Structural Components Research Articles

Shear buckling behaviour of sinusoidal corrugated web girders with stiffened circular openings

The mechanical properties and failure behaviours of three different specimens of sinusoidal corrugated web girders with stiffened circular openings were investigated experimentally and numerically. The experimental outcomes showed similarities in the mechanical properties and failure model of the specimens, despite differences in the geometric dimensions. The numerical simulations further confirmed the buckling as well as post-buckling behaviours of the experimental results. The influence of initial geometric imperfections on the shear buckling load of the corrugated web girders was quantified and neglecting geometric imperfections led to an overestimation of the actual shear load capacity, emphasizing the importance of considering imperfections in the design of structural components. The investigation results showed that the shear load capacities of the girders were significantly affected by the thickness of the opening stiffeners, and that the presence of openings reduced the load carrying capacity and the overall stiffness of the beams, whereas the existence of opening stiffeners increased both the ultimate load bearing capacity and the global stiffness. However, the strengthening effect of the opening stiffener becomes less pronounced beyond a specific thickness. Besides, a comparison between hand calculations and numerical simulations show that the recently developed calculation method provided a more reliable prediction of the shear buckling resistance of corrugated web with stiffened openings. This investigation provides valuable guidance on the shear buckling behaviour of sinusoidal corrugated web girders with circular opening stiffeners, thus benefiting the design and analysis of steel structural components with sinusoidal corrugated web.

Принцип полноты осмотра места происшествия: содержание и проблемы практической реализации

The article is devoted to the key provision of the tactics of inspection of the scene of the accident – the principle of completeness of its conduct. The practical implementation of this provision is complicated by the lack of a clear understanding of the content and methodology of its implementation by law enforcement officers during the inspection of the scene. The article reveals the structural components of this principle and analyzes the importance of methods of its implementation in the practice of conducting an investigative examination.

Design of Area Efficient Network-On-Chip Router: A Comprehensive Review

The number of uses for cutting-edge technologies has led to a further growth in a single chip's computational capacity. In this case, several applications want to build on a single chip for computing resources. As a result, connecting the IP cores becomes yet another difficult chore. The many-core System-On-Chips (SoCs) are being replaced by Network-On-Chip (NoC) as an on-chip connectivity option. As a result, the Network on Chip was created as a cutting-edge framework for those networks inside the System on Chip. Modern multiprocessor architectures would benefit more from a NoC architecture as its communication backbone. The most important components of any network structure are its topologies, routing algorithms, and router architectures. NoCs use the routers on each node to route traffic. Circuit complexity, high critical path latency, resource usage, timing, and power efficiency are the primary shortcomings of conventional NoC router architecture. It has been difficult to build a high-performance, low-latency NoC with little area overhead. This paper surveys previous methods and strategies for NoC router topologies and study of general router architecture and its components. Analysis is carried out to understand and work for a low latency, low power consumption, and high performance NoC router design that can be employed with a wide range of FPGA families. In the current work, we are structuring a modified four port router with the goals of low area and high performance operation.

The design elements of outpatient geriatric rehabilitation from patient, healthcare professional, and organizational perspective; a qualitative study

Purpose To gain a rich understanding of the experiences and opinions of patients, healthcare professionals, and policymakers regarding the design of OGR with structure, process, environment, and outcome components. Methods Qualitative research based on the constructive grounded theory approach is performed. Semi-structured interviews were conducted with patients who received OGR (n = 13), two focus groups with healthcare professionals (n = 13), and one focus group with policymakers (n = 4). The Post-acute Care Rehabilitation quality framework was used as a theoretical background in all research steps. Results The data analysis of all perspectives resulted in seven themes: the outcome of OGR focuses on the patient’s independence and regaining control over their functioning at home. Essential process elements are a patient-oriented network, a well-coordinated dedicated team at home, and blended eHealth applications. Additionally, closer cooperation in integrated care and refinement regarding financial, time-management, and technological challenges is needed with implementation into a permanent structure. All steps should be influenced by the stimulating aspect of the physical and social rehabilitation environment. Conclusion The three perspectives generally complement each other to regain patients’ quality of life and autonomy. This study demonstrates an overview of the building blocks that can be used in developing and designing an OGR trajectory.

