Support Structure Research Articles

Effect of some design parameters on the performance of side access nozzle and grooved plate of centre pivot sprinkler

This research evaluates the effect of various heights, pressures, nozzle size and groove numbers on the uniformity distribution of a developed pivot sprinkler. The experiment was set up at an open space in Niger State College of Agriculture Mokwa. The wind speed and temperature during the experiment were at an average of 2.2mph and 25°C. A nozzle of size 6mm, and deflection plate of 6 curved grooves were used in a centre pivot spray unit. In evaluating the performance of the spray unit components i.e. the nozzle and deflection plate, three different pressures of 5, 10, and 15 Psi and heights of 1, 1.2, and 1.5mm were used. The support structure for the experiment is an inverted U-shaped frame designed to support a spray sprinkler at different heights. The water source was a reservoir with a capacity of 3m3and a 1.5hp electric centrifugal pump was used. The volumetric or bucket method was used to measure flow rate. The application rate was measured using catch can method. The duration of each test was approximately 30min. The data obtained from the measurements were statistically analyzed with line graphs using Excel. Relationships were also established between discharge and pressure. The highest index of jet break up was 4.89 at 15Psi and 3.74 at 10Psi. The result shows that as the pressure increases with height the CU also increases. The highest uniformity of 79.4% was obtained at 1.5m height and 15Psi.

Support structure topology optimization considering the residual distortion for laser powder bed fusion metal additive manufacturing

Support structure topology optimization considering the residual distortion for laser powder bed fusion metal additive manufacturing

Study on the effect and mechanism of support structure and characteristic on Ag-based catalysts for low-temperature selective catalytic oxidation of ammonia

Herein, the influence of support type and properties on the catalytic activity and selectivity of Ag-based NH3-SCO catalyst was studied through the evaluation of NH3-SCO performance, the physicochemical characterization of H2-TPR, NH3-TPD, N2 isothermal adsorption–desorption, XPR and XPS, and the mechanism study of 1H MAS NMR, In-situ DRIFTS and DFT calculations. Ag/nano-TiO2, Ag/Al2O3, and Ag/MnO2 all showed better NH3-SCO activity because of more abundant Brønsted and Lewis acid sites of Al2O3 and TiO2 and more actual Ag loading amount due to the larger specific surface area and suitable surface chemistry. The N2 selectivity of Ag/nano-TiO2 is significantly better, which may be due to the highly dispersed Ag species and the abundant Brønsted acid sites with higher N2 selectivity. The mechanism study showed that the terminal hydroxyl was the preferred consumption target of Ag species, and this consumption promoted the effective dispersion and stable anchoring of Ag on the TiO2 surface.

Virtual Learning for Māori Students

This article provides a comprehensive literature review examining virtual learning in the New Zealand schools sector, with a specific focus on understanding and addressing the needs of Māori learners in these online environments. It begins by tracing the historical development of virtual learning in New Zealand from early correspondence courses to the emergence of e-learning clusters and increasing digital technology use. The authors highlight the distinct differences between teaching and learning virtually compared to traditional face-to-face classrooms, exploring unique pedagogical approaches, challenges, and support structures required for effective online instruction and student engagement. Emphasis is placed on the crucial role of fostering strong teacher-student relationships in virtual settings. The article then reviews culturally responsive pedagogies and strategies identified as effective for engaging and supporting Māori learners, and discusses potential frameworks for translating these approaches to online learning environments. The potential of virtual learning to provide more equitable educational opportunities for Māori students, particularly in rural areas, is examined. However, pre-existing socioeconomic inequalities and the digital divide exacerbated by COVID-19 are noted as barriers. Overall, the authors underscore the scarcity of research specifically examining Māori students' experiences and needs in virtual learning contexts. They call for further investigation to better understand and address these gaps, striving to ensure culturally responsive and equitable virtual education opportunities for Māori learners. The paper provides a valuable synthesis of literature and insights into this important issue in New Zealand education.

