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

Physical Sciences and Mathematics Commons™

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

Journal

Engineering

Universitas Indonesia

Articles 1 - 16 of 16

Full-Text Articles in Physical Sciences and Mathematics

Advancements In Characterization Of Ancient Potteries From Southeast Asia: A Review Of Analytical Techniques, Chitnarong Sirisathitkul Mar 2024

Advancements In Characterization Of Ancient Potteries From Southeast Asia: A Review Of Analytical Techniques, Chitnarong Sirisathitkul

Makara Journal of Science

Ancient potteries offer valuable information regarding technological advancements, life dynamics, cultural diversity, and trade routes in the past. Earthenware, stoneware, and porcelain from Southeast Asia have been characterized using several analytical techniques, as reviewed in this article. Fluorescent and diffracted X-rays give rise to elemental and phase compositions, respectively. Examination of molecular bonds requires vibrational spectroscopy, which is useful for the identification of organic materials in ancient potteries. With the advent of portable X-ray fluorescence and Raman spectrometry, on-site analysis of archeological ceramics is now possible. For in-depth analysis, synchrotron light sources can provide new insights into artifacts through X-ray …

Go to article

Nitrogen Gas Quenching Pressure Effect On Bs S155 Alloy Steel In Vacuum Furnace, Agus Mulyadi Hasanudin, Eddy Sumarno Siradj Dec 2023

Nitrogen Gas Quenching Pressure Effect On Bs S155 Alloy Steel In Vacuum Furnace, Agus Mulyadi Hasanudin, Eddy Sumarno Siradj

Journal of Materials Exploration and Findings

The production of metal and alloy products requires the use of heat treatment, when during the heat treatment process, quenching is a crucial step. The quenching medium can be anything from water, a salt bath, oil, air and gas. In a vacuum furnace, pressurized gas, most frequently nitrogen (N2) gas, serves as one of the quenching mediums. One of the drawbacks of the quenching process is the distortion and dimensional change of the parts. This paper aims to investigate the influence of nitrogen gas quenching pressure on the distortion and dimensional change of aerospace actuator gear planet parts …

Go to article

Combined Risk Based Inspection And Fault Tree Analysis For Repetitive 3-Phase Line Piping Leakage At West Java Offshore Topside Facility, Dona Yuliati, Akhmad Herman Yuwono, Datu Rizal Asral, Donanta Dhaneswara Dec 2023

Combined Risk Based Inspection And Fault Tree Analysis For Repetitive 3-Phase Line Piping Leakage At West Java Offshore Topside Facility, Dona Yuliati, Akhmad Herman Yuwono, Datu Rizal Asral, Donanta Dhaneswara

Journal of Materials Exploration and Findings

Hydrocarbon releases might result in serious consequences in various aspects. In addition to the contribution to environmental pollution, repetitive leakages need high repair costs. This study aim is to minimize potential repetitive leakage for other typical 3-phase piping systems. We conducted the risk assessment by adopting Risk Based Inspection (RBI) API 581 to identify risk level, calculating piping lifetime, recommended inspection plan and mitigations. The most relevant root causes can be obtained through quantitative Fault Tree Analysis (FTA). Observation and investigation was taken from eight 3-phase piping systems that experienced repetitive leakages. It has been found that the risk level …

Go to article

The Effect Of Heat Treatment And Chemical Treatment On Natural Fibre To The Durability Of Wood Plastic Composites – A Review, Nuratiqah Asyiqin Mohd Nasharudin, Nur Fatihah Sulaiman, Nurul Aziemah Mohammad, Wan Nor Raihan Wan Jaafar, Falah Abu Dr., Siti Norasmah Surip Jul 2023

The Effect Of Heat Treatment And Chemical Treatment On Natural Fibre To The Durability Of Wood Plastic Composites – A Review, Nuratiqah Asyiqin Mohd Nasharudin, Nur Fatihah Sulaiman, Nurul Aziemah Mohammad, Wan Nor Raihan Wan Jaafar, Falah Abu Dr., Siti Norasmah Surip

