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Irza Sukmana
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Journal of Engineering and Scientific Research (JESR)
Published by Universitas Lampung
ISSN : 26850338     EISSN : 26851695     DOI : https://doi.org/10.23960/jesr.v4i1.78
Core Subject : Science, Engineering,
Civil Engineering, Building, Construction & Architecture Computer Science & IT Control & Systems Engineering Engineering Industrial & Manufacturing Engineering
The focus and scopes of JESR is on but not limited to Mechanical Engineering and Material Sciences, Chemical and Environmental, Industrial and Manufacturing Engineering, Computer and Information Technology, Electrical and Telecommunication, Civil and Geodetic Engineering, Architecture and Urban Planning, Geophysical Science and Engineering, and other multidisciplinary research. The main criteria for publication are including the originality, scientific quality and interest to the aim and focus. JESR publishes twice a year for June and December editions. We welcome for publication collaborations with organizer of International Seminars, Conferences and Symposiums around the world. We are encouraging authors to submit their manuscript through our online system.
Arjuna Subject : Teknik (semua kategori) - Teknik (Lain-Lain)
Articles 130 Documents
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Analysis of Losses Due to Load Unbalance in a 2000 kVA Transformer at Supermall Mansion 2 Tower Tanglin Surabaya Reza Sarwo Widagdo; Aris Heri Andriawan
Journal of Engineering and Scientific Research Vol. 5 No. 2 (2023)
Publisher : Faculty of Engineering, Universitas Lampung Jl. Soemantri Brojonegoro No.1 Bandar Lampung, Indonesia 35141

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.23960/jesr.v5i2.144

Abstract

The load unbalance causes a neutral current, the current flowing in the neutral conductor will cause an increase in losses in the transformer. The greater the losses incurred, the efficiency and reliability of the transformer will decrease. Based on this, a study was conducted on analyzing the losses on distribution transformers at Supermall Mansion 2 Tower Tanglin which aims to determine the percentage value of transformer loading, the value of transformer imbalance, the value of transformer losses, and the value of transformer efficiency. This is done so that the value of the installed transformer does not exceed the applicable SPLN value. During the measurement, it was found that the percentage value of the transformer loading was 38.88% during the daytime and 48.89% at night (maximum SPLN 80%, minimum 40%). The load unbalance value is 11.66% during the daytime and 10.33% at night (SPLN is categorized as good if < 10%). Copper losses (Pcu) are 91.3 kW during the daytime and 94.2 kW at night. The value of losses due to neutral currents is 0.134 kW with a percentage of 0.0071% during the daytime and 0.173 kW with a percentage of 0.0090% at night. The percentage of the current value in the neutral conductor is 26.36% during the day and 24.04% at night (SPLN is categorized as good if < 20%).
A Influence of Reservoir Water Level Fluctuations of Reservoir B (Rusunawa) on Groundwater Availability at the Environment of Lampung University: English Erwanto, Erwanto
Journal of Engineering and Scientific Research Vol. 5 No. 2 (2023)
Publisher : Faculty of Engineering, Universitas Lampung Jl. Soemantri Brojonegoro No.1 Bandar Lampung, Indonesia 35141

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.23960/jesr.v5i2.145

Abstract

The presence of four reservoirs as rainwater collection infrastructure at the University of Lampung is expected to enhance the infiltration process and recharge the groundwater aquifers. However, the threat of water scarcity in the area may arise due to the reduction of recharge areas. Therefore, a comprehensive study is necessary to understand the important factors in maintaining groundwater availability. This research aims to analyze groundwater aquifers, identify fluctuations in the water level of Reservoir B, and analyze the relationship between the elevation of the water level in the reservoir and the availability of groundwater in the University of Lampung environment. The research methodology involves the interpretation of geoelectric data and the calculation of water level fluctuations in the reservoir. The analysis results indicate that the shallow groundwater aquifer is estimated to be located at depths ranging from 10 to 30 meters, while the deeper aquifer is situated at depths of 80 to 130 meters with a layer of sandy tuff. The highest fluctuation in water level is recorded at 14 cm during rainfall with an intensity of 52.1 mm/day. There were no significant changes in the water level observed during rainfall with intensities ranging from 0 to 2.4 mm/day, and the average fluctuation observed is approximately 0.5 cm every 8 hours.
BLDC Motor Stability Management Using Adaptive PID (MRAC-PID) Aulia, Zahwa Dinda; Murdika, Umi; Alam, Syaiful
Journal of Engineering and Scientific Research Vol. 5 No. 2 (2023)
Publisher : Faculty of Engineering, Universitas Lampung Jl. Soemantri Brojonegoro No.1 Bandar Lampung, Indonesia 35141

