2031 research outputs found
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Urban-Rural Differences in Electric Vehicle Adoption Intentions: Integrated TAM, TPB, UTAUT with Environmental Identity
Get PDFObjectives: This study examines urban-rural differences in electric vehicle (EV) adoption intentions to inform geographically targeted policy implementation for Thailand's goal of 30% EV production by 2030. Methods/Analysis: We integrated the Technology Acceptance Model, Theory of Planned Behavior, and Unified Theory of Acceptance and Use of Technology with environmental identity and trialability constructs. Data from 3,595 respondents (2,311 urban, 1,284 rural) across Thailand were analyzed using structural equation modeling and measurement invariance testing. Findings: Results revealed distinct adoption mechanisms between geographical contexts. Urban areas demonstrated stronger effects in system-related perceptions, with perceived ease of use more strongly influencing perceived usefulness (β=0.631 vs. 0.587) and perceived usefulness having a greater impact on behavioral intention (β=0.445 vs. 0.353). Rural areas showed stronger influences of individual characteristics and social factors, with personal innovativeness more strongly affecting attitudes (β=0.216 vs. 0.157) and environmental identity showing greater impact on perceived ease of use (β=0.350 vs. 0.291). Novelty/Improvement: This research uniquely combines established technological adoption theories with geographical context analysis, providing evidence-based recommendations for differentiated EV promotion strategies that address the specific challenges of urban and rural environments in developing countries. Doi: 10.28991/CEJ-2025-011-05-010 Full Text: PD
Analysis of GNSS-IMU Lidar Integration for Indoor Positioning Using Unscented Kalman Filter
No full textAccurate navigation systems are important in various vehicle applications, both indoors and outdoors. Global Navigation Satellite System (GNSS) and Inertial Measurement Unit (IMU) are sensors that are often used in vehicle navigation systems. GNSS has the advantage of providing accurate position and speed information, IMU is able to make measurements without being affected by environmental conditions, and LiDAR sensors can model the environment; however, the limited signal on GNSS in indoor environments results in decreased position accuracy. The development of GNSS-IMU integration has been widely carried out, one of which is by adding a LiDAR sensor. In this study, an improvement will be made to the integration algorithm on Vision RTK2, which produces GNSS-IMU coordinate data, and Backpack Lidar, which can display 3D visualization on the traversed path using the Unscented Kalman Filter (UKF) method to improve navigation accuracy, especially in indoor environments. The results of the study showed that the UKF simulation and free outage conditions showed high accuracy with RMSE of 0.00308 m and 0.00175 m for the Easting and Northing positions and MAE of 0.00088 m and 0.00024 m. However, in outage conditions, the RMSE values were 4.0881 m and 8.6317 m, and MAE of 5.9871 m and 7.4182 m. The results of the 3D point cloud of the LiDAR model that had been georeferenced using the UKF fusion results and the KKH calculation results were validated using a rolling meter. Validation of point cloud processing from the 3D LiDAR model using a rolling meter and georeferencing with KKH calculations showed a small RMSE value, which was 0.3420 m, and 0.0354 m for the distance dimension with a rolling meter. 0.6358 m for georeferenced RMSE using UKF fusion data, and 0.0779 for distance dimension using roll meters. The small RMSE results indicate a high level of agreement between point cloud data and measurements using a rolling meter used as reference data. This study shows that the integration of GNSS-IMU sensors with LiDAR using the UKF method can improve the accuracy and reliability of indoor navigation systems
Integration of Low-Cost GNSS and Multispectral Camera to Increase Oil Palm Position Accuracy and Health Monitoring
Get PDFThe Global Navigation Satellite System facilitates efficient agricultural initiatives, resolving land ownership and precise plantation monitoring issues. The oil palm sector is deeply integrated into various economies due to the world's use in food supplies, cosmetics, and oil biodiesel production. However, local farmers have trouble managing the plantation's condition and land ownership due to the underdeveloped modern technology at their disposal. The Normalized Difference Vegetation Index was employed in order to assess the NDVI camera oil palm tree growth, utilizing a MAPIR Survey3 RGN Multispectral Camera integrated with red, green, and near IR sensors. Images were taken directly on the surface level to enable focused analysis on the palm trees. This included the use of an MPAR calibration ground target placed beside the leaves for data accuracy and an operator that held the camera to the trees. Utilizing this strategy allowed for a more intricate and detailed analysis of each oil palm tree, and due to the coordination of the trees, aerial images were produced to create a detailed image. Low-cost GNSS instruments alongside RTK technology were employed in determining the coordinate position of the oil palm trees. Considerable relationships were found between NDVI and content in chlorophyll: NDVI-G and Chl a (r = 0.679), NDVI-B and Chl a (r = 0.618), and NDVI-B and Chl b(r = 0.657). The positional errors obtained varied within –0.105 to 0.166 meters for low-cost GNSS and –0.159 to 0.083 meters for geodetic GNSS, the latter recording the least MAE of 0.053. This research work found a cheap and accurate oil palm growth monitoring system using multispectral sensors. This method overcomes the technological gap of local farmers and provides an alternative strategy for the management of plantations. Doi: 10.28991/CEJ-2025-011-03-010 Full Text: PD