Stability analysis of deep foundation pit with a double-row cast-in-place piles and diagonal steel lattice braces under sloped excavation conditions

Existing deep foundation pit support structures are commonly composed of external earth-retaining structures, internal horizontal bracings, and vertical columns. A closed bracing system, often formed by a horizontal support through a bracket board, frequently impedes vertical excavation and soil removal operations in the foundation pit, and the processes of assembly and dismantling are complex and time-consuming. This study presents a combined support system and construction method consisting of cast-in-place piles and diagonal steel lattice braces. For sloped excavation, diagonal braces were constructed by slotting through the reserved soil, allowing the use of a single layer of support within the excavation depth. This approach significantly optimizes the construction process, reducing both project duration and overall cost. The field monitoring results indicated that the support method effectively controlled the lateral displacement of the pile bodies. Field monitoring results demonstrated that the proposed support system effectively controlled the lateral displacement of the pile bodies. The adoption of a support-first, excavation-second approach significantly controlled the settlement of the ground surface around the foundation pit, thereby preventing excessive increments in the axial force of the supports due to the large longitudinal depth excavation. The calculation results of the three-dimensional finite element model for foundation pit excavation and support indicate that the proposed support method results in a decreasing ratio of the maximum lateral deformation depth of the pile body, denoted as δh-m, to the excavation depth He as the excavation depth increases. This implied that the displacement of the pile body was strictly controlled. When the depth of the foundation pit excavation exceeded 10 m, the maximum lateral deformation occurred below 10 m along the pile shaft. The diagonal steel lattice braces transferred the load to the top of the cast-in-place piles at the bottom of the pit, where the stress concentration occurred. During construction, special attention must be paid to the strength of the connection between the pile top and the connecting beams.

An extreme thermal cycling reliability test of ATLAS ITk Strips barrel modules

At the end of Run 3 of the Large Hadron Collider (LHC), the accelerator complex will be upgraded to the High-Luminosity LHC (HL-LHC) in order to increase the total amount of data provided to its experiments. To cope with the increased rates of data, radiation, and pileup, the ATLAS detector will undergo a substantial upgrade, including a replacement of the Inner Detector with a future Inner Tracker, called the ITk. The ITk will be composed of pixel and strip sub-detectors, where the strips portion will be composed of 17,888 silicon strip detector modules. During the HL-LHC running period, the ITk will be cooled and warmed a number of times from about -35°C to room temperature as part of the operational cycle, including warm-ups during yearly shutdowns. To ensure ITk Strips modules are functional after these expected temperature changes, and to ensure modules are mechanically robust, each module must undergo ten thermal cycles and pass a set of electrical and mechanical criteria before it is placed on a local support structure. This paper describes the thermal cycling Quality Control (QC) procedure, and results from the barrel pre-production phase (about 5% of the production volume). Additionally, in order to assess the headroom of the nominal QC procedure of 10 cycles and to ensure modules don't begin failing soon after, four representative ITk Strips barrel modules were thermally cycled 100 times — this study is also described.

Analysis of the load‐bearing characteristics of hydraulic supports for top‐coal caving under the impact of coal and gangue

AbstractTo study the effect of different sizes and speeds of coal gangue falling on hydraulic supports for top‐coal caving discharge hydraulic support on the bearing characteristics of the hydraulic support, the ADAMS hydraulic support rigid‐flexible coupling analysis model was established. HyperMesh is used to flexibly process the hydraulic support, and the column and jack are equivalently replaced by spring damping system. By applying step loads of different sizes and speeds to simulate the impact force generated when the coal gangue falls on different positions of the cover beam, the dynamic response characteristics of the column, balance jack and other articulation points are obtained. Analyses show that: when the impact load is closer to the roof beam, the articulation point of the roof beam‐cover beam and the balancing jack are easy to be damaged. When the same impact load is applied to the cover beam, the faster the load is applied, the hydraulic support column and balancing jack may not be able to absorb and disperse the pressure effectively in time, resulting in the articulation points being subjected to a larger impact force, which is easy to cause damage or destruction. When different sizes and speeds of impact loads are applied to the cover beam, the latter has a greater impact on the dynamic response of the front and rear connecting rod articulation points and the cover beam‐roof beam articulation point than the former, and the hydraulic bracket will be more prone to vibration, deformation, and stress concentration, thus affecting the stability and safety of the bracket. The article is of guiding significance for designing and optimizing the structure and parameters of the hydraulic support, and improving the support performance and stability of the hydraulic support in the comprehensive release working face.

