Article Per Year (5 Year)
p-Index From 2021 - 2026
1.168
P-Index
This Author published in this journals
All Journal Rotasi Jurnal Pengabdian Masyarakat Creative Research in Engineering (CERIE) Multidisciplinary Innovations and Research in Applied Engineering
Saeful Rofi Romadhon
Universitas Muhammadiyah Brebes
Humanities Computer Science & IT Control & Systems Engineering Education Electrical & Electronics Engineering Energy Engineering Environmental Science Industrial & Manufacturing Engineering Languange, Linguistic, Communication & Media Materials Science & Nanotechnology Mechanical Engineering Public Health Other

Published : 7 Documents Claim Missing Document
Claim Missing Document
Check
Articles

Found 7 Documents
Search

 1 
Analisis Sifat Mekanis RTV Silicone Rubber dengan Variasi Silicone Oil untuk Pengembangan Injection Training Arm Romadhon, Saeful Rofi; Ismail, Rifky; Bachtiar, Yuriz; Prawibowo, Hartanto
ROTASI Vol 27, No 3 (2025): VOLUME 27, NOMOR 3, OKTOBER 2025
Publisher : Departemen Teknik Mesin, Fakultas Teknik, Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/rotasi.27.3.30-39

Abstract

RTV silicone rubber is widely used in medical simulation devices because of its properties that resemble human soft tissue, especially in injection training arms that require elasticity, tensile strength, tear resistance, and adequate hardness to withstand repeated needle penetration. This study aims to evaluate the effect of adding silicone oil on the mechanical properties of type 00A RTV silicone rubber through tensile testing (ISO 37:2024), tear testing (ISO 34-1:2022), and hardness testing (ASTM D2240). Three formulations were tested, namely pure RTV, RTV + 5 phr silicone oil, and RTV + 15 phr silicone oil. The results showed that the addition of 5 phr silicone oil produced the most significant improvement in mechanical properties, with a tensile strength of 0.57 N/mm², elongation of 363.4%, tear resistance of 0.42 N/mm, and hardness of 9.3 Shore A, compared to pure RTV which only reached 0.38 N/mm², 199.26%, 0.33 N/mm, and 7.2 Shore A. Conversely, the addition of 15 phr silicone oil reduced performance due to excessive plasticization, although the hardness value still increased to 9.9 Shore A. Thus, the 5 phr silicone oil formulation is recommended as the optimal composition for realistic and economical injection training arm applications.
The Effect of Infill Variation on the Tensile, Bending, Impact, Hardness, and Density Properties of PLA and ABS Materials Produced by FDM Saeful Rofi Romadhon; Wahyu Hidayat; Baskara Surya Widagdo
Multidisciplinary Innovations and Research in Applied Engineering Vol. 2 No. 2 (2025)
Publisher : Akademi Inovasi Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.70935/1nh12096

Abstract

Additive Manufacturing (AM) or 3D printing using the Fused Deposition Modelling (FDM) method offers high flexibility in the production of polymer components through process parameter settings, one of which is the infill percentage that affects mechanical performance. This study analyzes the effect of infill variations (25%, 50%, 75%, 100%) on the mechanical properties of two popular thermoplastic materials, Polylactic Acid (PLA) and Acrylonitrile Butadiene Styrene (ABS). Testing was conducted according to ASTM standards, including tensile strength, bending strength, impact strength, hardness, and density. The results show that PLA has higher tensile strength (47–53 MPa), bending strength, and hardness compared to ABS (33–38 MPa). Conversely, ABS demonstrates better toughness through higher impact values, while the difference in density is relatively small and insignificant. Increasing the infill percentage is proven to enhance strength and hardness in both materials, but this is accompanied by an increase in material consumption. These findings indicate a trade-off between stiffness and toughness, so material selection must be tailored to application requirements. PLA is more suitable for precision components requiring dimensional stability, while ABS is recommended for applications with dynamic loads and impact risks. This study provides a practical foundation for optimizing FDM parameters, particularly material and infill, in engineering, medical, and consumer product applications.
Development of a 13 L Portable Sandblasting System: Design, Fabrication, and Surface Roughness Analysis on Aluminum Rofi Romadhon, Saeful; Sugiarto, Tris; Ismail, Adhan; Priwintoko, Baharudin
Creative Research in Engineering (CERIE) Vol. 6 No. 1 (2026): Creative Research in Engineering (CERIE)
Publisher : Lembaga Publikasi Ilmiah dan Penerbitan (LPIP)

