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Full-Text Articles in Mechanical Engineering

The Effect Of Current Density And Hard Chrome Coating Duration On The Mechanical And Tribological Properties Of Aisi D2 Steel, Indah Uswatun Hasanah, Dedi Priadi, Donanta Dhaneswara Jul 2023

The Effect Of Current Density And Hard Chrome Coating Duration On The Mechanical And Tribological Properties Of Aisi D2 Steel, Indah Uswatun Hasanah, Dedi Priadi, Donanta Dhaneswara

Journal of Materials Exploration and Findings

The effect of hard chromium coating on AISI D2's mechanical properties and wear resistance has been investigated using the electrolysis technique with varying current and coating duration. The variations of current used are 0.8 A, 1.2 A, and 1.6 A, while the coating duration used are 300, 600 and 900 seconds. Characterization of the films was conducted using SEM-EDS, and XRD. It can be observed from SEM characterization that the chrome grains resulted from the electroplating process are fine. The XRD identify chrome compund on the surface coating. The highest hardness value was 520.6 HV on a sample with a …


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 …


Multi-Mode Total Focusing Method (Mtfm) To Detect High-Temperature Hydrogen Attack (Htha) – A Review, Anjar Oktikawati, Rini Riastuti, Nursidi Yuanto May 2023

Multi-Mode Total Focusing Method (Mtfm) To Detect High-Temperature Hydrogen Attack (Htha) – A Review, Anjar Oktikawati, Rini Riastuti, Nursidi Yuanto

Journal of Materials Exploration and Findings

High temperature hydrogen attack (HTHA) is a commonly observed harm component in carbon steels exposed to high temperature and pressure in a hydrogen-rich environment. Hydrogen together with carbon responds to produce methane. The formation of methane bubbles in steel can lead to loss of fracture toughness and lead to intergranular cracking. The main challenge of this problem lies in early warning systems that can detect these bubble clusters before they reach the advanced stage. Several advanced ultrasonic inspections have been developed over the years due to the challenges of inspecting materials for defects and discontinuities. These cover time-of-flight diffraction (ToFD), …


Estimating Remaining Life And Fitness-For-Services Evaluation Of Fuel Piping Systems, Sekar Putri Purwidyasari, Ahmad Isni Kurniawan, Deni Ferdian May 2023

Estimating Remaining Life And Fitness-For-Services Evaluation Of Fuel Piping Systems, Sekar Putri Purwidyasari, Ahmad Isni Kurniawan, Deni Ferdian

Journal of Materials Exploration and Findings

Assets life extension are required to predict the design life expiry based on condition and effects of deterioration. The remaining life assessment will answer the questions about timing of the component or equipment will lead to failure and shall be evaluated by inspection and maintenance monitoring. This study elaborates process calculation and analysis by using remaining life assessment and fitness for services method according to API 579-1/ASME FFS-1 for process piping area. The result of remaining useful life estimation and estimated life has been proposed. There are 11 piping systems based on the condition monitoring with thickness measurements. The result …


Performance Of A Solar Seawater Distillation With A Triangle Prism Cover And A Fin-Type Absorber, Risse Entikaria Rachmanita, Miftah Khoirul Umam Apr 2023

Performance Of A Solar Seawater Distillation With A Triangle Prism Cover And A Fin-Type Absorber, Risse Entikaria Rachmanita, Miftah Khoirul Umam

Makara Journal of Technology

Solar-powered distillation is a seawater distillation method that utilizes solar heat as its main energy source for the purpose producing freshwater and a by-product of the distillation process in the form of salt. This study aims to determine the performance of a solar seawater distillation design with a semi-batch system by combining a fin-type absorber plate and a triangular prism cover. This design is equipped with a reflector and absorber plate, which has a surface area of 0.3969 m2 with a volume capacity of seawater that can be accommodated in a basin of ±24 liters. It uses a knockdown system …


