Open Access. Powered by Scholars. Published by Universities.®

Computational Engineering Commons

Open Access. Powered by Scholars. Published by Universities.®

Journal

Discipline
Institution
Keyword
Publication Year
Publication

Articles 1 - 30 of 280

Full-Text Articles in Computational Engineering

Modeling Of Supersonic Wave And Shock Propagation Using The Lattice Boltzmann Method, Timothy P. Schroeder Aug 2026

Modeling Of Supersonic Wave And Shock Propagation Using The Lattice Boltzmann Method, Timothy P. Schroeder

Beyond: Undergraduate Research Journal

The lattice Boltzmann method (LBM) has emerged as a mesoscopic alternative to traditional Navier-Stokes solvers for modeling fluid dynamics offering advantages in computational efficiency, parallelization, and handling of complex boundaries. Despite these strengths, accurately reproducing compressible, shock-driven phenomena remains challenging. This study investigates the performance of LBM in simulating the Sod shock tube problem, a classical benchmark for compressible flow-using both single and double distribution function formulations across one- and two-dimensional lattice stencils. A MATLAB-based solver was developed to model the flow under isothermal conditions and compared to the analytical solution using the L2 norm error. The one-dimensional models achieved …


Exploring Red Palm Oil As A Sustainable Plasticizer For Carbon Black-Filled Ssbr/Br Tire Tread Compounds: A Comparative Evaluation Of Commercial Alternatives, Norma Arisanti Kinasih, Mohamad Irfan Fathurrohman, Santi Puspitasari, Dewi Kusuma Arti, Abdulhakim Masa Aug 2026

Exploring Red Palm Oil As A Sustainable Plasticizer For Carbon Black-Filled Ssbr/Br Tire Tread Compounds: A Comparative Evaluation Of Commercial Alternatives, Norma Arisanti Kinasih, Mohamad Irfan Fathurrohman, Santi Puspitasari, Dewi Kusuma Arti, Abdulhakim Masa

Journal of Materials Exploration and Findings

This study investigates the application of red palm oil (RPO) as an alternative vegetable oil resource to substitute petroleum-based plasticizers, which have environmental and health concerns, in carbon black (CB)-filled SSBR/BR tire tread compounds. The plasticizing effects of RPO were thoroughly evaluated by comparing them with a commercial bio-based plasticizer, Epoxidized Soybean Oil (ESBO), and two safer petroleum-based oils, Naphthenic Oil (NYNAS) and Treated Distillate Aromatic Extract (TDAE). The initial investigation shows that fatty acid composition is imposing regarding the plasticizing effect. The higher unsaturated fatty acid content in RPO than in ESBO improved tensile strength and degraded rolling resistance …


Metallurgical Investigation Of A Modified Eye Bolt Failure Caused By Improper Weld Extension, Specification Deviation, And Crevice Corrosion, Dimas Muhammad Fawwaz, Reza Miftahul Ulum, Johny Wahyuadi Soedarsono, Yudha Pratesa Aug 2026

Metallurgical Investigation Of A Modified Eye Bolt Failure Caused By Improper Weld Extension, Specification Deviation, And Crevice Corrosion, Dimas Muhammad Fawwaz, Reza Miftahul Ulum, Johny Wahyuadi Soedarsono, Yudha Pratesa

Journal of Materials Exploration and Findings

A modified eye bolt from the David Arm Manhole Storage Tank underwent thorough metallurgical study due to the consequences of the bolt's malfunction during operation. Safety issues arose when the manhole door detached during operation. The mechanical testing and chemical composition analysis of the bolts indicated they were manufactured from an ASTM A193 Grade B7 material used for high-temperature bolting. This material did not conform to the engineering drawing, which mentioned SA 563A, which is about nuts, not bolts. This contradiction clearly shows that the eye bolt which was installed does not conform to the intended design. Welded connections of …


Rejection Of Fe (Iron) And Kmno4 (Organic Substance) Parameters In Peat Water Using Organic Membranes, Muhamad Rafli Sakti Mulia Gonera, Siti Umi Kalsum, Sarah Fiebrina Heraningsih Aug 2026

Rejection Of Fe (Iron) And Kmno4 (Organic Substance) Parameters In Peat Water Using Organic Membranes, Muhamad Rafli Sakti Mulia Gonera, Siti Umi Kalsum, Sarah Fiebrina Heraningsih

