Structural Elements Research Articles

Impacts of Dampness on Structural Stability of Public Secondary School Buildings in Adamawa State, Nigeria

This research assessed the impact of dampness on the structural stability of public secondary school buildings in Adamawa state. Dampness as it were is the infiltration of water through the structural elements (interior and exterior) of an edifice, wetness of structural elements through moisture rise by capillary, or extreme quantity of moisture contained in building materials or the building components (Agyekum, Ayakwa, Koranteng & Adinyira, 2013a; Wilkowska, 2017). A percentage of building structures that deteriorate during wetness, dampness, or excessive moisture movements are perceived, visible, or measurable (Soldatova, Sansone, Stephens & Shah, 2011). A building is described as being affected by dampness when there is moisture that is not wanted to a certain degree in the building than its water- retaining capability such that finishes and structural members are stained or discoloured and certain secondary elements are either upturned or lifted (Ishak, Che Ani, Akashah &Kayan, 2013). The primary sources of moisture in buildings according to Sulaiman and Beithou (2011) are liquid water from precipitation or plumbing leaks; water vapour from the building exterior or activities/processes within the building; liquid and vapour from the soil adjoining a building; and moisture built-in with the materials of construction or brought in with goods and people. Young (2007) and Agyekum et al. (2013), categorise the primary sources of moisture into three types: penetration dampness, condensation, and rising dampness. Specifically, it; determined the common types of dampness and common causes of dampness, it also determined the extent of the impacts of dampness and suggested suitable procedures for treating the impact of dampness. A descriptive research design was adopted for the study. Four purposes and four research questions were raised to guide the study, the population for this study is Grade A public secondary schools in Adamawa State. Three sampling techniques were employed in this study, these are stratified sampling, purposive sampling, and simple random sampling. A checklist and a structured questionnaire were developed.

Accounting and analytical support of internal cost control in the health resort institutions

Subject. This article focuses on the development of methodological tools for accounting and analytical support of internal cost control in economic entities of the health resort complex. Objectives. The article aims to develop the theoretical and methodological foundations and detail practical provisions for accounting, control and analytical support of internal control of the costs incurred, confirming the voucher cost and helping minimize the amount of invested financial and intellectual resources. Methods. For the study, I used the methods of grouping, generalization, expert assessments, comparative analysis, classification, factor analysis, and modeling. Results. The article clarifies the concept of Health Resort Service, develops a set of principles that reveals the methodology for the formation of internal management reporting and its structural elements for grouping information, and it offers a variant of regulation of internal cost control. Conclusions and Relevance. The developed multi-component structured model of internal control for analytical assessment and monitoring of costs, determining their compliance with the planned ones, within the framework of the business process Providing a Comprehensive Health Resort Service, is universal for economic entities of the health resort complex, which optimizes control procedures. The key proposals for the formation of methodological approaches to the organization of internal cost control in health resorts can help minimize entrepreneurial risks and increase the efficiency of activities.

Asymmetric Impact of Economic, And Structural Factors on the Development of the Non-Oil Export Sector in GCC Economies 1992-2022: Structural Reform Priorities to Sustainable Economic Growth

The current study empirically investigates to explore the links between economic and structural variables of non-oil export industry development in GCC economies. The research spans the years 1992 to 2022. It is understandable to wonder why some oil-producing countries have been able to diversify and build their economy while others have not. We postulate that disparities in the diversification and development patterns of oil producers are related to differences in their economic and structural characteristics. Divergence in diversification and development trends may result from such discrepancies. We measure the role of economic and structural elements to test this idea. The findings indicate that economic and structural factors play a critical role in the process of diversification and development. Countries have the higher-quality infrastructure, in particular. The findings imply that GCC authorities should improve robust macroeconomic conditions to support their non-oil export sector and boost institutional quality drivers to accelerate non-oil export sector development in their nations. The empirical findings can assist GCC policymakers in better designing the economic policies required to accomplish the GCC countries' comprehensive and sustainable economic development. Asymmetric mechanisms in non-oil export responses to economic and structural factor changes are likely to differ across economic sectors in GCC countries. A sectoral examination of this link could provide further information and supplement our analysis. New capital and infrastructure must be accommodated to support domestic and export manufacturing.

