Spektra: Jurnal Fisika dan Aplikasinya
Not a member yet
254 research outputs found
Sort by
Advancing X-Ray Medical Imaging through Compton Scattering Technologies: A Systematic Review of Technological Developments and AI-Based Image Reconstruction
Full text linkCompton scattering has emerged as a promising advancement in X-ray medical imaging, offering enhanced spatial resolution and diagnostic precision compared to conventional techniques. This study employs a Systematic Literature Review (SLR) to evaluate the contributions of Compton scattering technologies in improving imaging performance. Forty peer-reviewed articles were selected from six major databases including Google Scholar, Scopus, PubMed, Web of Science, ScienceDirect, and arXiv based on predefined inclusion criteria. The review identifies three main technological approaches which are Compton cameras, inverse Compton X-ray sources, and Compton scattering tomography. Recent innovations in image reconstruction, particularly using deep learning and convolutional neural networks, have significantly improved image quality, reduced noise, and enhanced computational efficiency. These findings underscore Compton scattering’s clinical potential, especially in soft tissue visualization and early lesion detection. This paper provides a detailed overview of current progress and strategic pathways in the development of Compton based imaging systems towards their clinical application
Physicochemical and Mineralogical Characterization of Ciuyah Mud Volcano: Rare Earth Elements and Salt Minerals for the Advanced Materials Industry, Indonesia
Full text linkThe Ciuyah Mud Volcano in West Java is a notable geological feature resulting from mud extrusion driven by subsurface pressure, buoyancy, and thermal variations. Its unique characteristics provide valuable insights into Earth's subsurface processes. Materials ejected from mud volcanoes often contain valuable minerals that are crucial for scientific investigation and economic application. Of particular interest at this site is the presence of Rare Earth Elements (REEs), which are vital for modern technology. The aim of this study is to provide a comprehensive characterisation of the Ciuyah Mud Volcano. The objectives are to: (1) determine its physicochemical properties using electrical conductivity (EC), volumetric water content (VWC), and total dissolved solids (TDS) measurements; (2) identify the distribution of REEs using X-Ray Fluorescence (XRF) and Inductively Coupled Plasma-Optical Emission Spectrometry (ICP-OES); and (3) analyze the salt mineralogy using Scanning Electron Microscopy (SEM) and X-Ray Diffraction (XRD). The results revealed high conductivity in the mud, as evidenced by elevated EC and VWC values, as well as high TDS and salinity in the water samples. XRF and ICP-OES analyses confirmed the presence of twelve REEs: Ce, Dy, Eu, Gd, Ho, La, Nd, Pr, Sm, Tb, Sc, and Y. Furthermore, SEM and XRD identified Halite and Helvite as the primary salt minerals, characterized by large, hexagonal crystal structures. These findings highlight the potential of the Ciuyah Mud Volcano as a source of strategic REEs for Indonesia’s advanced materials and clean energy sectors, while also offering local socioeconomic applications, such as salt-based cosmetic products
Non-Relativistic Quantum Particle Confined on a Cylindrical Surface under a Stark-like Potential
Full text linkThis study explores the influence of a Stark-like perturbative potential on a quantum particle confined to a cylindrical surface (QPCS) and its implications for extra-dimensional theories. The QPCS framework is particularly relevant to Kaluza-Klein (KK) theory, which postulates extra spatial dimensions to unify electromagnetism and gravity. In KK theory, these extra dimensions are typically hidden and require high-energy conditions for detection. Motivated by the challenge of uncovering these dimensions more feasibly, this research applies a perturbative potential of the form ĤSL = βzV₀z(θ) to a QPCS characterized by length L and radius R₀. This potential is inspired by the Stark effect in hydrogen atoms, where energy level splitting serves as an indicator of an external influence. The study demonstrates that, for a degenerate configuration (R₀ = L/π), the Stark-like perturbation effectively induces energy level splitting, which can be interpreted as a means of revealing hidden dimensions. The first-order energy correction in this scenario depends explicitly on the quantum numbers nz and nθ, highlighting the potential for this approach to probe extra-dimensional effects in lower-energy quantum systems
Analyzing the Influence of Bedrock Geometry on Ambient Vibration Using HVSR and Particle Dynamics
Full text linkGround vibration signals recorded by low-frequency multi-channel geophones provide information about the physical characteristics of a medium. Using the passive seismic method, vibrations are measured in three channels, i.e. horizontal and vertical directions. Since the characteristics of mediums, such as sediment thickness and soil hardness, are contained in low-amplitude ambient vibrations, further data selection is required to remove spikes in the signals induced by active sources. This work is necessary to reveal the characteristics that reflect the mediums’ physical condition from the signal. Conventionally, signal processing is based on the Horizontal-to-Vertical Signal Ratio (HVSR) calculation. The information obtained, such as sediment thickness and sub-surface shear velocity (Vs30), as well as the amplification factor and seismic vulnerability, are crucial for geotechnical applications. This data can be extracted from HVSR analysis. However, a complete understanding of the complex vibration signal shape related to the medium and local geological conditions is not fully understood. To gain a deeper understanding of the mechanism, numerical modeling is performed using a particle dynamics method. The vibration pattern of chosen particles on the surface was studied and its relation to the geometry of the fixed base region was investigated. The simulation results show systematic changes in signal form when processed with a similar HVSR method as a response to the shape of the fixed base