Freespan Analysis For Subsea Pipeline Integrity Management Strategy, Nurul Hadi, Muhammad Helmi, Edo Cathaputra, Dedi Priadi, Donanta Dhaneswara Jan 2023

Freespan Analysis For Subsea Pipeline Integrity Management Strategy, Nurul Hadi, Muhammad Helmi, Edo Cathaputra, Dedi Priadi, Donanta Dhaneswara

Journal of Materials Exploration and Findings

Abstract. Over a rough seabed or on seabed subject to scour, freespans can occur when contact between a subsea pipeline and the seabed is lost over an acceptable distance. When this exceeds the allowable freespan length, design stresses can be exceeded, and a vortex induced vibration (VIV) response can be initiated, resulting in the risk of fatigue failure. If this is not predicted and controlled properly, it will affect pipeline integrity, leading to expensive rectification and intervention work. Freespan analysis consisted primarily of a screening check in which the as-found freespans from Remotely Operated Vehicle (ROV) or multibeam Side …


Effect Of Austenization And Repeated Quenching On The Microstructures And Mechanical Properties Of Wear-Resistant Steel, Yanuar Nugraha, Myrna Ariati Mochtar Jan 2023

Effect Of Austenization And Repeated Quenching On The Microstructures And Mechanical Properties Of Wear-Resistant Steel, Yanuar Nugraha, Myrna Ariati Mochtar

Journal of Materials Exploration and Findings

This study was focused on determining the effect of repeated austenitization and quenching on mechanical properties and microstructure. The experiment was carried out in a rolled quencher facility with a heat treatment process of one to two times, with parameters of an austenizing temperature of 9500C and quenching at a temperature of 8500C with pressurized water media. Testing of specimens, including microstructure observations and hardness testing. The repeated heat treatment process showed an increase in hardness of 0.79% on one-time repeated heat treatment and 1.65% on two repeated heat treatments. This occurs due to the presence accompanied by refinement of …


Development Of Automated Egg Incubator With Backup Power Supply, Allen N. Maroma, Dolly P. Maroma, Bernardo A. Pangilinan Jan 2023

Development Of Automated Egg Incubator With Backup Power Supply, Allen N. Maroma, Dolly P. Maroma, Bernardo A. Pangilinan

ASEAN Journal of Community Engagement

This study addresses the development of an automated egg incubator with backup power supply that could benefit farmer communities through the developmental research approach. A prototype is developed to respond to the needs for uninterrupted incubation which is affected by the frequent power outages that reduce its efficiency in egg handling. In this project, the automated egg incubator with a backup power supply is designed to hatch a capacity of 150 eggs (75 setters and 75 hatchers) every 21 days, ensuring continuous operation even in the absence of a consistent power supply. An inverter, connected to a battery, ensures a …


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 …


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 …


Damage Stability Study Of A 500 Dw Ro-Ro Ferry Vessel, Zulfaidah Ariany, Budhi Santoso, Sarwoko Sarwoko, Nauval Abdurrahman Prasetyo Dec 2022

Damage Stability Study Of A 500 Dw Ro-Ro Ferry Vessel, Zulfaidah Ariany, Budhi Santoso, Sarwoko Sarwoko, Nauval Abdurrahman Prasetyo

Makara Journal of Technology

The development of the crossing transportation industry is currently increasing in the island areas. The use of Ro-Ro type ferry boats is extremely efficient in moving people, goods, and vehicles. The current research focuses on the damage stability of the 500 DWT Ro-Ro ferry, which aims to meet the needs of the Ro-Ro ferry in the archipelago area. The previously existing initial design of a barge hull with a main size Lpp = 40.15 m, B = 12 m, H = 3.2 m, and T = 2.15 m was used to analyze the damage stability condition further. First, the drawings …


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 …


Structural Risk-Based Underwater Inspection (Rbui) As A Cost Reduction Of Field’S End Of Production Life, Ivan Fitrian Putra, Johny Wahyuadi Soedarsono, Mirza Mahendra, Yuki Haidir, Faisal Dwiyana Purnawarman, Iwan Sukirna, Widi Hernowo Dec 2022

