Faraday: Journal of Fundamental Physics, Research, and Applied Science

Characterization of RF Voltage and Self-Bias under Power Variations in 13.56 MHz RF Sputtering System

Aprilia Dewi Ardiyanti — 2025-07-31

RF Sputtering has been widely used as a deposition system on thin films. This study examines the impact of input power on RF voltage and self-bias voltage in an RF Sputtering system operating at a frequency of 13.56 MHz. Power variations were carried out in the range of 50 to 150 Watts to observe the changes in voltage produced during the plasma formation process. The experimental results indicate a linear dependency between power and both voltages, with a coefficient of determination (R²) above 0.9 and slope values of 2.86 and 0.96 for the RF voltage and self-bias voltage, respectively. The observed linear correlation indicates that adjusting power regulation can be utilized as an effective control parameter for both voltages, enabling the production of uniform and high-quality thin film deposition.

Rooftop PV System Optimization in an Educational Building Using SAM: A Case Study at UPN Veteran Jawa Timur

Yofinda Eka Setiawan — 2025-07-31

The implementation of sustanable energy in educational institutions recognizes the potential of rooftop photovoltaic (PV) systems as a viable energy source. This research aims to evaluate and optimize the design of a rooftop photovoltaic (PV) system for Building 1 of the Fakultas Teknik dan Sains (FTS) at Universitas Pembangunan Nasional "Veteran" Jawa Timur (UPNVJT) using the System Advisor Model (SAM) software. Integrated data including meteorological data, building characteristics, and solar panel system specifications were utilized. The available rooftop area for PV system installation is approximately 200 m² with a north-facing orientation, which is estimated to accommodate a 30 kWp PV system capacity. Tilt angle and azimuth scenarios were varied to achieve maximum energy production. Based on SAM simulations, the optimal installation angle of 15° tilt and azimuth generated an annual energy output of 44,052 kWh with a performance ratio of 71% and a capacity factor of 17%. This study confirms that rooftop PV installation at FTS UPNVJT is technically feasible, and it is expected to serve as a foundation for the gradual implementation of PV systems as part of green campus initiatives and energy transition in educational institutions.

Earthquake Analysis Using the Probabilistic Seismic Hazard Analysis (PSHA) Method in Palu City

Harsano Jayadi — 2025-07-31

Palu, Indonesia, is a region with high seismic activity due to its location on the active Palu-Koro fault line. This study aims to analyze the probability of earthquakes, the spatial and temporal distribution of earthquake occurrences, and disaster mitigation efforts in anticipation of earthquakes in the region. Earthquake data in Palu City were analyzed based on magnitude, depth, and frequency of occurrence. The results indicate that most earthquakes occur at shallow depths ranging from approximately 10 to 56.8 kilometers, with a dominance of moderate magnitude (5.0–5.7 M_w). Over the past two decades, there has been an increase in the temporal occurrence of earthquakes, with a significant surge in 2018 when a magnitude 7.5 earthquake triggered a tsunami and liquefaction. Probability analysis indicates that earthquakes with high seismicity indices are highly likely to occur within a 10- to 50-year timeframe. The spatial distribution reveals that earthquakes tend to be concentrated around the Palu-Koro fault, the primary source of seismic activity in the region. These findings provide important insights into the seismic patterns of Palu City and can inform community preparedness and disaster mitigation strategy development.

Review: Characterization of Optical and Structural Properties of Carbon Nanodots (CNDs) from Biomass Waste by Microwave Method

Ima Putriana — 2025-07-31

This review focuses on examining the synthesis and characterization of Carbon Nanodots (CNDs) from the utilization of Tandan Kosong Kelapa Sawit (TKKS) using the microwave method as an environmentally friendly approach. The resulting CNDs were characterized for their optical and structural properties to evaluate their potential application in the field of biosensors. The synthesis process involves carbonizing TKKS at 500℃ for 3 hours, followed by activation using a microwave at 450 Watts for 15 minutes. UV-Vis characterization shows an absorption peak at 280 nm, which indicates n-π* (C=O) and π-π* (C=C). Meanwhile, FTIR characterization aims to determine the presence of the carbonyl C=O functional group at 1990,98 cm^-1 and the aromatic C=C bond at 1416,2 cm^-1. The CNDs from TKKS exhibit photoluminescent properties and surface functional groupss that enhance adsorption performance and chemical reactivity. This research offers an efficient and sustainable method for synthesizing CNDs, while also being a breakthrough in utilizing biomass wate, particularly TKKS. The findings have the potential for developing carbon materials in environmental and energi applications.