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All Journal JPSE (Journal of Physical Science and Engineering) Metal Indonesia Jurnal TAMBORA JURNAL TEKNIK Specta Journal of Technology Jurnal Konversi Energi dan Manufaktur Bima Abdi: Jurnal Pengabdian Masyarakat Jurnal Pijar MIPA JURNAL TEKNIK INDUSTRI Hexagon AMMA : Jurnal Pengabdian Masyarakat
Fauzi Widyawati
Metallurgical Engineering Study Program, Faculty Of Environmental And Mineral Technology, Sumbawa University Of Technology
Aerospace Engineering Agriculture, Biological Sciences & Forestry Humanities Astronomy Automotive Engineering Biochemistry, Genetics & Molecular Biology Chemical Engineering, Chemistry & Bioengineering Chemistry Civil Engineering, Building, Construction & Architecture Computer Science & IT Control & Systems Engineering Decision Sciences, Operations Research & Management Economics, Econometrics & Finance Education Electrical & Electronics Engineering Energy Engineering Environmental Science Industrial & Manufacturing Engineering Languange, Linguistic, Communication & Media Law, Crime, Criminology & Criminal Justice Materials Science & Nanotechnology Mathematics Mechanical Engineering Nursing Physics Other

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Fabrication of Fe3O4/PEG 4000/Oleic Acid Ferrofluids on Crystal Structure and Magnetic Properties Using Rhee Sumbawa Iron Sand Bahtiar, Syamsul; Islam, Izzul; Jayatri, Adella Ulyandana; Widyawati, Fauzi; Yanuar, Emsal
Jurnal Pijar Mipa Vol. 20 No. 1 (2025)
Publisher : Department of Mathematics and Science Education, Faculty of Teacher Training and Education, University of Mataram. Jurnal Pijar MIPA colaborates with Perkumpulan Pendidik IPA Indonesia Wilayah Nusa Tenggara Barat

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.29303/jpm.v20i1.8108

Abstract

The fabrication of ferrofluid using Fe3O4 nanoparticles synthesized from Rhee Sumbawa iron sand has been successfully carried out. This fabrication was conducted to study the crystal structure characteristics and magnetic properties of the ferrofluid from Rhee iron sand. The fabrication used the co-precipitation method at room temperature to synthesise Fe3O4 nanoparticles. In contrast, the ferrofluid fabrication employed a magnetic stirrer with the addition of PEG 4000/Oleic Acid as a surfactant. The structure and magnetic characteristics of the Fe3O4/PEG 4000/AO ferrofluid will be investigated in this work. The results of the XRF characterization show an Fe content of 91.73%, indicating that the purity of Fe has been successfully increased using a permanent magnet separation method. The XRD characterization results show the formation of a cubic crystal system with lattice parameters a=b=c = 9.3797 Å, α=β=γ = 90°, and the crystal size obtained from the refinement is 8.42 nm. The TEM characterization results indicate that the morphology of the nanoparticles is spherical with a particle size of 7.34 nm. The VSM characterization results obtained the ferrofluid magnetization value in the 0.08–0.34 emu/g range.
Synthesis of Cellulose from Decorticated Sisal Plants (Agave sisalana) using the Acid Hydrolysis Method Widyawati, Fauzi; Hidayat, Syamsul; Wiradana, Aditya; Setyaningtyas, Ayunda Kinasih; Bahtiar, Syamsul; Yanuar, Emsal
Jurnal Pijar Mipa Vol. 20 No. 3 (2025)
Publisher : Department of Mathematics and Science Education, Faculty of Teacher Training and Education, University of Mataram. Jurnal Pijar MIPA colaborates with Perkumpulan Pendidik IPA Indonesia Wilayah Nusa Tenggara Barat

