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Evaluation of recycled steel properties originating from construction steel waste
Full text linkThis research presents an experiment of constructional recycled steel properties that has been remelted into component-shaped specimens using green sand casting. A series of tensile, compressive and toughness tests were conducted. Then, specimens were observed using Scanning Electron Microscopy (SEM) and Energy-Dispersive X-ray (EDX) for microstructure analysis and chemical composition determination. This experiment was done to determine whether the recycled steel quality met the industrial standards. All tests were conducted at Universiti Teknologi MARA (UiTM), providing data on the stress-strain relationship and toughness of recycled steel. The results indicated that recycled steel exhibited tensile characteristics below the standard strength range required by Eurocode. The changes in Young’s modulus of the steel were attributed to exposure to high temperatures, causing significant vibration within the steel atoms and increasing the distance between atoms, thereby reducing tensile strength. The influence of impurities may also be a factor affecting tensile strength. The tests also concluded that the recycled steel construction waste was a brittle material with an average V-notch toughness of 24J
Positioning of quality systems in lean manufacturing: integrated approach vs independent implementation in the food industry
Full text linkDespite the widespread adoption of Lean Manufacturing (LM), its effectiveness in the food industry remains underexplored, particularly regarding the integration of the Quality System (QS). The purpose of this research is to compare QS placement and LM implementation strategies in the food industry. This study utilized a comparative approach, analyzing empirical data from four food processing companies in Indonesia over six months, employing qualitative methods (expert interviews, document analysis) and quantitative analysis. Response Surface Methodology (RSM) with the Box-Behnken design was applied for optimization, while Principal Component Analysis (PCA) identified key variables influencing Lean Manufacturing success. Two implementation strategies were compared: phased implementation with a separate Quality System (Companies A and B) and simultaneous implementation with an integrated Quality System (Companies C and D). The findings revealed that Company A achieved the highest performance, with 88% in 5S and 85% in Just-In-Time (JIT), followed by Company B with 80% in JIT and 75% in 5S. In contrast, companies C and D exhibited lower performance. PCA results indicated that PC1 (80.40%) was associated with on-time delivery and sales growth, whereas PC2 (14.47%) was linked to rejection factors. Companies A and B excelled in PC1, while Companies C and D were more dominant in PC2. These findings suggest that phased implementation of LM tools is more effective than simultaneous application. This research not only addresses a critical gap in the literature but also provides practical insights for food industry practitioners seeking to enhance operational efficiency through Lean Manufacturing
An FFT-based vibration characterization on road profile of two-wheeler electric vehicle
No full textVibration is an inevitable physical phenomenon; excessive and uncontrolled amounts of vibration can result in damage and system failure. In accordance with various automotive product certification standards, vehicle batteries or rechargeable electrical energy stotrage system (REESS) must undergo a vibration test to assess their mechanical integrity. This study aims to broaden the perspective on vibration assessment by examining it during vehicle operation and assessing the protective capabilities of vehicle suspension against vibrations from damaged roads in two-wheeled electric motor vehicles. The proposed method involves installing an accelerometer on the battery pack body placed in the battery compartment. The experimental setup involved conducting tests on a 125-meter track, with the vehicle traversing roads characterized by concrete cracks, uneven surfaces, and potholes. Two distinct speed variations were selected for analysis: 10 and 15 kilometers per hour. The results obtained from the Rion VA 12 portable vibration analyzer are presented as a plot of the fast Fourier transform (FFT) graph. The maximum acceleration recorded was 2.35 and 1.98 G at the same frequency of 7 hertz (Hz). This research method and result aligns with others, including those focused on assessing road damage, passenger comfort, and vehicle component damage, such as shock absorbers. In the future, the development of a vehicle battery support structure is anticipated to further minimize vibration disturbance by reducing the peak acceleration values depicted in the FFT graph. The minimization of incoming vibrations is expected to enhance the safety and durability of the battery pack.
