2026-01-15
Boy Setiawan Boy et al.
This study focuses on designing and implementing a cost-effective and energy-efficient WiFi packet sniffer system using the ESP32. The ESP32-CAM module, which combines WiFi, Bluetooth, and microSD support, is used to capture IEEE 802.11 frames in real-time via promiscuous mode. Packets are stored in packet capture format, which is compatible with tools such as Wireshark and Scapy. Developed using the official ESP-IDF, it offers low-level control and high performance. Two user interfaces were implemented: a UART-based text menu and a web-based HTTPS menu hosted on the ESP32 itself. Functional and performance evaluations were conducted with a focus on capturing broadcast and management frames without payload decryption. The system achieves 99.99% packet capture accuracy at 500,000 packets with a total hardware cost of $25 and power consumption of 2.1 W during active capture, representing a 95% cost reduction and 80% power savings compared to commercial alternatives. The download and file-listing speeds through the web-based menu were also evaluated, revealing that the system performs optimally with fewer files but experiences interruptions during large-scale operations. The proposed system provides a lightweight, standalone, and highly portable alternative to conventional packet sniffing tools despite the limitations in encryption handling and resource constraints. This makes it suitable for educational, diagnostic, and preliminary network analysis, particularly in low-power scenarios.
2026-01-02
Mohammad Luqman Zulbakri et al.
The effects of airflow dynamics, heat transfer, and mechanical properties on the HDPE blown film extrusion process were examined using a single-lip air ring with a fixed compressed-air valve opening angle of 10°. Reynolds numbers ranging from 9175 to 25911 were analyzed to understand their impact on cooling efficiency, bubble morphology, and film properties. Numerical simulations employing the Standard k−ω turbulence model in ANSYS FLUENT v2023, with mesh refinement achieving y+ ≈ 1, captured detailed flow and heat transfer behavior. Results showed that higher Reynolds numbers significantly enhanced the heat transfer coefficient, with values increasing from 1096 W/m²·K at Reynold number of 9175 to 1438 W/m²·K at Reynolds number of 25911, reducing the axial cooling distance by up to 30%. This rapid cooling improved the cooling rate but led to a reduced lay-flat width (from 29.10 cm at a Reynolds number of 9175 to 27.50 cm at a Reynolds number of 25911) and thicker films. The tensile stress decreased from 25.25 MPa at a Reynolds number of 9175 to 20.84 MPa at a Reynolds number of 25911, reflecting the impact of turbulence on the polymer chain alignment. These findings emphasize the trade-offs between enhanced cooling efficiency and material properties, offering critical insights for optimizing blown film extrusion processes for improved quality and operational performance.
2025-12-31
An Vo Van et al.
In this study, a cascade PID control structure is proposed and implemented for a 6-degree-of-freedom (6-DOF) unmanned aerial vehicle (UAV) to enhance stability and trajectory tracking capabilities under both noise and non-noise conditions. The controller was designed based on the Tyreus–Luyben tuning method and was evaluated using quantitative metrics, including rise time, settling time, overshoot, and steady-state error. Simulation results on MATLAB/Simulink show that the controller achieves high performance in angular channels (ϕ, θ, ψ) and altitude (z) with a short rise time (
2025-10-14
Karolina Villa Delfia Ihut et al.
North Jakarta is predominantly composed of soft soil that is still undergoing consolidation. According to research by Raharjo et al . (2022), excess pore pressure is still present in the soils of Jakarta. The degree of consolidation and excess pore pressure values indicate that consolidation is not yet complete (Raharjo et al ., 2022). In this study, the researchers developed two methods to determine excess pore pressure using field testing. The Stress History and Normalized Soil Engineering Properties (SHANSEP) model equation from Ladd and Foot (1974), as well as Finite Element Method (FEM) modeling using the PLAXIS program, were utilized to estimate the excess pore pressure in the soil. The results from the SHANSEP-based analysis were then compared with those from the FEM analysis using PLAXIS. The comparison showed that the excess pore pressure estimated using PLAXIS closely matched the values obtained from CPTu tests based on the SHANSEP model. Interpretation of parameters from the Cone Penetration Test with pore pressure measurement (CPTu) indicates that the soil at the project site is still consolidating and undergoing settlement. Similarly, the settlement results from the PLAXIS analysis support this conclusion.
2025-01-06
Tue Duy Nguyen et al.
The lifetime of electronic devices strongly depends on the junction temperature. Heat sinks are a good choice for dissipating heat because of their enhanced heat transfer areas. Plate–fin heat sinks are commonly used for electronic components because of their simple construction. Recently, computational fluid dynamics (CFD) software, such as Ansys Fluent and OpenFOAM, has been widely used and has provided effective results. Autodesk CFD is a powerful simulation tool; however, its use in heat sink research remains relatively uncommon. In this study, two plate–fin heat sinks with heights of 30 and 50 mm were first designed using heat transfer equations and then compared with Autodesk CFD simulations under natural convection conditions. Temperature inputs of 60 °C, 70 °C, and 80 °C were assigned to determine the temperature distribution along the fins, heat dissipation, fin efficiency, and fin effectiveness for both types of heat sinks. The results of the heat transfer calculations and Autodesk CFD simulations are consistent, with negligible differences. These findings indicate that Autodesk CFD can produce reliable results for heat sink design. In addition, efficiency decreases with the increase in fin height, although the effectiveness and heat dissipation of the tall (50 mm) heat sink are higher than those of the short (30 mm) heat sink. Although the 50-mm-high fin heat sink has a heat transfer area approximately 63% larger than that of the 30-mm-high fin heat sink, its heat dissipation is only approximately 40% larger than that of the 30-mm-high fin heat sink. This finding indicates that the addition of more material alone may not proportionally increase heat transfer and could lead to wasted material. Therefore, when designing heat sinks, the height of the fins should be carefully considered and optimized to enhance efficiency and conserve materials.