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All Journal Reaktor International Journal of Renewable Energy Development TEKNIK Rotasi METANA BERKALA FISIKA JURNAL KIMIA SAINS DAN APLIKASI JURNAL TEKNOLOGI KIMIA DAN INDUSTRI Analisis: Jurnal Studi Keislaman Geoplanning : Journal of Geomatics and Planning Jurnal Riset Pendidikan Matematika Jurnal Riset Industri Mesin JUPE : Jurnal Pendidikan Mandala Universitas Muhammadiyah Yogyakarta Undergraduate Conference Proceeding Jurnal Sosial dan Sains International Journal of Renewable Energy Development Bulletin of Chemical Reaction Engineering & Catalysis Journal of Chemical Engineering Research Progress JURNAL REKAYASA KIMIA & LINGKUNGAN
I. Istadi
Department Of Chemical Engineering, Diponegoro University, Jl. Prof. Soedarto, Kampus UNDIP Tembalang, Semarang 50239
Agriculture, Biological Sciences & Forestry Astronomy Chemical Engineering, Chemistry & Bioengineering Chemistry Civil Engineering, Building, Construction & Architecture Computer Science & IT Control & Systems Engineering Decision Sciences, Operations Research & Management Earth & Planetary Sciences Economics, Econometrics & Finance Education Electrical & Electronics Engineering Energy Engineering Environmental Science Industrial & Manufacturing Engineering Law, Crime, Criminology & Criminal Justice Library & Information Science Materials Science & Nanotechnology Mathematics Mechanical Engineering Physics Public Health Social Sciences

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Backmatter (Publication Ethics, Right Transfer Agreement for Publishing Form) Istadi, Istadi
Bulletin of Chemical Reaction Engineering & Catalysis 2025: BCREC Volume 20 Issue 3 Year 2025 (October 2025)
Publisher : Masyarakat Katalis Indonesia - Indonesian Catalyst Society (MKICS)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.9767/bcrec.20481

Abstract

Backmatter (Publication Ethics, Right Transfer Agreement for Publishing Form)
Steady-State and Dynamic Simulation Study of Reactive Distillation for FFA Esterification in Biodiesel Synthesis Kusumaningtyas, Ratna Dewi; Prasetiawan, Haniif; Nugroho, Daniel Setiyo; Wulandari, Ajeng Riswanti; Istadi, Istadi; Hisyam, Anwaruddin
Jurnal Rekayasa Kimia & Lingkungan Vol 16, No 1 (2021): Jurnal Rekayasa Kimia & Lingkungan (June, 2021)
Publisher : Chemical Engineering Department, Syiah Kuala University, Banda Aceh, Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.23955/rkl.v16i2.19857

Abstract

Reactive distillation (RD) holds promise for process intensification in biodiesel production since it integrates reaction and separation. It simplifies the process and enhances the conversion of the equilibrium limited reactions. To ensure the stability in RD operation, sensitivity study and process control simulation are necessary. In this work, RD was employed for free fatty acid (FFA) esterification of mixed non edible oils in biodiesel synthesis. Non edible oils used were waste cooking oil, crude jatropha oil, and crude nyamplung oil (Calophyllum inophyllum L). Simulation was conducted using ASPEN Plus V8.8. Sensitivity study was carried out to determine the effects of the operating condition alteration. A dynamic simulation was performed as a Proportional-Integral-Derivative (PID) controller tuning. It was revealed that the highest FFA conversion was 85%, achieved at the feed stage of 7, distillate rate of 0.22 kmol/hr, and oil to methanol molar ratio of 1:5. Level, pressure and temperature controls were installed in RD. Then, a dynamic simulation was applied as a PID controller tuning. Three different controller tuning methods, viz. Ziegler-Nichols, Cohen-Coon, and Internal Model Control, were studied. The best PID parameter was obtained by using Cohen-Coon method which provided fastest rise time, lowest settling time and lowest overshoot.
Kemampuan Pemecahan Masalah Matemtis Pada Materi Teorema Pyhtagoras Ditinjau Dari Gaya Belajar Visual Dan Auditorial Siswa Kelas Viii Di Smp Negeri 2 Sampit Rakhmawati, Astri; Istadi, Istadi; Astuti, Fajar
JUPE : Jurnal Pendidikan Mandala Vol 8, No 2 (2023): JUPE : Jurnal Pendidikan Mandala (Juni)
Publisher : Lembaga Penelitian dan Pendidikan Mandala