Show Abstract | Download Original | Original Source | Check in Google Scholar

Abstract

Surface preparation plays a vital role in improving coating adhesion and corrosion resistance of metals. Conventional techniques such as sanding or chemical etching are often inefficient, hazardous, or unsuitable for small-scale workshops. Sandblasting provides a more effective solution; however, existing systems are typically bulky and costly. This study aimed to design and evaluate a portable dry sandblasting prototype with a 13 L pressure vessel and maximum operating pressure of 8 bar, developed using the Systematic Engineering Design Method. Aluminum specimens were blasted using silica sand (80 mesh) under varying air pressures (4, 5, and 6 bar) and nozzle distances (10, 15, and 20 cm), with spraying time fixed at 20 seconds. Surface roughness was measured with a Surfcorder Fowler SE1700 (JIS B 0601 standard), and macroscopic observations were performed to assess surface morphology. Results indicated that roughness increased with air pressure and decreased with nozzle distance. The untreated specimen had an Ra of 0.69 µm, rising to 7.92 µm at 6 bar and 10 cm. Several conditions, particularly ≥5 bar and ≤15 cm, produced Ra values above 5 µm, sufficient to improve coating adhesion. The study confirms the prototype’s effectiveness and novelty in combining design and validation, offering a compact, low-cost solution for SMEs and automotive workshops.
The Effect of Infill Variation on the Tensile, Bending, Impact, Hardness, and Density Properties of PLA and ABS Materials Produced by FDM Saeful Rofi Romadhon; Wahyu Hidayat; Baskara Surya Widagdo
Multidisciplinary Innovations and Research in Applied Engineering Vol. 2 No. 1 (2025)
Publisher : Akademi Inovasi Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.70935/1nh12096

Abstract

Additive Manufacturing (AM) or 3D printing using the Fused Deposition Modelling (FDM) method offers high flexibility in the production of polymer components through process parameter settings, one of which is the infill percentage that affects mechanical performance. This study analyzes the effect of infill variations (25%, 50%, 75%, 100%) on the mechanical properties of two popular thermoplastic materials, Polylactic Acid (PLA) and Acrylonitrile Butadiene Styrene (ABS). Testing was conducted according to ASTM standards, including tensile strength, bending strength, impact strength, hardness, and density. The results show that PLA has higher tensile strength (47–53 MPa), bending strength, and hardness compared to ABS (33–38 MPa). Conversely, ABS demonstrates better toughness through higher impact values, while the difference in density is relatively small and insignificant. Increasing the infill percentage is proven to enhance strength and hardness in both materials, but this is accompanied by an increase in material consumption. These findings indicate a trade-off between stiffness and toughness, so material selection must be tailored to application requirements. PLA is more suitable for precision components requiring dimensional stability, while ABS is recommended for applications with dynamic loads and impact risks. This study provides a practical foundation for optimizing FDM parameters, particularly material and infill, in engineering, medical, and consumer product applications.
Comparative Mechanical Performance of FDM-Printed PETG and ABS at Different Infill Percentages Saeful Rofi Romadhon; Baharudin Priwintoko; Wahyu Hidayat; Baskara Surya Widagdo
Multidisciplinary Innovations and Research in Applied Engineering Vol. 2 No. 2 (2025)
Publisher : Akademi Inovasi Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.70935/y4n8aq82

Abstract

The use of Fused Deposition Modeling (FDM) in additive manufacturing requires a material selection strategy that considers not only strength, but also the balance between stiffness, ductility, toughness, and surface resistance. This study evaluates the comparative mechanical performance of Acrylonitrile Butadiene Styrene (ABS) and Polyethylene Terephthalate Glycol (PETG) at 25%, 50%, 75%, and 100% infill using FDM printing and performance-map analysis. Specimens were designed according to ASTM standards and printed using the same printer, hexagonal infill pattern, print speed, and build orientation, while material-specific parameters such as extrusion temperature, heated bed temperature, layer height, first-layer height, enclosure, and cooling fan setting were adjusted according to ABS and PETG processing requirements. Mechanical characterization included tensile, flexural, impact, Shore D hardness, and density tests. The highest tensile strength was obtained by PETG at 100% infill, reaching 40.74 MPa, while ABS at the same infill reached 38.72 MPa. PETG also showed the highest elongation at break of 16.16%, flexural strength of 59.51 MPa, and impact strength of 0.053 J/mm². In contrast, ABS produced the highest surface hardness, reaching 84.17 Shore D at 100% infill, compared with 80.42 Shore D for PETG. The density values of both materials increased with infill and became similar at 100% infill, namely 1.00 g/cm³. These findings confirm a clear trade-off between strength, toughness, resilience, and hardness in FDM materials. PETG offers a more balanced mechanical profile for applications that require strength, deformation tolerance, and impact resistance, while ABS remains relevant for applications that prioritize rigidity and surface hardness.
Effect of Flow Rate Variation on Solar Water Heater Performance Baharudin Priwintoko; Agus Lutanto; Yusuf Subagyo; Saeful Romadhon; Agus Prasetyo
Multidisciplinary Innovations and Research in Applied Engineering Vol. 2 No. 2 (2025)
Publisher : Akademi Inovasi Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.70935/nrhaqe41

