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INDONESIA
Komunikasi Fisika Indonesia
Published by Universitas Riau
ISSN : 14122960     EISSN : 2579521X     DOI : 10.31258/jkfi
Core Subject : Science, Engineering,
Earth & Planetary Sciences Electrical & Electronics Engineering Energy Materials Science & Nanotechnology Physics
KFI mempublikasikan artikel hasil penelitian dan review pada bidang fisika, namun tidak terbatas, yang meliputi fisika murni, geofisika, plasma, optik dan fotonik, instrumentasi, dan elektronika, dan fisika terapan (aplikasi fisika).
Arjuna Subject : Fisika dan Astronomi - Fisika dan Astronomi (Lain-Lain)
Articles 390 Documents
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Evaluation of the Arima-Kalman model in predicting rainfall in Medan City in 2023 using observation data from 2013 – 2022 Lumbantoruan, Alva Josia; Darmawan, Yahya; Munawar, Munawar; Nardi, Nardi; Arifianto, Fendy; Ferdiansyah, Ervan
Indonesian Physics Communication Vol 22, No 1 (2025)
Publisher : Universitas Riau

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.31258/jkfi.22.1.15-22

Abstract

This paper aims to evaluate the ARIMA-Kalman model in predicting rainfall in Medan City for the year 2023. The data used are historical observation data of rainfall from 2013 to 2022 that have been tested for stationary and homogeneity, which proved not to require additional correction. The analysis results show that the ARIMA-Kalman model can capture the general pattern of rainfall well, and shows superiority in producing predictions that are closer to the actual data, with a mean absolute error (MAE) value of 54.11, which is lower than the MAE of the ARIMA model which reaches 55.66. Although the ARIMA model has a smaller root mean square error (RMSE) (66.67 compared to 69.75 for ARIMA-Kalman), the ARIMA-Kalman model shows better consistency, especially in capturing significant fluctuations, such as the peak rainfall that occurred in July 2023. Therefore, ARIMA-Kalman is proven to be more accurate and reliable for predicting rainfall in Medan city, making it a better choice to support water resources planning and management.
Making supercapacitor carbon electrodes from lemongrass leaf biomass with variations in physical activation temperature Jaliaz, Akmal; Awitdrus, Awitdrus
Indonesian Physics Communication Vol 22, No 1 (2025)
Publisher : Universitas Riau

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.31258/jkfi.22.1.49-52

Abstract

Supercapacitor is energy storage device consisting of current collector, electrodes, separator, and electrolyte. Material selection and fabrication of the electrodes play an important role in improving the performance of the supercapacitor. In this research, carbon electrodes of supercapacitors were made from citronella leaves using variations in physical activation temperature. The preparation of carbon electrodes were starts from the pre-carbonization at temperature of 200℃ for 2 hours, chemical activation using 0.3 M KOH as activating agent, carbonization process using N2 gas at temperature of 600℃ and physical activation using CO2 gas with temperature variations of 750℃, 800℃, and 850℃. The highest of percentage density reduction at temperature 800℃ is 51.42%. Analysis using X-ray diffraction showed that the sample has a semicrystalline structure with the highest of ratio Lc/La and average number of microcrystalline layer (Np) at temperature of 800℃, are 0.27 and 1.67 respectively. The highest of specific capacitance value is 122 F/g at temperature 800℃. The result show that the optimum physical activation temperature for carbon electrodes based on citronella leaves is 800℃.
Empirical orthogonal functions (EOF) analysis of spatial patterns of dominant variability in the Indian Ocean Manik, Willy Bonanja; Darmawan, Yahya; Munawar, Munawar; Nardi, Nardi; Arifianto, Fendy; Ferdiansyah, Ervan
Indonesian Physics Communication Vol 22, No 1 (2025)
Publisher : Universitas Riau

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.31258/jkfi.22.1.23-26

Abstract

The Indian Ocean plays a crucial role in the global climate system, particularly in influencing the seasons in Indonesia. Sea surface temperature (SST) variability in the Indian Ocean affects rainfall patterns, extreme events, such as droughts and floods, in Indonesia. This study analyzes SST variability during the dry season (June – July – August, JJA) and rainy season (December – January – February, DJF) using satellite and reanalysis data from 1981 to 2023 with the empirical orthogonal function (EOF) method. The analysis shows that the dominant SST variability pattern during JJA is related to the Indian Ocean dipole (IOD), which influences rainfall and temperature patterns in Indonesia. In DJF, SST variability is more associated with the Asian-Australian monsoon, affecting rainfall patterns and the potential for floods. This research enhances the understanding of climate dynamics in the Indian Ocean and its impact on Indonesia, and it can be used to predict extreme climate events associated with SST variability.
Effect of coagulation and filtration in slow sand filters on iron absorption in groundwater Cahyati, Ayu; Krisman, Krisman
Indonesian Physics Communication Vol 22, No 1 (2025)
Publisher : Universitas Riau