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.29303/jpm.v20i3.8099

Abstract

Sisal Plant Production Process (Agave sisalana) produces waste of around 95%, which is wasted and can be an environmental problem because it is not processed properly. Sisal decortication waste contains active biochemical compounds, one of which is cellulose, which has the potential to be used in various fields. Cellulose is one of the most widely distributed and abundant biopolymers on Earth, as the main source of renewable materials obtained from plant fibers. Initial Treatment of Fiber Alkalization using 5% NaOH solution (1:20) for 2 hours at a temperature of 80 °C at a speed of 200 rpm. Then the bleaching process(bleaching). Samples of the results of alkalization treatment using hydrogen peroxide solution (H2THE23%) at a temperature of 80 °C for 3 hours, repeated once. In the Acid Hydrolysis process, the resulting sample is bleached with acid using sulfuric acid (H2SO465%) at a temperature of 80 °C for 1 hour (1:20). Sample Characterization Fiber characterization using the NDF test to determine cellulose content. The results of the cellulose content test in sisal fiber decortication waste were 1.545 mg/L Based on the results of the study, nanocellulose with a high % crystallinity was successfully extracted from sisal fiber decortication waste using a chemical treatment method. The FTIR spectrum shows a broad band at 3358-3410 cm-1which is the vibration of the OH group of cellulose. The removal of lignin levels was successfully carried out, showing that the peak of the spectrum band produced was only 1279.26 cm-1. The average size of nanocellulose particles is around 10-30 nm and consists of 30-100 cellulose molecules.
Preparation of synthesis nanoparticles Fe3O4 based on iron sand Sumbawa Bahtiar, Syamsul; Widyawati, Fauzi; Yanuar, Emsal; Ramadhan, Risky; Zahra, Karen; Hidayat, Syamsul
Jurnal Pijar Mipa Vol. 18 No. 6 (2023): November 2023
Publisher : Department of Mathematics and Science Education, Faculty of Teacher Training and Education, University of Mataram. Jurnal Pijar MIPA colaborates with Perkumpulan Pendidik IPA Indonesia Wilayah Nusa Tenggara Barat

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.29303/jpm.v18i6.5644

Abstract

Iron sand generally contains minerals such as ilmenite, magnetite, and hematite. Based on the results of previous tests, the main composition of iron sand in Rhee, Sumbawa regency, is magnetite. One method to increase the Fe content in iron sand is by pre-treatment with NaOH. NaOH is also used to precipitate heavy metals in a mineral. In this study, three variations were carried out with the ratio of NaOH: iron sand, namely: 1: 4, 2: 4, and 3: 4 at a temperature of 300 C. Furthermore, the calcination results were followed by the synthesis of Fe3O4 nanoparticles using the coprecipitation method. The results of the XRF characterization showed an increase in Fe levels after being processed by the alkalization treatment. The highest concentration was obtained in 1:4, with a Fe percentage of 91.1%. The results of the XRD characterization showed that the synthesis of Fe3O4 was successfully carried out with single phase Fe3O4 amlording to the data reference 96-9005839 forms and the space group F d -3 m. Crystal size analysis Using the Debey-Scherrer equation, the respective sizes were 12.7 nm, 8.71 nm, and 9.76 nm, respectively.
Waste cellulose extraction and analysis decortication sisal plant (Agave sisalana) Sumbawa Labangka Widyawati, Fauzi; Malik Fajar Fatoni; Emsal Yanuar; Hidayat, Syamsul
Jurnal Pijar Mipa Vol. 18 No. 6 (2023): November 2023
Publisher : Department of Mathematics and Science Education, Faculty of Teacher Training and Education, University of Mataram. Jurnal Pijar MIPA colaborates with Perkumpulan Pendidik IPA Indonesia Wilayah Nusa Tenggara Barat

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.29303/jpm.v18i6.6065

Abstract

Waste utilization of decortication Sisal plants is minimal compared to the amount of waste produced, especially the cellulose content in the waste decortication sisal plant. This research aims to extract waste cellulose decortication sisal plants using acid and alkaline solutions with variations in NaOH solutions of 0%, 2%, 4%, 6%, and 8%. The process used is alkalization, bleaching, and acid hydrolysis by method analysis. Next, testing using SEM and FTIR methods is done to determine the morphology of waste cellulose decortication in the resulting sisal plants and the cellulose, lignin, and hemicellulose content in the waste decortication sisal plant. Before treatment, the cellulose content of the waste is given to decorticate the sisal plant at 31%, and after alkalization treatment, the cellulose content is 54%. Cellulose content in waste decortication Sisal plants in each process increases with found O-H bonds at waves 3000-3600 cm-1, C-H bonds belong to hemicellulose at wave numbers 2800-3000 cm-1 and remove lignin, which is in the waste decortication Sisal plants did not find C=C bonds belonging to lignin at waves of 1200-1300 cm-1. FTIR test results show an increase in cellulose intensity, with the resulting cellulose measuring 28.64762 µm and 33.69369 µm. The increase in cellulose intensity in FTIR is directly proportional to the SEM results, which show a loose layer with lignin and hemicellulose that has been eroded from the cellulose.
PENGARUH FRAKSI VOLUME SERAT SISAL DAN FILLER SERBUK KAYU JATI TERHADAP KEKUATAN TEKAN DAN TARIK PAPAN KOMPOSIT Dwi Nurul Fitriah Assyurah; Rita Desiasni; Fauzi Widyawati
Hexagon Vol 5 No 1 (2024): HEXAGON - Edisi 9
Publisher : Fakultas Teknologi Lingkungan dan Mineral - Universitas Teknologi Sumbawa