Journal of Materials Exploration and Findings

Peat water is a surface water source widely used by people in swampy and lowland areas, but it has poor quality characteristics such as high organic matter content, low pH, and dissolved metal levels such as iron that exceed the threshold. These conditions can cause health problems and reduce the quality of clean water so that effective treatment technology is needed. This study aims to analyze the effectiveness of ultrafiltration membranes made from chitosan from shrimp shell waste in rejecting iron (Fe) and organic substances in peat water, and to determine the effect of pressure on separation performance. This study …


Structural Design And Finite Element Analysis Of A 54 Ton Freight Wagon Bolster Test Rig Under Vertical Center Plate Load, Shandy Dwi Prayoga, I Dewa Gede Ary Subagia, I Ketut Adi Atmika, Abdul Rohman Farid, Yunior Lanang Satrio Jul 2026

Structural Design And Finite Element Analysis Of A 54 Ton Freight Wagon Bolster Test Rig Under Vertical Center Plate Load, Shandy Dwi Prayoga, I Dewa Gede Ary Subagia, I Ketut Adi Atmika, Abdul Rohman Farid, Yunior Lanang Satrio

Journal of Mechanical Engineering Science and Technology (JMEST)

Bolster is one of the bogie's components that receives direct loading from the car body and freight movement. One of the problems that occurs in the bolster is permanent deflection during vertical and transversal static loading. Therefore, a static loading test is required to evaluate the structural strength of the bolster. During the static loading test, a rig is required to hold the bolster so that the bolster is in a fixed position. The rig owned by PT. INKA (Persero) showed a plastic deformation at the vertical center plate load (VCP 5.22P). Therefore, a modified design of the rig is …


Numerical Simulation Of Centrifugal Pump Performance Under Impeller Blade And Suction Diameter Variations, Gunawan Budi Santoso, Susanto -, Akhmad Nuriyanis, Anang Budhi Nugroho, Rizka Noor Miftakhul Ulum, Suyono - Jul 2026

Numerical Simulation Of Centrifugal Pump Performance Under Impeller Blade And Suction Diameter Variations, Gunawan Budi Santoso, Susanto -, Akhmad Nuriyanis, Anang Budhi Nugroho, Rizka Noor Miftakhul Ulum, Suyono -

Journal of Mechanical Engineering Science and Technology (JMEST)

The objective of this study is to model variations in pump geometry to obtain optimal performance under the effects of cavitation. The resulting geometric variation models were then simulated using ANSYS Fluent software. The first geometric variation model used a standard 5-blade impeller with suction pipe diameter variations of 2, 2 ½, 2 ¾, 3, 3 ¼, 3 ½, and 4 inches. The second geometric variation model for simulation used a standard 3-inch suction pipe with impeller blade variations of 3, 4, 5, 6, 7, 8, and 9. The simulation results indicated that the number of blades without changes in …


Contemporary Cybersecurity Challenges In Emerging Technologies: A Systematic Literature Analysis, Faztudo Languisse Prof Jul 2026

Contemporary Cybersecurity Challenges In Emerging Technologies: A Systematic Literature Analysis, Faztudo Languisse Prof

Journal of Cybersecurity Education, Research and Practice

The accelerating convergence of artificial intelligence (AI), the Internet of Things (IoT), cloud computing, blockchain, and quantum computing has fundamentally transformed the global threat landscape, introducing cybersecurity challenges of unprecedented complexity and scale. This systematic literature review synthesizes findings from peer-reviewed publications, institutional reports, and regulatory documents published primarily between 2020 and 2025 to provide an integrated analysis of contemporary cybersecurity challenges across five key emerging technology domains. The review identifies critical vulnerabilities inherent to each domain, documents the evolution of threat actors and attack methodologies — including AI-powered ransomware, adversarial machine learning, and harvest-now-decrypt-later quantum attacks — and evaluates …


Effect Of Naoh Concentration On The Structural, Morphological, And Tensile Properties Of Pineapple Stem Fibers, Ahmad Norca Kurnia Zen, Heru Suryanto, Aminnudin Aminnudin, Fajar Nusantara, Joseph Selvi Binoj Jul 2026

Effect Of Naoh Concentration On The Structural, Morphological, And Tensile Properties Of Pineapple Stem Fibers, Ahmad Norca Kurnia Zen, Heru Suryanto, Aminnudin Aminnudin, Fajar Nusantara, Joseph Selvi Binoj

Journal of Mechanical Engineering Science and Technology (JMEST)