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.23960/jesr.v5i2.147

Abstract

BLDC motors have become popular in various industries such as automotive, consumer, healthcare, industrial automation, and instrumentation due to their optimal performance. To keep the BLDC motor in optimal condition, a control engineering system is required that serves as a controller. A single Proportional Integral Derivative (PID) control system is only suitable for linear conditions, so it cannot produce satisfactory output when there is a change in set point. To overcome this obstacle, an adaptive PID control system known as MRAC-PID control system is applied, which is able to control the stability of the BLDC motor as desired. Testing of this system is done under 4 different conditions using MATLAB software. After testing, the parameter values for the MRAC control system were obtained, namely ???????? = 0.4; ???????? = 50.75; ???????? = 0.0000867. Based on the test, the MRAC control system produces a system success rate of 81.2% to 98.9%.
The Effect of Sodium Hydroxide Concentration on Physical and Mechanical Properties of Magnesium AZ31 Coating for Biodegradable Bone Implant Application Safii, Rizal N; Wicaksono, Mahruri Arif; Gustiono, Dwi; Sukmana, Irza; Sugiyanto, Sugiyanto
Journal of Engineering and Scientific Research Vol. 5 No. 2 (2023)
Publisher : Faculty of Engineering, Universitas Lampung Jl. Soemantri Brojonegoro No.1 Bandar Lampung, Indonesia 35141

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.23960/jesr.v5i2.148

Abstract

Anodizing is a metal coating technique by converting a metal surface to form an oxide layer by electrolysis, one of which is to increase the hardness of a material. This research was carried out to know the effect of variations in electrolyte solution on the hardness of the coating resulting from the anodizing process. The electrolyte used is a solution of NaOH (Sodium Hydroxide) with a concentration of 1 M solution of 68% purity. The specimen used is magnesium AZ31, voltage 10 Volts, soaking time 10 minutes at room temperature. Based on the data analysis results, the magnesium layer's hardness value at 10 minutes at a voltage of 10 volts is 69 HV.In comparison, the coating thickness result at 10 minutes with a constant voltage of 10 volts is 6 ?m. While the concentration of the solution is 0.5 M, the purity is 68%. The specimen used is magnesium AZ31, voltage 10 Volts, soaking time 10 minutes at room temperature. Based on the results of data analysis, the hardness value of the magnesium layer at 10 minutes at a voltage of 10 volts is 67 HV. In comparison, the coating thickness at a time of 10 minutes with a constant voltage of 10 volts is 4 ?m. With variations in stress and time in different concentrations of the solution, there will be differences in the hardness value and thickness value of the AZ31 magnesium coating material.
Landslide Potential Zone Identification Using Electrical Resistivity Tomography Modeling Alghifarry, Muhammad Budzar; Dewanto, Ordas; Wibowo, Rahmat Catur
Journal of Engineering and Scientific Research Vol. 5 No. 2 (2023)
Publisher : Faculty of Engineering, Universitas Lampung Jl. Soemantri Brojonegoro No.1 Bandar Lampung, Indonesia 35141

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.23960/jesr.v5i2.149

Abstract

The Pidada area, Panjang sub-district, Bandar Lampung City, is located on the physiography of Bukit Barisan and is also influenced by the movement of the Sumatran fault and the Lampung-Panjang fault, so the morphological condition is hilly with steep slopes which cause natural disasters such as landslides. In this study, the knowledge of subsurface rock lithology and slip-slide-prone zones was carried out using the Wenner-Schlumberger geoelectric method. Based on the Wenner-Schlumberger configuration, the top layer consists of weathered rock associated with clay tuff and sandy tuff with a resistivity of 7.2 ?m - 135 ?m. Coarse-grained tuff and fine-grained tuff with resistivity values ??of 135 ?m - 437 ?m, and the third layer combines breccia and igneous rock from the Tarahan Formation with resistivity values ??of more than 437 ?m. The clay sand layer acts as a slip plane. The type of landslide developed in the research area is a crawling soil landslide.
Effect of nira (Arenga pinnata Merr) tapping tools on the abudance and identification of microorganisms TURNIP, NINA
Journal of Engineering and Scientific Research Vol. 5 No. 2 (2023)
Publisher : Faculty of Engineering, Universitas Lampung Jl. Soemantri Brojonegoro No.1 Bandar Lampung, Indonesia 35141