Design and Optimization of Steel Structures for Solar Panel Systems

Abstract: Structural components are fundamental for supporting mechanical machines in industrial settings. These structures are designed not only to bear the weight of the machines but also to withstand the vibrations generated during operation. The project at hand focuses on integrating basic structural sections to create a complete mechanical framework. Our goal is to collaborate with an industry specializing in support structures for various electrical units. From our initial analysis, we observed that many of these industries rely on conventional manufacturing practices and past experience to design structures, often leading to overdesign. No finite element analysis (FEA) or theoretical calculations are typically applied. We propose introducing modern FEA techniques and concepts to optimize and refine these designs for improved efficiency.

Navigating Challenges Resilience of Women Entrepreneurs in Khyber Pakhtunkhwa’s Entrepreneurial Ecosystem

This research paper examines how women entrepreneurs in Khyber Pakhtunkhwa navigate the entrepreneurial ecosystem and social support structures. Grounded in an interpretivist research philosophy, the study delves into the subjective experiences of women entrepreneurs, highlighting their roles in fostering economic stability within their communities. A hybrid inductive and deductive research approach, combined with a multiple case study method, was employed to gain a comprehensive understanding of the challenges faced by women entrepreneurs. Data were collected through in-depth semi-structured interviews with 18 purposively sampled women entrepreneurs. The analysis, using a hybrid thematic approach, identified key themes related to the resilience of women entrepreneurs in the face of social and financial challenges, social advocacy, and economic independence. The findings illustrate how these women overcome socio-cultural barriers and limited institutional support, leveraging their entrepreneurial ventures to create inclusive spaces and advocate for gender equality.

Developing a Model to Enhance Employability for Graduates with Disabilities in Negri Sembilan's Private Sector, Malaysia

Purpose: This research is to design a comprehensive strategy to improve employability of graduates who have disabilities in the business sector of Negri Sembilan in Malaysia. Notwithstanding their relevant qualities, these people encounter considerable obstacles to employment, such as attitudinal prejudices, insufficient workplace accommodations, and discrepancies between their skills and employer expectations. The study used a mixed-methods approach to identify significant obstacles and evaluate the readiness of private sector firms to employ handicapped graduates. Findings: The study indicates that while several private sector businesses are inclined to employ graduates with impairments, they encounter obstacles concerning accessibility, knowledge, and preparation. Identified key impediments are inadequate training opportunities, adverse views toward disability, and the absence of support structures inside enterprises. The suggested strategy includes specialized training programs, promotion of inclusive hiring practices, and strategic alliances with disability groups, designed to align the abilities of handicapped graduates with corporate needs. Implications/Values: The results underscore the need for systemic reform in employment processes to promote diversity and fairness throughout the workforce. This concept, by aligning with the United Nations Sustainable Development Goals—especially in fostering decent work and mitigating inequalities—has the potential to cultivate a more inclusive job environment in Negri Sembilan. The results are anticipated to provide significant insights for policymakers, employers, and disability advocacy organizations, facilitating improved socio-economic inclusion and empowerment with disabilities in the labor market.