Natural fiber reinforced composites are increasingly being developed due to their environmentally friendly nature, low production costs, and safety for human health. However, the presence of lignin and hemicellulose reduces adhesion properties between fiber and composite matrix. Alkalization treatment is an effective way to remove lignin and hemicellulose attached to cellulose. This study aims to determine the optimum concentration of NaOH used during alkalization process of pineapple stem fiber. The methods included the retting process of fibers from pineapple stems. The obtained fibers were soaked in variations of 2%, 4%, 6%, and 8% NaOH for 4 hours,  then dried and …


Evaluating Optimal Capacity And Investment Strategies For Renewable Energy Projects: A Combined Technical And Financial Approach, Helen Josephine, Indhumathi Shanmugasundaram, Sharad Gupta, Manjari Sharma May 2026

Evaluating Optimal Capacity And Investment Strategies For Renewable Energy Projects: A Combined Technical And Financial Approach, Helen Josephine, Indhumathi Shanmugasundaram, Sharad Gupta, Manjari Sharma

Northeast Journal of Complex Systems (NEJCS)

The global shift toward clean energy is accelerating, and by 2050 renewable sources are expected to supply more than 85% of the world’s electricity. This transition, however, introduces new layers of complexity. Wind and solar energy behave as interconnected subsystems whose output fluctuates with weather, season, and geography. Their interaction with fixed hourly demand, capital-intensive investments, and financing structures creates a multi-dimensional system in which small changes can trigger significant operational and economic consequences.  This study presents a simulation-driven framework designed to understand and optimize this complex behaviour. The framework models hourly wind and solar generation alongside projected demand to …


Optimization And Energy Efficiency Analysis Of An Automatic Feed Mixer With A Rotating Drum Mechanism, Kris Witono, Talifatim Machfuroh, Nurlia Pramita Sari, Lisa Agustriyana, Aini Lostari May 2026

Optimization And Energy Efficiency Analysis Of An Automatic Feed Mixer With A Rotating Drum Mechanism, Kris Witono, Talifatim Machfuroh, Nurlia Pramita Sari, Lisa Agustriyana, Aini Lostari

Journal of Mechanical Engineering Science and Technology (JMEST)

Energy-efficient feed mixer machines are important for improving the productivity and sustainability of small and medium-scale livestock farms. Previous studies primarily focused on either structural performance or mixing efficiency, with limited studies integrating both aspects. Therefore, this study evaluated an automatic rotating-drum feed mixer by combining Finite Element Method (FEM) analysis and energy modeling. The study used FEM simulations for different materials, namely A36 steel alloy, stainless steel 304, aluminium 6061, and galvanized steel, with thicknesses of 3 mm and 4 mm, as well as different drum systems. The FEM results showed that all evaluated materials met the minimum safety …


Influence Of Gas Atmosphere And Deposition Time On Si/Mno₂ Thin Films Properties Deposited By Magnetron Sputtering For Supercapacitor Application, Tansya Trisnatika Dewi, Boon Tong Goh, Reza Akbar Pahlevi, Ishmah Luthfiyah, Markus Diantoro May 2026

Influence Of Gas Atmosphere And Deposition Time On Si/Mno₂ Thin Films Properties Deposited By Magnetron Sputtering For Supercapacitor Application, Tansya Trisnatika Dewi, Boon Tong Goh, Reza Akbar Pahlevi, Ishmah Luthfiyah, Markus Diantoro

Journal of Mechanical Engineering Science and Technology (JMEST)

Thin films of MnO2 were successfully deposited onto Si substrates using the magnetron sputtering technique in various gas atmospheres and deposition times to study their influence on the structural, morphological, electrical, and electrochemical properties for application as supercapacitor electrodes. Structural analysis using XRD showed that deposition under an Ar+O2 gas atmosphere increased the crystallite size and crystallinity of the Si/MnO2 films, while shorter deposition times reduced the crystallite size and lowered the crystallinity. Surface morphology observation using SEM showed that the film deposited in an Ar+O2 gas atmosphere had smaller, more uniform, evenly distributed, and closely …


Influence Of Fiber Loading And Cu/Sio₂ Fillers On Mechanical And Physical Properties Of Sugarcane Bagasse Epoxy Composites, Ansor Salim Siregar, Indra Indra, Agung Fauzi Hanafi, Sunny Ineza Putri May 2026

Influence Of Fiber Loading And Cu/Sio₂ Fillers On Mechanical And Physical Properties Of Sugarcane Bagasse Epoxy Composites, Ansor Salim Siregar, Indra Indra, Agung Fauzi Hanafi, Sunny Ineza Putri

