cover
Article Per Year (5 Year)
All
Home Page
OAI Link
Editorial Team
Contact
Reviewer
Google Scholar
Contact Name
Mochamad Sulaiman
Contact Email
m.sulaiman@uniramalang.ac.id
Phone
+6282331527189
Journal Mail Official
m.sulaiman@uniramalang.ac.id
Editorial Address
Fakultas Sains dan Teknologi Universitas Islam Raden Rahmat Malang Jl. Raya Mojosari 02 Kepanjen-Malang
Location
Kota malang,
Jawa timur
INDONESIA
G-Tech : Jurnal Teknologi Terapan
Published by Universitas Islam Raden Rahmat Malang
ISSN : 25808737     EISSN : 2623064X     DOI : -
Core Subject : Science, Engineering,
Computer Science & IT Decision Sciences, Operations Research & Management Energy Engineering
Jurnal G-Tech bertujuan untuk mempublikasikan hasil penelitian asli dan review hasil penelitian tentang teknologi dan terapan pada ruang lingkup keteknikan meliputi teknik mesin, teknik elektro, teknik informatika, sistem informasi, agroteknologi, dll.
Arjuna Subject : Teknik (semua kategori) - Teknik (Lain-Lain)
Articles 897 Documents
 71   72   73   74   75 
Synthesis and Characterization of Cellulose Acetate Derived from Corn Stalk Cellulose Using FTIR Analysis Farisah Masturoh; Nur Hasanah; Kindriari Nurma Wahyusi
G-Tech: Jurnal Teknologi Terapan Vol 9 No 2 (2025): G-Tech, Vol. 9 No. 2 April 2025
Publisher : Universitas Islam Raden Rahmat, Malang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.70609/gtech.v9i2.6833

Abstract

The synthesis and characterization of cellulose acetate were carried out using cellulose derived from corn stalks. Cellulose acetate was obtained through the esterification of cellulose, a natural biopolymer commonly sourced from wood or plant fibers. During the acetylation stage, the hydroxyl groups in cellulose were replaced with acetate groups from acetic anhydride. The acetylation process involved varying the volume of glacial acetic acid (CH₃COOH) at 25, 35, 45, 55, and 65 milliliters and reaction times of 1, 1.25, 1.5, 1.75, and 2 hours, using 0.5 milliliters of 98 percent sulfuric acid as a catalyst. Cellulose was first extracted by delignification using 17.5 percent sodium hydroxide, followed by bleaching with 4 percent sodium hydroxide and 4 percent hydrogen peroxide. The results showed that increasing the volume of acetic acid led to an acetyl content of up to 40.4 percent and a degree of substitution of 2.5. Extension of the acetylation time to 1.5 hours also increased the yield of cellulose acetate to a maximum of 70.2631 percent before decreasing at longer durations. These optimal results, including 70.2631 percent yield, 40.4 percent acetyl content, and a degree of substitution of 2.5, were achieved with 65 milliliters of acetic acid and 1.5 hours of acetylation. FTIR analysis confirmed successful acetylation by identifying hydroxyl (O–H), carbonyl (C=O), and ester (C–O) functional groups.
Penggunaan Algoritma Greedy dan Deep Reinforcement Learning untuk Optimasi Jadwal Operasi dalam Adaptive Scheduling Muhammad Andika Fadilla; Tata Sutabri
G-Tech: Jurnal Teknologi Terapan Vol 9 No 2 (2025): G-Tech, Vol. 9 No. 2 April 2025
Publisher : Universitas Islam Raden Rahmat, Malang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.70609/gtech.v9i2.6844