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.58258/jupe.v8i2.5559

Abstract

Penelitian ini bertujuan untuk mendeskripsikan kemampuan pemecahan masalah matematis siswa ditinjau dari gaya belajar. Penelitian ini adalah penelitian kualitatif dengan pendekatan deskripsi kualitatif. Penelitian ini dilaksanakan di SMP Negeri 2 sampit. Subjek penelitian ini adalah 6 orang siswa dari 31 siswa dikelas VIII ruang A, 2 subjek visual dan 2 subjek auditorial. Instrumen yang digunakan yaitu angket gaya belajar, tes soal, dan wawancara. Data diperoleh dianalisis dengan cara reduksi data, penyajian data, dan penarik kesmpulan. Pengecekan keabsahan data menguunakan teknik triagulasi. Pemecahan masalah matematis dianalisis berdasarkan 4 indikator menurut Polya yaitu: (1) memahami masalah, (2) merencanakan pemecahan masalah, (3) menyelesaikan rencana pemecahan masalah, (4) mengecek/memeriksa kembali. Kemampuan pemecahan masalah matematis merupakan permasalahan yang diarahkan untuk mendapatkan suatu jawaban dengan cara berpikir. Berdasarkan hasil analisis data pemecahan masalah matematis siswa dengan menggunakan langkah Polya ditinjau dari gaya belajar adalah (1) Pada subjek SV1 dengan gaya belajar visual mampu dalam memahami masalah dengan cara membaca soal didalam hati, melakukan perencanaan pemecahan masalah, mampu melakukan perhitungan dengan tepat, dan tidak melakukan pemeriksaan kembali. Pada subjek SV2 dengan gaya belajar visual mampu dalam memahami masalah, melakukan perencanaan pemecahan masalah, belum mampu melakukan perhitungan dengan tepat, dan tidak melakukan pemeriksaan kembali. (2) Pada subjek SA1 dengan gaya belajar auditorial mampu dalam memahami masalah, melakukan perencanaan pemecahan masalah, mampu melakukan perhitungan dengan tepat, dan mampu melakukan pemeriksaan kembali hanya saja pada soal nomor 1 saja. Pada subjek SA2 dengan gaya belajar auditorial tidak mampu dalam memahami masalah dengan cara membaca soal didalam hati, melakukan perencanaan pemecahan masalah, mampu melakukan perhitungan dengan tepat, dan melakukan pemeriksaan kembali.
Backmatter (Publication Ethics, Copyright Transfer Agreement for Publishing Form) Istadi, Istadi
Bulletin of Chemical Reaction Engineering & Catalysis 2023: BCREC Volume 18 Issue 4 Year 2023 (December 2023)
Publisher : Masyarakat Katalis Indonesia - Indonesian Catalyst Society (MKICS)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.9767/bcrec.20083

Abstract

Backmatter (Publication Ethics, Copyright Transfer Agreement for Publishing Form)
Backmatter (Publication Ethics, Right Transfer Agreement for Publishing Form) Istadi, Istadi
Bulletin of Chemical Reaction Engineering & Catalysis 2025: BCREC Volume 20 Issue 4 Year 2025 (December 2025)
Publisher : Masyarakat Katalis Indonesia - Indonesian Catalyst Society (MKICS)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.9767/bcrec.20520

Abstract

Backmatter (Publication Ethics, Right Transfer Agreement for Publishing Form)
Comparative Study on the Characteristics and Performance of Ni-Impregnated and Non-Impregnated Natural Zeolite Catalysts in the Hydrocracking of Palm Oil to Biofuels Istadi, Istadi; Riyanto, Teguh; Salsabilla, Alda; Qotrunnada, Novaya Aulia
Journal of Chemical Engineering Research Progress 2025: JCERP, Volume 2 Issue 2 Year 2025 (December)
Publisher : UPT Laboratorium Terpadu, Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.9767/jcerp.20527