Active-Site Oxygen Accessibility and Catalytic Loop Dynamics of Plant Aromatic Amino Acid Decarboxylases from Molecular Simulations.

Aromatic amino acid decarboxylases (AAADs) are pyridoxal-5'-phosphate (PLP)-dependent enzymes that catalyze the decarboxylation of aromatic amino acid l-amino acids. In plants, apart from canonical AAADs that catalyze the straightforward decarboxylation reaction, other members of the AAAD family function as aromatic acetaldehyde synthases (AASs) and catalyze more complex decarboxylation-dependent oxidative deamination. The interconversion between a canonical AAAD and an AAS can be achieved by a single tyrosine-phenylalanine mutation in the large catalytic loop of the enzymes. In this work, we report implicit ligand sampling (ILS) calculations of the canonical l-tyrosine decarboxylase from Papaver somniferum (PsTyDC) that catalyzes l-tyrosine decarboxylation and its Y350F mutant that instead catalyzes the decarboxylation-dependent oxidative deamination of the same substrate. Through comparative analysis of the resulting three-dimensional (3D) O2 free energy profiles, we evaluate the impact of the key tyrosine/phenylalanine mutation on oxygen accessibility to both the wild type and Y350F mutant of PsTyDC. Additionally, using molecular dynamics (MD) simulations of the l-tryptophan decarboxylase from Catharanthus roseus (CrTDC), we further investigate the dynamics of a large catalytic loop known to be indispensable to all AAADs. Results of our ILS and MD calculations shed new light on how key structural elements and loop conformational dynamics underlie the enzymatic functions of different members of the plant AAAD family.

Evaluation of Destructive and Non-Destructive Testing of Existing Hotel Structures for Shopping Centre Conversion

Changes in the function of a building will affect the structural loading, which, based on government regulations in building permits, must be reviewed for the feasibility of building functions through structural assessment. This research aims to analyze the condition of the concrete quality of building beams, columns, and slabs that are more than 50 years old. The methods used include non-destructive testing (NDT) and destructive testing (DT) on the structures. From the results of the non-destructive UPV (Ultrasonic Pulse Velocity) Test on 20 elements (100 tests) using the PUNDIT tool, the average concrete quality based on BS 1881 and ASTM C597-16 standards was found to be 28.15 MPa for columns, 25.11 MPa for beams, and 25.60 MPa for slabs. The Hammer Test showed an average concrete quality of 27.95 MPa for columns, 31.41 MPa for beams, and 31.20 MPa for slabs. The destructive method using core drilling on 8 structural elements revealed an average concrete quality of 25.58 MPa for columns, 34.61 MPa for beams, and 35.89 MPa for slabs. The hardness test for reinforcing steel indicated an average yield strength of 361 MPa. The compressive strength results of the column structure concrete meet the minimum requirements of 21 MPa for special structure concrete quality based on SNI-2847-2019. It is recommended to recalculate the structure with concrete quality fc' 25 MPa and steel quality fy 360 MPa to identify elements that need structural strengthening.

A Compressive Load Bearing Analysis of 3D-Printed Circular Elements

Large-scale construction 3D printing is a promising platform technology that can be leveraged to fabricate structural elements such as columns, piers, pipes, and culverts. In this study, the axial compression and split tensile performance of 3D-printed steel-fiber-reinforced circular elements fabricated with different configurations (hollow, hybrid, mold-cast, and fully 3D-printed) is evaluated. This study further investigates the performance of multi-material circular hybrid elements (3D-printed shells with different backfilled core materials) in an attempt to assess their suitability as a new construction paradigm. The experimental results revealed that the fully 3D-printed steel-fiber-reinforced circular elements exhibited a higher load capacity (up to 36%) and a distinct crack pattern compared to the other configurations. The void ratio of circular elements has varying effects on its axial load capacity depending on the printing material and significantly influences its splitting tensile load capacity. Furthermore, the compatibility between the 3D-printed shell and the cast-in-place core is identified as an influential factor in the structural performance of the hybrid elements. The results suggest a promising construction approach where low-cement material can be utilized as infill material for a cost-effective 3D-printed permanent formwork, offering a viable solution for specific infrastructure development applications.