Journal of Mechanical Engineering Science and Technology (JMEST)

The rising worldwide need for lightweight, high-strength, and eco-friendly materials has driven considerable investigation into natural fiber composites. This research offers an extensive examination of the creation and characterization of a new hybrid composite designed for high-performance sports equipment. The composite structure consists of an epoxy matrix strengthened with sugarcane bagasse fibers and synergistic blend of copper and silicon dioxide hybrid particulate fillers. Three unique composite variations were created, with systematically adjusted weight fractions of sugarcane bagasse fiber (35%, 31%, 27%) and hybrid fillers. A thorough assessment of mechanical and physical properties was carried out following ASTM standards. The results …


The Digital Neuron: Neural Cellular Automata For Neural–Symbolic Translation, Nicole Assenza Apr 2026

The Digital Neuron: Neural Cellular Automata For Neural–Symbolic Translation, Nicole Assenza

SMU Data Science Review

A neural cellular automata (NCA) architecture, referred to as Pluto’s NCA, was developed to characterize bilateral communication and semantic reciprocity between symbolic representations and a spatially distributed update field. The architecture employs an encoder–automata–decoder pipeline that maps symbolic inputs into a multichannel state field and reconstructs them through agreement-driven attractor convergence within a stable semantic attractor landscape. System behavior was evaluated under controlled perturbations, including rhythmic desynchronization, graded ablations, correlated and independent noise, and percolation-based structural degradation. Quantities such as Agreement(t), internal coherence Aᵢ(t), the recovery time constant τ, and the critical percolation threshold pc were measured to assess stability, …


Techno-Enviro-Economic Analysis Of Precipitated Calcium Carbonate Production From Carbon Dioxide In Cement Industry Flue Gas And Calcium Hydroxide, Natalia Debora Panggabean, Widodo Wahyu Purwanto Apr 2026

Techno-Enviro-Economic Analysis Of Precipitated Calcium Carbonate Production From Carbon Dioxide In Cement Industry Flue Gas And Calcium Hydroxide, Natalia Debora Panggabean, Widodo Wahyu Purwanto

Journal of Materials Exploration and Findings

CCUS is a technological solution to reduce emissions from the cement industry, which is the second largest CO2-intensive industry. This study aims to analyze technical, economic, and environmental performance of Precipitated Calcium Carbonate (PCC) synthesis in cement industry flue gas. The process simulation includes the CO2 capture system from cement plant, CO2 captured used as feedstock for PCC synthesis process through its reaction with calcium hydroxide. The simulation was carried out using ASPEN Plus software. Technical analysis was performed to determine the CO2 capture efficiency and PCC synthesis efficiency. Economic analysis was conducted to calculate CO2 capture cost and production …


Feasibility Analysis Of Thermal Oxidizer To Determine Remaining Life Using Fitness- For-Service Level 3 Method, Yudhi Yudistirawan, Donanta Dhaneswara, Wahyuaji Narottama Putra, Gama Widyaputra, Dewi Kurnia Suci, Agung Putra Mahardhika Apr 2026

Feasibility Analysis Of Thermal Oxidizer To Determine Remaining Life Using Fitness- For-Service Level 3 Method, Yudhi Yudistirawan, Donanta Dhaneswara, Wahyuaji Narottama Putra, Gama Widyaputra, Dewi Kurnia Suci, Agung Putra Mahardhika

Journal of Materials Exploration and Findings

An aged thermal oxidizer (TOX) in the oil and gas industry necessitates a comprehensive evaluation to ensure its continued safe operation. This study presents a Remaining Life Assessment (RLA) and a Fitness for Service (FFS) evaluation for the four main components of the TOX, in accordance with API 510, API 579/ASME FFS-1, and ASME BPVC Section VIII Div-1 standards. The investigation includes the determination of maximum stress and maximum temperature required to assess the operational viability of the reactor. The four components are radiant, convection, transition, and stack sections—were modeled using the finite element method (FEM). Following the geometric modeling, …


Assessing Passenger Electric Vehicle Growth Strategies And Their Impacts On Electricity Demand Load And Co2 Emissions In Aceh Province To Achieve Net Zero Emission Target By 2060, Taufik Hidayat, Widodo Wahyu Purwanto Apr 2026

Assessing Passenger Electric Vehicle Growth Strategies And Their Impacts On Electricity Demand Load And Co2 Emissions In Aceh Province To Achieve Net Zero Emission Target By 2060, Taufik Hidayat, Widodo Wahyu Purwanto