Abstract

A catalyst was synthesized from Bayah’s natural zeolite with low crystallinity and uneven pore distribution. To overcome these limitations, the Bayah natural zeolite was subjected to activation and modification processes aimed at increasing its surface area, improving pore structure, and enhancing overall catalytic activity by impregnating with nickel metal which is active catalyst for cracking reaction. Therefore, this study compares the Ni-impregnated Bayah Natural Zeolite (Ni/ZAA) and non-impregnated Bayah Natural Zeolite (Ni/ZAA) with respect to performance of the hydrocracking of palm oil to biofuels (gasoline, kerosene, and diesel). The natural zeolite was pretreated via desilication using NaOH, followed by calcination. Ni was introduced into the zeolite through ultrasonic-assisted impregnation, and the resulting catalysts were characterized using XRD and XRF techniques. Hydrocracking was conducted at 500 °C with a WHSV of 0.1 min⁻¹ using both Ni/ZAA and non-impregnated ZAA catalysts. The liquid products were analyzed by GC-MS to determine selectivity and yield, including coke and gas formation. The desilication process enhanced slightly the Si/Al ratio and catalytic properties of the Bayah zeolite. While Ni impregnation was achieved, suboptimal processing conditions affected the quality of the resulting catalysts. Increasing Ni content improved crystallinity and catalytic activity but also promoted coke formation, which reduced reaction efficiency and liquid product yield. The highest biofuel yield was obtained using the non-impregnated ZAA catalyst, while the 10% Ni/ZAA catalyst showed reduced yield due to excessive coking and pore blockage. These findings suggest that while Ni enhances catalytic activity, excessive loading can lead to overactivity and reduced performance in biofuel production. Copyright © 2025 by Authors, Published by Universitas Diponegoro and BCREC Publishing Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).
Enhancing hierarchical factor (HF) and catalytic performance of Bayah’s natural zeolite catalyst for hydrocracking of palm oil to biofuels Istadi, Istadi; Alqurni, Wais; Riyanto, Teguh
International Journal of Renewable Energy Development Vol 15, No 2 (2026): March 2026
Publisher : Center of Biomass & Renewable Energy (CBIORE)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.61435/ijred.2026.61669

Abstract

This study investigates enhancement of Bayah’s Natural Zeolite (BNZ), an abundant resource from Banten, Indonesia, as a catalyst for hydrocracking palm oil into biofuels. The primary objective was to improve the zeolite's Hierarchical Factor (HF) and overall catalytic performance through a targeted modification process. The modification involved a two-step procedure: a desilication treatment using various concentrations of sodium hydroxide (NaOH) to create mesoporosity, followed by activation with an ammonium acetate (CH₃COONH₄) solution. The structural, textural, and chemical properties of the modified catalysts were systematically characterized using X-ray Diffraction (XRD), X-ray Fluorescence (XRF), and Brunauer-Emmett-Teller/Barrett-Joyner-Halenda (BET-BJH) analysis. The characterization results revealed that the NaOH treatment increased the HF, average pore diameter, pore volume, and specific surface area compared to the untreated BNZ. Catalytic performance was evaluated in a continuous hydrocracking reactor using palm oil as feedstock. Among the modified samples, the BNZ-3 catalyst exhibited the most promising activity, demonstrating an optimal average pore diameter of 3.83 nm and an HF value of 0.069. This catalyst achieved an impressive Organic Liquid Product (OLP) yield of 85.67% and a palm oil conversion rate of 97.22%. The conversion of triglycerides was monitored via Fourier Transform Infrared Spectroscopy (FT-IR) by observing the disappearance of the ester bond absorption peak at 1745 cm⁻¹. Furthermore, Gas Chromatography-Mass Spectrometry (GC-MS) analysis of the distilled biofuel confirmed the presence of desired hydrocarbons fractions, including gasoline, kerosene, and diesel components, alongside minor quantities of alcohols, esters, and acids. The DSC results corroborate the TG and DTG analyses, reinforcing the conclusion that BNZ‑3 experiences more extensive coke deposition and undergoes more intense thermal decomposition than the blank catalyst. These findings underscore the potential of modified natural zeolites as effective, low-cost catalysts for sustainable biofuel production.
Analisis Mitigasi Risiko pada Proyek Konstruksi Rehabilitasi Jaringan Irigasi D.I. Cikaduwen Istadi, Istadi; Afriadie, Chandra; Pratiwi, A. Andini Radisya
Jurnal sosial dan sains Vol. 5 No. 11 (2025): Jurnal Sosial dan Sains
Publisher : Green Publisher Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.59188/jurnalsosains.v5i11.32592

