Journal of Physics: Theories and Applications
Journal of Physics: Theories and Applications (cited as J. Phys.: Theor. Appl.) is an open-access journal, which is published twice a year by Physics Department, Sebelas Maret University. The journal is designed to serve researchers, developers, professionals, graduate students, and others interested in theoretical and applied physics.
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Synthesis of bimetallic Ag-Cu nanoparticles using chemical reduction method as antibacterial agents against Escherichia coli
Bimetallic nanoparticles offer enhanced antibacterial properties due to synergistic effects between different metal ions. In this study, Ag-Cu nanoparticles were synthesized using a chemical reduction method with NaBH₄ as the reducing agent and PVP as a stabilizer. The resulting nanoparticles showed a greenish-black color and an average particle size of 308.8 nm with narrow distribution. Antibacterial activity against Escherichia coli was tested using the disc diffusion method at concentrations of 5%, 10%, and 15%. The results showed a concentration-dependent increase in inhibition zones, with a maximum average of 7.8 mm. Although lower than the positive control, the findings confirm the potential of Ag-Cu nanoparticles as alternative antibacterial agents. Further optimization is recommended for biomedical applications.
Copyright (c) 2025 Journal of Physics: Theories and Applications
Low-cost implementation of damped harmonic motion for structural vibration studies
This study presents a low-cost experimental approach to investigating damped harmonic motion for structural vibration studies, using easily accessible electronic components and open-source microcontroller technology. The primary objective is to validate the feasibility of accurately capturing and analyzing vibrational behavior through an economical setup, making advanced physics experimentation accessible for educational and research purposes. The system comprises a spring-mass mechanism integrated with sensors such as ultrasonic rangefinders and LDRs connected to an Arduino Uno, allowing real-time data acquisition of displacement, velocity, and acceleration. The experiment begins with an initial phase of gravitational free fall, followed by a transition to damped harmonic oscillation once the spring is activated, triggered at a threshold displacement. Graphical and tabular representations of the motion illustrate the classic underdamped response, including phase-shifted oscillations and exponential decay of amplitude, closely matching theoretical models of second-order dynamic systems. This transition is marked by clear time and displacement boundaries, providing valuable insight into non-ideal spring behavior and real-world mechanical thresholds. The results confirm that key dynamic properties, such as damping ratio and natural frequency, can be qualitatively and quantitatively examined through low-cost means without sacrificing measurement reliability. Overall, the study highlights the pedagogical effectiveness and scalability of such a system in introducing fundamental mechanical vibration concepts. This work contributes to both physics education and applied engineering by promoting affordable, accurate, and adaptable experimental tools for the study of structural dynamics and harmonic motion in real-world scenarios
Predicting Newtonian cooling with machine learning: a comparative analysis of gradient boosting and random forest models
This study investigates the use of artificial intelligence, specifically machine learning models, to predict temperature reduction in Newtonian cooling experiments involving varying volumes of water. Two regression models, Gradient Boosting Regression and Random Forest Regressor, were utilized to learn from empirical data. The findings indicate that both models are capable of accurately predicting cooling behavior, with the Random Forest model demonstrating superior accuracy for the dataset used. The machine learning models effectively represent the theoretical model of Newton’s Law of Cooling, which is characterized by an exponential decay curve. Furthermore, the cooling constant for each volume was estimated using curve fitting techniques. This research underscores the potential of AI in modeling complex physical processes, particularly in real-world scenarios where the relationships between physical variables are intricate and challenging to express analytically. With sufficient data, AI can adeptly predict variable changes based on fluctuations in others. As technology continues to advance, AI is poised to assume an increasingly critical role in experimental and industrial applications involving complex physical systems. The novelty of this study lies in its comparative analysis to identify the optimal machine learning model—Gradient Boosting Regression or Random Forest Regressor—for accurately predicting Newtonian cooling behavior. Additionally, this research introduces an automated data acquisition approach using a datalogger, significantly enhancing precision and practicality compared to traditional manual methods involving a stopwatch and thermometer.