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.23960/jesr.v5i2.150

Abstract

Arenga trees are known to have economic value, especially its water, called nira. Nira contains sucrose with a neutral pH at the start of tapping, but after 4 hours, the quality of nira will decrease. This is due to the influence of air (aerobic), so that the presence of microbes in nira becomes abundant and causes the fermentation process to take place more quickly. The fermented nira is known as ‘tuak’, the traditional drink of Bataknese people. Batak people believe the benefits of drinking tuak for health. In this study, nira was collected using a simple tapping device (APUS) with the aim of minimizing contact between surrounding air and bunches. APUS was applied to Arenga bunches in Samosir. Nira from tapping with and without APUS will be observed for microbial abundance (its density). Furthermore, the microbes contained in nira will be identified based on their morphological characters (physically). Identification aims to determine the types of microbes that are present from a natural habitat. Next, the microbes are isolated and studied for their shape and properties, before the microbes are utilized further. The results of microscopic observations showed that the nira sample tapped without using APUS (sample A) had a higher and more turbid microbial density and showed non-uniform microbial size (from large to small, like powder), while nira sample tapped with APUS (sample B) showed almost uniform microbial size with cleaner looking spots. Furthermore, the microbes in sample B were isolated on specific media. Acquisition of colonies in the form of acetic acid bacteria (BAA), lactic acid bacteria (BAL), and yeast. BAA isolates showed a group of gram-negative bacteria that could not retain the crystal violet stain when rinsed with alcohol, because the peptidoglycan in gram-negative bacteria was thinner than gram-positive ones, while BAL isolates were the opposite. The measurement of the number of colonies was carried out using the TPC (Total Plate Count) method at 6 dilutions and obtained for BAL and yeast were 147 and 30 colonies respectively.
The Performance Comparison of Battery Charging Using MPPT and PWM Controllers on Amorphous Solar Panel-Based E-Scooters Asrori, Asrori; Adiwidodo, Satworo; Faizal, Elka; Martawati, Mira Esculenta; Mardyansyah, AA
Journal of Engineering and Scientific Research Vol. 6 No. 1 (2024)
Publisher : Faculty of Engineering, Universitas Lampung Jl. Soemantri Brojonegoro No.1 Bandar Lampung, Indonesia 35141

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.23960/jesr.v6i1.151

Abstract

Solar Panel-Based Electric Scooter (E-Scooter) is an electric vehicle in the form of a scooter that uses solar panels as a source of electrical energy for charging batteries and a BLDC motor as a wheel drive. With the development of the E-Scooter, it is necessary to know how to charge the battery. The purpose of this research is to determine the type of Solar Charge Controller (SCC) that can maximize battery charging on the E-Scooter. The research method is to compare SCC MPPT and SCC PWM. The research was conducted by monitoring the output current and voltage of the solar charger controller generated by the solar panels every 10 minutes. After that the recorded data will be stored in the monitoring device's storage memory for further processing. The results of the data that have been obtained on the e-scooter using the SCC MPPT type are capable of producing a power of 9.05 W with a current value of 0.33 A and a voltage of 27.47 V. Meanwhile, the PWM type SCC is capable of producing 8.22 W of power with a current value of 0.30 A and a voltage of 27.42 V. So that the MPPT type SCC is more economical than PWM for charging when the e-scooter is not moving. For the running conditions of the MPPT type SCC e-scooter is capable of producing 7.36 W of power with a current value of 0.27 A and a voltage of 27.26 V. Meanwhile, the PWM type SCC is capable of producing a current of 6.81 W with a value of 0.25 A and a voltage 27.24 V. So that the MPPT type SCC is more efficient than PWM for charging when the e-scooter is running.
Analysis the Effect of Different Surface Preparation Methods on Corrosion Resistance and Adhesion Strength of ASTM A36 Steel Substrate with Surface Tolerant Epoxy Paint as Coating Material Wijaya, Irwan; Aqila, Daffa; Riastuti, Rini; Ramadhani, Rizal T
Journal of Engineering and Scientific Research Vol. 6 No. 1 (2024)
Publisher : Faculty of Engineering, Universitas Lampung Jl. Soemantri Brojonegoro No.1 Bandar Lampung, Indonesia 35141