Renewable energy in chemical industrial buildings for cost performance
Full text linkDue to their potential benefits for a variety of industries, blockchain technologies have recently attracted a lot of attention from the scientific community as well as the business community. Blockchain provides distributed, secure, permissioned transactional ledgers, that successfully deal with these problems. The purpose of this study is to present a new conceptual framework that combines blockchain technology with building information modeling. This framework is specifically designed for smart contracts and digital transactions in the chemical industry's retrofitting of green buildings. Within this particular context, the main goals are to improve cost-effectiveness, bolster cybersecurity measures, improve information sharing and management, expedite payment transactions, and advance sustainability. In Cilegon, Banten, Indonesia, a chemical facility was the study's location. The study also makes use of partial least squares structural equation modeling
Experimental investigation on slope runoff, sediment, and hydraulic parameters under different underlying surface
Full text linkThis study utilizes a rainfall simulator to conduct an experimental investigation of slope and rainfall on various underlying surfaces. This study aimed to determine the relationship between various hydraulic factors and sediment concentration by estimating runoff, sediment concentration generation, and hydraulic parameters on various underlying surfaces. The flow velocity, flow depth, shear stress, and unit stream power are the hydraulic parameters in this experiment. The soil sample will be set up appropriately in the rainfall simulator with a slope of 20º and subjected to a rainfall event for two hours on four trays with various underlying surface types. The rainfall intensity of 10 Lmin⁻¹ was designated for the rainfall simulator. Throughout a two-hour period, the runoff flow was collected at intervals of 30, 60, 90, and 120 minutes. The measured sediment concentration using Total Suspended Solid (TSS). Then measurements were conducted of the sediment concentration, runoff discharge, and hydraulic parameters. According to the results, the stream power of the four covers is higher for the dried leaves (0.004606 ms-3), grass cover (0.003274 ms-3), gravel (0.00232 ms-³), and bare soil cover (0.00081 ms-³). But bare soil produces the maximum concentration of sediment and surface runoff, which is then followed by grass, gravel, and leaves. In general, the generation of sediment began with the bare surface, gravel, dry leaves, and grass in descending sequence. Research has shown that rain-induced plant cover can be used as a low-cost strategy to reduce soil erosion on construction slope sites.
Advanced shooting target with bullet collector, semi-automatic bulls-eye paper positioning and automatic shooting score
Full text linkShooting exercises in Indonesia typically use simple bulls-eye targets on wooden boards with sand backstops, requiring manual setup and score calculation. This setup is inefficient, especially for long-range shooting, as operators must walk far to retrieve targets, and bullets embedded in sand are hard to recycle. This project developed an advanced shooting target featuring a bullet collector, semi-automatic target setup, automatic scoring, and target monitoring. A system with such complete features is not available in the market. This target system has a roll of bulls-eye paper and the roller is powered by a servo motor controlled by a switch to command a fresh new page of bulls-eye its positioning is helped by an infrared sensor to detect markers in the paper for correct positioning. This system is equipped with a bullet collector system by directing the bullet to a container using 450 angled armor and a layer of sand in the container to stop the bullet. This system is also equipped with a camera pointing to the bulls-eye paper and its output is transmitted to a monitor close to the shooter to identify bullet tracks for evaluating his shooting performance and to improve his shooting strategy. The image from the same camera is used for image processing with the OpenCV library and Python scripts to calculate the shooting score automatically. Several physical tests have been conducted and the system proves to perform reasonably well in the tests with some errors of around 3% for single bullet holes and simple multiple bullet holes. Based on test results, the pistol bullets have quite different properties from the rifle bullets. Pistol bullets follow the impact deflection with a coefficient of restitution e = 0 while rifle bullets follow the impact deflection with e ≈ 0.5. The pistol bullets are completely disintegrated after impact while the rifle bullets are just distorted.
Understanding passenger satisfaction and expectations in free bus service based on socio-demographic characteristics in Johor and the Klang Valley, Malaysia
Full text linkFree bus service is known to serve passengers with the same goal as normal bus does. In fact, the implementation of free bus service acts as an alternative solution for those who have financial limitations. To keep a high satisfaction level of passengers regardless of various backgrounds, it is important for the free bus providers to maintain the quality of their service. Therefore, this study aims to understand the relationship between socio-demographic characteristics and the satisfaction level and expectation of passengers on free bus services allocated in Klang Valley and Johor, Malaysia. A survey was conducted among the free bus users to collect data on their socio-demographic characteristics and their experiences with the service quality offered. According to the survey, teens and single people were the primary passengers of the free bus service. Moreover, passengers who had low income, no driving license, and no vehicles were also more likely to use the service. The overall satisfaction level of passengers was high (mean score > 3.6), indicating that the service quality provided by the free bus service provider met the expectations of passengers. However, no evidence was found from this study to relate socio-demographic factors with satisfaction level.
