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Siti Utari Rahayu
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Journal of Technomaterial Physics
Published by TALENTA PUBLISHER
ISSN : 26560747     EISSN : 26560755     DOI : https://doi.org/10.32734/jotp
Core Subject : Science, Engineering,
Astronomy Civil Engineering, Building, Construction & Architecture Control & Systems Engineering Earth & Planetary Sciences Electrical & Electronics Engineering Energy Materials Science & Nanotechnology Physics
Journal of Technomaterial Physics (JoTP) is a peer-review national journal that is published twice a year, in February and August. JoTP provides an open access policy for the writer and free publication charge. Due to its open access policy, JoTP serves online publication and a fast review process. The scope of this journal are: 1. Theoretical Physics 2. Applied Physics 3. Material Physics 4. Computational Physics and Machine Learning 5. Experimental Physics 6. Nuclear Physics and Particle Physics 7. Biophysics and Medical Physics 8. Geophysics 9. Energy and Energy Conversion 10. Advanced Materials (photonics, nanomaterial and nanotechnology) 11. Electronics and Electrical Engineering 12. Metrology JoTP receives an original article with the maximal length of 10 pages and provides an open access policy for the writers and free publication charge.
Arjuna Subject : Fisika dan Astronomi - Fisika dan Astronomi (Lain-Lain)
Articles 140 Documents
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Reduction of COD and BOD Levels in Tofu Liquid Waste Processing Using the Electrocoagulation Method Suci, Suci Amanda; Masthura, Masthura; Jumiati, Ety
Journal of Technomaterial Physics Vol. 7 No. 2 (2025): Journal of Technomaterial Physics
Publisher : Talenta Publisher

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.32734/jotp.v7i2.22378

Abstract

Tofu liquid waste treatment is very important because of its high organic content and can cause environmental pollution. This research uses electrocoagulation method with cylindrical aluminum electrodes to lower Biochemical Oxygen Demand (BOD) and Chemical Oxygen Demand (COD) levels. The variation of the treatment time used is 45, 60, and 75 minutes with a voltage of 12 volts and a distance between the electrodes of 2 cm. The test results showed that the BOD concentration decreased from 816 mg/L to 57–104 mg/L (efficiency 87–93%), while COD decreased from 2696 mg/L to 78–118 mg/L (efficiency 95–97%). In addition, the pH increased from 3.44 to 6.03–6.99 so that it is close to neutral condition. All final results meet the quality standards of liquid waste according to the Regulation of the Minister of Environment and Forestry No. 5 Year 2014, as well as aluminum content according to drinking water quality standards according to Permenkes No. 492/MENKES/PER/IV/2010. Thus, electrocoagulation using cylindrical electrodes is proven to be effective, environmentally friendly, and potentially applied to small to medium-scale tofu waste treatment.
The effect of Electrode Type Differences on BOD and COD Reduction in Tofu Wastewater Treatment khofifahparawansyah, khofifah; Masturah, Masturah; Jumiati, Ety
Journal of Technomaterial Physics Vol. 7 No. 2 (2025): Journal of Technomaterial Physics
Publisher : Talenta Publisher

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.32734/jotp.v7i2.22431

Abstract

Research has been conducted aimed at testing the results of tofu liquid waste samples on the Biochemical Oxygen Demand (BOD) and Chemical Oxygen Demand (COD) parameters before and after the electrocoagulation process using Al, Cu, and Zn electrodes. This study used tofu liquid waste from Jl. Pasar V Helvetia. The BOD test results before electrocoagulation were 816 mg/L. The BOD test results after electrocoagulation with Al electrodes were 112 mg/L, Cu electrodes were 55 mg/L, and Zn electrodes were 115.2 mg/L. The COD level test results before electrocoagulation were 2696 mg/L. The COD level test results after electrocoagulation with Al electrodes were 95 mg/L, Cu electrodes were 62 mg/L, and Zn electrodes were 105 mg/L. From the electrode variations, the best results were obtained for testing the BOD and COD levels of tofu liquid waste on the Cu electrode.
The Influence of Tensile Strength Test Values on the Elongation of Eco-Friendly Paper Jumiati, Ety; Husnah, Miftahul
Journal of Technomaterial Physics Vol. 7 No. 2 (2025): Journal of Technomaterial Physics
Publisher : Talenta Publisher