Structural Risk-Based Underwater Inspection (Rbui) As A Cost Reduction Of Field’S End Of Production Life, Ivan Fitrian Putra, Johny Wahyuadi Soedarsono, Mirza Mahendra, Yuki Haidir, Faisal Dwiyana Purnawarman, Iwan Sukirna, Widi Hernowo

Journal of Materials Exploration and Findings

Mubadala Petroleum operates offshore platforms in a southern Makassar Straits that needs to be periodically inspected. The cost for the inspection is massive due to the high cost of mobilization and demobilization of vessels including crew and equipment. In response of a new approach to reduce cost, a Risk-Based Underwater Inspection (RBUI) methodology is developed. This RBUI purpose is to reduce the inspection interval of the offshore platform, from every 2 years to a longer period[1]. There are existing RBUI methodologies, which are already developed and implemented in other companies[5]. Purpose of this paper is to …


Risk Management Of Carbon Steel Piping In Sweet Environment Multiphase Fluid Production, Triadhi Panthun Tiggor, Rini Riastuti Dec 2022

Risk Management Of Carbon Steel Piping In Sweet Environment Multiphase Fluid Production, Triadhi Panthun Tiggor, Rini Riastuti

Journal of Materials Exploration and Findings

As well reserved depleted and limited, it is necessary to lower the capital expenditure so that lifting SZ reservoir be more profitable. This article first contextualizes the effort done to increase the hydrocarbon lifting in a mature field. Despite the importance to sustain the production, and massive studies done to quantify the associate risk, no structured methodology proposed to manage the risk in respect to optimize the production expenditure by selection of carbon steel as alternative for corrosion resistance material piping. Hence, this article proposed a framework to support the decision-making process to operate in safely manner. Real case study …


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 …


The Comparison Of Pipe Thickness Selection Method Using Full Flange Rating And Non-Full Flange Rating Of Cryogenic Services In An Lng Plant Construction, Ari Agustar, Isdaryanto Iskandar, Wahyuaji Narottama Putra Dec 2022

The Comparison Of Pipe Thickness Selection Method Using Full Flange Rating And Non-Full Flange Rating Of Cryogenic Services In An Lng Plant Construction, Ari Agustar, Isdaryanto Iskandar, Wahyuaji Narottama Putra

Journal of Materials Exploration and Findings

Significant growth of gas demand as a source of power generation for domestic use and industries, mainly in the developed countries, has forced the effort to secure the gas supplies located thousands of miles away across the sea as an economical way of gas transportation instead of transporting by pipeline. LNG technology was created as the solution. Natural gas is refrigerated below its boiling point (-160oC to -162oC), known as cryogenic temperature or cryogenic service. Material of Construction (MOC) selection report showed that 304/304L and 316/316L Stainless Steel pipe could withstand and be suitable for this …


Evaluation Of Material Request Order To Support Sustainable Construction, Fajar Susilowati, Nur Nahdiah Anggraeni Aug 2022

Evaluation Of Material Request Order To Support Sustainable Construction, Fajar Susilowati, Nur Nahdiah Anggraeni

Makara Journal of Technology

This study was conducted on one of Indonesia’s apartment projects, in which reinforced concrete is the main structure. Based on existing project data, this project experienced a decline in the construction work’s progress, thus reducing the project’s overall progress. This decline occurred because the delivery of concrete reinforcement material was delayed. This study aimed to determine the process of material request order and its relationship with the work implementation, as well as the factors that influenced the delayed arrival of concrete reinforcement material at the project site. The method used in this study was observation and interview. Data were analyzed …


Contents, Jaka Fajar Fatriansyah Aug 2022

Contents, Jaka Fajar Fatriansyah

Journal of Materials Exploration and Findings

No abstract provided.


Preface Of Volume 1 Issue 1 On Journal Of Materials Exploration And Findings (Jmef), Jaka Fajar Fatriansyah Aug 2022

Preface Of Volume 1 Issue 1 On Journal Of Materials Exploration And Findings (Jmef), Jaka Fajar Fatriansyah

Journal of Materials Exploration and Findings

No abstract provided.