Abstract

Operating room scheduling faces persistent challenges in healthcare facilities worldwide, with inefficiencies leading to resource wastage, extended patient waiting times, and staff burnout. This study addresses these challenges through three methodologies: greedy algorithm, deep reinforcement learning (DRL), and a novel hybrid model. Analysis of 35,000 surgical procedures revealed significant inefficiencies in current practices, including OR overutilization (463.87%), substantial waiting times (170.07 minutes), and frequent delays (58.39% of procedures). The hybrid model demonstrated superior performance, achieving a 34.2% reduction in OR utilization, 55.9% reduction in waiting times, and 87.5% improvement in on-time procedures compared to baseline. These improvements translated into significant clinical benefits, including reduced staff overtime (57.1%) and enhanced emergency case accommodation (17.6%). The hybrid model's resilience to operational disruptions and balanced performance across multiple dimensions provides compelling evidence for implementing adaptive scheduling methodologies in clinical practice, offering a comprehensive solution that balances efficiency, adaptability, and patient-centered care.
Selulosa Asetat dari Batang Singkong dengan Proses Cellanase Yogi Irfan Maulana; Esa Wahyu Nur Hidayat; Mutasim Billah
G-Tech: Jurnal Teknologi Terapan Vol 9 No 2 (2025): G-Tech, Vol. 9 No. 2 April 2025
Publisher : Universitas Islam Raden Rahmat, Malang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.70609/gtech.v9i2.6872

Abstract

Cassava stalks waste can be used as a material for making particleboard, crafts, briquettes, charcoal, bioethanol, and producing alpha-cellulose. Alpha-cellulose produced from cassava stems can be used as Cellulose Acetate. This study aims to obtain cellulose acetate from cassava stems and find relatively good conditions based on variations in acetylation time and volume of acetic anhydride. The process of making cellulose into cellulose acetate is carried out in several stages, namely pre-treatment, cellulose isolation, and acetylation. In the pre-treatment process, cassava stems will be reduced in size and softened to facilitate fiber extraction. Next, cellulose isolation is carried out by delignification and bleaching to obtain alpha-cellulose. In the acetylation stage, cellulose is first activated with glacial acetic acid before being acetylated with acetic anhydride. In this study, the effect of acetylation time (30, 60, 90, 120, 150 minutes) and the effect of adding volume (10, 12.5, 15, 17.5, 20 ml) on the acetyl content and degree of substitution of cellulose acetate from cassava stlaks were investigated. Based on the results of the study, the relatively good acetyl content and degree of substitution were obtained at a volume of 20 ml and a time of 150 minutes, with an acetyl content of 34.8% and a degree of substitution of 1.987. The synthesized cellulose is classified as monoacetate cellulose, which can be used in the manufacture of plastics and paints.
Kajian Alternatif Pemeliharaan Sungai Berdasarkan Kondisi Morfologi Kali Sumber Pinang Pasuruan Felix Nova Ramadhan; Vita Ayu Kusuma Dewi
G-Tech: Jurnal Teknologi Terapan Vol 9 No 2 (2025): G-Tech, Vol. 9 No. 2 April 2025
Publisher : Universitas Islam Raden Rahmat, Malang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.70609/gtech.v9i2.6879

Abstract

The Sumber Pinang River often overflows, especially in the rainy season due to the ability of the river's capacity to not be able to accommodate water discharge, causing flooding in Sidogiri Village, Pasuruan Regency every year. This study aims to determine the performance of rivers and river infrastructure, as well as the necessary maintenance actions on the Sumber Pinang River guided by the Circular Letter of the Directorate General of Water Resources No.05/SE/D/2016. This study uses primary data in the form of an inventory of the existing conditions of sumgai and river infrastructure, as well as secondary data in the form of technical drawings of rivers and unit prices of goods and services in Pasuruan Regency. The results of the study showed that the Sumber Pinang River had a performance value of 63.12 with the category of corrective maintenance actions. In a total of 8 observation point segments, the performance value is <50, namely at point 4, point 7, point 14, point 48 and requires maintenance actions in the rehabilitative category. Priority improvements are in the form of normalization of rivers and repair of river embankments in the form of earthen embankments and parapets. The total maintenance cost on the Sumber Pinang River was obtained as Rp 23.670.546.185.
The Effect of H₂SO₄ Catalyst and Electric Voltage on Hydrogen Gas Production via the Electrolysis of Distilled Water Siti Kotijah; Difa Adanisa; Sri Redjeki
G-Tech: Jurnal Teknologi Terapan Vol 9 No 3 (2025): G-Tech, Vol. 9 No. 3 July 2025
Publisher : Universitas Islam Raden Rahmat, Malang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.70609/gtech.v9i3.6880