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.32734/jotp.v7i2.22746

Abstract

Paper is a thin material in the form of sheets. Environmentally friendly paper is obtained from natural materials derived from discarded waste. This study aims to investigate the characteristics and the effect of elongation values on the tensile strength of the produced paper. The composition variations between taro peel and oil palm frond fibers in paper production were 30%:70% (sample A); 40%:60% (sample B); 50%:50% (sample C); 60%:40% (sample D); and 70%:30% (sample E). The pulp preparation process was carried out using the soda method, while the drying process was conducted naturally at room temperature for 12 hours. The results of the paper characterization for samples A, B, C, D, and E showed tensile strength values of 5.2570 kN/m, 6.2875 kN/m, 7.1985 kN/m, 8.8975 kN/m, and 9.5060 kN/m, respectively, while the elongation test values were 1.09%, 1.12%, 1.15%, 1.24%, and 1.52%. These values have met the requirements for printing paper grade A according to SNI 7274:2008. The results indicate that the higher the composition of oil palm frond fibers used, the greater the tensile strength and elongation values of the paper.
Effect of Magnitude and Distance on Peak Ground Acceleration Using a Modified Akkar & Boomer (2007) GMPE for North Sumatra Tia Melati; Lailatul Husna Lubis; Ratni Sirait; Angga Wijaya
Journal of Technomaterial Physics Vol. 7 No. 2 (2025): Journal of Technomaterial Physics
Publisher : Talenta Publisher

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.32734/jotp.v7i2.22751

Abstract

The Ground Motion Prediction Equation (GMPE) is very important in estimating the intensity of earthquake shocks as a basis for risk mitigation. This study aims to modify and validate the Akkar & Boomer (2007) GMPE using shallow earthquake data in the North Sumatra region for the period 2017–2023. The earthquake data were obtained from BMKG and included parameters such as magnitude, depth, and distance from the source. The analysis method involved nonlinear regression, data cleaning, and validation using residual analysis. The results showed that the maximum ground acceleration (PGA) tended to decrease nonlinearly with increasing distance from the earthquake source. The modified GMPE equation was: Log₁₀ PGA = −0.5916 + 0.5875M + 0.0576M² + (−0.8699 + − 0.1985M) Log₁₀(√R² + 8.2032²) + 0.105, with an R² value of 0.56 and prediction error values such as 0.21; MAE 0.36; RMSE 0.46; STD 0.46). Thus, the modification of GMPE based on local data can provide a more representative estimate of earthquake hazards to support mitigation efforts in North Sumatra.
Failure Mechanism Identification of Hook Components in Automatic Machines Using Visual and Material Analysis RAHMAWATI, NABILA DESY; LUTIYATMI
Journal of Technomaterial Physics Vol. 7 No. 2 (2025): Journal of Technomaterial Physics
Publisher : Talenta Publisher

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.32734/jotp.v7i2.23428

Abstract

The hook component in automatic packaging machines frequently experiences premature failure, leading to increased downtime, higher maintenance costs, and reduced production efficiency. This study aims to identify the failure mechanism of the hook through visual inspection, maintenance data analysis, and material characterization. Visual examination was conducted on broken hook specimens to identify fracture morphology and surface characteristics. Historical maintenance records from 2017 to 2024 were analyzed to identify the frequency and type of failure. Chemical composition testing was performed using Optical Emission Spectroscopy (OES), while Rockwell hardness testing (HRC) evaluated the material’s mechanical properties. The results revealed that the failure mode was categorized as brittle fracture, indicated by flat and granular fracture surfaces without plastic deformation. The main failure factor was the direct impact between the hook and the punch, caused by misalignment due to bearing wear. The material, classified as medium carbon steel with 0.599 wt.% C and 1.000 wt.% Mn, exhibited high hardness but low toughness, leading to a brittle fracture under impact loading. Surface hardening combined with light tempering and shot peening is recommended to improve wear resistance and toughness, thereby reducing the risk of brittle fracture.
Real-Time Ethanol Monitoring System for Palm Sap Fermentation Using a MiCS-5524 Gas Sensor and Arduino Uno Siregar, Dini Rizqi Dwi Kunti; Surbakti, M Syukri; Fadhli; zakaria; Susilawati; Akbar, Hikmal
Journal of Technomaterial Physics Vol. 8 No. 1 (2026): Journal of Technomaterial Physics
Publisher : Talenta Publisher