Journal of Materials Exploration and Findings

The application of WPC is not only limited to indoor applications but has been extended to exterior applications where properties of WPC could compromise during service life. WPC was derived from wood fiber of various sizes to reinforce polymers. Wood fiber has the advantage of a cheaper price, being abundantly available, and ease of processing, however, the critical factor is its hydrophilic nature, where moisture absorption is likely to occur. Thus, treatments for reducing the hydrophilicity of wood fibers are applied. By treatment of wood fiber, the surface impurities were removed, leaving the roughened surface of fibers, thus providing a …

Go to article

Utilization Of Cellulose Symbiotic Culture Of Bacteria And Yeast (Scoby) With Sweet Tea Media As Methylene Blue And Brilliant Green Biosorbent Material, Leonard Mateus Sigiro, Ahmad Maksum, Donanta Dhaneswara May 2023

Utilization Of Cellulose Symbiotic Culture Of Bacteria And Yeast (Scoby) With Sweet Tea Media As Methylene Blue And Brilliant Green Biosorbent Material, Leonard Mateus Sigiro, Ahmad Maksum, Donanta Dhaneswara

Journal of Materials Exploration and Findings

The cellulose from Symbiotic Culture of Bacteria and Yeast (SCOBY) can be used as a biosorbent for dye adsorption, such as Methylene Blue and Brilliant Green. This study used sweet tea with a 6% of sugar concentration and 14 days of fermentation time to synthesize biosorbent material from SCOBY. The results from this synthesis are then characterized using FTIR, SEM, and BET. From the result of characterization, it was found that SCOBY has pores formed from cellulose. The results of the average pore size are 1.5976nm with a pore volume of 0.229cc/g, while the specific surface area is 143.244m2/g. The …

Go to article

Enhancing Compatibility And Mechanical Properties Of Natural Rubber Composites, Krisma Yessi Sianturi, Adam Febriyanto Nugraha, Belle Kristaura, Mochamad Chalid May 2023

Enhancing Compatibility And Mechanical Properties Of Natural Rubber Composites, Krisma Yessi Sianturi, Adam Febriyanto Nugraha, Belle Kristaura, Mochamad Chalid

Journal of Materials Exploration and Findings

Pure natural rubber (NR) exhibits low mechanical properties, necessitating the incorporation of additives like vulcanizing agents and fillers. Carbon black and silica, conventional fillers, are relatively expensive and not environmentally friendly. This study explores using Oil Palm Empty Fruit Bunch (OPEFB) fiber as an affordable, abundant, and biodegradable alternative filler for NR. However, compatibility issues arise between the nonpolar NR and the polar OPEFB fiber. A latex-starch hybrid coupling agent (CA (NR-St)) was added to the composite formulation to address this. NR, OPEFB fiber, and the coupling agent were mixed using an open roll mill with a 10 phr OPEFB …

Go to article

Development Of Battery Materials To Function As Corrosion Protection On Car Body Plates, Tubagus Noor Rohmannudin, Sulistijono Sulistijono, Noval Adrinanda, Faridz Wira Dharma, Samuel Areliano Jan 2023

Development Of Battery Materials To Function As Corrosion Protection On Car Body Plates, Tubagus Noor Rohmannudin, Sulistijono Sulistijono, Noval Adrinanda, Faridz Wira Dharma, Samuel Areliano

Journal of Materials Exploration and Findings

Most car bodies made for mass production are made from steel or aluminum. Both are strong metals, but steel is cheaper than aluminum and is more commonly used in lower-end cars for a broader consumer range. The weakness of steel compared to aluminum is that it is susceptible to corrosion under certain conditions, and thus it may deteriorate over time without proper care. To prevent corrosion, modern cars are coated with paint to prevent direct contact with the environment. As a second line of protection, a car battery can be connected to the body to create an impressed current cathodic …

Go to article

Potential Of Biduri Fiber (Calotropis Gigantea) As Material For Oil Spill Absorbent, Anne Sukmawati, Wulan Septiani Jan 2023

Potential Of Biduri Fiber (Calotropis Gigantea) As Material For Oil Spill Absorbent, Anne Sukmawati, Wulan Septiani

Journal of Materials Exploration and Findings

Biduri fiber (Calotropis gigantea) is a natural hollow fiber with hydrophobic and oleophilic properties potentially used as oil spilled sorbent from seawater. This study aims to determine the absorption capacity and efficiency of the Biduri fiber and membrane to fuel oil. Measurement of oil absorption to seawater was carried out at various fiber weights (0.5-1.5 g), fiber composition (50-95%), contact time (10-90 minutes), temperature (30 and 50°C), and compared with commercial products. The results showed that the fiber weight variation of 0.5-1.5 g has an average absorption efficiency of 96.67%, and the highest absorption was obtained in a weight of …