Coordinative Study of Organic Material on Silver Nanoparticles and Its Application for Colorimetric Sensor
Full text linkMetal nanoparticles, especially gold and silver nanoparticles, have been applied in various fields of nanotechnology because of their unique optical properties called localized surface plasmon resonance (LSPR). Metal nanoparticles need capping material to stabilize and protect the metal core. The interaction between capping and metal core affects the physical and chemical properties of metal nanoparticles. Silver nanoparticles have a robust extinction coefficient compared to other metals of the same size. In addition, silver nanoparticles have been found to have antimicrobial properties. There has been a lot of research on the coordination between organic molecules with silver metal. However, the study about the coordination between organic molecules on silver nanoparticles has not been studied in detail. For this reason, the synthesis of silver nanoparticles capped by citrate (AgCA) and silver nanoparticles capped by 3-MPA (AgMPA) was optimized in order to form stable colloids. The interaction between capping molecules (citrate and 3-MPA) and silver core was studied experimentally and computationally. In the results, some different vibration peak positions of chemical coordination between free carboxylate and the carboxylate on silver nanoparticles were found, indicating the effect of strong chemical bonding and the effect of localized surface plasmon. Agreement was found between the experimental results and the calculation based on DFT simulation, which shows the same tendencies of vibration peak position. Moreover, colorimetric testing with Biocytin-Avidin was performed as a sensor application in the experiment
Effect of 30˚C Electrolyte Temperature on The Sensitivity Cu/Ni
Full text linkGiven the necessity of cryogenic storage and monitoring cryogenic temperatures is equally important. This study aims to determine the resistance value and sensitivity of copper wire before and after electroplating at 30˚C electrolyte temperature as a low temperature sensor. The electrolyte solution consists of NiSO4 260 g, NiCl2 60 g, H3BO3 40 g and Aquades 1000 mL. Electroplating was carried out with an electrolyte temperature of 30˚C, electrode distance of 4 cm, voltage of 4.5 volts and plating time of 4 minutes. The plating results were analyzed to determine the resistance and sensitivity of the sensor at temperatures from 0 to -160˚C. The results showed that the resistance value of the Cu coil obtained RCu = (1.44 ± 0.00) ohm and the resistance of the Cu/Ni coil RCu / Ni = (1.50 ± 0.00) ohm. The resistance value on the Cu/Ni coil (after plating) is greater than the Cu coil (before plating). While the test results of sensor sensitivity show that Cu and Cu/Ni coils have properties as low temperature sensors. Sensor sensitivity increases after plating. The sensitivity value obtained by Cu coil is S(T) = -1E-06T + 6E-05 and Cu/Ni coil S(T) = -2E-06T + 2E-05. The projection sensitivity at a temperature of -200 ˚C obtained is 0.00046 V/˚C less than the Cu/Ni coil 0.00082 V/˚C. So nickel plating on copper coil at 30˚C electrolyte temperature has successfully improved the sensitivity value of the low-temperature sensor
Rainfall Classification Analysis Using Naïve Bayes Classifier Based on Air And Wind Temperatures in Serang City
Full text linkThe city of Serang experiences relatively high annual rainfall, with an average total of more than 100 mm/year. Based on data obtained from BMKG, Serang City, in 2023, there will be a shift in the rainy season due to weather anomalies, affecting the amount of rainfall. Apart from that, Serang City is one of the cities with less rain throughout September, recorded within 15 days. In this case, a determination is needed in the form of rainfall classification. However, an exemplary method is required in order to classify rainfall so that the classification results are accurate. Several studies showed that the naïve Bayes classifier method is the best classification method compared to other analysis methods; namely, it only requires a probability. The parameters used are air temperature and wind speed. So, this research aims to determine the classification of rainfall using the Naïve Bayes classifier based on air temperature and wind in Serang City. The method used is non-experimental quantitative with naïve Bayes classifier analysis. Based on the data analysis using Microsoft Excel software, the results showed that in the Serang city area, February 2024 was classified as a humid month with rainfall of 100 - 200 mm, and March 2024 was classified as a dry month with rainfall <100 mm
Gravitational Lensing for A Spherically Symmetric Regular Charged Black Hole in Weak Field Limit
Full text linkGravitational lensing is an integral part of the study of general relativity, as it is one of the direct consequences of general relativity. The existence of singularity within the black hole due to gravitational collapse is one of the key properties of the black hole. However, the introduction of non-linear electrodynamics (NLED) offers an intriguing possibility: nonsingular black holes. This work focuses on calculating the deflection angle within the weak field limit. Here, the photon's effective geometry associated with NLED is not incorporated; instead, the regular metric is utilized as it is, without presupposing its origins in NLED. A correction term in the deflection angle to the Reissner-Nordstrom (RN) case was found. This term manifests as a displacement in the position of the third image associated with the black hole