Assessment of the endurance limit of light structural metal components using the fatigue surface development method

The paper presents a numerical method developed by the authors. The method consists in obtaining a three-dimensional component fatigue surface model according to the results of tests corresponding to two to four values of the operational factor, making it possible to plot the fatigue limit – operational parameter curve. A description of the algorithm of the method is presented, its validity is confirmed. The results show good agreement with outside empirical data for other values of the operational parameters. A model of the fatigue surface is constructed. The model specifies the calculation of strength of aircraft elements operating in rarified atmosphere (e.g. engine compartments of space complexes and upper stages of carrier rockets). The model increases the endurance calculation accuracy and enables structural mass optimization.

Instrumented indentation of PMMA/ZnO nanocomposites films

Piezoelectric nanocomposite films comprise zinc oxide (ZnO) nanoparticles as reinforcement and poly-methyl methacrylate (PMMA) as the matrix. These films can potentially be used as structural and functional components of microdevices that can harvest energy from ambient mechanical vibrations. The design of such energy-scavenging micro/nano-systems will require knowledge of the process-microstructure-property relationships of nanocomposite films. This study synthesized PMMA/ZnO nanocomposite films using ultrasonic probe sonication and solution-casting. The nanomechanical characterization of the nanocomposite films was conducted using a nanoindenter via quasi-static mode. Quasi-static nanoindentation revealed that the indentation modulus ranged from 3.49 ± 0.03 GPa for PMMA to 4.71 ± 0.07 GPa for PMMA/ZnO 5 wt% nanocomposite film. However, the indentation modulus of 10 wt% ZnO nanocomposites decreases, i.e. 4.22 ± 0.60 GPa. The indentation hardness varied from 311.97 ± 6 MPa for PMMA thermoplastic polymer to 432.94 ± 83.81 MPa for PMMA/ZnO 10 wt% nanocomposites film. In addition, the properties of the nanocomposite film vary, as supported by scanning electron micrographs.

Preparation, Deformation Behavior and Irradiation Damage of Refractory Metal Single Crystals for Nuclear Applications: A Review.

Refractory metal single crystals have been applied in key high-temperature structural components of advanced nuclear reactor power systems, due to their excellent high-temperature properties and outstanding compatibility with nuclear fuels. Although electron beam floating zone melting and plasma arc melting techniques can prepare large-size oriented refractory metals and their alloy single crystals, both have difficulty producing perfect defect-free single crystals because of the high-temperature gradient. The mechanical properties of refractory metal single crystals under different loads all exhibit strong temperature and crystal orientation dependence. Slip and twinning are the two basic deformation mechanisms of refractory metal single crystals, in which low temperatures or high strain rates are more likely to induce twinning. Recrystallization is always induced by the combined action of deformation and annealing, exhibiting a strong crystal orientation dependence. The irradiation hardening and neutron embrittlement appear after exposure to irradiation damage and degrade the material properties, attributed to vacancies, dislocation loops, precipitates, and other irradiation defects, hindering dislocation motion. This paper reviews the research progress of refractory metal single crystals from three aspects, preparation technology, deformation behavior, and irradiation damage, and highlights key directions for future research. Finally, future research directions are prospected to provide a reference for the design and development of refractory metal single crystals for nuclear applications.

Polar Lipids Supplementation Enhances Basal Excitatory Synaptic Transmission in Primary Cortical Neuron.

Polar lipids, such as gangliosides and phospholipids, are fundamental structural components that play critical roles in the development and maturation of neurons in the brain. Recent evidence has demonstrated that dietary intakes of polar lipids in early life are associated with improved cognitive outcomes during infancy and adolescence. However, the specific mechanisms through which these lipids impact cognition remain unclear. This study examines the direct physiological impact of polar lipid supplementation, in the form of buttermilk powder, on primary cortical neuron growth and maturation. The changes are measured with postsynaptic current response recordings, immunohistochemical examination of functional synapse localization and numbers, and the biochemical quantification of receptors responsible for neuronal synaptic neurotransmission. Chronic exposure to polar lipids increases primary mouse cortical neuron basal excitatory synapse response strength attributed to enhanced dendritic complexity and an altered expression of the excitatory α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor subunit 2 (GluR2). The present finding suggests that dietary polar lipids improve human cognition through an enhancement of neuronal maturation and/or function.