Go to article

Coconut Shell Waste Treatment Technology For A Sustainable Waste Utilization: A Case Study Of The Smes In Bohol Village, Indonesia, Wahyu Anggo Rizal, Ria Suryani, Roni Maryana, Dwi Joko Prasetyo, Diah Pratiwi, Yuli Ary Ratnawati, Dini Ariani, Andri Suwanto Dec 2022

Coconut Shell Waste Treatment Technology For A Sustainable Waste Utilization: A Case Study Of The Smes In Bohol Village, Indonesia, Wahyu Anggo Rizal, Ria Suryani, Roni Maryana, Dwi Joko Prasetyo, Diah Pratiwi, Yuli Ary Ratnawati, Dini Ariani, Andri Suwanto

ASEAN Journal of Community Engagement

This project focused on the introduction of liquid smoke and bio briquette manufacturing technology to small and medium enterprises (SMEs) located in Bohol Village, Gunungkidul, Indonesia through technology transfer, training, and mentoring. These SMEs are engaged in the food business with the main product jenang ketan, a traditional food from Gunungkidul, especially in Rongkop District, and very popular among communities around and outside Gunungkidul. The traditional preparation of jenang ketan produces several by-products in the form of waste, which is dominated by coconut shell biomass. The project’s technology transfer was carried out through the procurement of a series of pyrolysis …

Go to article

Urban Farming: Empowerment To Increase Economic, Education, And Nutritional Benefit For The Sub-Urban Community, Nasruddin Nasruddin, Yusuf Donner Dwiyantama, Banu Muhammad, Anom Bowalaksono, Dian Ayubi, Sarah Islamiati Pertiwi Dec 2022

Urban Farming: Empowerment To Increase Economic, Education, And Nutritional Benefit For The Sub-Urban Community, Nasruddin Nasruddin, Yusuf Donner Dwiyantama, Banu Muhammad, Anom Bowalaksono, Dian Ayubi, Sarah Islamiati Pertiwi

ASEAN Journal of Community Engagement

This article discusses the urban farming program at Sekolah Master in Beji, Depok, Indonesia, which aims to provide the community with broader benefits, such as economy, education, and increased nutritional value. The project involves planting method that was introduced to this school community. The program itself consists of several stages, starting from the preparation—dissemination of the program and designing a plan for the greenhouse, the implementation—constructing the greenhouse and installing the automatic water system, planting the vegetation, and monitoring and evaluation of the program. Eventually, an evaluation of the successful program is required to determine whether the program can be …

Go to article

Utilization Of Biopertalite For Fuel Efficiency And Reduction In Co And Co2 Gas Emissions In Four-Wheel Motor Vehicles, Ridwan Iskandar, Hadiyanto Hadiyanto, Suherman Suherman, Zainul Akmar Zakaria Dec 2022

Utilization Of Biopertalite For Fuel Efficiency And Reduction In Co And Co2 Gas Emissions In Four-Wheel Motor Vehicles, Ridwan Iskandar, Hadiyanto Hadiyanto, Suherman Suherman, Zainul Akmar Zakaria

Makara Journal of Technology

Emissions of carbon monoxide (CO) and carbon dioxide (CO2) gases are the main problem that must be rectified as they are harmful and contribute to global warming through the greenhouse gas effect. In Indonesia, motor vehicles, especially four wheelers, are one of the biggest contributors with up to 71 million tons of CO2 emissions and energy consumption of 179 million barrel of oil equivalent. Bioethanol has octane rating >100, which is higher than that of gasoline; and emission contribution of only 0.02 kg/L, which is lower than that from gasoline (2.23 kg/L). Accordingly, a mixture of gasoline and bioethanol is …

Go to article

Chitosan Oligosaccharides As A Nanomaterial Platform: Biological Properties And Applications In The Biomedical And Pharmaceutical Fields, Muhamad Alif Razi Dec 2022

Chitosan Oligosaccharides As A Nanomaterial Platform: Biological Properties And Applications In The Biomedical And Pharmaceutical Fields, Muhamad Alif Razi