Journal of Materials Exploration and Findings

The electrification of the transport sector is a crucial pathway for achieving Indonesia’s Net Zero Emissions (NZE) target by 2060. This study assesses the potential impact of passenger electric vehicle (EV) penetration on electricity demand and CO2 emissions in Aceh Province through a scenario-based modelling approach. Two policy-aligned scenarios are assessed: a low-penetration (LP) scenario and a high-penetration (HP) scenario. Using the Gompertz model and the ASIF framework, total CO2 emissions were projected from 2020 to 2060. Results show that although higher EV penetration reduces direct emissions from internal combustion engine (ICE) vehicles, total CO2 emissions increase more significantly under …


Behavioral Biases As Drivers Of Complexity In Stock Markets: An Agent-Based Modeling Approach, David Joseph Dr, Alwin Joseph, Blesson James, Kajal Dass Apr 2026

Behavioral Biases As Drivers Of Complexity In Stock Markets: An Agent-Based Modeling Approach, David Joseph Dr, Alwin Joseph, Blesson James, Kajal Dass

Northeast Journal of Complex Systems (NEJCS)

By modeling financial systems as Complex Adaptive Systems, this study investigates how behavioral biases influence emergent complexity in stock markets. The study integrates heterogeneous agents, such as rational traders, herding agents, overconfident traders, and anchoring/disposition-driven investors, within a Limit Order Book framework calibrated to both U.S. and Indian market conditions using an Agent-Based Modeling (ABM) approach implemented through the high-fidelity ABIDES simulation environment. Price dynamics, volatility patterns, and liquidity structures were analyzed by Monte Carlo simulation experiments with different behavioral compositions. The results show that behavioral biases cause nonlinear price reactions, produce heavy-tailed return distributions that distort order-book complexity, and …


Trusted Forms—The Case Of Barack Obama’S Birth Certificate, Karl-Heinrich Schmidt, Frederik Schlupkothen Feb 2026

Trusted Forms—The Case Of Barack Obama’S Birth Certificate, Karl-Heinrich Schmidt, Frederik Schlupkothen

Proceedings from the Document Academy

Documents can be understood as containers for information that enable remote communication between people across space and time. They are therefore fundamentally subject to issues of trust. The theoretical treatment of documents as a means of remote communication has a long history and has arrived in the age of electronic document exchange, as shown by the work of R. T. Pédauque, which is taken as a starting point here.

To take theory further, form-based documents are discussed here as an example. Form-based documents control the information provided by fillers by specifying form fields. The core of this paper is to …


Analysis Of Leakage In Nearshore Pipelines Using Fitness For Service Method To Ensure Mechanical Integrity Based On Api-579 Level 3, Elriandri Elriandri, Dedi Priadi Dec 2025

Analysis Of Leakage In Nearshore Pipelines Using Fitness For Service Method To Ensure Mechanical Integrity Based On Api-579 Level 3, Elriandri Elriandri, Dedi Priadi

Journal of Materials Exploration and Findings

The Fitness for Service (FFS) analysis is performed as a quantitative assessment to evaluate the integrity condition of a pipeline. Essentially, FFS assessment helps determine whether equipment components can operate safely despite existing deficiencies. This evaluation is carried out using the Finite Element Method (FEM). In the case of an underwater pipeline that experiences leak due to anchor pull at the flange connection, it undergoes plastic deformation and is lifted approximately 1 meter. As a mitigation step, inspection and repairs have been carried out by the company. Subsequently, modeling is performed to reconstruct the deformation process of the pipeline. Then, …


Assessment Of The Melt Quality Of A 30% Scrap Adc12 Aluminium Alloy Using The Inclusion And Fluidity Measurement Instrument (Ifmi) With Mullite Ceramic Filters, Gusti Ruri Ruri Lestari, Sandya Ananda Riswan, Muhammad Anis, Ahmad Ashari, Paramita Vidya Ayuningtyas, Bambang Suharno Prof, Donanta Dhaneswara Dec 2025

Assessment Of The Melt Quality Of A 30% Scrap Adc12 Aluminium Alloy Using The Inclusion And Fluidity Measurement Instrument (Ifmi) With Mullite Ceramic Filters, Gusti Ruri Ruri Lestari, Sandya Ananda Riswan, Muhammad Anis, Ahmad Ashari, Paramita Vidya Ayuningtyas, Bambang Suharno Prof, Donanta Dhaneswara

