FARADAY

The Effect of Inaccurate Electronic Component Values on The Output Frequency Characteristics of Fourth Order Butterworth Type Low-pass Filter Circuits

Akbar Sujiwa — 2025-01-31

The low-pass filter opamp circuit is an active electronic circuit used to pass low frequencies. In practice, making this circuit requires active components in the form of an operational amplifier and several passive components such as resistors and capacitors. To obtain the required passive component values, calculations are carried out according to theory, but the results of these calculations sometimes make it difficult for users to find the values for the same components. Components sold on the market do not always exactly match the user's needs, so sometimes these components are replaced with components whose size is close to the calculated value. Therefore, in this research, testing was carried out regarding the effect of inaccurate component values on the filter output characteristics. From the results of this research, it was found that the cut-off frequency decreased by 6.25% and that premature damping occurred at low frequencies at 100 Hz. However, overall this series of filters is still suitable for use.

The Impact of Plate Length and Material Variations on Tibial Bone Implants Analysis using Computational Biomechanics

Sakinah Sakinah — 2025-01-31

The aim of this research is to simulate the strength of the implant plate, as a method for healing tibia fractures by combining bone with a bone plate. Then model and analyze using ANSYS software to analyze loads such as deformation and the maximum distribution of von Mises stress values. The results of the Maximum Principal Stress analysis on the cobalt-chromium implant plate show a minimum value of -1.2527107 Pa (-12.527 MPa) and a maximum value of 7.57610 7Pa (75.76 MPa). Based on the research results, Co-Cr material has significant advantages compared to steel as an implant material. In addition, this material has excellent corrosion resistance and very good biocompatibility, making it safe for long-term use in the human body without significant risk of allergic reactions or irritation.

Comparison of Stress and Deformation Distribution in Steel and Cobalt Chromium Materials for Femoral Bone Implants using Computational Biomechanics Analysis

hamizatul hardiantati — 2025-01-31

This study analyzes the mechanical performance of femoral bone implants using two types of materials, namely Alloys and Cobalt Chromium Alloys, as well as two variations in implant length (72 mm and 24 mm, and 80 mm and 20 mm). Simulation was conducted using the Finite Element Method (FEM) to evaluate mechanical parameters, such as directional deformation, equivalent stress, maximum principal stress, and minimum principal elastic strain. The analysis results show that the Cobalt Chromium Alloys material has smaller deformation compared to the Alloys, indicating better stiffness and load-bearing capacity. However, the maximum principal stress value is higher in Cobalt Chromium Alloys, indicating a greater risk of stress concentration. Meanwhile, a longer implant length shows a more even stress distribution compared to a shorter length. This study provides important insights into the influence of material and implant length on its mechanical performance, and can serve as a basis for designing optimal implants for specific medical needs

Effectiveness of Science (Physics) Teacher Training Program on Conceptual Understanding at MTs Manado

Nailul Hasan — 2025-01-31

This study aims to evaluate the effectiveness of the physics science teacher training program in improving the understanding of physics concepts at one of the Madrasah Tsanawiyah (MTs) in Manado. Using pre-test and post-test data from 52 teachers, the Wilcoxon Signed-Rank Test was analyzed. The results showed significant improvement in trainees' understanding of physics concepts, with a p-value of 0.0004 and a large effect size (r = 0.60). These findings provide empirical evidence that the training is effective in improving teachers' conceptual understanding and can be used as a basis for developing similar programs in other regions.

Monitoring of Raw and Treated Water Quality Based on Nitrate Parameter at Ngagel Water Treatment Plant Using Spectrophotometry Method

Oka Akbar Sudrajat — 2025-01-31

This research focuses on monitoring the water quality at the Ngagel Water Treatment Plant in Surabaya by analyzing the nitrate (NO₃⁻) content in both raw and treated water. Nitrate is a key indicator of water pollution, often originating from agricultural runoff, sewage, and industrial discharge. Samples were collected monthly from January to March 2024 at two locations: the raw water intake from the Surabaya River and the treated water output ready for distribution. Laboratory testing using spectrophotometric methods showed that nitrate levels in raw water ranged between 2.44 mg/L and 3.50 mg/L, while treated water showed a slightly lower range between 2.00 mg/L and 3.00 mg/L. These results indicate a consistent reduction in nitrate concentrations after treatment, demonstrating the efficiency of the Ngagel Water Treatment Plant’s processes. Importantly, all measured values were significantly below the maximum allowable limit of 50 mg/L, as stated in the Indonesian Ministry of Health Regulation No. 492/MENKES/PER/IV/2010. This confirms that the treated water is safe for human consumption with regard to nitrate levels. The study highlights the importance of continuous water quality monitoring to ensure public health protection and to maintain the effectiveness of water treatment facilities over time.

Implant Design Femur Bone using CAD Computation with Variation in Implant Plate Length

Oka Akbar Sudrajat — 2025-01-31

Femoral fractures are among the most common and severe musculoskeletal injuries, necessitating effective and reliable treatment strategies. This study explores the biomechanical performance of femur implants by evaluating the effects of material selection and implant design using the finite element method (FEM). Three biocompatible materials—titanium alloy Ti-6Al-4V, stainless steel, and PEEK—were analyzed under linear elastic isotropic conditions. Implant designs varied in length (10.02 mm, 13.37 mm, and 15.60 mm) with a fixed head thickness of 3 mm. Simulations assessed stress distribution, deformation, and overall structural performance under physiological loading conditions. Results demonstrated that implant length significantly affects mechanical behavior. The 15.60 mm implants exhibited the most uniform stress distribution and minimal deformation, indicating superior mechanical stability. In contrast, shorter implants (e.g., 10.02 mm) showed increased stress concentrations and deformation, suggesting a higher risk of mechanical failure. Among the materials tested, Ti-6Al-4V outperformed others due to its favorable combination of strength and biocompatibility. The study concludes that longer implants made from titanium alloy provide improved structural integrity, offering safer and more durable options for femoral fracture repair. These findings contribute to the optimization of implant design for enhanced clinical outcomes in orthopedic applications