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Menumbuhkan Keterampilan Berfikir Kritis dan Kepedulian Terhadap Lingkungan dengan Pembelajaran Berbasis PBL Fajar Riyadi; Syamsiah, Nur; Pudjiwati, Sri
Journal in Teaching and Education Area Vol. 1 No. 3 (2024): JITERA - Journal in Teaching and Education Area
Publisher : Yayasan Al Hidayah

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.69673/s2fzxh52

Abstract

Penelitian ini bertujuan untuk mengkaji efektivitas model pembelajaran Problem Based Learning (PBL) dalam menumbuhkan keterampilan berpikir kritis dan kepedulian terhadap lingkungan hidup pada siswa kelas 5 SDN 05 Madiun Lor. Penelitian ini menggunakan metode kuantitatif dengan rancangan quasi-eksperimen pretest-posttest group design. Sampel dalam penelitian ini adalah seluruh siswa kelas 5 SDN 05 Madiun Lor yang dibagi menjadi 2 grup yaitu grup eksperimental dan grup kontrol. Sampel di ambil dengan menggunakan purposive sampling yang peneliti anggap memiliki kemampuan dan karakteristik yang sesuai dengan kebutuhan penelitian. Pre-test dan post-test digunakan untuk menguji hasil efektifitas dari PBL. Dengan menggunakan Uji T, hasil penelitian menunjukkan bahwa terdapat peningkatan yang signifikan pada keterampilan berpikir kritis dan kepedulian terhadap lingkungan hidup siswa yang mengikuti pembelajaran dengan model PBL dibandingkan dengan siswa yang mengikuti pembelajaran dengan model konvensional. Hal ini menunjukkan bahwa model pembelajaran PBL efektif dalam menumbuhkan keterampilan berpikir kritis dan kepedulian terhadap lingkungan hidup siswa
Heat Distribution Simulation in a Square Aluminum 7075 Plate Using Laplace Equation and MATLAB Pudjiwati, Sri; Sudarma, Andi Firdaus; Tarigan, Kontan; Khaerudini, Deni Shidqi; Djajadiwinata, Eldwin
International Journal of Innovation in Mechanical Engineering and Advanced Materials Vol 6, No 2 (2024)
Publisher : Universitas Mercu Buana

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22441/ijimeam.v6i2.25356

Abstract

The efficient management of heat transfer from aircraft engines to the wings is vital for maintaining thermal efficiency and structural integrity in modern aircraft design. Excessive heating of the wings, caused by engine-generated heat, can negatively impact aerodynamic performance and safety. This study focuses on analyzing heat distribution in a square aluminum 7075 plate to better understand heat transfer mechanisms. Using the Laplace equation, implemented through MATLAB (2023 Online Version), we aim to simulate and analyze heat distribution on the plate. The numerical method employed in this research involves solving the Laplace equation with Neumann boundary conditions, which represent insulated edges. The Liebmann method is used to iteratively reduce error to less than 1%. Simulations are conducted on an aluminum 7075 plate of dimensions 4x10⁻² m x 4x10⁻² m under various temperature conditions at the edges. Numerical results show that at the 9th iteration, the error reaches 0.71%, while MATLAB simulations yield an error of 0.4681% at the same iteration. The heat distribution across the plate is clearly visualized, and the analysis indicates that increasing the number of grids improves both the clarity and accuracy of the simulation results. In conclusion, this study demonstrates that applying the Laplace equation via MATLAB is an effective approach for analyzing heat distribution in aluminum 7075 plates. The results show that a finer grid resolution enhances accuracy, with a 101-grid system providing particularly clear and precise heat distribution patterns. These findings contribute to the optimization of thermal system designs, especially in aviation-related applications.
Use of Hibiscus rosa-sinensis as a Green Corrosion Inhibitor for Valve Materials in RO Water Pudjiwati, Sri; Sanusi, Yasa; Arwati, I Gusti Ayu
International Journal of Innovation in Mechanical Engineering and Advanced Materials Vol 7, No 2 (2025)
Publisher : Universitas Mercu Buana