The Optimization Of Failure Risk Estimation On The Uniform Corrosion Rate With A Non-Linear Function, Fernanda Hartoyo, Jaka Fajar Fatriansyah, Imam Abdillah Mas'ud, Farhan Rama Digita, Hanna Ovelia, D. Rizal Asral Aug 2022

The Optimization Of Failure Risk Estimation On The Uniform Corrosion Rate With A Non-Linear Function, Fernanda Hartoyo, Jaka Fajar Fatriansyah, Imam Abdillah Mas'ud, Farhan Rama Digita, Hanna Ovelia, D. Rizal Asral

Journal of Materials Exploration and Findings

Failures in the oil and gas pipeline system are conditions that must be avoided and anticipated because the losses due to the failures can occur at a very high level. Internal corrosion is one of the significant causes of the failures in pipeline systems. In addition, this type of corrosion is due to the high content of carbon dioxide and other corrosive substances in crude oil and natural gas. Therefore, an optimal inspection scheduling system is required to prevent the possibility of pipeline failures due to corrosion and to avoid any overspending on the budget due to excessive inspection scheduling. …


Material Selection Of Below-Knee Leg Prosthetics, Raihan Kenji Rizqillah Aug 2022

Material Selection Of Below-Knee Leg Prosthetics, Raihan Kenji Rizqillah

Journal of Materials Exploration and Findings

The effort to select the best pylon material, part of below-knee leg prosthetic, has been performed. It begins with function analysis to generate design requirement, which concludes that the objective is to select material that gives proper mechanical properties with lowest weigth and cost. Constraint requirements eliminate unsuitable material. Material indices, a scoring function, are derived from objective with respect to a function, and used for ranking material candidates. Ranking from material indices gives top material candidates of woods. Al alloy, Mg alloy, and ferrous alloy. Further seek of documentation is undertaken by failure analysis, value analysis, fabrication, and environmental …


The Effect Of Sample Placement In The Furnace During The Heat Treatment Process Of 7075-T6 Aluminum Alloy On Microstructure, Hardness, And Electrical Conductivity, Donanta Dhaneswara, Hardi Rindharto, Muhammad Syauqi Aqilafif Aug 2022

The Effect Of Sample Placement In The Furnace During The Heat Treatment Process Of 7075-T6 Aluminum Alloy On Microstructure, Hardness, And Electrical Conductivity, Donanta Dhaneswara, Hardi Rindharto, Muhammad Syauqi Aqilafif

Journal of Materials Exploration and Findings

This paper reports the effects of sample placement during the heat treatment on the microstructural morphology and mechanical properties of 7075 Al alloy such as hardness value and electrical conductivity. The material was in the formed of Al alloy sheets where samples were machined into a square with dimensions of 1.5 x 1.5 inch. The 7075-T0 Al alloy as samples were given heat treatment by precipitation hardening (aging) at temperature 120°C for 24 hours, so it becomes 7075-T6 Al alloy. Samples were subjected to some mechanical tests and the morphology of the resulting microstructures were characterized by optical microscopy. The …


Planning Of Air Conditioner Cooling Load In The Dean Room Of The Faculty Of Engineering And Information Technology University Of Pgri Semarang, Slamet Supriyadi, Irna Farikhah, Suhartono Suhartono Aug 2022

Planning Of Air Conditioner Cooling Load In The Dean Room Of The Faculty Of Engineering And Information Technology University Of Pgri Semarang, Slamet Supriyadi, Irna Farikhah, Suhartono Suhartono

Journal of Materials Exploration and Findings

The specification of the cooling load or chiller in the FTI UPGRIS dean's room currently requires a review of the distribution of cooling air in the room due to the number of electronics and occupants in the room and the size of the air conditioner. Therefore, the room must be taken into account to prevent insufficient cooling load, As a result, it is impossible to reach the desired temperature and humidity set. The FTI Dean's room has an air conditioner with a cooling capacity of 1 unit. It should be able to cover the amount of cooling in the room. …