Advantages of using template guides in children for the correction of congenital spinal deformities and thoracic anomalies

BACKGROUND: In children, progressive congenital deformities of the thoracic spine combined with thoracic anomalies require surgical intervention to correct the curvature and prevent further progression during the child’s growth. Surgical correction of congenital deformity caused by segmentation disorders of the lateral surfaces of the vertebral bodies with unilateral rib synostosis aims at full correction of the existing curvature using the transpedicular spinal system and is an effective and reliable treatment option for these patients. However, this technology requires precise and correct installation of the supporting elements of the metal structure to exclude possible irreversible complications. A solution is the use of template guides in the installation of the support elements of the spinal metal structure. AIM: This study aimed to conduct a comparative analysis of the results of using template guides for the placement of transpedicular screws with the free-hand method in children during surgical correction of congenital spinal deformities combined with thoracic anomalies. MATERIALS AND METHODS: The results of surgical treatment of 20 patients, aged 3–9 years, were analyzed retrospectively to compare the time and accuracy of spinal metal support element placement with and without the use of template guides. The data collected included demographic information, time of bone canal formation, accuracy of spinal transpedicular screw placement, and various complications. RESULTS: Compared with the free-hand method, the use of template guides in the surgical correction of congenital spinal deformities combined with thoracic anomalies in children reduces the time of bone canal formation and increases the accuracy of metal screw placement. These results confirm the efficacy and safety of using template guides during spinal surgery in children with these congenital malformations. CONCLUSIONS: The use of template guides is an effective and reliable method of inserting transpedicular metal screws in the correction of congenital spinal deformities combined with thoracic anomalies in children, which increases the accuracy of implantation of support elements and reduces the surgical time. These results confirm the necessity of using template guides in the correction of congenital spinal deformities in children.

Petrification, Chaos, Primitive Triangulation and the Therapeutic Power of Game-Play

ABSTRACT This article discusses the use of traditional structured games such as Monopoly, Draughts, War and UNO, in psychoanalytic psychotherapy with children in severely disturbed states of mind. The author focuses on two opposite poles of disturbance: states of psychic petrification, typical of children on the Autism spectrum, and states of chaos, typical of children in psychotic states of mind. It is suggested that these structured games can serve as a vehicle for what Alvarez terms the language of “fatherese,” a call to psychic growth, structuring, and communication with the outside world. Drawing on Houziel’s and Rhode’s thinking on the bisexuality of the psychic skin, it is proposed that structured games combine male elements of structure and solidity with female elements of emotion, uncertainty, and porosity, thereby enabling work on a primitive level of triangularity. Two clinical examples are presented: the first where the therapist introduced a process of negotiation into a game of Monopoly with a child adhesively addicted to petrified game-play; the second where the therapist initiated a game of SET to introduce psychic structuring and a space to think. These clinical examples are analyzed in terms of Bion’s concepts of the Establishment and the Messianic and Amir’s concepts of psychic tonality and atonality.

Saturation Mutagenesis and Molecular Modeling: The Impact of Methionine 182 Substitutions on the Stability of β-Lactamase TEM-1

Serine β-lactamase TEM-1 is the first β-lactamase discovered and is still common in Gram-negative pathogens resistant to β-lactam antibiotics. It hydrolyzes penicillins and cephalosporins of early generations. Some of the emerging TEM-1 variants with one or several amino acid substitutions have even broader substrate specificity and resistance to known covalent inhibitors. Key amino acid substitutions affect catalytic properties of the enzyme, and secondary mutations accompany them. The occurrence of the secondary mutation M182T, called a “global suppressor”, has almost doubled over the last decade. Therefore, we performed saturating mutagenesis at position 182 of TEM-1 to determine the influence of this single amino acid substitution on the catalytic properties, thermal stability, and ability for thermoreactivation. Steady-state parameters for penicillin, cephalothin, and ceftazidime are similar for all TEM-1 M182X variants, whereas melting temperature and ability to reactivate after incubation at a higher temperature vary significantly. The effects are multidirectional and depend on the particular amino acid at position 182. The M182E variant of β-lactamase TEM-1 demonstrates the highest residual enzymatic activity, which is 1.5 times higher than for the wild-type enzyme. The 3D structure of the side chain of residue 182 is of particular importance as observed from the comparison of the M182I and M182L variants of TEM-1. Both of these amino acid residues have hydrophobic side chains of similar size, but their residual activity differs by three-fold. Molecular dynamic simulations add a mechanistic explanation for this phenomenon. The important structural element is the V159-R65-E177 triad that exists due to both electrostatic and hydrophobic interactions. Amino acid substitutions that disturb this triad lead to a decrease in the ability of the β-lactamase to be reactivated.

