such as collagen, coconut soap, potassium soap, vegetable oil and marshmallow root were tested. The hygroscopic behaviour of the treated samples has been evaluated from the capillarity water absorption and the contact angle, due to their high hygroscopicity. On the other hand, the density and porosity, surface hardness and thermal conductivity of the samples have also been determined.

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