Enhancement Of Biogas Production Through Solid-State Anaerobic Co-Digestion Of Food Waste And Corn Cobs, Lukhi Mulia Shitophyta, Anisa Salsabila, Firanita Angraini Putri, Siti Jamilatun Apr 2022

Enhancement Of Biogas Production Through Solid-State Anaerobic Co-Digestion Of Food Waste And Corn Cobs, Lukhi Mulia Shitophyta, Anisa Salsabila, Firanita Angraini Putri, Siti Jamilatun

Makara Journal of Technology

Although biogas has been primarily produced through liquid anaerobic digestion, this method leads to the floating and stratification of fibers and non-homogeneous mixing, which can reduce the biogas yield. Alternatively, biogas can be produced by the solid-state anaerobic digestion (SS-AD) of organic material with a high solid content, such as corn cobs. We investigated the co-digestion of food waste and corn cobs as a biomass feedstock for SS-AD in biogas production. We measured the effects of the total solid (TS) content, percentage of food waste, and reduction in volatile solids (VS), from which we determined its appropriate kinetic model. We …


Control Strategy For Solar Energy-Saving Lamps For Optimized Energy Utilization And Sustainability Of Operation Durability: Indonesia Case, Burhanuddin Halimi, Agus Purwadi, Nana Heryana Apr 2022

Control Strategy For Solar Energy-Saving Lamps For Optimized Energy Utilization And Sustainability Of Operation Durability: Indonesia Case, Burhanuddin Halimi, Agus Purwadi, Nana Heryana

Makara Journal of Technology

To solve the electrification ratio issue, the Indonesian government has promoted the use of solar energy-saving lamps. This study proposes a control strategy that adopts current reference time-based profiling for solar energy-saving lamps. For optimal energy consumption, the current reference profile is determined according to users’ daily energy requirements. From the aspect of user comfort, a gradual step reference profile is also introduced to provide a subtle change in lighting intensity level. The proposed control strategy can minimize energy consumption and optimize the operation durability of the system. The concept is verified by simulating four scenarios, the results of which …


Poly(2-Hydroxyethyl Methacrylate) Hydrogels For Contact Lens Applications–A Review, Kushendarsyah Saptaji, Nurlaely Rohmatul Iza, Sinta Widianingrum, Vania Katherine Mulia, Iwan Setiawan Sep 2021

Poly(2-Hydroxyethyl Methacrylate) Hydrogels For Contact Lens Applications–A Review, Kushendarsyah Saptaji, Nurlaely Rohmatul Iza, Sinta Widianingrum, Vania Katherine Mulia, Iwan Setiawan

Makara Journal of Science

The emerging technology in biomedical engineering requires biocompatible materials, which are also referred to as biomaterials. For a material to be considered biocompatible, it should not interact with human tissues in a harmful way, and vice versa. Various properties of biocompatible materials, such as mechanical and optical properties, have to be considered for different biomedical applications. One of the most popular applications of biomaterials is for contact lenses. Hydrogels, specifically poly(2-hydroxyethyl methacrylate) (PHEMA) hydrogels, are among the most popular ones in ophthalmologic applications, especially in soft contact lenses. This paper reviews the use of PHEMA hydrogels as one of the …


Comparison Of Concrete And Steel Jacket Methods For Reinforcing A Concrete Bridge Pier By Numerical And Experimental Studies, Hadi Faghihmaleki Aug 2021

Comparison Of Concrete And Steel Jacket Methods For Reinforcing A Concrete Bridge Pier By Numerical And Experimental Studies, Hadi Faghihmaleki