De novo variants in the RNU4-2 snRNA cause a frequent neurodevelopmental syndrome.

Around 60% of individuals with neurodevelopmental disorders (NDD) remain undiagnosed after comprehensive genetic testing, primarily of protein-coding genes1. Large genome-sequenced cohorts are improving our ability to discover new diagnoses in the non-coding genome. Here, we identify the non-coding RNA RNU4-2 as a syndromic NDD gene. RNU4-2 encodes the U4 small nuclear RNA (snRNA), which is a critical component of the U4/U6.U5 tri-snRNP complex of the major spliceosome2. We identify an 18 bp region of RNU4-2 mapping to two structural elements in the U4/U6 snRNA duplex (the T-loop and Stem III) that is severely depleted of variation in the general population, but in which we identify heterozygous variants in 115 individuals with NDD. Most individuals (77.4%) have the same highly recurrent single base insertion (n.64_65insT). In 54 individuals where it could be determined, the de novo variants were all on the maternal allele. We demonstrate that RNU4-2 is highly expressed in the developing human brain, in contrast to RNU4-1 and other U4 homologs. Using RNA-sequencing, we show how 5' splice site usage is systematically disrupted in individuals with RNU4-2 variants, consistent with the known role of this region during spliceosome activation. Finally, we estimate that variants in this 18 bp region explain 0.4% of individuals with NDD. This work underscores the importance of non-coding genes in rare disorders and will provide a diagnosis to thousands of individuals with NDD worldwide.

Multi-hierarchical assemble nano-fibrous dressing for burn wound ultra-fast healing with dynamical exudate regulation, thermal management, and non-leaching sterilisation

To endow the nano-fibrous wound dressing with moisture-absorption, moisture-retention, thermal-management and anti-bacterial performances, a multi-hierarchical assemble process including electro-micro-encapsulation, electro-interpenetration and electro-deposition was used to create a structural integration including core–shell structure, interpenetrated structure and in-situ coating. First, a phase-transition thermal-management electro-spun consisting of PVDF shell and n-hexadecane core was fabricated from the coaxial electro-spinning, the heat-absorbing effect from n-hexadecane melting offers a cool feeling to make burn wounds feel comfortable. Second, an interpenetration process between PVA electro-spun and PVDF@n-hexadecane core–shell electro-spun was carried out by a heterologous co-electro-spinning device. By regulating the area density and the continuity of the hydrophilic phase and hydrophobic phase as well, the moisture-absorption and the moisture-retention performances can be manipulated. Third, a nano-capsule consisting of PCL outer shell and dual-component anti-bacterial agents as core was obtained from coaxial electrospray and then was further electro-deposited on the surface of the obtained interpenetrated membrane. After the melting of the PCL outer shell, not only the in-situ immobilization of anti-bacterial particles on the membrane surface (non-leaching sterilisation) was carried out, but also the exposure of anti-bacterial components. Owing to the collaborative integration of multiple functional ingredients and various structural elements, this composite nano-fibrous dressing displays a good moisture-absorption performance for removing exudate, a desired moisture-retention performance for offering wet surrounding to promote tissue regeneration, a comfortable absorption-heat effect and an excellent anti-bacterial performance. Combined with cytotoxicity and animal experiment evaluations, this multi-functional dressing presents a quicker healing period for second-degree burn compared to existed commercial fibrous dressing.

Quality measures in primary care skin cancer management: a qualitative study of the views of key informants

ObjectivesThis study explored potential quality measures to improve skin cancer management in primary care settings, and the barriers and facilitators associated with their implementation.DesignSemistructured interviews and qualitative proforma surveys were...

