Article Per Year (5 Year)
p-Index From 2021 - 2026
3.979
P-Index
This Author published in this journals
All Journal Natural B Jurnal Fisika Unand Jurnal Informatika dan Teknik Elektro Terapan Jurnal Fisika FLUX JPSE (Journal of Physical Science and Engineering) AGREGAT AKSIOLOGIYA : Jurnal Pengabdian Kepada Masyarakat Journal of Physics and Its Applications Indonesian Physical Review Jurnal Fisika dan Terapannya Mitra Mahajana: Jurnal Pengabdian Masyarakat Jurnal El Tarikh: Journal of History, Culture, and Islamic Civilization Progressive Physics Journal Jurnal Ilmu dan Inovasi Fisika Lontar Physics Today InSTEM Frontier Advances in Applied Science and Engineering
Ahmad Zarkasi
Universitas Mulawarman
Religion Aerospace Engineering Agriculture, Biological Sciences & Forestry Humanities Astronomy Automotive Engineering Biochemistry, Genetics & Molecular Biology Chemical Engineering, Chemistry & Bioengineering Chemistry Civil Engineering, Building, Construction & Architecture Computer Science & IT Control & Systems Engineering Decision Sciences, Operations Research & Management Earth & Planetary Sciences Education Electrical & Electronics Engineering Energy Engineering Environmental Science Health Professions Industrial & Manufacturing Engineering Materials Science & Nanotechnology Mathematics Mechanical Engineering Medicine & Pharmacology Physics Public Health Social Sciences Transportation Other

Published : 28 Documents Claim Missing Document
Claim Missing Document
Check
Articles

Found 28 Documents
Search

 1   2   3 
IMPEDANCE ANALYSIS FOR FOUR TYPES OF MINERAL WATER AND AQUADES USING ELECTRICAL IMPEDANCE SPECTROSCOPY (EIS) AT FREQUENCIES OF 1 Hz - 50 kHz Wulandari, Darmawati; Zarkasi, Ahmad; Nurhanafi, Kholis
Indonesian Physical Review Vol. 7 No. 1 (2024)
Publisher : Universitas Mataram

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.29303/ipr.v7i1.269

Abstract

The Electrical Impedance Spectroscopy (EIS) method can be used to identify minerals in mineral water. The EIS method measures the impedance of a material by injecting alternating current in a certain frequency range, which is non-invasive and non-destructive. This study aims to analyze the impedance of mineral water and aquades based on the influence of the dissolved content using EIS equipment that provides flexibility in adjusting the desired frequency spectrum. The study used a frequency range from 1 Hz to 50 kHz with a four-electrode configuration. The measurement graph results were analyzed using Bode graph with impedance plot and phase shift angle to determine the impedance characteristics of mineral water. Equivalent circuit modeling helped to identify the electrochemical properties of materials such as the Warburg circuit, Constant Phase Element (CPE), and Randles circuit. The results show that the aquades has a higher impedance compared to the four mineral waters. Additionally, the four mineral waters exhibit varying impedances, attributed to their respective mineral content. Mineral water is characterized by an impedance that is dominated by Warburg impedance (Zw) at low frequencies, charge transfer resistance (Rct) and double layer capacitance (Cdl) at middle frequencies, and electrolyte resistance at high frequencies. However, the impedance of aquades dominated by electrolyte resistance (Re) at low frequency and Re+Rct at high frequency.
A GUI-BASED DATA ACQUISITION SYSTEM FOR EIT USING TWO CURRENT INJECTION METHODS Zarkasi, Ahmad; Hananda Putra, Muhammad Fauzan; Natalisanto, Adrianus Inu; Nurhanafi, Kholis; Hidayatullah, Muhammad; Kusmiran, Amirin; Nuraidha, Amalia C
Indonesian Physical Review Vol. 7 No. 3 (2024)
Publisher : Universitas Mataram