Analytical solutions of relativistic quantum harmonic oscillators
We present analytical solutions for relativistic quantum harmonic oscillators using a Hermite polynomial series approach. Our method yields closed-form energy eigenvalues and normalized eigenfunctions accurate to order , providing improved precision beyond existing first-order relativistic treatments. Through numerical validation, we demonstrate that relativistic corrections become substantial for systems where particle velocities approach appreciable fractions of the speed of light. The theoretical framework offers a foundation for investigating quantum phenomena in relativistic regimes with potential applications to high-energy physics and astrophysics.
Universal I-Love-Q Relation in Anisotropic Quark Stars within Rastall Gravity
This study investigates the universal I-Love-Q relation in anisotropic quark stars within the Rastall gravity framework. We employ the 4th-order Runge-Kutta numerical method to solve the slow rotation and tidal deformation equations. The analysis utilizes the MIT Bag equation of state with the Bag parameter (<!--[if gte msEquation 12]><m:oMath><m:r>B</m:r></m:oMath><![endif]--> <!--[if gte vml 1]><v:shapetype id="_x0000_t75" coordsize="21600,21600" o:spt="75" o:preferrelative="t" path="m@4@5l@4@11@9@11@9@5xe" filled="f" stroked="f"> <v:stroke joinstyle="miter"/> <v:formulas> <v:f eqn="if lineDrawn pixelLineWidth 0"/> <v:f eqn="sum @0 1 0"/> <v:f eqn="sum 0 0 @1"/> <v:f eqn="prod @2 1 2"/> <v:f eqn="prod @3 21600 pixelWidth"/> <v:f eqn="prod @3 21600 pixelHeight"/> <v:f eqn="sum @0 0 1"/> <v:f eqn="prod @6 1 2"/> <v:f eqn="prod @7 21600 pixelWidth"/> <v:f eqn="sum @8 21600 0"/> <v:f eqn="prod @7 21600 pixelHeight"/> <v:f eqn="sum @10 21600 0"/> </v:formulas> <v:path o:extrusionok="f" gradientshapeok="t" o:connecttype="rect"/> <o:lock v:ext="edit" aspectratio="t"/> </v:shapetype><v:shape id="_x0000_i1025" type="#_x0000_t75" style='width:8.25pt; height:16.5pt'> <v:imagedata src="file:///C:/Users/D1401DA/AppData/Local/Temp/msohtmlclip1/01/clip_image001.png" o:title="" chromakey="white"/> </v:shape><![endif]--> ) and the Color Flavor Locked (CFL) equation of state with the CFL parameter parameter (<!--[if gte msEquation 12]><m:oMath><m:r>Δ</m:r></m:oMath><![endif]--> <!--[if gte vml 1]><v:shapetype id="_x0000_t75" coordsize="21600,21600" o:spt="75" o:preferrelative="t" path="m@4@5l@4@11@9@11@9@5xe" filled="f" stroked="f"> <v:stroke joinstyle="miter"/> <v:formulas> <v:f eqn="if lineDrawn pixelLineWidth 0"/> <v:f eqn="sum @0 1 0"/> <v:f eqn="sum 0 0 @1"/> <v:f eqn="prod @2 1 2"/> <v:f eqn="prod @3 21600 pixelWidth"/> <v:f eqn="prod @3 21600 pixelHeight"/> <v:f eqn="sum @0 0 1"/> <v:f eqn="prod @6 1 2"/> <v:f eqn="prod @7 21600 pixelWidth"/> <v:f eqn="sum @8 21600 0"/> <v:f eqn="prod @7 21600 pixelHeight"/> <v:f eqn="sum @10 21600 0"/> </v:formulas> <v:path o:extrusionok="f" gradientshapeok="t" o:connecttype="rect"/> <o:lock v:ext="edit" aspectratio="t"/> </v:shapetype><v:shape id="_x0000_i1025" type="#_x0000_t75" style='width:7.5pt; height:16.5pt'> <v:imagedata src="file:///C:/Users/D1401DA/AppData/Local/Temp/msohtmlclip1/01/clip_image001.png" o:title="" chromakey="white"/> </v:shape><![endif]--> ) to model the material properties of anisotropic quark stars. The universal I-Love-Q relation are explored by varying the Rastall parameter (<!--[if gte msEquation 12]><m:oMath><m:r>ζ</m:r></m:oMath><![endif]--> <!--[if gte vml 1]><v:shape id="_x0000_i1025" type="#_x0000_t75" style='width:6pt;height:16.5pt'> <v:imagedata src="file:///C:/Users/D1401DA/AppData/Local/Temp/msohtmlclip1/01/clip_image003.png" o:title="" chromakey="white"/> </v:shape><![endif]--> ) and the anisotropic parameter (<!