The Irradiation Effects in Ferritic, Ferritic-Martensitic and Austenitic Oxide Dispersion Strengthened Alloys: A Review.

High-performance structural materials (HPSMs) are needed for the successful and safe design of fission and fusion reactors. Their operation is associated with unprecedented fluxes of high-energy neutrons and thermomechanical loadings. In fission reactors, HPSMs are used, e.g., for fuel claddings, core internal structural components and reactor pressure vessels. Even stronger requirements are expected for fourth-generation supercritical water fission reactors, with a particular focus on the HPSM's corrosion resistance. The first wall and blanket structural materials in fusion reactors are subjected not only to high energy neutron irradiation, but also to strong mechanical, heat and electromagnetic loadings. This paper presents a historical and state-of-the-art summary focused on the properties and application potential of irradiation-resistant alloys predominantly strengthened by an oxide dispersion. These alloys are categorized according to their matrix as ferritic, ferritic-martensitic and austenitic. Low void swelling, high-temperature He embrittlement, thermal and irradiation hardening and creep are typical phenomena most usually studied in ferritic and ferritic martensitic oxide dispersion strengthened (ODS) alloys. In contrast, austenitic ODS alloys exhibit an increased corrosion and oxidation resistance and a higher creep resistance at elevated temperatures. This is why the advantages and drawbacks of each matrix-type ODS are discussed in this paper.

A nose beam segmental construction process for large-span composite emergency bridges

The effectiveness of the incremental launching method with lightweight, flexible nose beam in the construction and erection of emergency bridges with large-span composite materials is investigated through a combined experimental and numerical study. A theoretical model is developed to characterize the additional bending movement induced during the flexible nose launching process and analyze stress fluctuations in structural components during critical launching stages, providing theoretical underpinning the for lightweight nose beam design. Results indicate that the stress attributable to the additional bending moment during critical launching stages constitutes approximately 9.6 %, significantly impacting lightweight nose beam design con-siderations. Additionally, it was shown that conventional static analyses are difficult to adequately capture the internal force changes during the launch of a flexible nose beam. Therefore, a finite element model accounting for geometric and contact non-linearity is proposed, exhibiting higher precision in predicting additional bending movement values compared to traditional finite element models. The accuracy of the finite element model is confirmed through scaled-down experiments.

A pivotal nutritional potential of understory vascular plants in Patagonian forests

Native forests can support wild and domestic herbivores, but their nutritional potential of understory vascular plants is rarely explored. We analysed the composition of understory plant species and their biochemical components to reveal the nutritional potential of forest types (deciduous, evergreen, mixed) and their associated open-lands (e.g. grasslands in forestlands) in Northern Patagonia. We proposed an approach combining our data (e.g. plant composition, occurrence frequency) with bibliographic research (e.g. Scopus database) to develop our findings. Data were evaluated using descriptive statistical analyses and multivariate analyses. This study presents the nutritional values for the 20 pivotal species under examination. The results highlight the significant impact of taxonomic families on nutritional profiles, where the species that presented the most relevant occurrence frequency: the herbs T. officinale (60.4 % of total occurrence frequency-TOF) and T. repens (47.9 % TOF), the graminoid H. lanatus (58 % TOF), and the fern B. penna marina (44.4 % TOF). Multivariate analyses showed that the first two PCA axes explained 76.1 % (p = 0.001) and 10.5 % (p = 1.000) of forest type variation, with ñire forests and open-lands having the highest palatable plant coverage. Biochemical PCA axes explained 52.1 % (p = 0.024) and 22.5 % (p = 0.874) of the variation, distinguishing species by protein content and structural components. The deciduous forests exhibited the highest coverage of palatable plants, while target plants with low palatability and high coverage were predominantly found in evergreen forest types. The confirmed presence of pivotal species across forest types and open-lands underscores its nutritional potential, characterised by highly digestible dry matter, crude protein, highly digestible non-nitrogenous nutrients, and relative feed value. Considering their widespread distribution and nutritional factors, the native and non-native plants merit attention due to their pivotal nutritional potential.