Advanced Digital Modeling of Stress–Strain Behavior in Rock Masses to Ensure Stability of Underground Mine Workings
Get PDFThis study focuses on optimizing underground support systems through advanced numerical modeling and geomechanical assessment. The research aims to refine reinforcement parameters for underground mine workings by analyzing the stress-strain behavior of rock masses using Rocscience RS2 software. The study integrates geological and geotechnical data, including field observations and numerical simulations, to enhance the accuracy of support system designs. The methodology is based on the finite element method (FEM) and the Hoek–Brown softening model, allowing the identification of plastic deformation zones and stress redistribution patterns. The results confirm that maximum stress increases by 35–40% for every 100 m of depth, necessitating enhanced reinforcement. The study evaluates hybrid support systems, specifically steel-polymer bolts with shotcrete, demonstrating a 15% reduction in plastic deformations compared to conventional methods. The findings highlight the importance of continuous geotechnical monitoring and adaptive reinforcement strategies to ensure stability in highly fractured rock masses. The proposed approach provides a more precise prediction of excavation stability, contributing to the development of safer and more efficient underground mining practices. Future research may include the integration of intelligent monitoring systems equipped with real-time sensors to further optimize support strategies and long-term stability assessments. Doi: 10.28991/CEJ-2025-011-03-014 Full Text: PD
Sustainable Asphalt Mixtures Comprising Steel Slag Filler and SBS-Modified Binder: An Experimental Investigation
Get PDFUtilizing steel slag powder as a mineral filler in asphalt concrete mixtures has garnered increasing attention due to its attractive benefits in both sustainability and material properties. The paper aims to critically evaluate the replacement of mineral filler with steel slag to produce a sustainable mixture. The replacement was made at 3 varied contents, i.e., 0%, 50%, and 100%, and meanwhile working together with a modified asphalt binder using 4% styrene-butadiene-styrene polymer. All designed mixtures were tested for volumetric properties and Marshall stability; an indirect tensile test was performed to determine the moisture susceptibility of all the mixtures of optimized binder content. At last, Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray (EDX) analyses were performed to examine the crystal structure, microscopic attributes, and chemical composition of the steel slag particles and the limestone dust and compare their differences. The study showed that steel slag used for mineral filler can significantly enhance Marshall properties and moisture susceptibility of asphalt mixtures. Working together with the SBS-modified binder, the positive effect was further pronounced. SEM analysis revealed that steel slag has a rough, angular surface texture with a high porosity and specific surface area. EDX analysis confirmed the pozzolanic composition of steel slag. Doi: 10.28991/CEJ-2025-011-04-04 Full Text: PD
Bearing Capacity and Strength of Bacterial Soil Columns Full-Scale Tests
Get PDFInfrastructure development often faces challenges due to soils with low bearing capacity, which can potentially cause instability and subsidence and threaten the safety of structures. Therefore, an efficient and environmentally friendly stabilization method is required. This study aims to evaluate the effectiveness of Microbial Induced Calcite Precipitation (MICP) in improving bearing capacity and soil strength through the formation of bacterial soil columns. This study employed a full-scale physical model test using 40 cm diameter and 200 cm deep soil columns filled with soil mixed with Bacillus subtilis, compacted, and cured for 56 days. The results showed significant improvements in the geotechnical characteristics of the soil, with CBR values increasing from 5.5% to over 12%, unconfined compressive strength reaching 345 kPa, and modulus of elasticity increasing to 12.5 MPa. Soil cohesion increased to 65 kPa, while internal friction angle increased from 10° to 34°. The novelty of this research is the application of MICP technology in the form of bacterial soil columns as an innovative, effective, and sustainable stabilization method to improve the mechanical properties of soft soils. Doi: 10.28991/CEJ-2025-011-04-06 Full Text: PD
Performance of Auto Glass Powder-High Calcium Fly Ash Geopolymer Mortar Exposed to High Temperature
Get PDFWaste glass enhances concrete sustainability by reducing virgin material use and recycling waste. In traditional concrete, it boosts strength through pozzolanic reactions, while in geopolymer concrete, it improves durability, insulation, and resistance to harsh conditions. This study investigated the viability of substituting auto glass powder (AGP) for high-calcium fly ash (FA) in geopolymer mortar formulations. AGP was utilized as a substitute for high-calcium FA at substitution levels ranging from 0% to 40% by weight. The study examined the physical properties, compressive strength, thermal insulation, and high-temperature performance of the geopolymer composites. The findings indicated that a higher AGP content corresponded with a reduced mortar flow, while increasing the proportion of AGP resulted in the diminished compressive strength of the geopolymer composites. Incorporating 10–20% AGP into the geopolymer mortar gave satisfactory compressive strengths (75–85%) compared to the reference mortar. Thermal conductivity testing indicated that AGP enhanced the thermal insulating properties of mortar. Notably, the compressive strength, after being exposed to 600–900°C, improved with the inclusion of the AGP. Based on XRD, the combeite crystalline phase was present in the mortars containing 20% and 40% AGP after being subjected to 900ºC. This phase contributed to the durability and stability of the material. Thus, it was confirmed that AGP not only served as a beneficial additive but also could play a crucial role in the thermal resilience of geopolymer systems