--[if gte msEquation 12]><m:oMath><m:sSub><m:sSubPr><m:ctrlPr></m:ctrlPr></m:sSubPr><m:e><m:r>λ</m:r></m:e><m:sub><m:r>H</m:r></m:sub></m:sSub></m:oMath><![endif]--> <!--[if gte vml 1]><v:shapetype id="_x0000_t75" coordsize="21600,21600" o:spt="75" o:preferrelative="t" path="m@4@5l@4@11@9@11@9@5xe" filled="f" stroked="f"> <v:stroke joinstyle="miter"/> <v:formulas> <v:f eqn="if lineDrawn pixelLineWidth 0"/> <v:f eqn="sum @0 1 0"/> <v:f eqn="sum 0 0 @1"/> <v:f eqn="prod @2 1 2"/> <v:f eqn="prod @3 21600 pixelWidth"/> <v:f eqn="prod @3 21600 pixelHeight"/> <v:f eqn="sum @0 0 1"/> <v:f eqn="prod @6 1 2"/> <v:f eqn="prod @7 21600 pixelWidth"/> <v:f eqn="sum @8 21600 0"/> <v:f eqn="prod @7 21600 pixelHeight"/> <v:f eqn="sum @10 21600 0"/> </v:formulas> <v:path o:extrusionok="f" gradientshapeok="t" o:connecttype="rect"/> <o:lock v:ext="edit" aspectratio="t"/> </v:shapetype><v:shape id="_x0000_i1025" type="#_x0000_t75" style='width:13.5pt; height:16.5pt'> <v:imagedata src="file:///C:/Users/D1401DA/AppData/Local/Temp/msohtmlclip1/01/clip_image001.png" o:title="" chromakey="white"/> </v:shape><![endif]--> ). The universal I-Love-Q relation is satisfied when variations in <!--[if gte msEquation 12]><m:oMath><m:r>ζ</m:r></m:oMath><![endif]--> <!--[if gte vml 1]><v:shape id="_x0000_i1025" type="#_x0000_t75" style='width:6pt;height:16.5pt'> <v:imagedata src="file:///C:/Users/D1401DA/AppData/Local/Temp/msohtmlclip1/01/clip_image003.png" o:title="" chromakey="white"/> </v:shape><![endif]--> , <!--[if gte msEquation 12]><m:oMath><m:sSub><m:sSubPr><m:ctrlPr></m:ctrlPr></m:sSubPr><m:e><m:r>λ</m:r></m:e><m:sub><m:r>H</m:r></m:sub></m:sSub></m:oMath><![endif]--> <!--[if gte vml 1]><v:shapetype id="_x0000_t75" coordsize="21600,21600" o:spt="75" o:preferrelative="t" path="m@4@5l@4@11@9@11@9@5xe" filled="f" stroked="f"> <v:stroke joinstyle="miter"/> <v:formulas> <v:f eqn="if lineDrawn pixelLineWidth 0"/> <v:f eqn="sum @0 1 0"/> <v:f eqn="sum 0 0 @1"/> <v:f eqn="prod @2 1 2"/> <v:f eqn="prod @3 21600 pixelWidth"/> <v:f eqn="prod @3 21600 pixelHeight"/> <v:f eqn="sum @0 0 1"/> <v:f eqn="prod @6 1 2"/> <v:f eqn="prod @7 21600 pixelWidth"/> <v:f eqn="sum @8 21600 0"/> <v:f eqn="prod @7 21600 pixelHeight"/> <v:f eqn="sum @10 21600 0"/> </v:formulas> <v:path o:extrusionok="f" gradientshapeok="t" o:connecttype="rect"/> <o:lock v:ext="edit" aspectratio="t"/> </v:shapetype><v:shape id="_x0000_i1025" type="#_x0000_t75" style='width:13.5pt; height:16.5pt'> <v:imagedata src="file:///C:/Users/D1401DA/AppData/Local/Temp/msohtmlclip1/01/clip_image001.png" o:title="" chromakey="white"/> </v:shape><![endif]--> , <!--[if gte msEquation 12]><m:oMath><m:r>B</m:r></m:oMath><![endif]--> <!--[if gte vml 1]><v:shape id="_x0000_i1025" type="#_x0000_t75" style='width:8.25pt;height:16.5pt'> <v:imagedata src="file:///C:/Users/D1401DA/AppData/Local/Temp/msohtmlclip1/01/clip_image003.png" o:title="" chromakey="white"/> </v:shape><![endif]--> , and <!--[if gte msEquation 12]><m:oMath><m:r>Δ</m:r><m:r> </m:r></m:oMath><![endif]--> <!--[if gte vml 1]><v:shape id="_x0000_i1025" type="#_x0000_t75" style='width:9.75pt;height:16.5pt'> <v:imagedata src="file:///C:/Users/D1401DA/AppData/Local/Temp/msohtmlclip1/01/clip_image005.png" o:title="" chromakey="white"/> </v:shape><![endif]--> do not affect the linear relationship between the moment of inertia (<!--[if gte msEquation 12]><m:oMath><m:r>I</m:r></m:oMath><![endif]--> <!