Journal of Materials Exploration and Findings

The increasing demand for sustainable practices in the metal casting industry has driven the use of recycled aluminum alloys such as ADC12. However, the addition of aluminum scrap tends to increase oxide inclusions, which reduce melt fluidity and compromise casting quality. This study utilizes the Inclusion and Fluidity Measurement Instrument (IFMI), equipped with mullite ceramic filters, to assess the melt quality of ADC12 aluminum alloy containing 30% scrap. Fluidity and inclusion characteristics were evaluated at five pouring temperatures (660°C, 680°C, 700°C, 720°C, and 740°C). The results show that fluidity increased with temperature, reaching a peak of 84.6 g·s⁻¹ at 740°C, …


Equipment Criticality Analysis To Determine Asset Integrity Management System Scheme In Supporting Production Optimization Scenarios In The Aeging Field, Donny Andryanto, Donanta Dhaneswara Dec 2025

Equipment Criticality Analysis To Determine Asset Integrity Management System Scheme In Supporting Production Optimization Scenarios In The Aeging Field, Donny Andryanto, Donanta Dhaneswara

Journal of Materials Exploration and Findings

This research investigates the production decline and cost increase in the X&Y oil and gas fields from 2022 to 2023. Production fell by 34%, while production costs per barrel rose by 79%. To address these issues, a series of optimization processes are proposed. These aim to restructure and enhance the production facilities to reduce current production costs. The optimizations include reducing pressure at the PPP Platform in 2024. Additional steps include shutting down CPP-ORF 14” pipelines and most processes at CPP 2 Platform by 2027 to convert it into an accommodation platform. Further, the plan involves optimizing the release of …


Morphological Test Of Areca Nut Fiber Ceramic Membrane Using Scanning Electron Microscopy Energy Dispersive X-Ray Mapping Spectroscopy, Amelia Marzain, Siti Umi Kalsum, Marhadi Marhadi, Ahmad Nabil Shahab Dec 2025

Morphological Test Of Areca Nut Fiber Ceramic Membrane Using Scanning Electron Microscopy Energy Dispersive X-Ray Mapping Spectroscopy, Amelia Marzain, Siti Umi Kalsum, Marhadi Marhadi, Ahmad Nabil Shahab

Journal of Materials Exploration and Findings

This study investigates the potential of ceramic membranes derived from areca nut fiber as a cost-effective and environmentally sustainable material for the removal of iron (Fe) and manganese (Mn) from groundwater. Two types of membranes were fabricated: one without activation and one chemically activated using 10% sodium hydroxide (NaOH). The morphological and elemental characteristics of both membranes were analyzed using Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray (EDX) mapping. The concentrations of Fe and Mn before and after treatment were measured using Atomic Absorption Spectroscopy (AAS). The NaOH-activated membrane exhibited a more porous surface structure and higher oxygen content, …


Spray Angle On The Performance Of Split-Type Ac Condenser Installed On Concrete Rooftop In Tropical Climate, Kennedy Kennedy, I N Frenki Aryana, Basri Basri Nov 2025

Spray Angle On The Performance Of Split-Type Ac Condenser Installed On Concrete Rooftop In Tropical Climate, Kennedy Kennedy, I N Frenki Aryana, Basri Basri

Journal of Mechanical Engineering Science and Technology (JMEST)

This study investigated the influence of different water spray angles (0°, 15°, and 30°) on the thermal and energy performance of a split-type air-conditioning (AC) condenser installed on a concrete rooftop in a tropical climate. An experimental setup was designed to replicate actual concrete rooftop conditions, focusing on the condenser inlet temperature, compressor power consumption, and system coefficient of performance (COP). A 6-minute ON and 6-minute OFF intermittent spray cycle was employed to optimise water usage and minimise excessive humidity. Experimental measurements were conducted on a 9,000 Btu/h split-type unit equipped with a nozzle system connected to a 200 L …


Effect Of Argon Gas Flow Rate On Crystal Structure, Morphology, And Optical Properties Of Cigs Film For Photodetector Applications, Nurul Lathi’I Fatul Chamidah, Fadilah Wulan Cahyani, I Gusti Ayu Isnaini Fatha Ramadhani, Erma Surya Yuliana, Nasikhudin Nasikhudin, Safwan Abd. Aziz, Nandang Mufti Nov 2025