Influence of Axial Restraint and Fire Exposure Scenarios on the Fire Resistance of One-Way Reinforced Concrete Slabs
Get PDFThis study investigates the behavior of one-way simply supported reinforced concrete slabs under fire conditions, focusing on the effects of axial restraint and fire exposure scenarios on their fire resistance. The slabs are subjected to standard ISO 834 fire exposure, and the nonlinear analysis is carried out via the SAFIR2016 computer program, which employs the finite element method. A comparison of the numerical results with experimental results from various studies has shown good agreement. To verify the reliability of the numerical results, it is essential that the test parameters match those used in the simulations. This study aims to evaluate the accuracy and reliability of fire safety regulations for designing one-way simply supported slabs and to identify potential discrepancies between design codes and numerical findings. A 3D analysis is performed, with discretization using shell elements. The results reveal that axial restraint significantly influences the fire resistance of slabs. When axially restrained and exposed to fire from the bottom, the slab achieves fire resistance exceeding ten hours. However, under the same boundary conditions, the fire resistance of the slab is 339 minutes if the fire acts from the top. Without axial restraint, the direction of fire exposure becomes critical. When the fire acts from the bottom, the primary reinforcement is exposed to high temperatures, causing the slab to lose stability as the resisting moment decreases than the acting moment. Conversely, when the fire acts from the top, the slab without axial restraint shows high fire resistance, as the reinforcement remains in the cooler zone, leading to a fire resistance greater than ten hours. Doi: 10.28991/CEJ-2025-011-04-03 Full Text: PD
Impact of Unhydrated Lime on the Geotechnical Properties of Clayey Soil
Get PDFThis study investigates the impact of quicklime (CaO) on improving the geotechnical properties of clayey soil. Quicklime was mixed with soil in varying proportions (2%, 5%, and 8% by dry weight) to assess its effects. The results showed that increasing lime content reduced specific gravity, while the optimum moisture content (OMC) and plasticity index increased. Additionally, the liquid limit, plastic limit, and plasticity index decreased, and there were improvements in compressive strength, friction angle, and unconfined compressive strength. Compression parameters such as the compression index (Cc), rebound index (Cr), volume change coefficient (mv), and compression modulus (av) decreased with increasing lime content. The most significant improvement was observed at 2% lime, with further increases to 5% and 8% resulting in less improvement. X-ray diffraction (XRD) and scanning electron microscopy (SEM) analyses were conducted to explore the mineralogical and structural changes in the soil, demonstrating the chemical and physical interactions between lime and soil. This research provides valuable insights into the role of quicklime in modifying clayey soil properties, with implications for improving geotechnical performance in civil engineering applications, particularly in road and infrastructure projects. Doi: 10.28991/CEJ-2025-011-05-012 Full Text: PD
Energy Optimization in Residential Buildings: Evaluating PCM-CLT Wall Systems Across U.S. Climate Zones
Get PDFBuildings consume approximately 43% of their electricity for space heating and cooling, emphasizing the need for energy-efficient solutions. Among the strategies to reduce this demand, phase change materials (PCM) have been recognized for their potential to enhance thermal performance. While PCM has been extensively studied in building envelopes, its integration with cross-laminated timber (CLT) remains unexplored. Additionally, the optimal placement of PCM within wall assemblies lacks consensus, as previous studies have reported inconsistent findings. This study addresses these research gaps by investigating the performance of PCM-integrated CLT (PCM-CLT) wall systems across 17 climate zones in the United States. Using EnergyPlus simulation, five wall configurations were analyzed, including three PCM-CLT configurations with PCM positioned at different locations within the assembly. The results demonstrate that the PCM-CLT system significantly enhances energy efficiency, achieving cooling energy savings of up to 72.48% and heating energy savings of up to 96.94% in certain locations. Moreover, the findings reveal that placing PCM on the interior side of CLT walls consistently outperforms other configurations across all climate zones. Furthermore, PCM-CLT walls help reduce peak energy loads, alleviating stress on power grids. This research contributes to enhancing building energy performance through PCM-CLT integration, providing valuable insights for both retrofitting and new construction, and advancing sustainable building design. Doi: 10.28991/CEJ-2025-011-05-05 Full Text: PD