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.36761/hexagon.v5i1.3147

Abstract

Semakin meningkatnya permintaan akan bahan material ramah lingkungan untuk mengurangi dampak negatif terhadap kualitas udara global, kesehatan dan iklim global. Beberapa peneliti mulai fokus pada komposit berbasis biokomposit. Komposit dari serat alam dan partikel alam merupakan salah satu alternatif untuk komposit polimer karena keunggulannya dibandingkan dengan serat sintetis. Pada penelitian ini fraksi volume yang digunakan antara serat sisal dan serbuk kayu jati yaitu 5% serat : 15% partikel, 10% serat : 10% partikel, dan 15% serat : 5% partikel dengan volume resin tetap yaitu 80% menggunakan standar ASTM untuk uji bending dan uji tarik. Dari pengujian yang dilakukan, akan didapatkan beberapa data hasil pengujiam, nilai uji bending yaitu MOE teringgi pada variasi 15% serat : 5% partikel dengan nilai 6334,67 MPa dan nilai MOR sebesar 98,21 MPa diikuti dengan hasil terrendah pada variasi 5% serat : 15% partikel dengan nilai MOE sebesar 3987,13 MPa dan nilai MOR sebesar 68,19 MPa. Pada uji tarik didapatkan hasil tertinggi pada variasi 15% serat : 5% partikel dengan nilai nilai tegangan sebesar 71,36 MPa, regangan sebesar 1,61%, dan modulus elastisitas memperoleh nilai sebesar 44,31 GPa, pada variasi 10% serat : 10% partikel diperoleh hasil uji tarik terendah nilai tegangan 50,26 MPa, regangan sebesar 1,34%, dan modulus elastisitas sebesar 37,56 GPa. Hasil dari pengujian menunjukkan bahwa semakin meningkatnya fraksi volume serat membuat kekuakatan mekanik komposit semakin tinggi, penambahan serbuk kayu sebagai campuran filler komposit berfungsi untuk mengisi kekosongan pada pada selah-selah serat dan matriks saat proses pembuatan komposit.
Pengaruh Komposisi Serat Sisal Terhadap Konduktivitas Termal Dan Penyerapan Suara Papan Komposit fatmawati hendrik fatma; Fauzi Widyawati
Hexagon Vol 5 No 1 (2024): HEXAGON - Edisi 9
Publisher : Fakultas Teknologi Lingkungan dan Mineral - Universitas Teknologi Sumbawa

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.36761/hexagon.v5i1.3250

Abstract

Thermal conductivity and sound absorption are two key characteristics in the development of innovativecomposite materials. Thermal conductivity reflects a material's ability to conduct heat from one place toanother, while sound absorption indicates a material's ability to absorb sound waves. Composite boardsare increasingly popular in various applications, especially in the furniture industry, as they creatematerials with superior properties compared to single materials used in their production. Previousresearch has identified the potential of natural fibers as reinforcement in composite boards due to theireco-friendly and biodegradable nature. However, research combining thermal conductivity and soundabsorption in composite boards with natural fibers is still limited. This study aims to explore the influenceof various compositions of sisal fibers on the thermal conductivity and sound absorption of compositeboards. Sisal fibers were chosen as the reinforcement due to their eco-friendly nature, low density, specific strength, and high modulus. The results show a significant increase in thermal conductivity ofcomposite boards at 10% to 30% volume fraction of sisal fibers. The uniform distribution of sisal fiberswithin the composite matrix and good fiber orientation enhance the heat transfer efficiency in thecomposite. Sound absorption testing reveals that composite boards with 30% volume fraction of sisalfibers have the highest sound absorption coefficient, 0.494 at 200 Hz, while those with 10% volumefraction have the lowest coefficient, 0.059 at 800 Hz. This study unveils the potential of sisal fibercomposite boards as an eco-friendly alternative material with good thermal conductivity and effectivesound absorption. The findings are expected to contribute to the development of high-performancecomposite materials for various applications, including construction and furniture. Further research isneeded to optimize the performance of this material and explore its potential in broader industrial andenvironmental contexts.
PENGARUH VARIASI VOLUME LIMBAH SERBUK KAYU MAHONI DENGAN PERLAKUAN ALKALI TERHADAP KEKUATAN MEKANIK DAN MIKROSTRUKTUR KOMPOSIT PARTIKEL fatmawati hendrik fatma; Rita Desiasni; Fauzi Widyawati
Hexagon Vol 5 No 1 (2024): HEXAGON - Edisi 9
Publisher : Fakultas Teknologi Lingkungan dan Mineral - Universitas Teknologi Sumbawa