--[if gte vml 1]><v:shapetype id="_x0000_t75" coordsize="21600,21600" o:spt="75" o:preferrelative="t" path="m@4@5l@4@11@9@11@9@5xe" filled="f" stroked="f"> <v:stroke joinstyle="miter"/> <v:formulas> <v:f eqn="if lineDrawn pixelLineWidth 0"/> <v:f eqn="sum @0 1 0"/> <v:f eqn="sum 0 0 @1"/> <v:f eqn="prod @2 1 2"/> <v:f eqn="prod @3 21600 pixelWidth"/> <v:f eqn="prod @3 21600 pixelHeight"/> <v:f eqn="sum @0 0 1"/> <v:f eqn="prod @6 1 2"/> <v:f eqn="prod @7 21600 pixelWidth"/> <v:f eqn="sum @8 21600 0"/> <v:f eqn="prod @7 21600 pixelHeight"/> <v:f eqn="sum @10 21600 0"/> </v:formulas> <v:path o:extrusionok="f" gradientshapeok="t" o:connecttype="rect"/> <o:lock v:ext="edit" aspectratio="t"/> </v:shapetype><v:shape id="_x0000_i1025" type="#_x0000_t75" style='width:5.25pt; height:16.5pt'> <v:imagedata src="file:///C:/Users/D1401DA/AppData/Local/Temp/msohtmlclip1/01/clip_image001.png" o:title="" chromakey="white"/> </v:shape><![endif]--> ), Love number (<!--[if gte msEquation 12]><m:oMath><m:r>Λ</m:r></m:oMath><![endif]--> <!--[if gte vml 1]><v:shapetype id="_x0000_t75" coordsize="21600,21600" o:spt="75" o:preferrelative="t" path="m@4@5l@4@11@9@11@9@5xe" filled="f" stroked="f"> <v:stroke joinstyle="miter"/> <v:formulas> <v:f eqn="if lineDrawn pixelLineWidth 0"/> <v:f eqn="sum @0 1 0"/> <v:f eqn="sum 0 0 @1"/> <v:f eqn="prod @2 1 2"/> <v:f eqn="prod @3 21600 pixelWidth"/> <v:f eqn="prod @3 21600 pixelHeight"/> <v:f eqn="sum @0 0 1"/> <v:f eqn="prod @6 1 2"/> <v:f eqn="prod @7 21600 pixelWidth"/> <v:f eqn="sum @8 21600 0"/> <v:f eqn="prod @7 21600 pixelHeight"/> <v:f eqn="sum @10 21600 0"/> </v:formulas> <v:path o:extrusionok="f" gradientshapeok="t" o:connecttype="rect"/> <o:lock v:ext="edit" aspectratio="t"/> </v:shapetype><v:shape id="_x0000_i1025" type="#_x0000_t75" style='width:7.5pt; height:16.5pt'> <v:imagedata src="file:///C:/Users/D1401DA/AppData/Local/Temp/msohtmlclip1/01/clip_image001.png" o:title="" chromakey="white"/> </v:shape><![endif]--> ), and quadrupole moment (<!--[if gte msEquation 12]><m:oMath><m:r>Q</m:r></m:oMath><![endif]--> <!--[if gte vml 1]><v:shape id="_x0000_i1025" type="#_x0000_t75" style='width:8.25pt;height:16.5pt'> <v:imagedata src="file:///C:/Users/D1401DA/AppData/Local/Temp/msohtmlclip1/01/clip_image003.png" o:title="" chromakey="white"/> </v:shape><![endif]--> ). The universal I-Love-Q relation holds when <!--[if gte msEquation 12]><m:oMath><m:r>B</m:r></m:oMath><![endif]--> <!--[if gte vml 1]><v:shape id="_x0000_i1025" type="#_x0000_t75" style='width:8.25pt;height:16.5pt'> <v:imagedata src="file:///C:/Users/D1401DA/AppData/Local/Temp/msohtmlclip1/01/clip_image005.png" o:title="" chromakey="white"/> </v:shape><![endif]--> and <!--[if gte msEquation 12]><m:oMath><m:r>Δ</m:r></m:oMath><![endif]--> <!--[if gte vml 1]><v:shape id="_x0000_i1025" type="#_x0000_t75" style='width:7.5pt;height:16.5pt'> <v:imagedata src="file:///C:/Users/D1401DA/AppData/Local/Temp/msohtmlclip1/01/clip_image007.png" o:title="" chromakey="white"/> </v:shape><![endif]--> are varied , but breaks down when ζ and are altered.
Copyright (c) 2026 Journal of Physics: Theories and Applications
Photoacoustic imaging of oil-treated tissues for the potential support of halal product identification
Photoacoustic Imaging (PAI) has successfully demonstrated its capability as a non-destructive method for distinguishing biological tissues based on oil absorption characteristics. Chicken meat samples were soaked in coconut oil, sesame oil, and lard for 10 minutes, 60 minutes, and 24 hours. The PAI system employed a 532 nm green laser, condenser microphone, and a two-dimensional scanning stage to capture spatial images. Grayscale and pseudocolor images were analyzed to extract numerical features including mean intensity, standard deviation, and entropy. Results showed that tissues treated with lard consistently exhibited higher values of numerical feature, particularly after 24 hours, compared to samples with vegetable oils. These variations are linked to stronger optical absorption and increased structural complexity caused by oil infiltration. The study demonstrates that PAI can effectively detect oil-specific changes in tissue, suggesting its potential role in supporting halal product verification.