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.31258/jkfi.22.1.53-56

Abstract

The study was done to analyze the results of the filtration system of deep pearl housing groundwater using slow sand filtration methods. The analysis is based on the physical and chemical parameters of color/frequency, pH, iron and Escherichia coli with variations in coagulant, clay and alloy. The color/frequency of frequency before filtration has a value of 16.9 NTU, after value filtration declines 0.6%. The phasing of water before filtration was acid 6, having done filtration the pH of water down to 5.8 but had not reached a normal limit (6.5 – 8.5), so slow sand filters had not been effective in curbing the pH of water. The content of iron metals (Fe) before filtration was 0.1867 mg/l, after being made filtrating the content of iron metals (Fe) on the water was down to 0.021 mg/l. The content of Escherichia coli before filtration was 7 CFU / 100 ml, after exfiltration of the Escherichia coli content was reduced to zero CFU / 100 ml. The study suggests that slow sand filters use variations in coagulating and clay materials are effective in improving the quality of the groundwater in the high-yield housing projects.
Visualization and simulation of ZnO microstructure with various crystal structures and doping compositions based on XRD patterns using VESTA Aminnurdin, Dikri; Rini, Ari Sulistyo
Indonesian Physics Communication Vol 22, No 1 (2025)
Publisher : Universitas Riau

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.31258/jkfi.22.1.27-34

Abstract

Crystal structure visualization and X-ray diffraction pattern simulation of various types of ZnO microstructures have been successfully carried out using the VESTA software program. The purpose of this study was to obtain the relationship between the shape of the structure, microstructure, and composition to changes in the pattern and peak diffraction. The software program produces information on the shape of the crystal structure and representative X-ray diffraction patterns for ZnO microstructures. This program requires input in the form of coordinates of each constituent atom, lattice parameters, and spatial symmetry. The output obtained is a graph of the diffraction pattern and crystal structure that provides an overview of the profile and type (phase) of the ZnO microstructure. The results showed that the peak position and intensity of the diffraction pattern were influenced by the arrangement of atoms in the unit cell. In variations in structure and microstructure, the position of the diffraction peak provides a different picture for each type of structure depending on the arrangement of atoms in the unit cell, where each crystal structure has a different position and spatial symmetry, resulting in different diffraction patterns. The nanorod structure has a monoclinic crystal system (a ≠ b ≠ c) with a space group of C 2 / c and lattice parameters a = 15.4170 Å, b = 25.3560 Å, and c = 14.3840 Å. The nanowire structure has a triclinic crystal system (a ≠ b ≠ c) with lattice parameters a = 12.0380 Å, b = 2.4910 Å, c = 16.8890 Å and a space group of P-1 and is the simplest form of symmetric lattice. The nanoflower structure has an orthorhombic crystal system (a ≠ b ≠ c) with lattice parameters a = 9.47310 Å, b = 13.52960 Å, c = 29.0220 Å and space group P b c a.
Interpretation of groundwater potential based on the Cooper Jacobs method combined with Schlumberger geoelectricity in Simpang Tiga Village, Pekanbaru City Kurniawan, Joko; Muhammad, Juandi
Indonesian Physics Communication Vol 22, No 1 (2025)
Publisher : Universitas Riau

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.31258/jkfi.22.1.57-60

Abstract

This study aims to analyze the aquifer parameter values including storativity, transmisivity, and hydraulic conductivity in Simpang Tiga Village, Pekanbaru City. This research is motivated by the community's increasing need for water due to higher population growth, and the Simpang Tiga Village which is close to the city center. Pumping test results using the Cooper Jacobs method showed an aquifer transmisivity value of 247.21 m2/day in the high category and a storativity value of 0.0845. The results of the geoelectrical test with the Schlumberger configuration obtained that the aquifer layer is in the fourth layer with a thickness of 11 m. The hydraulic conductivity obtained is 22.473 m/day and is included in the fast category.
Volumetric-gravimetric synergy in biomass-derived carbon supercapacitors: A case study on dried banana leaf waste Apriwandi, Apriwandi
Indonesian Physics Communication Vol 22, No 1 (2025)
Publisher : Universitas Riau

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.31258/jkfi.22.1.1-10

Abstract

Biomass-derived carbon-based supercapacitors are a compelling solution for environmentally friendly electrochemical energy storage, playing a crucial role in the transition to sustainable energy. Despite this potential, much of the existing research has overly concentrated on theoretical evaluations, hindering practical application. This study decisively addresses the performance of supercapacitors on both a volumetric and practical scale, underscoring their global applicability. The carbon material utilized in this research was expertly produced from dried banana leaf biomass, converted into solid carbon through a process of chemical activation with NaOH and high-temperature pyrolysis. The pyrolysis was carried out in an integrated fashion, combining carbonization and physical activation stages within a carbon dioxide (CO₂) gas atmosphere at temperatures of 700°C, 800°C, and 900°C. Initial characterization focused on density analysis to assess the structural integrity of the porous carbon electrodes. Electrochemical performance was rigorously evaluated using cyclic voltammetry (CV) for volumetric capacitance and galvanostatic charge-discharge (GCD) for gravimetric capacitance within a two-electrode system using a 1000 mmol/L Na2SO4 electrolyte. The results are compelling: the carbon material activated at 900°C achieved an exceptional volumetric capacitance of 198 F/cm³ and a gravimetric capacitance of 181 F/g. These results clearly demonstrate that banana leaf-derived activated carbon is not only viable but also a highly promising electrode material for supercapacitors, paving the way for practical applications in the field.
Modification of magnetic properties and morphology of iron oxide particles of natural sand from Rokan River through copper doping and preparation using ball milling method Gultom, Elika; Sinuraya, Salomo; Amiruddin, Erwin; Awitdrus, Awitdrus
Indonesian Physics Communication Vol 22, No 1 (2025)
Publisher : Universitas Riau