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.29303/ipr.v7i3.356

Abstract

The current injection method played an essential role in the data quality of impedance measurement using the electrical impedance tomography (EIT) technique. Previous studies have largely utilized only a single current injection method with limited interface access, which restricts the effectiveness of EIT systems. In this paper, a graphical user interface (GUI)-based data acquisition system was designed to improve user interaction and optimize the control system. The system was equipped with multiple current injection methods, allowing researchers to choose which method to use in the measurement process. The designed hardware comprises a V-to-I converter circuit, multiplexer, electrodes, peak detector, and filter circuit. Testing results indicate that the V to I converter circuit has an average peak difference between voltage and current of 4.86% and an average error of 0.69% in the peak detector circuit. The multiplexer circuit switches quickly and consistently, while the filter circuit remains stable at the 50 kHz frequency used in this study. These results demonstrate that the designed circuits perform adequately and effectively, ensuring reliable and accurate measurements.  Additionally, the data acquisition software, presented as a GUI, effectively facilitates the selection of current injection methods and the display of boundary data simulation (BDS) on the object. This is demonstrated by the spatial inhomogeneity patterns visible through BDS in both the adjacent and opposite methods
Desain Alat Identifikasi Tipe Oli Berdasarkan Nilai Intensitas Cahaya Menggunakan Sensor Light Dependent Resistor Berbasis Mikrokontroler Zarkasi, Ahmad; Kusmiran, Amirin; Putri, Erlinda Ratnasari
Jurnal Fisika Unand Vol 10 No 4 (2021)
Publisher : Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/jfu.10.4.518-524.2021

Abstract

Oli memiliki kompatibilitas yang berbeda-beda pada suatu unit alat berat dan dapat mempengaruhi performa mesin. Oleh karena itu, alat identifikasi tipe oli telah dikembangkan pada penelitian ini dengan menggunakan sensor light dependent resistor (LDR). Oli yang dijadikan objek pengujian bermerek Caltex dengan tipe SAE 10, SAE 30, SAE 40, SAE 60, dan SAE 90 dengan nilai viskositas berturut-turut yakni 6,0 cSt, 11,7 cSt, 13,7 cSt, 14,2 cSt, dan 25,5 cSt. Pengujian dilakukan dengan menempatkan sampel oli di antara sumber cahaya dan sensor LDR. Intensitas cahaya yang diterima oleh sensor sangat dipengaruhi oleh kecerahan warna sampel oli yang digunakan. Nilai analog dari sensor selanjutnya diakuisisi oleh mikrokontroler Arduino Nano untuk diproses lebih lanjut. Hasil pengujian menunjukkan bahwa alat yang dirancang sudah bekerja dengan baik dan mampu mengenali tipe oli dengan tingkat akurasi sebesar 96,7 %. 
Analisis Pergerakan Partikel terhadap Rekaman Mikrotremor di Permukaan Sungai Bawah Tanah Bribin, Kawasan Karst Gunung Sewu Nurhanafi, Kholis; Zarkasi, Ahmad; Intifadhah, Sahara Hamas; Wibowo, Nugroho Budi; Purnama, Aditya Yoga
Jurnal Fisika Unand Vol 12 No 3 (2023)
Publisher : Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/jfu.12.3.471-478.2023

Abstract

Microtremor has been widely used to determine soil characteristics and dynamics. In this research, particle motion analysis was conducted on 15 microtremor data recordings around the surface of the Bribin Underground River in the Gunungsewu Karst Area. Spectrum analysis was conducted as a basis for determining the frequency range for the particle motion analysis process. Particle motion analysis was only carried out on the horizontal component of the microtremor signal which is expected to provide a representation of the river flow path. The results of particle motion analysis of microtremor recordings in the surface area of the Bribin Underground River show that there are only two points that have a motion-resultant oriented to certain direction, which is perpendicular to the river channel.The points are A4 and B4 which are located in the eastern part of the river flow path.
APLIKASI SENSOR MICRO ELECTRO MECHANICAL SYSTEM (MEMS) ACCELEROMETER BERBASIS IOT DALAM PENGUKURAN PERCEPATAN MAKSIMUM GETARAN STRUKTUR JEMBATAN Rahayu, Rafika Ade; Nurhanafi, Kholis; Syahrir, Syahrir; Zarkasi, Ahmad
Jurnal Informatika dan Teknik Elektro Terapan Vol. 12 No. 2 (2024)
Publisher : Universitas Lampung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.23960/jitet.v12i2.4134