Evaluation of the physical, electrical, and magnetic properties of iron sand and its potential applications for advanced technology
This study examines the physical, electrical, and magnetic properties of iron sand from Bayuran Beach to evaluate its potential as a functional material in advanced technology applications. Iron sand samples with particle sizes between 100 and 300 mesh were analyzed using the two-point method, LCR meter, and X-ray Diffraction (XRD). The XRD results indicate that the samples are dominated by the magnetite phase (Fe₃O₄). The 150 mesh sample showed the highest resistivity of 3.38 × 10⁹ Ω·m and a maximum capacitance of 0.16 nF. The magnetic susceptibility value reached 3.34 × 10⁻⁴ m³/kg, with a magnetic mineral content of 79.80% and a density of 2.52 g/cm³. These findings indicate that Bayuran iron sand has strong potential as a soft magnetic material for inductor cores and magnetic field sensors, microwave absorbers for electromagnetic applications, and dielectric substrates in electronic systems. The capacitance variation between dry and wet conditions also indicates its potential as a humidity sensor. Furthermore, the presence of the Fe₃O₄ phase opens up opportunities for further development as an electrode material in supercapacitors or other energy storage devices through morphological engineering. Overall, this local iron sand is a promising candidate for development into a natural resource-based functional material.
Advancing string theory with 4G model of final unification
In the framework of the recently proposed 4G model of final unification, integrating three large atomic gravitational constants corresponding to the electromagnetic, strong, and electroweak interactions, we explore the physical existence of a fundamental electroweak fermion of rest energy ≈ 585 GeV. This particle is envisioned as the “zygote” of all elementary fermions and as the weak‐field counterpart to photons and gluons. Using three core assumptions and five defining relations, the model quantitatively reproduces key nuclear and particle physics observables, including the strong coupling constant, nuclear binding energies, neutron lifetime, charge radii, and several dimensionless large numbers. Theoretical string tensions and energies are derived for each atomic interaction (weak, strong, electromagnetic) using experimentally relevant scales (GeV–MeV–eV) rather than the inaccessible Planck scale, thus extending string theory’s applicability to testable low‑energy domains. Comparative analysis (Tables 1 and 2) demonstrates close agreement between calculated string energies and known interaction energies, providing a bridge between quantum gravity concepts and measurable nuclear data. The model also predicts possible astrophysical signatures of the 585 GeV fermion through annihilation and acceleration processes capable of generating TeV–multi‑TeV photons. While the approach is qualitative in some mathematical details, its ability to fit fundamental constants and nuclear properties within a unified string–gravitational paradigm offers a promising, experimentally approachable route toward a physically grounded final unification theory.