Dissolved organic matter released from beach wrack is source-specific and molecularly highly diverse

AbstractBeach wrack is an important supplier of nutrients and organic matter to sandy beach ecosystems and underlying subterranean estuaries (STEs), producing metabolic hotspots in these otherwise organic carbon- and nutrient-poor environments. To assess the impact of beach wrack type (e.g., marine, terrestrial, plant, animal) and environmental settings (e.g., tidal inundation, precipitation, and solar irradiation) on nutrient and dissolved organic matter (DOM) release, a series of leaching experiments was conducted. Quantities of leached nutrients and dissolved organic carbon (DOC) were determined, and DOM molecular composition was investigated using Fourier-transform ion cyclotron resonance mass spectrometry (FT-ICR-MS). Millimolar—to molar amounts of DOC and dissolved nitrogen were released from the beach cast per kg dry weight, with type of wrack and leaching medium (fresh- vs. saltwater) exerting the biggest influences. Exemplary for animal cast, jellyfish leached up to two 100-fold more, mostly organic, nitrogen compared to all other beach wrack types. FT-ICR-MS data of solid-phase extracted DOM indicated that beach wrack releases compounds with putative mono- and oligosaccharide-, amino acid- and vitamin-type molecular formulae, which likely serve as valuable substrate for heterotrophic microorganisms. DOM from the brown seaweed Fucus sp. was more aromatic than seawater DOM and even beach wrack of terrestrial origin, probably from structural components and secondary metabolites such as phlorotannins. We conclude that DOM and nutrient release from beach wrack strongly depends on wrack type and leaching medium, may obscure molecular provenance proxies (e.g., terrestrial indices), and adds a nutritional boost to infiltrating sea- and rainwater which likely impact microbial respiration rates in the STE.

Ovarian cancer deaths attributable to asbestos exposure in Lombardy (Italy) in 2000–2018

ObjectivesWe aimed to estimate the fraction of deaths from ovarian cancer attributable to asbestos exposure in Lombardy Region, Italy, using a novel approach that exploits the fact that ovarian cancer...

Insulin-like growth factor-binding protein 7 (IGFBP7): A microenvironment-dependent regulator of angiogenesis and vascular remodeling.

Insulin-like Growth Factor-Binding Protein 7 (IGFBP7) is an extracellular matrix (ECM) glycoprotein, highly enriched in activated vasculature during development, physiological and pathological tissue remodeling. Despite decades of research, its role in tissue (re-)vascularization is highly ambiguous, exhibiting pro- and anti-angiogenic properties in different tissue remodeling states. IGFBP7 has multiple binding partners, including structural ECM components, cytokines, chemokines, as well as several receptors. Based on current evidence, it is suggested that IGFBP7's bioactivity is strongly dependent on the microenvironment it is embedded in. Current studies indicate that during physiological angiogenesis, IGFBP7 promotes endothelial cell attachment, luminogenesis, vessel stabilization and maturation. Its effects on other stages of angiogenesis and vessel function remain to be determined. IGFBP7 also modulates the pro-angiogenic properties of other signaling factors, such as VEGF-A and IGF, and potentially acts as a growth factor reservoir, while its actual effects on the factors' signaling may depend on the environment IGFBP7 is embedded in. Besides (re-)vascularization, IGFBP7 clearly promotes progenitor and stem cell commitment and may exhibit anti-inflammatory and anti-fibrotic properties. Nonetheless, its role in inflammation, immunomodulation, fibrosis and cellular senescence is again likely to be context-dependent. Future studies are required to shed more light on the intricate functioning of IGFBP7.