Evaluation of double-stage Anaerobic Fluidized Bed Reactor (AFBR) for digestion of leachate: correlation of kinetic parameter with operational condition and process
Full text linkThe objective of this study is to investigate the performance of using an advanced fluidized bed reactor (AFBR) of a double column configuration in breaking down leachate into biogas. The relationship of the kinetic parameters with the operating conditions and the performance of the double-column reactor during anaerobic digestion was examined. The substrate concentration, microorganism population, hydraulic retention time value, growth rate, and death rate of microorganisms were employed as reference points for evaluating anaerobic digestion performance and assessing the operating conditions. The results demonstrated that there was no notable correlation between the formation of volatile fatty acids (VFA) in the acidogenic reactor (R1), the degradation of VFA in the methanogen reactor (R2), and the methane production rate in the methanogen reactor (R2). The simulation results for VFA formation (dCVFA1/dt) and VFA degradation (dcVFA2/dt) exhibited a tendency to overestimate when operated at low HRT and underestimate at short HRT compared to the experimental results. The steady state of the simulation results exhibited a faster rate of progression than the experimental outcomes. The fitting data for Ksx1 and Ksx2 predominantly comprise dynamically evolving values that exert an influence upon um1 and um1, as well as kd1 and kd2, when the reactor is operated in continuous mode. Furthermore, the factors of inhibitor compounds and microorganism adaptation were not observed across all HRT values in this investigation.
Real-time dental caries segmentation with an efficient Deformable U-Net (DU-Net) for teledentistry system
Full text linkDigital technology has greatly improved teledentistry by facilitating telediagnostics and teleconsultations, particularly benefiting those in remote areas. Additionally, AI advancements enhance diagnostic accuracy and streamline clinical decision-making, reducing costs and resource disparities in dental care. This study presents an improved U-Net architecture, Deformable U-Net (DU-Net), for semantic dental caries segmentation, leveraging deformable convolutions to dynamically adjust sampling points for improved feature extraction and reduced computational redundancy. By connecting encoder-decoder blocks via skip-connections, the DU-Net architecture enables efficient real-time segmentation and balance accuracy while reducing computational demands. The deformable block in DU-Net and DDR U-Net shows a balanced performance and efficiency while maintaining accuracy despite reduced FLOPs. The proposed architecture was implemented in real-time dental caries segmentation on a Dual Core Cortex A72 system and web server. It shows a significant improvement in Dice score, reducing CPU and memory usage compared to conventional U-Net models. Moreover, the DU-Net and its half variants achieved competitive performance with much lower computational demands makes suitable for web servers and embedded applications. The result highlights the DU-Net capability to optimize both computational efficiency and segmentation accuracy, offering a promising solution for real-world applications where speed and resource management are critical, particularly in the medical imaging field
Performance of speech enhancement models in video conferences: DeepFilterNet3 and RNNoise
Full text linkAs remote work and online education continue to gain prominence, the importance of clear audio communication becomes crucial. Deep Learning-based Speech Enhancement has emerged as a promising solution for processing data in noisy environments. In this study, we conducted an in-depth analysis of two speech enhancement models, RNNoise and DeepFilterNet3, selected for their respective strengths. DeepFilterNet3 leverages time-frequency masking with a Complex Mask filter, while RNNoise employs Recurrent Neural Networks with lower complexity. The performance evaluation in training revealed that RNNoise demonstrated impressive denoising capabilities, achieving low loss values, while DeepFilterNet3 showed superior generalization. Specifically, "DeepFilterNet3 (Pre-Trained)" exhibited the best overall performance, excelling in intelligibility and speech quality. RNNoise also performed well in subjective quality measures. Furthermore, we assessed the real-time processing efficiency of both models. Both RNNoise variants processed speech signals almost in real-time, whereas DeepFilterNet3, though slightly slower, remained efficient. The findings demonstrate significant improvements in speech quality, with "DeepFilterNet3 (Pre-Trained)" emerging as the top-performing model. The implications of this study have the potential to enhance video conference experiences and contribute to the improvement of remote work and online education