Feasibility Study of Capacitor-Based Smart Washer Sensor Systems for Highway Sign, Luminaire/Light, and Traffic Signal Structures

This paper aims to provide an improvement on the current inspection methods for anchor bolts used in highway sign, luminaire/light, and traffic signal (SLTS) support structures to reduce the risk of structural failure as well as human labor costs. A feasibility study on a capacitance-based smart washer system was conducted. The capacitor-based sensor system design combined with customized polylactic acid three-dimensional printed attachments was proposed and tested. Laboratory tests on multiple sets of sensors were performed through initial testing and tightening–loosening testing; results have shown that the performance of the sensor system follows the working principle of the capacitor and, with a less than 5% error tolerance, a capacitance–pretension relationship was developed in the laboratory. Then the sensor system was installed at a sign structure specimen for long-term evaluation; the 12-month consecutive monitoring results show that the sensor system was able to perform steadily with a proper waterproof cover applied. The change of the capacitance was found at ±5% of the reference value, and torques were applied to verify the measurement results from the sensor system, indicating that the minor capacitance change was caused by a change of temperature. The results have proven the feasibility of this capacitor-based smart washer system that detects the pretension change inside the anchor bolts and performs steadily in a controlled on-site environment with a high durability. In summary, this study provides the possibility of improving the monitoring methods for anchor bolts in highway SLTS structures.

Preservice Teachers' Perceptions, Attitudes, and Challenges of Using Scratch as a Coding Tool to Foster Active Learning in Life Sciences Classrooms

In the contemporary educational landscape, integrating technology into teaching practices is crucial for promoting active engagement and learning, particularly in science classrooms. This study investigated preservice teachers' perceptions of using Scratch as a coding tool to enhance active learning in Life Sciences classrooms. Adopting a qualitative research design, the study used purposive sampling to select five preservice teachers with relevant Life Sciences teaching experience. Data collection involved semi-structured interviews and classroom observations, and thematic analysis was employed to examine the data. The study found that Scratch was perceived positively by preservice teachers as a tool that could foster essential twenty-first-century skills such as collaboration, problem-solving, critical thinking, innovation, and communication. Preservice teachers demonstrated varying levels of familiarity with and adaptability to Scratch, influencing their methods of integration into teaching. While the tool showed promise in engaging students and enhancing active learning, the study also uncovered significant challenges, including resource limitations, inadequate teacher support, and logistical issues such as load shedding. These findings underscore the potential of Scratch to support innovative teaching practices and develop critical skills in learners. However, they also highlight the need for improved resources and support structures to maximise the effectiveness of technology integration. The study offers valuable insights for curriculum developers, higher education institutions, educational communities, and teachers, emphasising the need for strategic interventions to address implementation challenges and optimise the use of Scratch in fostering 4IR skills and preparing students for future careers.

Fabrication Time Diagrams for In-Space Manufacturing of Large Reticulated Structures

Abstract In-space manufacturing (ISM), or the on-orbit construction of structures from raw feedstock materials, is a promising approach for building large structures for future space missions. Most research and development on ISM to date has focused on ground-based or microgravity-based demonstrations of candidate fabrication processes; however, the combined design of the fabrication process and the ISM spacecraft has not been fully investigated. In this paper, we estimate the fabrication times for ISM of reticulated support structures subject to various spacecraft constraints, including the available fabrication power, the available attitude control authority, and the avoidance of undesirable control-structure interactions. We summarize the insights in fabrication time diagrams which depict the dominant constraints and estimates of the fabrication time for a wide range of structural geometries. Our results indicate that for large, dense structural geometries such as the curved gridshell and tetrahedral truss, the angular momentum storage of the ISM spacecraft's attitude control system (ACS) is the dominant constraint on fabrication time. Additionally, our results suggest the following strategies for reducing fabrication time: manufacturing with multiple spacecraft; using stiff, lightweight feedstock; maximizing fabrication power and ACS capability; and minimizing spacecraft bus mass. Altogether, our results emphasize how the design of an ISM spacecraft cannot be considered independently of the fabricated structure and motivate future work on selecting optimal fabrication paths and attitude control strategies to fabricate large structures in the shortest time.

