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Pengaruh Elektroplating Ni-Cr terhadap Wetability dan Ketahanan Korosi Sumuran pada Baja Tahan Karat 316L dalam Media Infus 0,9% NaCl Pakpahan, Binsar Maruli Tua; Pasaribu, Muhammad Nuh Hudawi; Simatupang, Lisnawaty; Silaban, Robert; Pakpahan, Natal Toga Hot Tua; Sihombing, Prada; Sinaga, Sabas DK
IRA Jurnal Teknik Mesin dan Aplikasinya (IRAJTMA) Vol 4 No 1 (2025): April
Publisher : CV. IRA PUBLISHING

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.56862/irajtma.v4i1.197

Abstract

This study aims to evaluate the effect of Ni-Cr electroplating on wettability characteristics and pitting corrosion resistance of 316L stainless steel in 0.9% NaCl infusion media. The electroplating process consisted of a nickel base coating for 15 minutes, followed by chromium plating with durations ranging from 10 to 22.5 minutes. Contact angle measurements showed that Ni-Cr coating increased the contact angle from 71.25° to 86.77°, indicating a surface transformation from hydrophilic to more hydrophobic. This increase in contact angle demonstrates the effectiveness of Ni-Cr plating in enhancing the material’s resistance to liquid penetration, a critical property for biomedical applications. Corrosion tests revealed a reduction in pit count and depth after plating, suggesting a significant improvement in resistance to localised corrosion. These findings indicate that Ni-Cr electroplating significantly improves pitting corrosion resistance. This technique can be implemented to enhance the durability of 316L-based implant materials in corrosive body environments, particularly in applications where long-term biocompatibility and surface stability are essential.
E-LKPD BERBASIS PROBLEM BASED LEARNING: MENINGKATKAN KEMAMPUAN BERPIKIR KOMPUTASIONAL R. Mursid; Muslim; Pasaribu, Muhammad Nuh Hudawi
Jurnal Teknologi Pendidikan (JTP) Vol. 17 No. 2 (2024): Oktober - Jurnal Teknologi Pendidikan
Publisher : Universitas Negeri Medan

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24114/jtp.v17i2.65197

Abstract

Abstract: Penelitian dan pengembangan ini bertujuan untuk menghasilkan media pembelajaran E-LKPD berbasis PBL untuk meningkatkan kemampuan berpikir komputasional peserta didik. Jenis penelitian ini adalah penelitian pengembangan yang menggunakan model pengembangan 4D yaitu: (1) define, (2) Design, (3) Develop, dan (4) Disseminate. Hasil penelitian menunjukan: (1) Uji validasi ahli materi bahwa media yang dikembangkan sangat layak skor rata-rata 84%. (2) Uji validasi Ahli Desain Instruksional kriteria sangat layak skor rata-rata 87%. (3) Uji validasi Ahli Media kategori sangat layak skor rata-rata 83%. (4) Uji coba perorangan kriteria sangat baik dengan skor rata-rata 90%. (5) Uji coba kelompok kecil kriteria sangat baik dengan skor rata-rata 87%. Dan, (6) Uji coba lapangan kriteria sangat baik dengan skor rata-rata 89%. Uji kepraktisan oleh guru sangat baik dengan skor rata-rata 88%, sedangkan hasil uji kepraktisan pada siswa skor rata-rata 90% kategori sangat baik. Hasil percobaan penggunaan E-LKPD berbasis PBL pada kelas eksperimen rata-rata hasil belajar 86, sedangkan siswa yang diajarkan tanpa menggunakan E-LKPD berbasis PBL nilai rata-rata 70. Pengujian hipotesis menggunakan Independent t-test mendapatkan hasil sig. (2-tailed) sebesar 0,000 yang mana hasil tersebut < 0,05 terdapat perbedaan yang signifikan antara kelas yang dibelajarkan menggunakan E-LKPD berbasis PBL dengan kelas tanpa menggunakan E-LKPD berbasis PBL. Oleh karena itu, penggunaan E-LKPD berbasis PBL dalam pembelajaran efektif untuk meningkatkan kemampuan berpikir komputasional peserta didik. Kata Kunci: E-LKPD, Problem Based Learning, berpikir komputasional Abstract: This research and development aims to produce E-LKPD learning media based on PBL to improve students' computational thinking skills. This type of research is development research using the 4D development model, namely: (1) define, (2) Design, (3) Develop, and (4) Disseminate. The results of the study showed: (1) The validation test of the material expert that the media developed was very feasible with an average score of 84%. (2) The validation test of the Instructional Design Expert criteria was very feasible with an average score of 87%. (3) The validation test of the Media Expert category was very feasible with an average score of 83%. (4) Individual trials criteria were very good with an average score of 90%. (5) Small group trials criteria were very good with an average score of 87%. And, (6) Field trials criteria were very good with an average score of 89%. The practicality test by the teacher was very good with an average score of 88%, while the results of the practicality test on students had an average score of 90% in the very good category. The results of the experiment using PBL-based E-LKPD in the experimental class average learning outcomes of 86, while students who were taught without using PBL-based E-LKPD had an average score of 70. Hypothesis testing using the Independent t-test obtained sig. (2-tailed) results of 0.000 which results <0.05 there is a significant difference between classes taught using PBL-based E-LKPD and classes without using PBL-based E-LKPD. Therefore, the use of PBL-based E-LKPD in learning is effective in improving students' computational thinking skills. Keywords: E-LKPD, Problem Based Learning, computational thinking