Claim Missing Document
Check
Articles

Found 37 Documents
Search

Pengaruh Jumlah Sudu Prototype Pembangkit Listrik Tenaga Mikrohidro Tipe Whirlpool Terhadap Kinerja Umurani, K; Siregar, Ahmad Marabdi; Al-Amin, Surya
Rekayasa Material, Manufaktur dan Energi Vol 3, No 2: September 2020
Publisher : Fakultas Teknik UMSU

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30596/rmme.v3i2.5272

Abstract

The water turbine is a device that converts water flow energy into shaft mechanical energy. Before being converted into mechanical energy in the turbine, the potential energy needs to be converted into kinetic energy first. The vortex will move the turbine blades which cause the runner to rotate so that there is a change in the kinetic energy of the water into mechanical energy in the turbine which is used to drive the generator and then into electrical energy. The purpose of this research is to analyze the torque that occurs on the shaft and turbine power. Water is flowed to the test with a pump through a control valve. The water flow is read by a rotameter attached to the pipe to the upper reservoir, while the torque is measured using a load cell, while the rotation is measured using a photo sensor interrupt to read the movement of the counter wheel. Data from load cell and photo sensor interruptor is read using Arduino Uno then the data is stored on laptop in excel file using plx-daq software. The minimum torque for the 8 blades is 9,12 kg.mm and 7.61 kg.mm for 6 blades at a water flow rate of 90 l / min. The maximum torque occurs at the 8 blades of 10.06 kg.mm while the maximum torque at blade 6 is 9,12 kg.mm at the same water flow rate of 150 l / min. The minimum turbine power for the 8 blades is 0.47 W and 0.27 W for the 6 blades at a water flow rate of 90 l / min. The maximum turbine power at blade 8 is 1.03 W, while the maximum power at blade 6 is 0.91 W at the same water flow rate of 150 l / min. From the data analysis, it can be seen that the power for the turbine with the number of blades 8 tends to be greater than the power for the turbine with 6 blades, but if the percentage increases in power between the 8 blades and 6 blades the trend decreases even though the flow rate is increasing.
Kajian Eksperimen Kemampuan Penyerapan Energi Pada Struktur Sarang Lebah Yang Diuji Secara Statis Lubis, Sudirman; Siregar, Ahmad Marabdi; Siregar, C A; Siregar, Irpansyah
Rekayasa Material, Manufaktur dan Energi Vol 4, No 1: Maret 2021
Publisher : Fakultas Teknik UMSU

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30596/rmme.v4i1.6697

Abstract

The honeycomb structure is a natural or man-made structure (material) that has a honeycomb geometry, which is aimed at lightweight construction material companies, also getting a quality level from the material selection. The purpose of this study was to analyze the energy absorption ability of the statistical pressure tester. Energy absorption is a method of how an object attenuates due to external pressure. The energy absorption test was carried out by means of a statistical press test, the test object made from aluminum plates in the form of a honeycomb structure with different hexagonal size variations. This section will compare the results of the stress-strain and energy absorption data on each tested specimen to see which one is more efficient among the three specimens with different hexagonal sizes. The final result of this tester will use a graph of vertical stress - strain and energy absorption capability by horizontal and vertical testing. Therefore the results of the greatest energy absorption are in the horizontal test position with a hexagonal size of 2 mm, and the energy placement is in a vertical test position with a hexagonal size of 6 mm.
Karakteristik Unjuk Kerja 2 Pompa Sentrifugal Dengan Susunan Seri Sebagai Turbin Pat Lubis, Sudirman; Siregar, Irpansyah; Siregar, Ahmad Marabdi
Rekayasa Material, Manufaktur dan Energi Vol 3, No 2: September 2020
Publisher : Fakultas Teknik UMSU

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30596/rmme.v3i2.5270

Abstract

The pump is a device used to move fluid from one place to another through a media pipe or channel. The energy in the fluid is produced from the impeller which converts the kinetic energy (velocity) of the liquid into potential (dynamic) energy. Besides being used to move fluid (fluid) at this time the pump can also be used as a turbine by changing the working principle of the pump by giving a drop of water at an altitude to rotate the impeller on the pump so that the pump can operate upside down or called a pump as turbine), in this study the impeller on the pump as a turbine is driven by a water flow or water pressure that is large enough, the water flow is sourced from two centrifugal pumps with a series arrangement that functions as a driving force or fluid distributor which is assumed to be a high water fall or head. The use of centrifugal pumps with a series arrangement is so as to produce a large head to get a high water fall or a maximum head for turning a pump as a turbine. This study uses an experimental method that is using two centrifugal pumps as a fluid distributor and one pump that is used as a turbine and uses a variation of 5 watt and 10 watt light bulb. From the calculation of the suction pump and pump as a turbine without using a light bulb pump speed namely 920.5 rpm and the specific speed of the turbine produced is 76.61 rpm. by using a 5 watt light bulb load the pump rotation speed is 553 rpm and the specific turbine speed produced is 44.24 rpm, using a 10 watt light bulb load the pump rotation speed is 335 rpm and the specific turbine speed produced is 26.8 rpm. The greater the value of the pump head, the resulting water discharge will be smaller and vice versa, the size and size of the pump head obtained is also influenced by the presence of load on theturbine.
Karakteristik Gugus Fungsi dan Kekuatan Impak Material Komposit Berpenguat Serat Serbuk Daun Nanas Tanjung, Iqbal; Lubis, Riadini Wanty; Nofri, Irfan; ., Affandi; Siregar, Chandra A; Siregar, Ahmad Marabdi; Efrida, Rizki
Rekayasa Material, Manufaktur dan Energi Vol 8, No 2: JULI 2025
Publisher : Fakultas Teknik UMSU