Abstract

Hydrogen is an environmentally friendly alternative energy source with great potential in the renewable energy sector. One efficient method for hydrogen production is water electrolysis, which can be influenced by catalyst concentration and applied electric voltage. This study aims to analyze the effect of varying H₂SO₄ concentrations and electric voltage on hydrogen production via water electrolysis. The concentrations used were 0.05 M, 0.075 M, 0.1 M, 0.25 M, and 0.5 M, while the applied voltages were 16 V, 18 V, 20 V, 22 V, and 24 V. Constant parameters included 500 mL of distilled water and a 2-minute hydrogen collection time. Gas analysis using Gas Chromatography-Thermal Conductivity Detector (GC-TCD) showed hydrogen detection at a retention time of 2.88 minutes. The highest hydrogen content, 11.143% mol, was achieved at 0.075 M H₂SO₄ and 24 V, with a maximum gas volume of 0.000659 m³. Based on RSNI ISO 14687:2019, the minimum fuel-grade hydrogen requirement is 50% mol. Therefore, further optimization is necessary to improve efficiency. Future studies are recommended to explore alternative catalysts, extend electrolysis time, or modify electrodes, as well as include tests without catalysts to evaluate reaction sustainability and compare hydrogen yields with and without catalytic influence.
Study of the Causes of Change Orders in Infrastructure Work Implementation and its Impact on Project Performance Moh. Sholahuddin; Ichwan Hadi Saputra
G-Tech: Jurnal Teknologi Terapan Vol 9 No 3 (2025): G-Tech, Vol. 9 No. 3 July 2025
Publisher : Universitas Islam Raden Rahmat, Malang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.70609/gtech.v9i3.6919

Abstract

Infrastructure work often undergoes changes during the construction phase to adapt to field conditions that differ from the initial planning. These changes may involve adding work volume, modifying technical specifications, or adjusting work schedules due to field conditions, policy changes, or other external factors. If not managed properly, these changes can lead to cost overruns, project delays, and even disputes among the parties involved. This research aims to identify the factors causing changes in orders and their impact on project performance. The method used is the distribution of questionnaires to involved contractors, followed by data analysis using the Relative Importance Index (RII) approach. The results show that there are 7 main factors, namely Planning and Design, Natural Factors, Owners, Construction, External Causes, Administration, and Policy Changes, with 40 indicators causing changes in orders in infrastructure projects. Additionally, it was found that changes in orders impact project performance in terms of cost, quality, and time, with 15 indicators representing those impacts. This finding makes an important contribution to project management practices, particularly in efforts to control changes in work during construction execution. The results of this research can serve as a basis for consideration in planning, monitoring, and decision-making to minimize the risks of work changes and improve overall project performance.
Feature Selection Optimization using Binary Particle Swarm Optimization in Smartphone-based Real Human Activity Recognition Ikrahmi Ikrahmi; Ema Utami
G-Tech: Jurnal Teknologi Terapan Vol 9 No 3 (2025): G-Tech, Vol. 9 No. 3 July 2025
Publisher : Universitas Islam Raden Rahmat, Malang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.70609/gtech.v9i3.6949