Abstract

Solar energy potential in Indonesia is very large, yet its utilization for daily thermal needs still requires improvement through simple, economical, and efficient collector designs. This study analyzes the effect of fluid flow-rate variation on the performance of a trickle-type solar water heater with a V-shaped collector under local outdoor testing conditions. The novelty of the work lies in the combined evaluation of a V-shaped zinc-sheet absorber, trickle-type flow arrangement, north-facing 30° collector orientation, and practical flow-rate range of 2, 4, 6, and 8 L/min. The outdoor experiment was conducted from 09:00 to 12:00 Western Indonesia Time with repeated field observations for each flow-rate condition. Inlet temperature, outlet temperature, ambient temperature, collector temperature, cover temperature, wind speed, and solar radiation intensity were recorded and processed to determine useful heat gain, heat absorbed by the fluid, collector efficiency, fluid heat-absorption efficiency, and total efficiency. The results show that a lower flow rate produces a greater increase in fluid temperature, but it does not always produce the highest total efficiency. The 4 L/min flow rate provided the best performance, with a total efficiency of 55%, fluid heat-absorption efficiency of 71%, average fluid heat-transfer rate of 559.53 W, and estimated test-period fluid energy of 1678.59 Wh (6.04 MJ) during the 3 h test period. These findings indicate an optimum balance between fluid residence time and mass flow rate in improving solar water heater performance.
Model Desentralisasi Program Makan Bergizi Gratis (MBG) Berbasis Sekolah: Memangkas Rantai Pasok dan Mencegah Penyelewengan Cahyo Wibowo; Muhammad Muryanto; Saeful Rofi Romadhon
Jurnal Pengabdian Masyarakat - PIMAS Vol. 5 No. 3 (2026): Agustus
Publisher : LPPM Universitas Harapan Bangsa Purwokerto

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.35960/pimas.v5i3.2671

Abstract

The Free Nutritious Meals Program (MBG), launched in January 2025, is one of the national priority programs with a budget of Rp223 trillion in 2026. However, its centralized implementation through the Nutrition Fulfilment Service Units (SPPG) faces various serious systemic problems. By the end of 2025, there were more than 20,000 reported cases of food poisoning, two fatalities, as well as chronic distribution delays, substandard nutritional quality, targeting inaccuracies, and corrupt practices involving non-essential actors. This article aims to formulate a school-based MBG decentralization model with three main pillars: (1) the phased elimination of all SPPGs, (2) the direct disbursement of funds from the National Nutrition Agency (BGN) to schools without intermediaries, and (3) a ban on the involvement of non-essential institutions in the distribution chain. The methods used include a projected case study with comparative policy analysis and a systematic literature review of 30 indexed journals from the past 10 years. The proposed model channels funds directly from the BGN to school accounts; preparation, cooking, and distribution are carried out on school premises with the rotating involvement of parents; raw material suppliers are selected from local farmers/vendors through a rotation system; monitoring is conducted by both the school committee and parents; and meal portions are adjusted according to the actual number of students present. This model recommends the phased discontinuation of the SPPG over a 6-month period, as well as the closure of the entire distribution chain involving non-essential actors. The main recommendation is a limited pilot program in 20–30 non-urban schools as the basis for reforming the national MBG governance system
Co-Authors Agus Lutanto Agus Prasetyo Bachtiar, Yuriz Baharudin Priwintoko Baskara Surya Widagdo Baskara Surya Widagdo Cahyo Wibowo Ismail, Adhan muhammad muryanto Prawibowo, Hartanto Priwintoko, Baharudin Rifky Ismail Tris Sugiarto Wahyu Hidayat Wahyu Hidayat Yusuf Subagyo