Makara Journal of Technology

Various rehabilitation and strengthening procedures have been developed in recent decades. A study to determine which methods can be implemented to increase the useful life of the bridge before strengthening must be performed. In this study, the seismic behavior of a reinforced concrete bridge pier with dimension 3.5 × 3.5 m, which was reinforced by two steel and a concrete jacket, was investigated. Nonlinear geometric models and materials were analyzed to estimate the seismic parameters of the pier. Results show an increase in energy absorption, ultimate strength, and ductility for the steel jacket, as well as a greater increase in …


Effect Of Arc Plasma Sintering On The Structural And Microstructural Properties Of Fe-Cr-Ni Austenitic Stainless Steels, Parikin Parikin, M. Dani, A. Dimyati, N. D. Purnamasari, B. Sugeng, M. Panitra, A. Insani, T. H. Priyanto, S. Mustofa, Syahbuddin Syahbuddin, A. Huang Aug 2021

Effect Of Arc Plasma Sintering On The Structural And Microstructural Properties Of Fe-Cr-Ni Austenitic Stainless Steels, Parikin Parikin, M. Dani, A. Dimyati, N. D. Purnamasari, B. Sugeng, M. Panitra, A. Insani, T. H. Priyanto, S. Mustofa, Syahbuddin Syahbuddin, A. Huang

Makara Journal of Technology

X-ray diffraction techniques were performed to determine the actual crystal structure of A2 austenitic stainless steel (ASS) as-cast and A2 ASS after arc plasma sintering (APS) for 2 s. Computations were conducted on the basis of the Bragg arithmetic formula by comparing the S2 arithmetic with the interplanar spacing. The Bragg arithmetic formula is a simple series for the determination of the crystalline phase of materials based on the Miller indices of cubic shapes or other shapes. A2 ASS as-cast was identified to have a crystal structure of face-centered cubic with lattice parameter a = 3.58 Å. A similar crystal …


Trend Significance Levels Of Rain Onset And Cessation And Lengths Of The Wet And Dry Seasons In Epe, Lagos State, Nigeria, Adekunle Adedeji Alli, Olorunwa Eric Omofunmi Aug 2021

Trend Significance Levels Of Rain Onset And Cessation And Lengths Of The Wet And Dry Seasons In Epe, Lagos State, Nigeria, Adekunle Adedeji Alli, Olorunwa Eric Omofunmi

Makara Journal of Technology

This study aims to reduce crop failure resulting from a dry spell, which is the first occurrence of unsustainable rainfall that deceives farmers into planting. Thus, trends need to be tested using hypothesis, kurtosis, and other statistics to analyze the risks associated with unstable planting calendars and their possible mitigation strategies. The daily rainfall data from 1982 to 2018 were obtained from the archive of NASA/POWER SRB/FLASH, and the research location is Epe, Lagos State, Nigeria, which lies at latitude 6.585° N and longitude 3.962° E. Microsoft Excel was used to perform the tests. Results show that the null hypothesis …


Kinetic Modeling Study Of Laminar Burning Velocity Of Gasoline–Ethanol–Methanol Blends At Elevated Temperature And Pressure, Ahmad Syihan Auzani, Cahyo Setyo Wibowo, Riesta Anggarani, Yulianto Sulistyo Nugroho, Bambang Sugiarto Aug 2021

Kinetic Modeling Study Of Laminar Burning Velocity Of Gasoline–Ethanol–Methanol Blends At Elevated Temperature And Pressure, Ahmad Syihan Auzani, Cahyo Setyo Wibowo, Riesta Anggarani, Yulianto Sulistyo Nugroho, Bambang Sugiarto

Makara Journal of Technology

Gasoline–ethanol–methanol (GEM) blends have been considered to replace pure gasoline as spark ignition engine fuel. Their physical and chemical properties and performance and emission measurements from real engines have been reported previously. However, a fundamental study that can explain the unique results of GEM compared with those of pure gasoline is lacking. This study aims to compare the laminar burning velocity of GEM blends at different mixtures, equivalence ratios, temperatures, and pressures with that of pure gasoline. A laminar flame propagation model and reaction mechanisms from the literature were were for a numerical simulation. In this study, the chemical components …