Industrialisasi otomotif modern mendorong penggunaan komposit polimer teknik untuk mengurangi bobot kendaraan dan meningkatkan ketahanan komponen pada suhu tinggi. Penelitian ini mengevaluasi kinetika degradasi termo-oksidatif dan ketahanan thermal aging PA6-GF30, PA66-GF30, dan PBT-GF30. Accelerated thermal aging dilakukan sesuai ASTM D3045 pada 130, 150, dan 170 °C selama 0–1000 jam. Sifat mekanik diuji berdasarkan ASTM D638, sedangkan perubahan fisikokimia dan morfologi dianalisis menggunakan DSC, TGA, dan SEM. Hasil menunjukkan strain at break lebih sensitif terhadap degradasi dibandingkan tensile strength. Pada 170 °C selama 1000 jam, retensi tensile strength PA6-GF30, PBT-GF30, dan PA66-GF30 masing-masing 92,7%, 87,3%, dan 85,6%. Pemodelan orde kesatu–Arrhenius menghasilkan energi aktivasi 52,49 kJ/mol untuk PA6-GF30 dan 36,04 kJ/mol untuk PA66-GF30, sedangkan PBT-GF30 menunjukkan perilaku non-Arrhenius. Proyeksi RTI pada retensi 50% selama 5.000 jam masing-masing mencapai 187,3 °C, 169,8 °C, dan 161,0 °C. Analisis DSC, TGA, dan SEM mengonfirmasi embrittlement, penurunan stabilitas termal, serta kerusakan mikrostruktur. Secara keseluruhan, PA6-GF30 menunjukkan ketahanan penuaan termal dan reliabilitas umur pakai terbaik untuk aplikasi otomotif under-the-hood bersuhu tinggi.
The integration of renewable energy systems, particularly rooftop solar panels, in industrial buildings has increased as part of efforts to improve energy efficiency and sustainability. However, the installation of solar panels on a Pre-Engineered Building (PEB) introduces additional permanent loads that may affect structural performance. This study aims to evaluate the effect of solar panel installation on the structural performance of a PEB warehouse in Medan. The analysis was conducted by comparing the existing structural condition with the condition after the addition of a solar panel load of 0.15 kN/m². A structural model was developed using structural analysis software, while the evaluation considered the utilization ratio (UR) of selected structural members, including the main column, rafter haunch, roof purlin, rafter mid span, and end wall column. The results indicate that solar panel installation increases the utilization ratio of all evaluated structural members. The roof purlin experienced the highest increase, from 0.74 to 0.91, corresponding to 22.97%, while the rafter haunch showed the lowest increase of 11.54%. The critical structural member also shifted from the main column in the existing condition (UR = 0.79) to the roof purlin after solar panel installation (UR = 0.91). Nevertheless, the maximum utilization ratio remains below 1.00, indicating that the evaluated structural members remain within their design capacity. The findings demonstrate that rooftop solar panel installation can be implemented on PEB structures with appropriate structural assessment and load evaluation.
Although numerous studies have evaluated asphalt modifiers, systematic comparisons of multiple microscale additives under an identical experimental framework remain limited. To address this gap, this study analyzed the rheological performance and microstructural characteristics of asphalt binders modified with four micro-material additives: fly ash (FA), cement (Ce), crumb rubber (Cr), and silica (Si). Particle size reduction was carried out by milling, producing micro-scale particles, which were then blended with pure asphalt pen 60/70 (PG-64) at dosages of 1–3%. Performance was evaluated using conventional physical tests, rotational viscosity, Scanning Electron Microscope (SEM), and Dynamic Shear Rheometer (DSR) tests, including temperature sweeps under three aging conditions: original, RTFO and PAV. Results showed that the micromaterial modifiers significantly affected the physical and rheological characteristics of asphalt binders, reducing penetration values, raising softening points and enhancing viscoelastic performance across aging conditions. Temperature strongly influences binder viscosity, with higher temperatures producing lower viscosity and varying levels of temperature sensitivity among binders. The modified binders, including Cement (VCe), Fly Ash (VFA), Crumb Rubber (VCr) and Silica (VSi) exhibited increased complex modulus (G∗ ) and reduced phase angle (δ), indicating improved stiffness, structural stability, and elastic behavior. Rheological evaluation further revealed that increasing temperature reduced rutting and fatigue performance, while modified binders generally exhibited lower fatigue parameter (G∗sin δ) values than the virgin binder, indicating enhanced fatigue cracking resistance. The VCr mixture, particularly VCr-3, demonstrated the most effective improvement in long-term fatigue resistance and elastic performance.
Stingless bee entrance monitoring requires a non-invasive tool to measure colony traffic without disrupting foraging. A hybrid edge-cloud object identification system and physics-aware vision instrumentation framework are used to track stingless bees in this paper. The system uses a Raspberry Pi 4 edge node, Sony IMX296 Global Shutter camera, Only Look Once (YOLO)-based detection, and Observation-Centric Simple Online and Realtime Tracking (OC-SORT) tracking. Because entry activity implies foraging intensity, the traffic count can be a non-invasive proxy for colony health and yield. The edge-side YOLO11 and OC-SORT tracking pipeline found trajectory fragmentation during high-speed ingress. A frame interval of 0.0667 s was achieved using a 15 FPS edge processing rate. Inter-frame displacement may approach 0.333 m for bee motion exceeding 5 ms-1, producing missed detections and identity switching. Thus, a sampling-based tracking failure situation happens when a bee travels more than the tracker's maximum association distance between two processed frames. This illustrates that frame rate, bee velocity, field-of-view scale, detector recall, tracker association tolerance, and biologically meaningful bee counting interpretation all affect bee tracking reliability. Validation using 14 one-minute Geniotrigona thoracica entrance videos showed an average IN counting accuracy of 85.0%, OUT counting accuracy of 66.7%, and total counting accuracy of 76.3% compared with manual video counting.
Buton Rock Asphalt (BRA) shows potential as a sustainable asphalt mixture, but its high stiffness limits performance. This study evaluates performance improvements in BRA through softening with waste engine oil (WEO) and elastomeric reinforcement with nano crumb rubber (NCR), focusing on rheological response and rutting resistance under aging conditions. Modified BRA mixtures with 15 % WEO and 1.5 %-2.0 % NCR were tested using a Dynamic Shear Rheometer under Pressure Aging Vessel (PAV), Resilient Modulus, and Wheel Tracking Machine conditions. Data analysis employed mechanistic methods, including Modulus Decay, Response Surface Methodology (RSM), and the Multivariate Rational Response Surface Model (MRRSM). Results indicate that increasing temperature decreases the Resilient Modulus across all mixtures. By analyzing Modulus Decay and changes in permanent deformation, the need for NCR additives in aggregate asphalt mixtures can be designed. Under PAV conditions, the Resilient Modulus is primarily influenced by the binder rheological parameter |G|& sdot;sin(delta). RSM and MRRSM analysis demonstrate that increasing binder stiffness at extreme temperatures does not necessarily enhance rutting resistance. The integration of WEO and NCR into BRA significantly improves mechanistic performance, a MRRSM serving as a quantitative method for performance-based asphalt pavement design under aging and extreme temperatures
