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All Journal Journal of Mechanical Engineering Science and Technology ComTech: Computer, Mathematics and Engineering Applications Abdi Dosen : Jurnal Pengabdian Pada Masyarakat Journal of Fibers and Polymer Composites
Wibowo, Robertoes Koekoeh Koentjoro
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Religion Humanities Computer Science & IT Education Energy Engineering Industrial & Manufacturing Engineering Materials Science & Nanotechnology Mathematics Mechanical Engineering Public Health Social Sciences

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Heat Treatment and Its Effect on Tensile Strength of Fused Deposition Modeling 3D-Printed Titanium-Polylactic Acid (PLA) Darsin, Mahros; Susanti, Rizqa Putri; Sumarji, Sumarji; Ramadhan, Mochamad Edoward; Sidartawan, Robertus; Yudistiro, Danang; Basuki, Hari Arbiantara; Wibowo, Robertoes Koekoeh Koentjoro; Djumhariyanto, Dwi
ComTech: Computer, Mathematics and Engineering Applications Vol. 15 No. 2 (2024): ComTech
Publisher : Bina Nusantara University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21512/comtech.v15i2.11255

Abstract

Titanium is a biocompatible metal commonly applied in biomedical fields such as bone and dental implants. Recently, the produced titanium-Polylactic Acid (PLA) filament for 3D printing Fused Deposition Modeling (FDM) technique is easier to operate and affordable. This filament contains less than 20% PLA, which is also biocompatible but hydrophobic and capable of producing inflammation of the surrounding artificial living tissue. Therefore, a heat treatment is needed to reduce or even eliminate PLA. The research aimed to optimize the mechanical properties and biocompatibility of titanium-PLA filaments through heat treatment, demonstrating significant advancements in 3D printing applications for biocompatible materials. A Thermogravimetric Analysis (TGA) was carried out to find out the right temperature for reducing PLA levels. Specimens were heat treated with four temperatures at 100oC, 160oC, 190oC, and 543oC, and two holding times of 60 and 120 minutes. The mass of the specimens was weighed before and after heat treatment to determine the mass reduction and tested for tensile, micrograph, and fractography observation. The result is a meagre mass reduction. The highest tensile strength of the heat-treated specimen with a heat treatment temperature of 160oC and a holding time of 60 minutes is 18.310 MPa. However, it is still below the strength of the non-heat treated specimen, 19.890 MPa. Specimens with low tensile strength have a microstructure that shows an uneven distribution of titanium particles. Last, fractography shows porosity in the specimens with the lowest tensile strength.
Optimization of the Number of Cylinder Blades in Coffee Pulper Machine: Finite Element Analysis and Simple Additive Weighting Methods Syahriza, Mochamad Rifki; Djumhariyanto, Dwi; Ilminnafik, Nasrul; Darsin, Mahros; Yudistiro, Danang; Basuki, Hari Arbiantara; Wibowo, Robertoes Koekoeh Koentjoro; Syuhri, Ahmad; Sumarji, Sumarji
Journal of Mechanical Engineering Science and Technology (JMEST) Vol 8, No 2 (2024)
Publisher : Universitas Negeri Malang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.17977/um016v8i22024p476

Abstract

The increasing interest in coffee in all circles means that coffee production and quality must always increase due to consumer demands. One way to maintain the quality of coffee beans is by breaking them down using a huller machine. This research aims to improve the optimization of coffee machines by modifying the cylinder blades of huller machines with variations of 3, 4, 5, and 7 cylinder blades in terms of static loading design and quality and production capacity of coffee bean breaking. The experiment was carried out using 400 rpm and breaking 10kg of dry coffee cherries every time the sample was taken. The research results show that the best sample collection is the variation of 3 cylindrical blades with the maximum stress and lowest deformation values of 6.67 MPa and 0.000737 mm. In terms of production quality, it shows that the best sampling was the three cylindrical blade variations with 50% whole and good coffee beans. In terms of production capacity, the most significant capacity was the seven cylindrical blade variations with a value of 294.11 kg/hour. Sampling from the four most optimal variations uses the SAW (Sample Additive Weighting) method. The most optimal result from the 4 test criteria, the variation of 3 cylindrical blades is the best because it has the highest score with a value of 0.9754.
Mechanical Characteristics of Stearic Acid Addition in Polylactic Acid (PLA) and Cassava Starch Bioplastic Blends Yusuf, Muhammad; Fatah, Ghaibi Alimul; Wibowo, Robertoes Koekoeh Koentjoro; Pradiza, Revvan Rifada; Ilyas, Rushdan Ahmad; Asrofi, Mochamad
Journal of Fibers and Polymer Composites Vol. 4 No. 2 (2025): Journal of Fibers and Polymer Composites
Publisher : Green Engineering Society