Abstract

Alat ukur getaran dengan sensor Micro Electro Mechanical System (MEMS) berbasis Internet of Things (IoT) merupakan alat yang dapat diaplikasikan pada pengukuran nilai percepatan maksimum getaran struktur jembatan. Tujuan penelitian ini adalah untuk merancang alat ukur getaran dengan sensor MEMS berbasis IoT dengan harga yang relatif rendah dan mengukur standar deviasi pada alat ukur tersebut. Pada penelitian ini alat ukur dibuat dengan sensor MEMS tipe ADXL345 yang dihubungkan dengan mikrokontroler NodeMCU Esp8266 lalu diprogram pada interface Arduino IDE agar dapat terhubung dengan platform IoT Blynk. Sistem alat ukur yang dirancang dapat merekam data pada Cloud Blynk dengan nilai sampling 1 Hz. Nilai standard deviasi pada 3 titik pengukuran jembatan tiap sumbunya yaitu: pada titik 1 dengan sumbu x, y, dan z secara berturut-turut sebesar 0.0137 g, 0.0163 g, 0.0228 g; titik 2 sumbu x, y, z secara berturut-turut sebesar 0.0139 g, 0.0195 g, 0.0299 g; titik 3 sumbu x, y, z secara berturut-turut sebesar 0.0139 g, 0.0285 g, 0.0313 g.
Arduino Uno Based Automatic Fruit Maturity Detection System for Orange (Citrus sp.) and Bell Fruits (Syzygium aqueum) Using Electrical Conductivity Ummah, Auliya Rahmatul; Fitriani, Ade; Nur Hanafi, Kholis; Syahrir, Syahrir; Supriyanto, Supriyanto; Zarkasi, Ahmad
Lontar Physics Today Vol 4, No 3 (2025): November 2025
Publisher : Universitas PGRI Semarang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.26877/lpt.v4i3.25513

Abstract

Accurate determination of fruit ripeness is essential to maintain product quality, flavor, and market value. However, traditional manual assessment methods, which rely on sensory observation (color, aroma, and texture), are often subjective and inconsistent. This study aims to design and develop an automatic fruit ripeness detection system based on electrical conductivity measurement in oranges and bell fruits. The system utilizes a three-electrode stainless steel needle probe connected to an ADS1115 Analog-to-Digital Converter (ADC) module and an Arduino Uno microcontroller. A refractometer was used for system calibration and reference data acquisition. Measurements were performed by inserting the probe into the fruit pulp to read the voltage value of the fruit's fluid. This electrical signal was correlated with the reference sugar content (%Brix) and subsequently classified into three categories: ripe, half-ripe, and unripe. Results show that the average voltage range for oranges in the ripe, half-ripe, and unripe categories was 2.74 V, 2.58 V, and 2.32 V, respectively. For bell fruits, the corresponding voltage ranges were 2.48 V, 2.26 V, and 2.08 V. These voltage values were derived from the experimental data presented in Table 1 and  Table 2. The abstract  reports the average voltage for each ripeness category, whereas the tables list individual measurement values, resulting in slight differences between the summarized and detailed data. The average relative error of the measurement was found to be approximately 5 %, which is considered acceptable for practical field application. This indicates that the developed system is capable of classifying fruit ripeness in a non-destructive, accurate, and rapid manner.
Pemanfaatan Pasir Besi dan Pasir Pantai sebagai Agregat Halus pada Campuran Asphalt Concrete – Binder Course Fitrayudha, Adryan; Maolida Uci Handayani; Anwar Efendy; Ahmad Zarkasi; Aulia Muttaqin; Isfanari
AGREGAT Vol 10 No 2 (2025)
Publisher : Universitas Muhammadiyah Surabaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30651/ag.v10i2.29252

Abstract

Penelitian ini bertujuan untuk mengevaluasi pemanfaatan pasir besi dan pasir pantai sebagai substitusi sebagian agregat halus pada campuran Asphalt Concrete – Binder Course (AC-BC) serta menentukan proporsi optimum yang mampu memenuhi persyaratan kinerja menurut Spesifikasi Bina Marga 2018 Revisi 2. Pengujian laboratorium dilakukan menggunakan pasir besi dari Pantai Kerakat dan pasir pantai dari Pantai Malimbu, sedangkan agregat kasar dan abu batu diperoleh dari AMP setempat. Pengujian Marshall dilakukan dengan kadar aspal optimum sebesar 5,15% dengan parameter yang dianalisis meliputi stabilitas, kelelehan, Marshall Quotient, Void in Mineral Aggregate (VMA), Void in Mix (VIM), dan Void Filled with Bitumen (VFB). Hasil penelitian menunjukkan bahwa meskipun beberapa campuran tidak memenuhi kriteria VIM dan VFB, dua variasi 5% pasir besi + 5% pasir pantai dan 7,5% pasir besi + 2,5% pasir pantai menunjukkan keseimbangan interaksi antarbutir, interlock agregat yang baik, dan struktur internal yang stabil sehingga memenuhi seluruh spesifikasi yang dipersyaratkan. Secara ilmiah, pencapaian kinerja tersebut disebabkan oleh karakteristik pasir besi yang meningkatkan kerapatan struktur dan pasir pantai yang memperbaiki kemampuan kerja sehingga mencegah over compaction. Sebaliknya, campuran dengan dominasi pasir pantai menghasilkan rongga udara tinggi, sedangkan campuran dengan dominasi pasir besi menjadi terlalu rapat, keduanya menyebabkan ketidaksesuaian spesifikasi. Secara keseluruhan, penelitian ini membuktikan bahwa proporsi terkontrol dari kedua material lokal ini dapat dimanfaatkan secara efektif sebagai substitusi agregat halus dalam campuran AC-BC
Mahkota Siger Masyarakat Adat Lampung Pepadun: Simbol Identitas, Spiritualitas, dan Pergeseran Makna Sosial di Era Kontemporer Leo Anugerah Putra; Ahmad Zarkasi; Shonhaji
El Tarikh : Journal of History, Culture and Islamic Civilization Vol. 6 No. 2 (2025): Islamic History: Intellectual Figures and Social Transformation
Publisher : Universitas Islam Negeri Raden Intan Lampung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24042/00202562775200