Effect Of Argon Gas Flow Rate On Crystal Structure, Morphology, And Optical Properties Of Cigs Film For Photodetector Applications, Nurul Lathi’I Fatul Chamidah, Fadilah Wulan Cahyani, I Gusti Ayu Isnaini Fatha Ramadhani, Erma Surya Yuliana, Nasikhudin Nasikhudin, Safwan Abd. Aziz, Nandang Mufti

Journal of Mechanical Engineering Science and Technology (JMEST)

CIGS material can be used as a material for photodetector applications. The deposition of CIGS thin films remains challenging. Generally, argon is used as a gas to bombard the CIGS material through the sputtering method. This study fabricated photodetectors by varying the argon gas flow rate (50-80 sccm) to investigate its effect on device performance. XRD, SEM, UV-Vis, and photoresponse tests were characterized. Structural analysis using XRD showed a weak (112) diffraction peak, indicating that the resulting film was not fully crystalline, but rather consisted of a nanocrystalline phase, even partly amorphous, with small crystallite sizes. According to the SEM …


Numerical Analysis Of The Effect Of Vortex Generator On The Aerodynamic Performance Of Naca 6412 Airfoils Using Large Eddy Simulation, Dedet Hermawan Setiabudi, Joan Bayuaji Nugroho, Eli Kumolosari, Lazuardy Rahendra Pinandhita, Okto Dinaryanto Nov 2025

Numerical Analysis Of The Effect Of Vortex Generator On The Aerodynamic Performance Of Naca 6412 Airfoils Using Large Eddy Simulation, Dedet Hermawan Setiabudi, Joan Bayuaji Nugroho, Eli Kumolosari, Lazuardy Rahendra Pinandhita, Okto Dinaryanto

Journal of Mechanical Engineering Science and Technology (JMEST)

Aerodynamic performance of an airfoil is significantly affected by flow separation, especially at high angles of attack. One common strategy to control flow separation is adding a triangular vortex generator (VG), which creates small vortices that help keep the airflow attached. The present study investigated the impact of triangular vortex generators on a NACA 6412 airfoil using Computational Fluid Dynamics (CFD) method. Large Eddy Simulation (LES) was applied due to its ability to show the vortices more clearly than other methods. It can also accurately capture the flow separation. To obtain the lift, drag, and lift-to-drag ratio (CL/CD) data, four …


Impact Of Cpo And B35 On Diesel Engine Rocker Arm Wear During Long-Term Operation, Fawwaz Aqilah Nurmansyah, Nur Fadilah Rizky Supramono, Muhammad Ikhsan, Erwan Adi Saputro, Wiliandi Saputro Nov 2025

Impact Of Cpo And B35 On Diesel Engine Rocker Arm Wear During Long-Term Operation, Fawwaz Aqilah Nurmansyah, Nur Fadilah Rizky Supramono, Muhammad Ikhsan, Erwan Adi Saputro, Wiliandi Saputro

Journal of Mechanical Engineering Science and Technology (JMEST)

The increasing number of motor vehicles has led to higher fossil fuel consumption, contributing to greenhouse gas emissions, climate change, and environmental degradation. As a renewable alternative, biodiesel offers a way to reduce these impacts. Indonesia, with its abundant natural resources, has significant potential for biodiesel production. Crude palm oil (CPO) is a promising feedstock due to its availability and relatively low environmental impact. However, the high costs associated with the transesterification process make direct use of pre-heated CPO an area worth exploring. This study investigates the impact of pre-heated pure CPO compared to B35 ("Dexlite") on rocker arm wear …


The Effect Of Heat Treatment Duration On The Psychochemical, Mechanical, And Biodegradability Of Polyvinyl Alcohol/Gambir Extract Biocomposite Films, Ainul Kahfi Muhlasin, Poppy Puspitasari, Heru Suryanto, Diki Dwi Pramono, Dieter Rahmadiawan, Billie Jack Pasion Nov 2025

The Effect Of Heat Treatment Duration On The Psychochemical, Mechanical, And Biodegradability Of Polyvinyl Alcohol/Gambir Extract Biocomposite Films, Ainul Kahfi Muhlasin, Poppy Puspitasari, Heru Suryanto, Diki Dwi Pramono, Dieter Rahmadiawan, Billie Jack Pasion

Journal of Mechanical Engineering Science and Technology (JMEST)