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.55043/jfpc.v4i2.264

Abstract

This study aims to determine the effect of adding stearic acid (SA) to a bioplastic mixture of cassava starch (CS) and polylactic acid (PLA). The bioplastic was produced using a solvent casting method. The addition of SA can affect the mechanical properties of the film. The maximum tensile strength of the film increased from 5.12 MPa (without SA) to 7.61 MPa (5% SA). The same trend also applies to the Young's modulus and elongation at break, which increased from 25.45 MPa and 20.17% to 35.02 MPa and 21.64% after the addition of 5% SA. This improvement in mechanical properties is supported by the compatibility of PLA and CS due to the optimal presence of SA. These findings prove that SA is an effective compatibilizer in improving the mechanical properties of PLA and CS-based bioplastics. The resulting film products have the potential to be used as environmentally friendly packaging materials that are competitive with synthetic materials such as Low-Density Polyethylene (LDPE) and Ethylene Vinyl Acetate (EVA).
DUAL-FUNCTION COFFEE SKIN PEELING MACHINE TO IMPROVE THE WELFARE OF SUMBERCANDIK COFFEE FARMERS JELBUK JEMBER Darsin, Mahros; Djumhariyanto, Dwi; Wibowo, Robertoes Koekoeh Koentjoro; Basuki, Hari Arbiantara; Danang Yudistiro, Danang Yudistiro; Lindriati, Triana
Abdi Dosen : Jurnal Pengabdian Pada Masyarakat Vol. 8 No. 1 (2024): MARET
Publisher : LPPM Univ. Ibn Khaldun Bogor

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.32832/abdidos.v8i1.2266

Abstract

Panduman Village, Jelbuk Jember District, is a fostered village by the University of Jember. Sumbercandik is one of the hamlets in Panduman Village with a geography of mountain slopes and hills and at an altitude that is very supportive for coffee farming/plantations. It is no wonder that the best coffee products are produced from this village. Ironically, the lives of many coffee farmers still fall into the pre-prosperous group. One of the reasons is that farmers sell coffee logs or wet-skinned coffee at relatively low prices. At the same time, factory-made chemical fertilizers have skyrocketed in price, and availability is strict. Various efforts have been made by the local government and other service teams related to these coffee farmers, but they have not touched those in Sumbercandik Hamlet. This community service seeks to uplift the economy of Panduman Village, especially the coffee farmers of Sumbercandik Hamlet, with the introduction of post-harvest coffee technology, utilization of coffee waste for fertilizer and briquettes, and management and cooperatives. This grant ceiling will carry out the proposal in three years. The first year was with the introduction of post-harvest technology in the form of wet and dry skin stripping (horn skin). In the second year, intensive drying techniques using technical and thermal methods. In addition, farmer group formation and simple production management. Year three, post-harvest waste processing technology. The first year's focus was on providing a coffee skin peeling machine. Each year will involve different lecturers with agricultural, management and cultural competencies. This activity is in line with the 2021-2025 RIPP of the University of Jember with the featured topic "Development of people's coffee towards an organic system to improve community welfare".
SUSTAINABLE FARMING THROUGH COMMUNITY EFFORTS: THE IMPACT OF ORGANIC COMPOSTING IN KUWON VILLAGE, MAGETAN REGENCY, INDONESIA Darsin, Mahros; Basuki, Hari Arbiantara; Djumhariyanto, Dwi; Yudistiro, Danang; Wibowo, Robertoes Koekoeh Koentjoro; Elhamzah, Denaldy Elza Setya; Yahya, Hafiz Indratma; Rossy, Rio Martha Febriana; Salmansyah, Dathantara; Rizal, Ahmad Ayyub Syaiful
Abdi Dosen : Jurnal Pengabdian Pada Masyarakat Vol. 9 No. 1 (2025): MARET
Publisher : LPPM Univ. Ibn Khaldun Bogor

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.32832/abdidos.v9i1.2566

Abstract

This paper presents a community engagement initiative in Kuwon Village, Magetan Regency, aimed at enhancing agricultural productivity through compost production mechanization. The project, a collaboration between university researchers and local farmers, introduced organic composting techniques using a specially designed compost chopper machine. The initiative sought to address the challenges of high fertilizer costs and limited subsidized fertilizers, promoting sustainable agricultural practices and improving farmers' livelihoods. The primary goal was to provide an efficient, cost-effective method for producing organic compost, reducing dependency on chemical fertilizers, and improving soil health. The project followed a participatory approach, involving farmers at every stage—from needs assessment to design, fabrication, training, and implementation—ensuring solutions suited to the local community's needs. The compost chopper machine reduced time and labor in compost production, and farmers reported improved soil health and higher crop yields. The project also fostered community collaboration as farmers worked together to adopt new practices. Economic benefits included lower input costs and increased income from higher productivity. The success of this initiative highlights the potential of combining technological innovation with community involvement to tackle challenges faced by rural farmers in Indonesia, promoting sustainable agricultural development and improving livelihoods.
Co-Authors Ahmad Syuhri Danang Yudistiro Danang Yudistiro, Danang Yudistiro Dwi Djumhariyanto Elhamzah, Denaldy Elza Setya Fatah, Ghaibi Alimul Hari Arbiantara Basuki Ilyas, Rushdan Ahmad Mahros Darsin Mochamad Asrofi Mochamad Edoward Ramadhan Muhammad Yusuf Nasrul Ilminnafik Pradiza, Revvan Rifada Rizal, Ahmad Ayyub Syaiful Robertus Sidartawan Rossy, Rio Martha Febriana Salmansyah, Dathantara Sumarji Susanti, Rizqa Putri Syahriza, Mochamad Rifki Triana Lindriati Yahya, Hafiz Indratma