Abstract

Proyek rehabilitasi jaringan irigasi merupakan bagian penting dalam menjaga keberlanjutan sistem irigasi guna mendukung sektor pertanian. Namun, dalam pelaksanaannya, proyek ini menghadapi berbagai risiko yang dapat mempengaruhi biaya, waktu, dan mutu pekerjaan. Penelitian ini bertujuan untuk menganalisis peran rehabilitasi dalam mitigasi risiko pada proyek rehabilitasi jaringan irigasi D.I. Cikaduwen. Metode penelitian yang digunakan adalah metode kuantitatif dengan pendekatan analisis risiko yang melibatkan identifikasi, penilaian, dan pemetaan risiko. Data dikumpulkan melalui survei dengan kuesioner serta studi literatur yang relevan. Risiko dikategorikan berdasarkan aspek teknis, finansial, operasional, dan lingkungan. Hasil penelitian menunjukkan bahwa risiko teknis, seperti kesalahan perencanaan dan penggunaan material yang tidak sesuai, merupakan faktor dominan yang mempengaruhi keberhasilan proyek. Selain itu, faktor operasional, seperti keterlambatan pengadaan material dan tenaga kerja, juga memberikan dampak signifikan. Pemetaan risiko menggunakan matriks probabilitas dan dampak menunjukkan bahwa beberapa risiko memiliki tingkat keparahan tinggi yang memerlukan strategi mitigasi lebih efektif. Kesimpulan dari penelitian ini adalah bahwa strategi mitigasi risiko yang terintegrasi sangat diperlukan dalam proyek rehabilitasi jaringan irigasi untuk mengurangi dampak negatif terhadap pelaksanaan proyek. Rekomendasi yang diberikan mencakup peningkatan manajemen proyek, perencanaan yang lebih matang, serta pemantauan risiko secara berkelanjutan.
Backmatter (Right Transfer Agreement for Publishing Form) Istadi, Istadi
Bulletin of Chemical Reaction Engineering & Catalysis 2026: BCREC Volume 21 Issue 1 Year 2026 (April 2026)
Publisher : Masyarakat Katalis Indonesia - Indonesian Catalyst Society (MKICS)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.9767/bcrec.20645

Abstract

Backmatter (Right Transfer Agreement for Publishing Form)
Backmatter (Right Transfer Agreement for Publishing Form) Istadi, Istadi
Bulletin of Chemical Reaction Engineering & Catalysis 2026: BCREC Volume 21 Issue 2 Year 2026 (August 2026)
Publisher : Masyarakat Katalis Indonesia - Indonesian Catalyst Society (MKICS)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.9767/bcrec.20682

Abstract

Backmatter (Right Transfer Agreement for Publishing Form)
Co-Authors Afriadie, Chandra Ajeng Riswanti Wulandari Alqurni, Wais Amin N.A.S. Amin Amin Nugroho Aminuyati Anggun Kurniawan Anindita Indriana Aniyati Khoiriyah Anwar Muttaqien, Anwar Anwaruddin Hisyam Anwaruddin Hisyam Ardian D. Yudhistira Ardian Dwi Yudhistira Aribowo, Windarto Astri Rakhmawati Atanasius Priharyoto Bayuseno Bahrudin, Moh. Bambang Pramudono Bambang Tri Nugroho Bintang Ayu Kalimantini Chusnul Khotimah D. A. Rahmawati D. Intaningrum Daniel Setiyo Nugroho Daniel Setiyo Nugroho, Daniel Setiyo Dian Rahmayanti Didi D. Anggoro Didi D. Anggoro Didi D. Anggoro Didi D. Anggoro Didi Dwi Anggoro Dinara, Daniella Cipta Dini Wulandari Dorothy Hoo Wei Ling Dyah Hesti Wardhani Eko Hidayanto Fachmy Adji Pangestu Setiawan Fajar Astuti Febriansyar, Rosyad Adrian Haniif Prasetiawan Heri Mulyanti Heri Sutanto Herlina Hidayati Iis Nurhasanah Inshani Utami Inshani Utami Karimullah, Suud Sarim Kursius, Catherine M. Kursius, Catherine Mentaya Luqman Buchori M.C.T. Wahyu Utami Maryanto - Muhamad, Theobroma Guntur Nani Harihastuti, Nani New Pei Yee Nofi Marlini Nor Aishah Saidina Amin Nor Aishah Saidina Amin Nor Aishah Saidina Amin P Purwanto Pakpahan, Agnes J. Pakpahan, Andre W. S. Permatasari, Astrid Eka Pratiwi, A. Andini Radisya Purwanto . Purwanto Purwanto Purwanto Purwanto Putut Marwoto Qotrunnada, Novaya Aulia Rahma Amalia Rahmat Gernowo Ratna Dewi Kusumaningtyas Riyanto, Teguh Roikhatus Solikhah Roikhatus Solikhah Salsabila, Unik Hanifah Salsabilla, Alda Saputra, Roni Ade Sitompul, J. P Slamet Priyanto Suherman Suherman Sulistyo Sulistyo Teguh Riyanto Teuku Irfan Maulana Udin Mabruro Wahyu Ambikawati Wulandari, Ajeng Riswanti