In silico Investigation on the Structural Insights into the Binding of Squalamine Inhibitor with Membrane-Bound Α-Synuclein

Background: Parkinson's disease (PD) and its associated symptoms are closely associated with the self-assembly of α-Synuclein (α-Syn). Squalamine is a naturally occurring chemical substance with established antiviral and anticancer properties, and its profound impact on the α- Syn aggregation both in vivo and in vitro is well studied. Examining its interaction with lipid vesicles, which are known to encourage nucleation, can signify the mechanism of action of squalamine. The squalamine molecule is believed to displace α-Syn from the surfaces of the lipid vesicles, therefore preventing the initial steps in the process of aggregation. Additionally, the squalamine molecule reduces the harmful effects of α-Syn oligomers in human neuroblastoma cells by preventing them from interacting with lipid membranes. Objective: The aim of this study was to perform computational investigation of the conformational changes of membrane-bound α-Syn in the presence of squalamine inhibitor molecule objective: Computational investigation of the conformational changes of membrane-bound α-Synuclein in the presence of squalamine inhibitor molecule Method: Molecular Dynamics (MD) trajectory analysis was carried out to study the structural change of the α-Syn-squalamine conformers as a function of simulation time. The percentage of the secondary structural components of the α-Syn-squalamine complex was determined. Optimization of small molecule inhibitors was carried out using Density Functional Theory (DFT) analysis. Additionally, the values of electrophilicity (ω), nucleophilicity (N), Electron affinity (EA), and ionization potential (IP) were calculated. Results: The docking of the α-Syn-squalamine complex revealed the binding site and the best structure was selected based on the highest docking vina score (-5.8), and the contact residues were listed. From the conformational snapshots of the α-Syn-squalamine complex, it was evident that the α-Syn remained stable, maintaining its integrity throughout the simulation. The α-helical content was found to be retained from the secondary structural content analysis. The ω and N of the squalamine molecule were calculated to be -0.84 and 3.25, respectively. Conclusion: Our findings suggest that in the presence of a squalamine inhibitor molecule, α-Syn adopts a helical conformation that ensures stability and may indicate that the squalamine molecule causes gradual displacement of α-Syn across different regions within the lipid membrane.

The Impact of the Capital Structure on the Financial Default / an Analytical Research in Sample of Companies of the Ministry of Industry and Minerals

The objective of this research is to study the effect of capital structure on financial default. As it is the first research of its kind that deals with this sample of companies affiliated to the Ministry of Industry and Minerals and these companies were chosen especially because they suffer from financial deficit problems. The importance of this research lies in determining the importance of the components of the capital structure and knowing their impact on financial default in the research sample companies. The research sample represented a number of companies of the Ministry of Industry and Minerals located in Baghdad Governorate. The statistical methods represented in used financial ratios in the analysis to evaluate the research variables, which are both capital structure ratios (Long-term debt ratio to equity and long-term debt to total asset) and liquidity ratios (Current ratio, Quick ratio, Cash ratio) and used the programs (SPSS v26) and (Excel 2010) and the moment structure analysis program (AMOS) was adopted in order to calculate each of the standard deviation, correlation coefficient and specificity to find the relationship between the research variables and test its hypotheses. The results showed that the capital structure had no effect on the cases of financial defaults in the companies.

Preparation and characterization of high load‐bearing needled composite preform based on novel ordered short fiber network needling method

AbstractNeedled preform and its composite using felt and base cloth stacked needled have small fiber volume fraction and relatively weak mechanical properties, which are difficult to meet the service requirements of structural and functional integrated components of high‐speed aircraft. Responding to this issue, this paper proposed a new method for preparing high load‐bearing needled composite preform based on ordered short fiber network needling. The high load‐bearing needled preforms were prepared by designing different structural parameters of ordered short fiber network and forming process parameters, and then preform structure was characterized and mechanical properties were tested. The results showed that using ordered short fiber network as carrier of the short fibers, the formed needled fiber bundles were longer and denser, volume content of needled fiber bundles and mechanical properties of needled preform were greatly improved, and needled fiber bundles volume content of ordered short fiber network reinforced needled preform was 1.5 times and 46.3 times that of half‐cut cloth and felt respectively. Compared with traditional felt needled preform and half‐cut cloth needled preform, the interlaminar peeling strength of the ordered short fiber network reinforced needled preform increased by up to 246.4% and 49.2%, respectively. The tensile strength of ordered short fiber network reinforced needled preform was 12.9% higher than that of half‐cut cloth in X‐axis direction. In addition, the effects of ordered short fiber network structure, short fiber length, areal density and needling density on the needled preform structure and properties were also revealed.Highlights High load‐bearing needled composite preform was prepared based on novel ordered short fiber network needling method. The needled fiber bundles formed by using ordered short fiber network were longer and denser, and their volume content was 46.3 times that of felt needled preform. The interlaminar peeling strength of the ordered short fiber network reinforced needled preform increased by up to 246.4%. The tensile strength of ordered short fiber network reinforced needled preform was 12.9% greater than half‐cut cloth in the X‐axis direction.