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30596/rmme.v8i2.25533

Abstract

The objective of this study is to investigate the impact strength and functional group characteristics, as identified through FTIR spectroscopy, of composite materials reinforced with pineapple leaf powder fibers that have undergone physical property enhancement via alkali treatment (NaOH). A series of processes were conducted to produce the pineapple leaf powder, starting with drying fresh pineapple leaves until they turned brown. The dried leaves were then cleaned and soaked in a 5% NaOH solution for durations of 1, 3, 5, 7, and 9 hours to modify their physical properties. After treatment, the leaves were rinsed thoroughly and oven-dried at 60°C for 5 hours. The dried leaves were subsequently ground and sieved using a 150-mesh screen. This study involved two main observations: functional group analysis using FTIR spectroscopy and mechanical performance evaluation through impact testing. A total of 30 composite specimens were prepared and fabricated using a stepwise lamination method, following the ASTM D256 impact testing standard. The results indicate that alkali treatment progressively degraded the hemicellulose and lignin content in the pineapple leaf fibers, significantly enhancing the impact energy absorption of the composite material. However, extended treatment durations adversely affected the fiber quality, leading to structural damage and reduced interfacial cohesion between the composite components.
DESAIN DAN PEMBUATAN ALAT PEMBERSIH INJECTOR PORTABLE SEPEDA MOTOR BERBASIS FLASHER Firdaus Hutasoit, Ricky Togu; Siregar, Ahmad Marabdi; Siregar, C A
Jurnal Pendidikan Vokasi Otomotif Vol. 6 No. 1 (2023): (November)
Publisher : Universitas Negeri Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21831/jpvo.v6i1.66000

Abstract

In the motorcycle system there is a component and the Electrical Full Injection System (EFI) of this Injector component functions to inject high-pressure fuel from the common rail according to the signal given by the ECU in a Tensioner contact state or the condition of the combustion chamber engine at Timin Injection optimum, the amount of fuel injection, fuel injection ratio and fogging conditions.Two-Way Electromagnetic controls the pressure in the chamber of the injector to control the start and finish of fuel injection.Orifice in the control chamber controls the angle of opening of the nozzle to control the ratio of fuel injection.Clogging of the nozzle holes causes the effect is that the acceleration power of the motorbike engine is decreasing. this makes it difficult for motorbikes to be operational again. After cleaning the dirt that clogs the injectors in the nozzle holes, making this tool can also extend the life of the injectors.Development is a process that is used to develop and investigate a product. The test results of this tool show that the injector cleaner works well. During testing with the Vario 125 motorbike, the injector misting produced +- 35 ml/minute. If an injector produces more than 15-20 ml/minute. Then the injector is still feasible to use and use.
Utilization and Experimental Use of Stainless Steel Metal Scrap Machinery Waste, St-40 Iron, Copper and Aluminum to Reduce Co, Hc, Co2 Elements in Vehicle Exhaust Siregar, Ahmad Marabdi; Siregar, Chandra A; Umurani, Khairul
Jurnal Pendidikan Vokasi Otomotif Vol. 6 No. 2 (2024): (Mei)
Publisher : Universitas Negeri Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21831/jpvo.v6i2.73269

Abstract

Air pollution due to motor vehicle exhaust emissions is increased. Polluted air harms human health dan the environment. Consequently, it is essential to make a sustained effort to reduce air pollution. The purpose of this research is to investigate the effect of adding aluminum scrap to the exhaust system of a motor vehicle on gas emissions composition. The motor vehicle exhaust system was modified to accommodate aluminum scrap placement. A gas analyzer was utilized to observe exhaust gas composition, such as carbon dioxide, hydrocarbon, and carbon monoxide.  Aluminum scrap with different masses was wrapped around the exhaust's inner tube in 50 gr, 70 gr and 90 gr. The engine speed was maintained at 500 rpm throughout the testing process. It was found that the temperature of the outer exhaust tube is in a range of 40 degrees Celsius to 50 degrees Celsius. The results revealed that the most appropriate amount of aluminum scrap was 90 gr n to reduce carbon monoxide, hydrocarbon, and carbon dioxide in an exhausts gas. The surprising outcome was 76.78 % of carbon monoxide content declined, and furthermore hydrocarbon, and carbon dioxide content were deteriorated by 61.63% and 78.37%, respectively.
Effectiveness of Ceiling Cassette Air Conditioner Placement on Building Comfort and Energy Efficiency: A Systematic Literature Review Dharma, Budi -; Siregar, Ahmad Marabdi
Rekayasa Material, Manufaktur dan Energi Vol 9, No 1: JANUARI 2026
Publisher : Fakultas Teknik UMSU

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30596/rmme.v9i1.28067

Abstract

The installation location of ceiling cassette air conditioning units is a critical factor in Heating, Ventilation, and Air Conditioning (HVAC) system design, particularly in public service buildings where high thermal comfort and energy efficiency are essential. This study aims to systematically examine the influence of ceiling cassette air conditioner placement on airflow distribution, thermal comfort, and building energy performance through a Systematic Literature Review (SLR) approach. The review analyzes peer-reviewed, open-access scientific articles published between 2020 and 2025, selected using a structured and transparent literature screening protocol. The synthesis results indicate that improper unit placement can lead to uneven temperature distribution, increased thermal discomfort, and higher energy consumption. Conversely, strategic placement that accounts for room geometry, airflow orientation, and occupied zones consistently improves thermal uniformity and enhances HVAC energy efficiency. These findings highlight that ceiling cassette unit placement should be considered an integral component of HVAC design rather than a secondary technical decision. This study contributes to the existing body of knowledge by providing evidence-based insights that support more effective and sustainable HVAC design practices for both researchers and industry practitioners.