Analysis of the Influence of Rock Mechanics Variables on the Stability of Tunnel Surrounding Rock Based on Engineering Mathematics Applications

Tunnels are essential infrastructure elements, and it is critical to maintain their stability for both operation and safety. Using engineering techniques, this study examines the correlation between rock mass motorized characteristics and tunnel surrounding rock stability. This study utilizes the multi-sensor monitoring data of the surrounding rock mechanical characteristics and tunnel support structure collected during tunnel boring machine construction as its research object. The integrated cuckoo search optimized Upgraded dynamic convolutional neural network (ICSO-UDCNN) has been utilized for predicting the tunnel parameters. In general, the surrounding rock’s hardness correlates with its level, which in turn determines how quickly tunnels are being excavated. There is a stronger correlation of 98\% between the field penetration index (FPI) variables of the rock’s characteristic slope along the conditions surrounding the tunnel. The most significant factor influencing its deformation is the surrounding rock’s mechanical characteristics. For engineers and other decision-makers engaged in tunnel design, building, and maintenance, the study’s findings add a greater understanding of the variables affecting tunnel stability. This research provides an establishment for enhancing security protocols, lowering hazards related to tunneling operation, and optimizing tunnel engineering techniques by quantitatively evaluating the influence of rock mass mechanical factors on solidity.

Dimensional reliability in CAD/CAM production of complete denture bases: A comparative study of milling and various 3D printing technologies.

This study aims to assess the dimensional accuracy of complete denture bases fabricated from different CAD/CAM technologies and a conventional method, including milling (CNC), PolyJet (PJ), laser sintering (SLS), digital light processing (DLP), and injection molding (IM). It also examines the influence of the removal of technology-specific connectors or support structures when present. Denture base surfaces were digitized using a laboratory scanner, and virtual measurement points were calculated with tetrahedral reference geometries. Defined distances were measured in all spatial directions and compared to design data (p<0.05), revealing significant differences in sagittal (p=0.004), transversal (p<0.001), and vertical (p<0.001) dimensions. Connector removal had no significant impact for CNC but significantly affected DLP. All technologies yielded clinically acceptable results, with CNC milling demonstrating the best overall outcome.

TECHNOLOGICAL SUPPORT FOR ONLINE LEARNING OF FUTURE GEOGRAPHY TEACHERS

The article determines that in the context of reforming modern geographical education, geography teachers face various challenges and problems related to the complication of access to educational services. It is proved that the use of distance learning, which is regulated by state educational documents, is an important mechanism for ensuring the continuity of the educational process. The paper notes that digital skills are an essential part of the professional competence of a geography teacher. Based on the analysis of numerous sources of scientific and pedagogical domestic and foreign literature, the author has developed and proposed his own model of components of technological conditions for the implementation of distance learning in geography, aimed at integrating new technologies. The essence of the components of the developed model is defined and substantiated. The learning management systems, video conferencing platforms and collaboration tools that belong to the software of distance learning in geography are characterised. The features of material and technical support and its components are outlined. The structure of the necessary methodological support and the problems of its development are determined. The importance of security and confidentiality as a condition for online learning is highlighted. Attention is paid to technical support and the main directions of its implementation are described. Attention is focused on the need for systematic and comprehensive compliance with certain technological conditions of distance learning, since its technical, methodological and informational components are integral parts of the online learning environment.