The Key Role of Floors for the Sustainability of Retrofit Interventions in Older Existing Reinforced Concrete Buildings

In recent decades, the seismic performance of existing reinforced concrete (RC) buildings has played a key role. Nevertheless, the performance and reliability verification of important structural elements such as floors has often been neglected. Floors are primary structural elements that can affect the life cycle life of a building. However, the widespread lack of maintenance planning over time and the original construction practice (which was not always correct) are frequently the cause of unpredictable local or global collapse. In addition, although recent standards and codes recognize the importance of floors by prioritizing their verification with respect to gravitational load conditions, the verification of floor reliability with respect to the load combinations required by modern standards and codes is often not satisfied. Consequently, the intervention costs could be significantly affected by the floor conditions, and their overall amount might even discourage the implementation of interventions. The main purpose of this study is to evaluate the effects (in terms of sustainability) of interventions on residential RC buildings, considering the need to retrofit their existing floors. To this aim, the most vulnerable and potentially most degraded floor types are identified, and their capacity–demand relationships are evaluated. In the case of unverified floors, the main and most popular intervention methods are evaluated and related to the overall intervention costs, taking into account the main uncertainties in performance and cost predictions. The problems and critical issues of floors are key in determining the safety of the building and the cost-effectiveness (i.e., sustainability) of the retrofit intervention. Professionals and decision makers could benefit from the proposed study cost model to define intervention strategies on a regional or national scale.

Morphology of Pornography: Magical and Fairy-Tale Roots of Modern Porn Discourse

In this article, the author analyzes visual discourses of physicality in modern porn discourse through the prism of structuralist theory proposed by Russian researcher Vladimir Propp. The article is one of the first attempts in modern historiography to transplant the methods and principles proposed by Vladimir Propp to analyze the current state of porn in popular culture. The purpose of the article is to analyze the relationships and interdependencies between modern porn culture, presented in visual forms, and its historical predecessors. It is assumed that the origins of pornographic discourse, which operates in visual forms, can be localized in folk traditional culture. Forms and dimensions of physicality and actions of the heroes of modern pornographic discourse are perceived as structural elements of mass culture. The results of the study can be summarized in the following way: 1) the visual structure of modern porn has lost its uniqueness and originality in the consumer society; 2) the plots and sequence of actions of the heroes of modern pornographic discourse can be compared with similar plots and behavioral strategies of folk discourse; 3) porn in modern society plays roles that are similar to ones played by fairy tales in the traditional culture of pre-modern societies. The author believes that modern porn discourse imitates reality, although initially the behavior of the characters and the plots are fantastic and unrealistic in their nature. It is shown that the development of porn became a reaction to the demand of consumer society for visualized narrative constructions based on the archetypes of traditional folk culture.

Experimental analysis of instability and self-oscillations in an electrohydraulic servo drive

The tendency to self-oscillations is one of the most important problems of closed-loop hydraulic systems. In actual systems losses occur, variation of the transmitted energy and the strength of the system structural elements are always limited. This is the reason why self-oscillations are most often present. The main purpose of the research is to reveal the mechanisms of instability and self-oscillations in an electro-hydraulic servo drive to make a numerical simulation of the drive characteristics. A servo drive has all the conditions for the generation of self-oscillations: the oscillatory element – the movable member of the drive and a column of elastic liquid, the source of energy. Regular oscillations in a drive are maintained due to the energy of compressed liquid, feedback, non-linear character of generated and absorbed energy etc. An experimental analysis of a servo system of the FESTO training simulator was carried out. The aim of the research was to accumulate materials for the development of mathematical models that would adequately represent the main properties of actual systems.

A Closer Look at Type I Left-Handed β-Helices Provides a Better Understanding in Their Sequence-Structure Relationship: Toward Their Rational Design.

Understanding the sequence-structure relationship in protein is of fundamental interest, but has practical applications such as the rational design of peptides and proteins. This relationship in the Type I left-handed β-helix containing proteins is updated and revisited in this study. Analyzing the available experimental structures in the Protein Data Bank, we could describe, further in detail, the structural features that are important for the stability of this fold, as well as its nucleation and termination. This study is meant to complete previous work, as it provides a separate analysis of the N-terminal and C-terminal rungs of the helix. Particular sequence motifs of these rungs are described along with the structural element they form.