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.36761/hexagon.v5i1.3636

Abstract

The strength of the mechanical and physical properties of particle composite materials is influenced by the volume fraction of the powder and matrix. Fraction variations used are 30:70%, 50:50%, and 70:30% with the hand lay up method. The pretreatment was carried out by soaking 2% NaOH for 1 hour. The results of the MOE treatment mechanical test received the highest test value at the powder volume fraction of 30:70%, which was 6145.51 kgf/cm² and the highest MOR test value at the 30:70% volume fraction, which was 167.38 kgf/cm². Meanwhile, the highest non-treatment MOE value at the 30:70% powder volume fraction was 5540.9 kgf/cm² and the highest MOR test value at the 30:70% volume fraction was 156.6 kgf/cm². The results of the physical properties test were the highest density at the 30:70% powder volume fraction of 0.87 gr/cm³ and the highest density at the 30:70% non-treatment powder volume fraction of 0.78 gr/cm³. The results of the MOE mechanical test do not meet the JIS A 5908-2003 standard while the MOR mechanical test and physical test have met the JIS A 5908- 2003 standard. The results of microstructure testing showed that at a fraction of powder volume of 30:70% it was seen that the particles were coarser which blended perfectly with the matrix. Meanwhile, in the volume fraction of non-treatment powder 30:70% it looks finer particles and powders with a matrix seem to not glue well, this is because of the wax coating on the powder.
ANALISIS PENGARUH KONSENTRASI SIANIDA DAN RASIO PADAT CAIR PADA PROSES PELINDIAN EMAS DARI BIJIH EMAS DESA MOKONG Emsal Yanuar; Anggina Kalara; Kholida Tul Khairy; Syamsul Bahtiar; Fauzi Widyawati
Hexagon Vol 7 No 1 (2026): EDISI 11
Publisher : Fakultas Teknologi Lingkungan dan Mineral - Universitas Teknologi Sumbawa

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.36761/hexagon.v7i1.7176

Abstract

Emas merupakan logam mulia bernilai ekonomi tinggi yang dimanfaatkan secara luas dalam berbagai bidang, seperti perhiasan, elektronik, kesehatan, dan teknologi. Peningkatan produksi emas di Indonesia selama sepuluh tahun terakhir mendorong aktivitas eksploitasi di berbagai daerah, termasuk Desa Mokong, Kecamatan Moyo Hulu. Pengolahan emas di wilayah ini umumnya masih menggunakan metode amalgamasi yang memiliki tingkat toksisitas tinggi dan efisiensi ekstraksi yang rendah, sehingga diperlukan metode alternatif yang lebih efektif, seperti sianidasi. Penelitian ini bertujuan untuk menganalisis pengaruh konsentrasi natrium sianida (NaCN), rasio padat–cair, dan waktu pelindian terhadap persen ekstraksi emas. Variasi konsentrasi NaCN yang digunakan adalah 250, 500, dan 750 ppm dengan rasio padat–cair 1:10, 1:15, dan 1:20 serta waktu pelindian 0,5; 6; 12; 24; dan 48 jam. Hasil penelitian menunjukkan bahwa peningkatan konsentrasi NaCN dan rasio padat–cair secara signifikan meningkatkan persen ekstraksi emas. Kondisi optimum diperoleh pada konsentrasi NaCN 750 ppm dengan rasio padat–cair 1:20 selama 48 jam, menghasilkan persen ekstraksi emas sebesar 91%. Hasil penelitian ini diharapkan dapat menjadi dasar pengembangan teknologi pengolahan emas yang lebih efektif dan berkelanjutan, khususnya bagi pertambangan emas skala kecil.
Pembinaan Dan Penerapan Mesin Pencacah Limbah Pertanian Bagi Kelompok Petani Di Kab. Rejang Lebong Prayoga Setyawan, Harry; Widyawati, Fauzi; Setiawan, Apri; Maksum, Hanni
AMMA : Jurnal Pengabdian Masyarakat Vol. 4 No. 12 : Januari (2026): AMMA : Jurnal Pengabdian Masyarakat
Publisher : CV. Multi Kreasi Media