Overview and confirmatory and exploratory factor analysis of AI literacy scale

Comprehensive concepts of AI literacy (AIL) and valid measures are essential for research (e.g., intervention studies) and practice (e.g., personnel selection/development) alike. To date, several scales have been published, sharing standard features but differing in some aspects. We first aim to briefly overview instruments identified from unsystematic literature research in February 2023. We identified four scales and one collection of items. We describe the instruments and compare them. We identified common themes and overlaps in the instruments and developmental procedure. We also found differences regarding scale development procedures and latent dimensions. Following this literature research, we came to the conclusion that the literature on AI literacy measurement was fragmented, and little effort was undertaken to integrate different AI literacy conceptualizations. The second focus of this study is to test the factorial structures of existing AIL measurement instruments and identify latent dimensions of AIL across all instruments. We used robust maximum-likelihood confirmatory factor analysis to test factorial structures in a joint survey of all AIL items in an English-speaking online sample (N=219). We found general support for all instruments' factorial structures with minor deviations from the original factorial structures for some of the instruments. In a second analysis step, to address the issue of fragmented research on AI literacy conceptualization and measurement, we used principal axis exploratory factor analysis with oblique rotation to identify latent dimensions across all items. We found four correlated latent dimensions of AIL, which were mostly interpretable as the abilities to use and interact with AI, to design/program AI (incl. in-depth technical knowledge), to perform complex cognitive operations regarding AI (e.g., ethical considerations), and a common factor for the abilities to detect AI/differentiate between AI and humans and manage persuasive influences of AI (i.e., persuasion literacy). Our findings sort the multitude of AIL instruments and reveal four latent core dimensions of AIL. Thus, they contribute importantly to the conceptual understanding of AIL that has been fragmented so far.

Mechanical response analysis of primary support for shallow buried loess tunnel under surface surcharge

At present, the research on the influence of surrounding soil deformation induced by tunnel construction under the action of surcharge is generally based on the situation after the tunnel has been built, and less consideration is given to the existence of surface surcharge near the planned route of the tunnel when the tunnel is not built. Therefore, based on the Luochuan tunnel under construction, this study monitors the deformation of shallowly buried loess tunnels under different surcharge conditions and analyzes the influence of varying surcharge conditions on the deformation and stress of the tunnel through numerical simulation to determine the effective range of surface surcharge. The results show that the influence of surcharge load on tunnel stability is the most significant when located at the tunnel axis, and the influence degree increases with the increase of load. The adverse effects of surcharge load mainly occur in the range of 2 times the tunnel diameter. Once the range is exceeded, the internal force of the tunnel support structure is not sensitive to the surcharge load. In engineering, the surface surcharge can be controlled within the safety displacement limit by referring to the displacement calculation results.

Making Mathematics Accessible to Visually Impaired High School Learners in South Africa: Teachers’ Instructional Approaches, Assistive Devices and Challenges

ABSTRACT This case study explored the instructional approaches and assistive devices employed by high school mathematics teachers in teaching visually impaired (VI) learners and the challenges encountered by the teachers in facilitating the learners’ construction of mathematical knowledge. The participants were two high school mathematics teachers from a special school for the visually impaired in South Africa. Data was collected via semi-structured interviews and lesson observation. Inadequate skills in using Braille codes, time constraints, lack of learners’ home support structure, and technology failure are some of the challenges encountered by the teachers in teaching the VI learners. The approaches used by the teachers to teach mathematics to the VI learners in this study are direct instruction, contextual linking, scaffolding, peer tutoring, and problem-solving. The technologies the teachers used included text enlargers, text translators, text embossers, structure embossers, and scientific talking calculators. The study recommends in-service training for teachers teaching mathematics to

Quantitative assessment of the 3D pore space and microglobule clustering network to understand chromatographic transport phenomena in polymeric monolithic columns

The 3D pore space and microglobule clustering network of polymer monolithic columns, which exhibited similar external porosity but significantly different chromatographic dispersion and permeability characteristics, were subjected to tomographic imaging followed by stereological analyses. The morphologies of the monolithic support structures were examined using serial-block-face scanning electron microscopy. The statistically computed characteristic chord-length, hydraulic radius and tortuosity of the pore are strongly associated to chromatographic transport processes, in particular, eddy dispersion and mass-transfer resistance contributing to chromatographic dispersion, and permeability of monolithic columns. Moreover, Giddings’ trans-column velocity bias has been quantified in monoliths for the first time. With demonstrated method robustness, the proposed morphological descriptors and the streamlined analysis workflow provide novel insights bridging the structure-performance relationship for future chromatography column design.