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.32734/jotp.v8i1.23866

Abstract

This study aims to develop a real-time alcohol monitoring instrument for palm sap fermentation using the MiCS-5524 gas sensor integrated with an Arduino Uno. The system consists of the MiCS-5524 sensor, an Arduino Uno microcontroller, and a 16×2 I2C LCD for real-time display. Sensor calibration was performed using ethanol solutions at 10%, 20%, 30%, 40%, 50% and 60% to establish a linear regression model relating sensor resistance to ethanol concentration. Fermentation monitoring was carried out for 72 hours, with measurements taken every 24 hours. Sensor outputs were converted from ADC values into voltage, resistance, and ethanol concentration using the calibration equation. The calibration yielded a strong linear correlation (R² = 0.982). Fermentation tests showed a consistent increase in ethanol concentration, reaching 53.9% after 72 hours. Comparison with a digital alcohol meter produced relative errors ranging from 2.8% to 6.4%, demonstrating good accuracy, low drift, and stable sensor response. Overall, the developed instrument effectively measures ethanol concentration in palm sap fermentation in real time. Its simple configuration, low cost, and reliable performance make it suitable for small-scale palm sap processing, quality control, and laboratory applications. Further improvements, such as environmental compensation and IoT-based monitoring, are recommended to enhance system performance.
Entrance Surface Air Kerma (ESAK) in Adult Posteroanterior (PA) Chest Radiography: An Exploratory Analysis Intan Mulia Sari; Irhamni, Irhamni; Safitri, Rini; Yufita, Evi; Dewi, Ariana Shafira
Journal of Technomaterial Physics Vol. 8 No. 1 (2026): Journal of Technomaterial Physics
Publisher : Talenta Publisher

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.32734/jotp.v8i1.24603

Abstract

This study estimated Entrance Surface Air Kerma (ESAK) for adult posteroanterior (PA) chest radiography and described ESAK patterns in relation to selected technical parameters and patient characteristics as an initial facility-level baseline. A descriptive–exploratory observational study was conducted in 10 adult patients using a Siemens digital radiography system equipped with Automatic Exposure Control (AEC). ESAK was estimated from X-ray tube output obtained from acceptance/constancy testing and combined with routinely recorded exposure parameters. Incident air kerma (INAK) was calculated first and then converted to ESAK using a backscatter factor assumed to be constant at 1.35. All examinations were performed at 125 kVp with a fixed source-to-image distance (SID) of 180 cm. Focus-to-skin distance (FSD) was not recorded directly and was estimated from SID and the recorded chest thickness. ESAK ranged from 0.09 to 0.17 mGy (mean, 0.13 mGy), and all values were below the BAPETEN optimization reference level of 0.2 mGy. In this limited sample, graphical patterns indicated that ESAK increased with mAs and body weight and decreased with increasing FSD. These findings are preliminary and require confirmation in a larger cohort; however, they may serve as a temporary local baseline for internal dose auditing and to inform the design of subsequent dose optimization studies.
Preliminary Analysis of Machine Learning Performance and the Effect of Outliers in Daily Rainfall Classification in Jambi City Naufal, Muhammad Risyad; Erni; Marathur Rodhiyah
Journal of Technomaterial Physics Vol. 8 No. 1 (2026): Journal of Technomaterial Physics
Publisher : Talenta Publisher

