Article Per Year (5 Year)
p-Index From 2021 - 2026
0.659
P-Index
This Author published in this journals
All Journal SIGMA TEKNIKA International Journal of Innovation in Mechanical Engineering and Advanced Materials
Abdul Mutalib Leman
Universiti Tun Hussein Onn Malaysia
Automotive Engineering Civil Engineering, Building, Construction & Architecture Control & Systems Engineering Electrical & Electronics Engineering Energy Engineering Industrial & Manufacturing Engineering Materials Science & Nanotechnology Mechanical Engineering

Published : 3 Documents Claim Missing Document
Claim Missing Document
Check
Articles

Found 3 Documents
Search

 1 
IDENTIFIKASI BOTTLENECK SIRKULASI BUKU PERPUSTAKAAN SEKOLAH MENGGUNAKAN MODEL SYSTEM DYNAMICS Dimas Akmarul Putera; Arief Andika Putra; Tania Alda; Abdul Mutalib Leman; Sari Rahmiati; Anastasia Anastasia; Erica Erica; Friyanti Phang
SIGMA TEKNIKA Vol 9, No 1 (2026): SIGMATEKNIKA, VOL.9, N0. 1, JUNI 2026
Publisher : Fakultas Teknik, Universitas Riau Kepulauan

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.33373/sigmateknika.v9i1.8952

Abstract

Penelitian ini bertujuan untuk mengidentifikasi bottleneck struktural dalam sistem sirkulasi buku pada perpustakaan sekolah menggunakan pendekatan System Dynamics. Sistem sirkulasi perpustakaan sering mengalami ketidakseimbangan antara laju peminjaman dan pengembalian buku, yang berdampak pada menurunnya ketersediaan koleksi bagi pengguna. Data operasional perpustakaan selama 36 periode dianalisis untuk memodelkan interaksi antara tingkat kunjungan pengguna, volume peminjaman, ketersediaan koleksi, serta keterlambatan pengembalian buku. Pemodelan diawali dengan penyusunan Causal Loop Diagram (CLD) untuk memetakan hubungan sebab–akibat antar variabel, yang kemudian diterjemahkan ke dalam model stock and flow dan disimulasikan menggunakan perangkat lunak AnyLogic. Hasil simulasi menunjukkan bahwa bottleneck utama sistem terletak pada subsistem pengembalian buku, khususnya pada interaksi antara keterlambatan pengembalian dan durasi peminjaman yang memperlambat aliran buku kembali ke stok. Kondisi ini menyebabkan perilaku sistem yang fluktuatif dan tidak stabil dalam jangka menengah. Validasi model menggunakan Mean Absolute Percentage Error (MAPE) menghasilkan nilai rata-rata sebesar 18,24%, yang berada dalam kategori good forecasting, sehingga model dinilai cukup representatif dalam menggambarkan dinamika sistem sirkulasi perpustakaan. Hasil penelitian ini memberikan dasar analitis bagi pengelola perpustakaan dalam memahami sumber kemacetan sistem dan merancang kebijakan pengelolaan koleksi yang lebih efektif
Sustainable Biodiesel Production from Waste Cooking Oil and Crude Palm Oil Using a Custom Mini Pilot Plant Alan Ooi Lim Siang; Abdul Mutalib Leman; Dafit Feriyanto; Samir Sani Abdulmalik; Supaat Zakaria
International Journal of Innovation in Mechanical Engineering and Advanced Materials Vol. 6 No. 1 (2024)
Publisher : Universitas Mercu Buana

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22441/ijimeam.v6i1.23734

Abstract

The widespread practice of reusing Waste Cooking Oil (WCO) in hawker food stalls, often for multiple frying cycles, presents a significant public health concern due to the degradation of the oil, which can lead to the formation of toxic compounds. These practices not only pose health risks, such as increasing the potential for cardiovascular diseases and cancer, but also contribute to environmental pollution when the oil is improperly disposed of. This study seeks to address these issues by converting WCO, along with crude palm oil (CPO), into biodiesel using a custom-designed mini pilot plant. The biodiesel production process involved a two-step reaction. The first step, esterification, was conducted using a 55:100 alcohol-to-oil volume ratio with 1% by volume sulfuric acid (H₂SO₄) as the acid catalyst, at 60°C, with a reaction time of 30 minutes and a stirring speed of 800 rpm. The second step, transesterification, utilized a 6:1 alcohol-to-oil molar ratio, with 1 wt.% sodium hydroxide (NaOH) as the alkaline catalyst, carried out at 70°C over the course of one hour. These conditions were carefully selected to optimize the conversion efficiency and to minimize the free fatty acid content, which is crucial for achieving a high yield of biodiesel. The results demonstrated that the mini pilot plant is highly effective in producing biodiesel from both WCO and CPO. The study also led to the development of a standard operating procedure (SOP) for the biodiesel production process, ensuring reproducibility and efficiency.
GREEN TECHNOLOGY FOR SUSTAINABLE AGRICULTURE: BIO-FERTILIZER PRODUCTION FROM MUNICIPAL WASTE TO PRESERVE THE ENVIRONMENT Muhamad Afifi Muhamad Sidik; Abdul Mutalib Leman; Dafit Feriyanto; Samir Sani Abdulmalik; Supaat Zakaria
International Journal of Innovation in Mechanical Engineering and Advanced Materials Vol. 5 No. 3 (2023)
Publisher : Universitas Mercu Buana

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22441/ijimeam.v5i3.23743

Abstract

This study addresses the pressing issue of municipal waste (MW) management by proposing an innovative approach to transform residential solid waste into a valuable resource using green technology. MW, sourced from diverse sectors, undergoes various disposal methods, including incineration, recycling, and landfilling. In Malaysia, the composition of MW aligns with global trends, with food waste and plastic being the predominant categories. This research focuses on producing fertilizer from residential solid waste through a green technology process, utilizing a sequential procedure involving high pressure, high temperature, and energized water to de-polymerize hemicellulose and lignin, followed by microbial enzymatic fermentation. The developed green technology introduces a novel apparatus designed for treating MW in a high-temperature, low-pressure rotating vessel using indirect heating with thermal fluid. The experimental protocol involves four batches of MW samples, evaluating the mass differential before and after the treatment process. Furthermore, a 7-week observation period assesses chili plant growth as an indicator of fertilizer effectiveness. Results indicate a significant 71% mass reduction of MW, amounting to 201.26 kg, emphasizing the efficacy of the developed process. The investigation extends to plant height, comparing MW-derived fertilizer with commercial fertilizer over a 5-week period. Remarkably, chili plants fertilized with MW-derived fertilizer exhibit a greater height of 8.6 cm, surpassing the 7.3 cm observed with commercial fertilizer. This study concludes that MW-derived fertilizer is highly recommended for enhancing plant growth and health in Malaysia, suggesting a sustainable production system. The research not only contributes to waste management but also aligns with broader goals of promoting environmentally conscious and sustainable agricultural practices, emphasizing the potential of green technology in addressing the challenges of municipal waste.
Co-Authors Alan Ooi Lim Siang Anastasia Anastasia Arief Andika Putra Dafit Feriyanto Dimas Akmarul Putera Erica Erica Friyanti Phang Muhamad Afifi Muhamad Sidik Samir Sani Abdulmalik Sari Rahmiati Supaat Zakaria Supaat Zakaria Tania Alda