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

Abstract

The agricultural sector in Babakan Baru Village faces significant challenges in managing crop residues, which are traditionally burned, leading to environmental pollution. This Community Service (PkM) program implements Appropriate Technology (TTG) through an agricultural waste shredding machine to enhance farmers' productivity and self-sufficiency. The methodology involves partner coordination, CAD-based design, manufacturing, technical assistance, and operational training. The project successfully developed a shredder unit with a 100 kg/hour capacity powered by a 7.5 HP gasoline engine. This implementation delivers transformative impacts: technically, it increases the efficiency of converting waste into compost raw materials, while economically, it reduces dependence on commercial chemical fertilizers. Furthermore, the training improved the farmer groups' human resource capacity regarding machine maintenance and Occupational Health and Safety (OHS) procedures. Overall, the program fosters sustainable agricultural modernization that is environmentally friendly and economically beneficial in Rejang Lebong Regency.
Effectiveness of Epoxy Coating on Metal Surfaces of NEW773CAT Heavy Equipment Units Subeno, Agus; Setiawan, Angga; Okviyanto, Toni; Sumarna, Herlin; Setiawan, Dibyo; Widyawati, Fauzi
Jurnal Konversi Energi dan Manufaktur Vol. 11 No. 1 (2026)
Publisher : Universitas Negeri Jakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21009/JKEM.11.1.6

Abstract

This study investigates the effectiveness of the epoxy coating system on NEW773CAT heavy equipment unit operating in a mining environment. The research primarily focuses on the influence of surface preparation methods, dry film thickness (DFT), and coating type on corrosion resistance and adhesion strength. Field case studies, thickness measurements, and visual inspections were employed to assess the performance of coating system. The results reveal that average coating thickness of 396 μm significantly exceeds the minimum ISO 12944 category C5-I standard, which specifies a DFT of 320-400 μm for high corrosivity environments. The surface preparation process using high-pressure cleaning and power tool cleaning (ST 3.0) was found to produce an ideal substrate for epoxy coating application. The use of high-built epoxy mastic as the primer and Aliphatic Polyurethane as the top coat demonstrated excellent corrosion protection and optimal interlayer adhesion. The spray application technique resulted in a uniform coating with no visible defects. This study emphasizes the importance of combining effective surface preparation and precise coating specifications to ensure long-term protection of metal surfaces in harsh environments. The findings suggest that epoxy coating systems, when correctly applied and prepared, can provide robust protection against corrosion, extending the service life of heavy equipment exposed to aggressive conditions like those found in mining operations.
Co-Authors Amirin Kusmiran Andani Nurul Hidayah Angga Setiawan Anggina Kalara Bahtiar, Syamsul Chandra, Rico Dian Anggreini Dwi Nurul Fitriah Assyurah fatmawati hendrik fatma Hermanto, Koko I Putu Widiantara Imam Wierawansyah Eltara izzul islam Jayatri, Adella Ulyandana Kholida Tul Khairy Maksum, Hanni Malik Fajar Fatoni Marano, Lino Maulana Malik Ibrahim Muhammad Hisyam Muhammad Nurdin Muhammad, Saiful Musbihin Musbihin Nabila, Maitsa Fikri Nur Azman Okviyanto, Toni Prayoga Setyawan, Harry Ramadhan, Risky Ridwan Tanjung Rita Desiasni Rita Desiasni Riza Monica Setiawan, Apri setiawan, Dibyo Setyaningtyas, Ayunda Kinasih Shinta Esabella Solahudin, Muhammad Miftah Subeno, Agus Sumarna, Herlin Supianto Cibro Syamsul Bahtiar Syamsul Bahtiar SYAMSUL HIDAYAT Syamsul Hidayat Syamsul Hidayat Syamsul Hidayat Wafdan Muzakki Wiradana, Aditya Yanti, Sahri Yanuar, Emsal Yuliana Fitri Sersaningsih Zahra, Karen