Makara Journal of Science

Chitosan oligosaccharides (COS) have been introduced as marine-derived biomaterials with potential health benefits and good water solubility properties. This study presents an overview of the promising nanomaterial platform for biomedical and pharmaceutical applications of COS. The health benefits of COS, primarily their antioxidant and protective effects, anti-inflammatory activity, antidiabetic properties, and cholesterol-lowering effects are discussed. Furthermore, the promising recent articles on specific topics such as drug delivery systems and nanobiomaterials, are highlighted

Go to article

Investigation Of The Effect Of Corundum Layer On The Heat Transfer Of Sic Slab, Sri Elsa Fatmi, Donanta Dhaneswara, Muhammad Anis, Ahmad Ashari Dec 2022

Investigation Of The Effect Of Corundum Layer On The Heat Transfer Of Sic Slab, Sri Elsa Fatmi, Donanta Dhaneswara, Muhammad Anis, Ahmad Ashari

Journal of Materials Exploration and Findings

Aluminum is the most widely used metal in industry. Aluminum smelting is one of the important steps that needs to be carried out to produce products made of aluminum metal with good quality. In the process of smelting aluminum there are several problems that occur, one of which is the growth of corundum in Si C refractories which affects the quality of aluminum melt and the durability of Si C refractories. This research was conducted to see the heat transfer in Si C and the effect of the presence of Corundum on heat transfer. This research was carried out by …

Go to article

Dynamic Rbi With Central Difference Method Approach In Calculation Of Uniform Corrosion Rate: A Casestudy On Gas Pipelines, M.Riefqi Dwi Alviansyah, Fernanda Hartoyo, Zahra Nadia Nurullia, Ari Kurniawan Dec 2022

Dynamic Rbi With Central Difference Method Approach In Calculation Of Uniform Corrosion Rate: A Casestudy On Gas Pipelines, M.Riefqi Dwi Alviansyah, Fernanda Hartoyo, Zahra Nadia Nurullia, Ari Kurniawan

Journal of Materials Exploration and Findings

The oil and gas industry generally uses a piping system to drain fluids. Even though the pipes used have been well designed, the use of pipes as a means of fluid transportation still provides the possibility of failure that can occur at any time, one of which is due to uniform corrosion. The use of standard Risk Based Inspection (RBI) according to the API RBI 581 document has been widely used to anticipate potential failures to pipe components. The use of standard RBI can reduce the risk of failure significantly. Because the standard RBI considers the component risk value to …

Go to article

Estimation Of The Bubble Point Pressure Of Multicomponent Reservoir Hydrocarbon Fluids, Benjamin Sunday Usen, Chidi Obi Sep 2022

Estimation Of The Bubble Point Pressure Of Multicomponent Reservoir Hydrocarbon Fluids, Benjamin Sunday Usen, Chidi Obi

Makara Journal of Science

This study developed a novel C-sharp (C#) programming language for the estimation of bubble point pressure (BPP) of various hydrocarbon mixtures at equilibrium state. The methodology was based on vapor–liquid equilibrium calculation using Peng Robinson equation of state implementation, thermodynamic equilibrium calculation and Newton-Raphson’s method for the successive substitution of the unknown variables. The equal fugacity constraint can be satisfied by obtaining the equilibrium which serves as a criterion for two or more phases to exist at equilibrium. The problem was resolved by searching for a pressure that will satisfy the two constraints. Complex calculation was performed by successively substituting …

Go to article

Function, Meaning, And Message Of The Natural Environtment In The Story Of Keong Mas, Adinda Bunga Utami, Nanny Sri Lestari Jul 2019

Function, Meaning, And Message Of The Natural Environtment In The Story Of Keong Mas, Adinda Bunga Utami, Nanny Sri Lestari

International Review of Humanities Studies

This research discusses the meaning and function of the natural environment in one folk tale that is well known in the Javanese community. This folktale is known in all circles of society, despite having social differences. An interesting problem in this folklore is the placement of functions and environmental meanings as the main elements of stories or tales. The focus of this research is to raise the function and meaning of the natural environment contained in one story of Keong Mas. This study aims to explain carefully the function and meaning of the natural environment which is the background of …

Go to article