Abstract

Penelitian ini mengkaji tentang makna filosofis dari Mahkota Siger sebagai simbol identitas masyarakat Lampung, serta dinamika sosial dari simbol ini ditengah perubahan nilai masyarakat modern. Karena selama ini kajian yang ada lebih fokus pada aspek estetika dan fungsi seremonialnya. Dengan menggunakan metode kualitatif dengan pendekatan fenomenologis, penelitian ini dilakukan melalui penelitian lapangan yang melibatkan wawancara mendalam dengan tiga tokoh kunci adat dan pengamatan langsung di Lampung dan sekitarnya. Temuan tersebut mengungkapkan bahwa Mahkota Siger bukan hanya benda hias dalam upacara adat, tetapi simbol budaya yang mewakili nilai-nilai moral, struktur sosial, dan kedalaman spiritual. Ini mewujudkan identitas kolektif masyarakat Pepadun melalui makna simbolis seperti "pi'il pesenggiri", status, kehormatan, dan integrasi filosofis nilai-nilai Islam terutama relevansi simbolis dari sembilan cabangnya. Namun, dalam konteks kontemporer, pergeseran makna yang signifikan telah terjadi, terutama di kalangan generasi muda yang cenderung menganggap Siger sebagai lambang budaya dekoratif tanpa memahami esensi sucinya. Pergeseran semantik ini menimbulkan ancaman bagi integritas budaya dan spiritual simbol. Penelitian ini merekomendasikan revitalisasi strategis melalui pendidikan budaya, dialog antargenerasi, dan keterlibatan kelembagaan yang lebih kuat dari para pemimpin adat untuk melestarikan dimensi materi dan immaterial Mahkota Siger. Memperkuat nilai-nilainya baik di ruang budaya formal maupun informal sangat penting untuk memastikan keberlanjutannya dalam menghadapi tantangan sosial-budaya modern.
Co-Authors -, Syahrir A. Andira Maharani abdurrouf Abdurrouf Ade Fitriani, Ade Aditya Yoga Purnama Adrianus Inu Natalisanto Adryan Fitrayudha Akbar Perdana Akbar Perdana Alris Sanca Pratama Putra Amirin Kusmiran Andi Syam Rizal Anwar Efendy Ariyanthi, Gita Putri Aulia Muttaqin Dadan Hamdani Dadan Hamdani, Dadan Didik Rahadi Santoso Erlinda Ratnasari Putri Hananda Putra, Muhammad Fauzan Hasan, Aly Hemelia, Junita Hidayatullah, Muhammad Idris Mandang Idris Mandang, Idris Intifadhah, Sahara Hamas Isfanari Jerri, Alyadris Kasturi Ramadani Kholis Nurhanafi Kormil Saputra Leo Anugerah Putra Maolida Uci Handayani Minarti Minarti Mislan Mislan Mislan Mohammad Asrul Muhammad Awaluddin Muhammad Fawzy Ismullah Massinai Munir, Rahmawati Nugroho Budi Wibowo Nugroho Budi Wibowo Nur Hanafi, Kholis Nuraidha, Amalia C Nurohman, Ali Perdana, Akbar Pradana, Andre Juliko Putri, Devina Rayzi Perwitasari Sutaji Putri, Devina Rayzy Perwitasari Sutaji Rafika Ade Rahayu Rahayu, Rafika Ade Rita Desiani Sahara Shonhaji Supriyanto Supriyanto Syahrir Syahrir Syahrir Syahrir Syahrir Syahrir Ummah, Auliya Rahmatul Wahidah Wahidah Wahidah Wahidah Wardani, Pratiwi Sri Wulandari, Darmawati