Effect of Recycled Concrete Aggregates on the Concrete Breakout Resistance of Headed Bars Embedded in Slender Structural Elements

Recycled concrete aggregates are potentially interesting for the precast concrete industry as they provide a new use for high-quality waste from its products’ life cycle. In precast concrete structures, it is common to use headed bars in several connection types between structural members. This paper presents the results of experimental tests to investigate the impact of replacing coarse natural aggregates with coarse recycled concrete aggregates in the concrete breakout strength of cast-in headed bars embedded in slender structural elements. Results of 12 tests on 16 mm headed bars embedded in 500 × 200 × 900 mm concrete members with an effective embedment depth of 110 mm are presented. The percentage of replacement of natural aggregates by recycled concrete aggregates was 0%, 30%, and 100%, and the flexural reinforcement ratio of the structural elements varied from 0.5% to 3.5%. The behavior and strength of the tested specimens are discussed, and comparisons with theoretical strength estimates are presented. The results showed that the concrete breakout strength of the headed bars was not affected by the use of recycled concrete aggregates and that the flexural reinforcement ratio significantly impacts the load-carrying capacity of the headed bars as they control the crack widths before failure.

Effect of Recycled Concrete Aggregates on the Concrete Breakout Resistance of Headed Bars Embedded in Slender Structural Elements

Recycled concrete aggregates are potentially interesting for the precast concrete industry as they provide a new use for high-quality waste from its products’ life cycle. In precast concrete structures, it is common to use headed bars in several connection types between structural members. This paper presents the results of experimental tests to investigate the impact of replacing coarse natural aggregates with coarse recycled concrete aggregates in the concrete breakout strength of cast-in headed bars embedded in slender structural elements. Results of 12 tests on 16 mm headed bars embedded in 500 × 200 × 900 mm concrete members with an effective embedment depth of 110 mm are presented. The percentage of replacement of natural aggregates by recycled concrete aggregates was 0%, 30%, and 100%, and the flexural reinforcement ratio of the structural elements varied from 0.5% to 3.5%. The behavior and strength of the tested specimens are discussed, and comparisons with theoretical strength estimates are presented. The results showed that the concrete breakout strength of the headed bars was not affected by the use of recycled concrete aggregates and that the flexural reinforcement ratio significantly impacts the load-carrying capacity of the headed bars as they control the crack widths before failure.

INTERCONNECTIONS AND INTERDEPENDENCIES OF ECONOMIC DEVELOPMENT AND SHADOW BANKING SECTOR IN DEVELOPING AND TRANSITIONAL ECONOMIES

The research objective is defined as the identification and confirmation of empirical relationships between shadow banking activities and economic development in developing and transitional economies to establish a theoretical basis for minimizing potential risks associated with shadow banking. The methodological design is based on a quantitative approach, implemented through correlation-regression analysis and ARIMA forecasting methods. The research findings confirm Hypothesis 1: China’s shadow banking is closely interconnected with the country’s economic development. However, Hypothesis 2 (the reduction of shadow banking in China contributes to per capita GDP growth) is only supported for specific structural elements of shadow banking that contribute to economic overheating. In contrast, for other structural elements, such as entrusted loans, a strong direct correlation exists, promoting a positive impact of shadow banking on the country’s economic development. This highlights the need for a highly balanced state policy to minimize shadow banking risks. The research results can be valuable for professionals in public administration and academic researchers, particularly in terms of shaping future research directions.

Structure-based mechanism of riboregulation of the metabolic enzyme SHMT1.

RNA can directly control protein activity in a process called riboregulation; only a few mechanisms of riboregulation have been described in detail, none of which have been characterized on structural grounds. Here, we present a comprehensive structural, functional, and phylogenetic analysis of riboregulation of cytosolic serine hydroxymethyltransferase (SHMT1), the enzyme interconverting serine and glycine in one-carbon metabolism. We have determined the cryoelectron microscopy (cryo-EM) structure of human SHMT1 in its free- and RNA-bound states, and we show that the RNA modulator competes with polyglutamylated folates and acts as an allosteric switch, selectively altering the enzyme's reactivity vs. serine. In addition, we identify the tetrameric assembly and a flap structural motif as key structural elements necessary for binding of RNA to eukaryotic SHMT1. The results presented here suggest that riboregulation may have played a role in evolution of eukaryotic SHMT1 and in compartmentalization of one-carbon metabolism. Our findings provide insights for RNA-based therapeutic strategies targeting this cancer-linked metabolic pathway.