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.23960/jesr.v6i1.152

Abstract

In the industrial world, to extend the service life of materials, protection methods are carried out to slow down the material's corrosion rate. The protection method that is often used is the coating method. The coating method is a protection method by coating the substrate material using a coating material to prevent contact between the substrate material and the environment. In this research, the substrate material used is ASTM A36 steel and the coating material used is Surface Tolerant Epoxy paint. The independent variable used in this study lies in the surface preparation method which consists of: solvent cleaning, hand tool cleaning, power tool cleaning, power tool to bare metal cleaning, and abrasive blast cleaning. Different preparation methods result in different roughness and cleanliness of the surface. This can affect changes in the mechanical properties of the coating material, such as corrosion resistance and adhesion strength. Based on the corrosion resistance test, it is found that the abrasive blast cleaning and power tool to bare metal cleaning methods produce the highest corrosion resistance properties because both have a rating number of 8 in the salt spray test results. Based on the adhesion strength test, it is found that the abrasive blast cleaning method also produces the highest adhesion strength. This conclusion refers to the results of the tape x-cut test where the sample produces a rating number 5A where the sample does not experience peeling after testing. In addition, the abrasive blast cleaning method produced the highest adhesion strength in the pull-off test, which was 7.16 Mpa. Thus, the abrasive blast cleaning method is the most effective surface preparation method for ASTM A36 steel before being coated with the coating material. In addition, it can also be concluded that the higher the surface roughness of the sample, the better the corrosion resistance and adhesion strength.
Green Innovation for SMEs in Indonesia – A Literature Analysis Panuju, Achmad Yahya Teguh; Bakri, Samsul
Journal of Engineering and Scientific Research Vol. 6 No. 1 (2024)
Publisher : Faculty of Engineering, Universitas Lampung Jl. Soemantri Brojonegoro No.1 Bandar Lampung, Indonesia 35141

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.23960/jesr.v6i1.157

Abstract

Improving the performance of small and medium enterprises (SME) means enhancing the economics of a nation, considering that SMEs are the biggest part in global economic activities. The higher the SME’s activities, the higher the economic growth occurs in a country. However, nurturing SMEs activities affect the environment, while the damage inclines every day in a worrying level. There is a huge demand to suppress down the environmental damage rate globally, as if it causes a contradictive goal with the economic perspective. Thus, a compromise should be made between both expectations, even it is not easy to do so. Answering to the problem, discussions have been made among scholars around the world, including in Indonesia as an emerging country. Theories and methods were proposed, varying based on characteristics in each region. Especially in Indonesia, there is a lack of literature review on this field, which is actually required to depict the current condition, to evaluate the discussion effectiveness and to develop future improvements. Therefore, this article aims to fill this gap by presenting scientific articles related to the topic and reviewing the discussion. Subsequently, a classification of the articles based on identified themes is conducted. And further the classification is used to see more specific gaps in the discussion and to provide recommendation for the next studies.
Comparison of SVM & Naïve Bayes Methods in Sentiment Analysis of Electric Vehicle Subsidy Policy Based on X Data Wiguna, I Wayan Darma; Waas, Devi Valentino; Wiguna, I Komang Arya Ganda; Radhitya, Made Leo
Journal of Engineering and Scientific Research Vol. 6 No. 1 (2024)
Publisher : Faculty of Engineering, Universitas Lampung Jl. Soemantri Brojonegoro No.1 Bandar Lampung, Indonesia 35141

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.23960/jesr.v6i1.158

Abstract

The policy of subsidizing electric vehicles has become a widely discussed issue on social media platform X. The provision of electric vehicle subsidies by the Indonesian government aims to stimulate higher adoption of electric vehicles, with the overarching goal of mitigating air pollution. However, the presence of electric vehicle subsidies continues to elicit both support and opposition among the public. On social media platform X, there is a wealth of data suitable for text mining, particularly concerning the current hot topic of electric vehicle subsidies. This research aims to compare the performance of Support Vector Machine (SVM) and Naïve Bayes methods in conducting sentiment analysis on discussions related to the electric vehicle subsidy policy on social media platform X. The testing technique involves using 20% of the total dataset, comprising 5553 data points, and employing 10-fold cross-validation. The results from the 20% test data indicate that the Support Vector Machine (SVM) method's confusion matrix performance is superior, with the highest values achieved using the RBF kernel: accuracy 83.02%, precision 84.61%, and recall 83.02%. In the performance evaluation testing with 10-fold cross-validation, the Support Vector Machine (SVM) method outperforms, especially with the RBF kernel, yielding an average accuracy of 82.88% over 10 iterations.

Page 11 of 13 | Total Record : 130

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