Continuous damage of concrete structures due to reinforcement corrosion: A micromechanical and multi-physics based analysis

Deterioration of concrete and composite structures due to the corrosion of embedded steel components (rebar, structural steel components, and steel fiber, etc.) is a self-accelerating process involving multiple chemophysical processes that occur concurrently in the heterogeneous structure of concrete. The multiple-inclusion matrix of concrete and the multi-chemophysics nature of steel corrosion synergistically challenge an accurate analysis and evaluation of the deterioration process using homogeneity-based continuum mechanics. This study presents a three-dimensional micromechanical model developed for quantifying the continuous deterioration of concrete by steel corrosion. Continuous damage theory of solid-state materials was applied to a steel-concrete sample that consists of mortar, aggregate, and steel phases as were reconstructed from high-resolution X-ray CT images. With due consideration of the variations in environmental temperature and moisture, the complex chemophysical processes involved in corrosion-induced deterioration of concrete were solved concurrently using finite element analysis. Results of the study indicate that capillary suction in a variably saturated concrete plays an important role in steel corrosion and that removal of chloride by an externally applied electrical field can effectively mitigate steel corrosion and the incurred concrete deterioration.

MUNICIPAL GOVERNANCE IN GERMANY: PRACTICE RECOMMENDATIONS FOR UKRAINE

Establishing a municipal governance system is a long process focused on selecting the best practices that have proven to be effective and efficient. One of the methods is the transit of elements of municipal systems borrowed from other countries. The experience of ensuring democratic participation of the community formed in Germany is of interest. The purpose of the article is to identify the components of the German model of municipal governance that can be used by Ukraine to improve the efficiency of the national system of local self-government and bring it closer to EU standards. The elements of the comparative analysis in the article are the analysis of the institutional model of municipal governance and its state and political basis; determination of the specifics of the distribution of powers between the state and local governments and the nature of community participation in local self-government; characterization of the system of financial guarantees and the budget system; determination of the principles of cooperation and coordination of municipalities. The article uses the methodology of comparative analysis based on the identification and analysis of the legal, structural, organizational, political and economic components of municipal governance in Ukraine and Germany.

Methodological Aspects of Elaborating Marketing Strategy of Innovation Bank Products and Services

Today the key factor of influencing banking sector is the development of information systems and overall strategy of economy digitalization as its consequence. On today’s competitive banking market we can observe the necessity to elaborate and promote approaches to banking product and service marketing that are meant to provide finance stability of banking business and orientation of marketing innovation bank functioning not only to their opportunities but also to market needs. In spite of a big number of publications dealing with this issue, academic research should be developed further. In research by Russian scientists there are actually no developments dealing with the problem of finding structural components for elaborating marketing strategy of banking products and services. Insufficient attention was paid to approaches of defining the essence of banking product and service marketing. The problem of assessing the level of the impact of banking innovation marketing on competitive positions and finance stability of banks has not been settled yet. The article showed components necessary to elaborate strategy of banking product and service marketing, among which the author underlined their characteristics depending on the model of commercialization, sub-system of their implementation process and interconnection between the chosen marketing strategy and classification features of banking innovation. The author designed a structural and logical scheme of elaborating strategy of baking product and servicer marketing and formulated its definition.