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.32734/jotp.v8i1.24702

Abstract

Rainfall is a crucial meteorological parameter that significantly affects various sectors, particularly in tropical regions such as Jambi City. However, daily rainfall data often contain outliers and imbalanced class distributions, which can degrade the performance of machine learning-based classification models. This study aims to conduct a preliminary analysis of the performance of several machine learning algorithms for daily rainfall classification in Jambi City by examining the effects of outlier removal. The algorithms evaluated include Support Vector Machine (RBF), K-Nearest Neighbor, Naive Bayes, Decision Tree, and Random Forest. Model performance was assessed using accuracy and macro F1-score metrics. The rainfall classes used in this study consist of four categories: no rain, light rain, moderate rain, and heavy rain. The results indicate that outlier removal improves the accuracy of all evaluated algorithms, with the most substantial improvement observed in the Decision Tree model with accuracy improved from 45.71% to 57.36% and macro F1-score from 28.99% to 38.78%. Overall, the implementation of outlier removal yields more balanced and representative rainfall classification results, potentially serving as a basis for future quantitative rainfall regression studies.
Reactive Diffusion Model in Determining Dissolution Rate of Edible Electronics Materials Sihombing, Yuan Alfinsyah; Sawitri, Asti; Rodhiyah, Marathur
Journal of Technomaterial Physics Vol. 8 No. 1 (2026): Journal of Technomaterial Physics
Publisher : Talenta Publisher

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.32734/jotp.v8i1.24766

Abstract

Edible electronic materials have emerged as an attractive research with broad potential applications. In the healthcare field, these materials can be utilized for diagnosing, monitoring, and treating organs within the gastrointestinal tract. A key characteristic of these materials is their ability to be digested and dissolved in water or bodily fluids. This study aims to theoretically investigate and predict the dissolution behavior of edible electronic materials using a one-dimensional (1D) reactive diffusion model. This model indicates that the dissolution behavior is governed by two primary parameters: the reaction rate constant (k) and the water diffusivity (D). Materials such as magnesium (Mg), zinc (Zn), and molybdenum (Mo) exhibit average dissolution rates ranging from 2.51 × 10-12 cm s-1 to 3.40 × 10-8 cm s-1 for diffusivity values between 10-17 and 10-10 cm2 s-1. In addition, the ratio of effective thickness to initial thickness (h/h0) increases and is influenced by the molar mass of the material, following the order Mo > Zn > Mg. The dissolution rate modeling results demonstrate that the reactive diffusion model is capable of representing trends that are consistent with experimental observations.
Preparation and Characterization of Hierarchical Zeolite from Natural Zeolite Using Tandem Acid–Base Treatments Indah Revita Saragi; Devi Yanti Christine
Journal of Technomaterial Physics Vol. 8 No. 1 (2026): Journal of Technomaterial Physics
Publisher : Talenta Publisher

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.32734/jotp.v8i1.24887

Abstract

Hierarchical zeolite was successfully synthesized from Lampung natural zeolite via sequential tandem acid–base treatments. The combined dealumination–desilication approach generated additional mesoporosity while preserving the zeolite's crystalline framework, as confirmed by X-ray diffraction (XRD). Nitrogen adsorption–desorption isotherms revealed a transformation from Type I to Type IV behavior, indicating successful mesoporous formation. The BET surface area increased from 4.795 to 16.855 m²/g, accompanied by a significant increase in mesopore volume. Elemental analysis showed that the Si/Al ratio decreased from 8.42 to 2.44 due to the dominant extraction of silicon during alkaline treatment. The modified zeolite (Zeolite-PTAB) exhibited enhanced Cu²⁺ adsorption capacity (19.3 mg/g) compared to raw zeolite (16.1 mg/g), with removal efficiency improving from 53.7% to 64.3%. These findings demonstrate that tandem acid–base treatment provides a simple and effective strategy for upgrading Indonesian natural zeolite into a hierarchical adsorbent for heavy-metal removal applications.

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