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.31258/jkfi.22.1.35-42

Abstract

The magnetic susceptibility, magnetic properties, morphological properties, and composition of iron oxide nanoparticles of the natural sand in Rokan River, Rokan Hulu Regency, doped copper and prepared by the ball milling method. Processing of the magnetic and non-magnetic particle separation was carried out using iron sand separator (ISS). The ball milling process is ground in two stages for 70 hours and 30 hours and is divided into 3 parts and doped copper with concentrations (weight%) 0 wt%, 5 wt%, and 10 wt%, called BM2A, BM2B, and BM2C products. The calculation of the magnetic susceptibility of the sample is carried out based on the values (BT) and (B0). The resulting magnetic susceptibility decreases as the percentage of copper doping increases. Vibrating sample magnetometer (VSM) shows the magnetic properties of iron oxide particles produced, namely magnetization saturation (MS) decreases, coercivity value (HC) and loop squareness (Mr/MS) grow up, and remanent magnetization (Mr) and loop area (A) varies as doping concentration increases. Morphological properties and composition of iron oxide particles using a scanning electron microscope with energy dispersive X-ray (SEM-EDX). The average measurement of particles produced decreased with the increase in copper doping given, that is 121.960 ± 47.493 nm, 119.730 ± 37.03 nm, and 84.244 ± 34.392 nm. Copper element increased with the increase in doping concentrations given which were 0.76%, 7.11%, and 8.13%, while elements O, Si, and Fe decreased.
The effect of reaction time and oil-to-methanol ratio on the calorific value of biodiesel produced from chicken fat oil Habib, Alltop Amri Ya; Emrinaldi, Tengku; Yolanda, Yogi; Azis, Yelmida
Indonesian Physics Communication Vol 22, No 1 (2025)
Publisher : Universitas Riau

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.31258/jkfi.22.1.11-14

Abstract

The energy content of a fuel is represented by its calorific value. When biodiesel combusts in the presence of air or oxygen, the heat released during the combustion process is expressed as the calorific value. This study aims to analyze the effect of reaction time (60, 120, and 180 minutes) and the volume ratio of chicken fat oil-to-methanol (OM) (25:30 and 25:50) in the transesterification process on the calorific value of the produced biodiesel. The transesterification process was conducted using MgO as a catalyst under various reaction times and OM ratios. The produced biodiesel was then analyzed to determine its calorific value as a key fuel quality parameter. The results indicate that a longer reaction time and a higher OM volume ratio lead to an increase in the calorific value. The highest calorific value obtained in this study was 9952 kcal/kg, achieved at a reaction time of 180 minutes and an OM volume ratio of 25:50.
The effect of variations in the size of milling balls on the magnetic properties and morphology of natural sand particles in the Rokan River Afriyunita, Dini; Sinuraya, Salomo; Amiruddin, Erwin; Muhammad, Juandi
Indonesian Physics Communication Vol 22, No 1 (2025)
Publisher : Universitas Riau

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.31258/jkfi.22.1.43-48

Abstract

Magnetic susceptibility, magnetic properties and morphological properties of natural sand from the Rokan river based on variations in milling ball size. Natural sand samples were put into the iron sand separator for separation between magnetic and non-magnetic particles which were then carried out in a ball milling process for 80 hours using iron balls with a diameter of 1, 2, and 3 cm. The results of the ball milling were then separated using NdFeB magnets, these products are called BM I, BM II, and BM III products. The susceptibility values generated in this study increased with increasing milling ball sizes, for milling ball sizes of 1, 2, and 3 cm the magnetic susceptibility values were 12906.293 × 10-5, 13390.387× 10-5, and 14816.736 × 10-5. The results of the VSM test showed that the saturation magnetization obtained by the BM I, BM II, and BM III products was 2.89, 2.28, and 4.71 emu/g, the remanent magnetization values obtained by 0.45, 0.35, and 0.27 emu/g and the coercivity obtained was 249.07, 263.89, and 275.85 Oe. The results of the SEM-EDX identification showed that Fe increased from 16.24% to 22.68%, while in non-magnetic elements Si decreased from 24.49% to 18.76% with an average particle size getting smaller with increasing size milling ball.

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