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22441/ijimeam.v7i2.32806

Abstract

Valves are mechanical devices that regulate the flow of oil and gas fluids and are typically constructed from materials that are heat-resistant, corrosion-resistant, and capable of withstanding high pressure. However, observations from valve manufacturing companies in the Banten area have shown that valve components made from medium carbon steel ASTM A105N are susceptible to corrosion during hydrotesting, particularly when using reverse osmosis (RO) water as the testing medium. This corrosion can degrade product quality before delivery to customers. To address this issue, this study investigates the use of Hibiscus rosa-sinensis as a green corrosion inhibitor. The objective of this research is to evaluate the corrosion rate, inhibitor efficiency, and surface morphology of ASTM A105N valve materials using Hibiscus rosa-sinensis in RO water media, with varying inhibitor concentrations and immersion durations. The electrochemical methods used include Potentiodynamic Polarization, Electrochemical Impedance Spectroscopy (EIS), Chronoamperometry, and Scanning Electron Microscopy (SEM). Results from the corrosion rate tests indicated that the highest inhibitor efficiency—59.04%—was achieved at 24 hours of immersion with a 2 g inhibitor concentration. This condition also yielded the lowest corrosion rate of 1.2231 × 10⁻² mm/year and the lowest corrosion current (Icorr) of 3.2601 × 10⁻⁶ A/cm². Chronoamperometry testing confirmed these findings with the lowest electric charge value of 0.0125 C. SEM analysis further revealed a more uniform and homogeneous protective coating on the metal surface under these conditions. Based on these results, Hibiscus rosa-sinensis demonstrates promising performance as a green corrosion inhibitor and is recommended as an additive in RO water for valve hydrotesting. This study highlights the potential of environmentally friendly and cost-effective inhibitors in reducing corrosion risk in valve materials.
Correlation Analysis of Battery Capacity, Range, and Charging Time in Electric Vehicles Using Pearson Correlation and MATLAB Regression Sanusi, Yasa; Pudjiwati, Sri; Tarigan, Kontan; Ginting, Dianta; Adnan, Farrah Anis Fazliatun; Timuda, Gerald Ensang; Darsono, Nono; Chollacoop, Nuwong; Khaerudini, Deni Shidqi
International Journal of Innovation in Mechanical Engineering and Advanced Materials Vol 7, No 3 (2025): Article in Press
Publisher : Universitas Mercu Buana

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22441/ijimeam.v7i3.31800

Abstract

The increasing adoption of electric vehicles (EVs) reflects growing global awareness of climate change and air pollution challenges. As a sustainable alternative to conventional internal combustion vehicles, EVs produce zero tailpipe emissions and can significantly reduce carbon emissions—particularly when powered by renewable energy sources. However, one of the primary barriers to widespread EV adoption remains the high cost of battery components, which are essential to vehicle performance and energy storage. In Indonesia, two dominant battery types used in EVs are Lithium Ferro Phosphate (LFP) and Nickel Manganese Cobalt (NMC), each offering distinct advantages. LFP batteries are recognized for their thermal stability and longer life cycles, making them suitable for everyday use, while NMC batteries offer higher energy density and are preferred for performance-focused and long-distance applications. This study aims to evaluate the correlation between battery capacity, driving range, and charging time for LFP and NMC batteries using Pearson correlation and regression analysis through MATLAB simulation. The results indicate a strong and statistically significant correlation among the key parameters, with a Pearson coefficient of 0.576 for battery capacity and range, and an R-square value of 0.99 for the regression model, demonstrating high predictive accuracy. Furthermore, the analysis reveals that LFP batteries have a higher average energy efficiency of 7.53 km/kWh compared to 6.84 km/kWh for NMC batteries, indicating more consistent performance in energy usage. These findings offer valuable insights for optimizing battery selection in EV applications and contribute to strategic planning for the development of more efficient electric vehicle systems. The combination of statistical and simulation-based analysis provides a robust foundation for future research and policy-making in the field of electric mobility.
STUDY OF FINITE DIFFERENCE METHOD IN HEAT FLOW SIMULATION OF TWO-CHAMBER THERMOS SEPARATOR MADE OF POLYPROPYLENE USING MATLAB APPLICATIONS Pandriana, Aap; Pudjiwati, Sri; Alva, Sagir; Tarigan, Kontan; Sudarma, Andi Firdaus; Khaerudini, Deni Shidqi
Jurnal Teknik Mesin (Journal Of Mechanical Engineering) Vol 13, No 2 (2024)
Publisher : Universitas Mercu Buana

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22441/jtm.v13i2.27803

Abstract

Heat transfer can be defined as transfer of energy from one area to another as a result of temperature differences in objects. This indicates heat transfer not only explains how heat energy is transferred from one object to another, but can also predict the rate of heat transfer that occurs under certain conditions. In this case, what is related to the heat flow model equation is two-chamber thermos separator where the separator is made of polypropylene. This separator functions to prevent the flow of heat from one side to the other side of the thermos tube. Polypropylene is included in the insulator category, although heat transfer still occurs. The heat transfer will be calculated using the finite difference method in parabolic partial differential equations using the Matlab application. The heat transfer process is assumed to occur by conduction, with a separator length of 1 cm. Assume the first side of the divider has a right temperature of 100°c, and the other side 20°c. The temperature point measured on the separator is located in the center of the separator. After completing the solution using the Matlab application with the finite difference method, a heat transfer flow simulation was obtained in the two-chamber thermos separator which shows the heat flow transfer at any time. At 0.1 seconds the temperature at T1 is 2.4°c, while at 10 seconds  is 65.9704°c. Then at 0.1 seconds the temperature at T4 is 0.48°c, while at 10 seconds 19.5436°c. The conclusion is in the separator of the two-chamber thermos there is significant heat flow from the side of the first tube to the other side.