Abstract

Feature selection is a critical step in enhancing the accuracy and efficiency of machine learning models, particularly in the field of human activity recognition (HAR) using smartphone sensor data. This research explores the use of Binary Particle Swarm Optimization (BPSO) to reduce the dataset's dimensionality while retaining essential information. Out of 90 initial features, BPSO successfully selected 34 optimal features. These features were then used to train various machine learning models, achieving exceptional classification performance. The Random Forest algorithm achieved the highest accuracy at 99,92%, followed by K-Nearest Neighbour (KNN) at 99,08%, Support Vector Machine (SVM) at 98,68%, Multi-Layer Perceptron (MLP) at 96,01%, Decision Tree (DT) at 95,07%, and Naïve Bayes (NB) at 68,69%. The accuracy of all these algorithms exceeded the accuracy of the same algorithms without PSO-based optimization, as reported in previous studies used as baselines, except for Naive Bayes. These findings highlight the effectiveness of BPSO in feature selection for HAR tasks and its capability to improve machine learning model performance in practical applications.
Synthesis of Aragonite Polymorphs from Five Types of Sea Shells by Carbonation Method Prasetyo Hadi; Wahyu Hidayah; Sani Sani; Srie Muljani
G-Tech: Jurnal Teknologi Terapan Vol 9 No 3 (2025): G-Tech, Vol. 9 No. 3 July 2025
Publisher : Universitas Islam Raden Rahmat, Malang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.70609/gtech.v9i3.6998

Abstract

Shell waste accumulates along the coastal areas of Surabaya and Sidoarjo, with various types of shells including blood shells, green shells, feather shells, kampak shells, and batik shells. Currently, the waste from these shells is not being utilized optimally. Marine shell waste contains more than 95% calcium carbonate (CaCO3), making it suitable for the production of aragonite crystals, which can serve as raw materials for applications such as bone regeneration, paper manufacturing, and as fillers in rubber and plastics. The objective of this research is to synthesize aragonite from five types of marine shells and to investigate the effect of carbonation temperature on the percentage of aragonite formation. The method employed for synthesizing aragonite crystals is carbonation. Initially, the CaCO3 derived from marine shells is calcined at 900°C to produce calcium oxide (CaO). This calcium oxide is then dissolved in hydrochloric acid (HCl) to form calcium chloride (CaCl2). Subsequently, sodium hydroxide (NaOH) is added to CaCl2, and carbon dioxide (CO2) gas is bubbled through the solution to precipitate CaCO3 along with by-products of NaCl and water. The variables examined include comparisons among five types of shells (blood shells, green shells, feather shells, kampak shells, and batik shells) at calcination temperatures of 30°C, 60°C, and 90°C. The best results were obtained from the synthesis using green shells, yielding an aragonite crystal polymorph percentage of 76.4% at a carbonation temperature of 90°C. Conversely, the smallest yield of aragonite crystal polymorph was observed with batik shells at 26.0%.
Analysis of User Satisfaction and Preferences in Choosing a Digital Game Platform (Study Case: Steam vs Epic Games Store) Muhammad Nabil; Dhani Ariatmanto
G-Tech: Jurnal Teknologi Terapan Vol 9 No 3 (2025): G-Tech, Vol. 9 No. 3 July 2025
Publisher : Universitas Islam Raden Rahmat, Malang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.70609/g-tech.v9i3.7012

Abstract

In the digital era, the gaming industry has expanded rapidly, influencing social, cultural, and economic aspects. This study examines user satisfaction and preferences between Steam and Epic Games Store using the End User Computing Satisfaction (EUCS) model. A quantitative approach with descriptive and explanatory methods was employed. The study aims to identify which technical factors most influence user satisfaction and preferences between Steam and Epic Games Store. Using the EUCS model, the research will provide insights for developers to enhance user experience and inform strategies for improving digital gaming platforms. The findings will contribute to understanding technical drivers of user behavior and offer recommendations for creating user-centered design strategies in the competitive gaming market. Data analysis reveals that Steam holds a significant advantage in Content, Ease of Use, and Timeliness, leading to higher satisfaction. Steam offers a broader game selection, better community features, and a more functional interface than Epic Games Store. Statistical tests confirm Steam’s superiority. The study concludes that users prefer platforms with richer content, better experiences, and more efficient update systems, providing strategic insights for platform developers to improve competitiveness and user satisfaction.
Medium and Low Voltage Quality Improvement with Shunt Bank Capacitor and Transformer Tap on Morocco Tapung Feeder Duri Sepannur Bandri; Liliana Liliana; Rafika Andari; Zuriman Anthony
G-Tech: Jurnal Teknologi Terapan Vol 9 No 3 (2025): G-Tech, Vol. 9 No. 3 July 2025
Publisher : Universitas Islam Raden Rahmat, Malang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.70609/g-tech.v9i3.7021