This study investigates PVA-based films with the addition of gambir and heat treatment to improve the characteristics of the film. Methods include the synthesis of PVA film with gambir addition (0.5%), treated by heat treatment for 40 minutes and 60 minutes. The film was characterised by physicochemical, mechanical properties, and biodegradability. Data was analyzed using ANOVA with a significance of 95%. Results indicate that the surface of PVA/gambir films is smoother and more homogeneous as the heat treatment duration increases. New peaks of functional groups were identified after the addition of gambir at the C-C and C-O groups. After heat …


Surface Modification Of Local Natural Fibers Via Alkali Treatment For Improved Mechanical And Molecular Properties Of Bamboo Fiber, Pineapple Leaf Fiber, And Sisal Fiber, Jibril Maulana, Muhammad Ilman Nur Sasongko, Dewi Izzatus Tsamroh, Muchammad Yafis, Syekhan Maulana Nov 2025

Surface Modification Of Local Natural Fibers Via Alkali Treatment For Improved Mechanical And Molecular Properties Of Bamboo Fiber, Pineapple Leaf Fiber, And Sisal Fiber, Jibril Maulana, Muhammad Ilman Nur Sasongko, Dewi Izzatus Tsamroh, Muchammad Yafis, Syekhan Maulana

Journal of Mechanical Engineering Science and Technology (JMEST)

A major development in materials science toward reinforcement materials in biopolymer composites has been caused by a worldwide trend toward sustainable manufacturing and the rise of the circular economy. However, their mechanical properties can often be affected by their hydrophilic properties, lack of surface compatibility, and their presence of molecular bonding, such as lignin and hemicellulose. Alkaline surface modification has been widely reported as an effective technique to increase structural stability and fibermatrix adhesion. This study evaluated the effects of alkalizing three types of local natural fibers—bamboo fiber (BF), pineapple leaf fiber (PALF), and sisal (SF)—with sodium hydroxide (NaOH) at …


Thermophysical, Rheological And Wear Resistance Of Canola Oil Biolubricant With Calcium Carbonate Additive Nanoparticle As Coolant In Cnc Machining, Alfandi Jaelani, Poppy Puspitasari, Diki Dwi Pramono, Alief Muhammad, Muhammad Kozin, Muhammad Kashif Nov 2025

Thermophysical, Rheological And Wear Resistance Of Canola Oil Biolubricant With Calcium Carbonate Additive Nanoparticle As Coolant In Cnc Machining, Alfandi Jaelani, Poppy Puspitasari, Diki Dwi Pramono, Alief Muhammad, Muhammad Kozin, Muhammad Kashif

Journal of Mechanical Engineering Science and Technology (JMEST)

Vegetable oil-based cutting fluids are of great importance in supporting green and sustainable manufacturing. This research introduces a new groundbreaking vegetable lubricant formulated with canola oil as the base material, coupled with CaCO3 nanoparticles synthesized from scallop shell waste and used as a cutting fluid in the AISI 1045 CNC machining process steel sprayed with minimum quantity lubrication (MQL). This investigation delves into the thermophysical, rheological, and wear resistance of the developed bio-lubricant. The results of this analysis show density value increased in the canola + CaCO3 0.15% sample by 3.28% of the pure canola sample, as did the viscosity …


Improvement Of Thermal Energy Storage Performance In Al-Al2o3 Composites Through Additions Of Copper: Evaluation Of Microstructure And Thermal Properties, Muhammad Hasan Basri, Ramang Magga, Muhammad Syaiful Fadly, Zikri Arifansyah Djaba, Muhammad Iqbal Ibrahim, Hidayat Hidayat, Yandi Yandi Nov 2025

Improvement Of Thermal Energy Storage Performance In Al-Al2o3 Composites Through Additions Of Copper: Evaluation Of Microstructure And Thermal Properties, Muhammad Hasan Basri, Ramang Magga, Muhammad Syaiful Fadly, Zikri Arifansyah Djaba, Muhammad Iqbal Ibrahim, Hidayat Hidayat, Yandi Yandi

Journal of Mechanical Engineering Science and Technology (JMEST)

The study aims to evaluate the influence of adding copper aluminum–alumina composite (Al–Al₂O₃) against characteristic thermal properties through metallurgical powder. Three variations of the composition of weight copper were used, namely 5%, 10%, and 15%, with aluminum as the matrix and alumina as the reinforcement. Thermal test covering analysis of thermal conductivity, specific heat, and microstructure characterization using SEM-EDX. The results show that adding Cu increases thermal conductivity significantly, with the highest mark achieved in the 15% Cu composite (6.47 W/m.°C). However, the increase in Cu content above 10% causes the agglomeration of particles and enhancements in porosity, which harms …