Abstract

Voltage and frequency quality are paramount in 20 kV distribution systems that supply both medium and low voltage feeders. This study explores the significant voltage deficiency in the Maroko Tapung extension of PT PLN (PERSERO), ULP Duri, which dropped 16% from the nominal value. The main objective is to implement a comprehensive voltage restoration strategy to improve the efficiency of the 20 kV distribution system so that it reaches a better standard. The restoration was carried out by setting tap changers, installing shunt capacitor banks, and gradually increasing the tap settings on distribution transformers. Simulation results show a significant improvement in the minimum voltage level across the network, with the lowest voltage on the medium voltage side increasing to 91.69% and on the low voltage side to 90.47%. These outcomes demonstrate that the implemented multi-stage restoration procedures effectively brought the voltage quality within the acceptable limits defined by SPLN 1: 1987 standards, which permit a deviation of +5% and -10% from the nominal voltage. This study highlights the effectiveness of combined tap adjustments and shunt capacitor installation in mitigating voltage drops and ensuring compliance with regulatory standards in distribution systems.

Page 73 of 90 | Total Record : 897

 71   72   73   74   75 

Filter by Year

2017 2026


Reset
Filter By Issues
All Issue Vol 10 No 1 (2026): G-Tech, Vol. 10 No. 1 January 2026 Vol 9 No 4 (2025): G-Tech, Vol. 9 No. 4 October 2025 Vol 9 No 3 (2025): G-Tech, Vol. 9 No. 3 July 2025 Vol 9 No 2 (2025): G-Tech, Vol. 9 No. 2 April 2025 Vol 9 No 1 (2025): G-Tech, Vol. 9 No. 1 January 2025 Vol 8 No 4 (2024): G-Tech, Vol. 8 No. 4 Oktober 2024 Vol 8 No 3 (2024): G-Tech, Vol. 8 No. 3 Juli 2024 Vol 8 No 2 (2024): G-Tech, Vol. 8 No. 2 April 2024 Vol 8 No 1 (2024): G-Tech, Vol. 8 No. 1 Januari 2024 Vol 7 No 4 (2023): G-Tech, Vol. 7 No. 4 Oktober 2023 Vol 7 No 3 (2023): G-Tech, Vol. 7 No. 3 Juli 2023 Vol 7 No 2 (2023): G-Tech, Vol. 7 No. 2 April 2023 Vol 7 No 1 (2023): G-Tech, Vol. 7 No. 1 Januari 2023 Vol 6 No 2 (2022): G-Tech, Vol. 6 No. 2 Oktober 2022 Vol 6 No 1 (2022): G-Tech, Vol. 6, No. 1, April 2022 Vol 5 No 1 (2021): G-Tech, Vol. 5, No. 1, Oktober 2021 Vol 4 No 2 (2021): G-Tech, Vol. 4, No. 2, April 2021 Vol 4 No 1 (2020): G-Tech, Vol. 4, No. 1, Oktober 2020 Vol 3 No 2 (2020): G-Tech, Vol. 3, No. 2, April 2020 Vol 3 No 1 (2019): G-Tech, Vol. 3, No. 1, Oktober 2019 Vol 2 No 2 (2019): G-Tech, Vol. 2, No. 2, April 2019 Vol 2 No 1 (2018): G-Tech, Vol. 2, No. 1, Oktober 2018 Vol 1 No 2 (2018): G-Tech, Vol. 1, No. 2, April 2018 Vol 1 No 1 (2017): G-Tech, Vol. 1, No. 1, Oktober 2017 More Issue