Thermal and nonthermal behaviors of electron–H2O in presence of laser field
Electron–water (H2O) molecule scattering under the influence of laser and thermal fields is a fundamental process in atomic and molecular physics, with significant implications for radiation chemistry, photonics, and quantum control. The interaction of electrons with H2O in the presence of an external laser field modifies the scattering dynamics by introducing additional energy and momentum channels, while thermal effects influence electron oscillations and resonance behavior. Understanding these combined effects is essential for accurately predicting differential cross-sections (DCS) and controlling scattering probabilities in experimental and applied settings, including laser-assisted spectroscopy, nanostructure interactions, and thermally tunable quantum devices. The aim of this work is to study the nature of electron-H2O in presence of laser and heat using scattering technique. For this we desing a theorical model which include thermal wave function, potential of water molecules, S-matrix, Besel function and Kroll-Watson approximation for DCS. The developed model was computed used temperature (293–300 K), scattering angles (0.057°–57°), momentum transfer (0.3–1 eV), distance separation (1–1.5 Å), field strength (0.3–5 a.u.), relative field strength (0.5–2.5 a.u.), electron conductivity (0.1–15 a.u.), polarization (linear, circular, elliptical), and Bessel function order. The computed result shows thermal effects enhance DCS compared to non-thermal conditions (0 K), with resonances observed at specific energies (0.25–1 eV). Higher scattering angles produce larger DCS, while lower angles generate sharper resonances with damping-like behavior. Elliptical polarization yields the highest DCS, followed by circular and linear. Distance separation and electron conductivity modulate constructive and destructive interference patterns, whereas higher-order Bessel functions stabilize DCS, indicating equilibrium between electrostatic interaction and particle rest energy. These findings suggest that controlled temperature and field parameters can manipulate scattering probability in thermal systems.
Green composite Fe₃O₄/CaO (0.5 g) for biodiesel production with preliminary structural, functional and morphological characterization
The development of environmentally friendly heterogeneous catalysts is crucial to support sustainable biodiesel production. This study aims to develop an eco-friendly Fe₃O₄/CaO (0.5 g) composite synthesized from local iron sand of Tulungagung as the Fe₃O₄ source and waste eggshells as the CaO source for potential catalytic applications in biodiesel production. The synthesis was carried out through a simple method while maintaining sustainability aspects by utilizing natural resources and agricultural waste. The composite was characterized using X-ray Diffraction (XRD) to identify the crystal structure, Fourier Transform Infrared Spectroscopy (FTIR) to investigate functional groups, and Scanning Electron Microscopy–Energy Dispersive X-ray Mapping (SEM–EDX Mapping). The results showed that the obtained composite consisted of two dominant phases, namely Fe₃O₄ as the magnetic phase and CaO as the active basic phase, with average crystallite sizes of 10.08 nm and 31.07 nm, respectively, indicating a high degree of crystallinity. FTIR analysis confirmed the presence of characteristic Fe–O and Ca–O functional groups at the wavenumber range of 500–600 cm⁻¹, while SEM images revealed an agglomerated oval-spherical morphology with an average particle size of 57.36 ± 0.85 nm. EDX analysis further confirmed the presence of Fe, O, and Ca elements, with Ca distribution, though relatively small, remaining consistent as active basic sites. The combination of crystalline properties, nanometer-scale morphology, and elemental composition supports the role of Fe₃O₄/CaO as a heterogeneous catalyst that is not only easily separable by a magnetic field but also potentially enhances catalytic activity in transesterification reactions. Therefore, this material demonstrates strong prospects as an environmentally friendly heterogeneous catalyst derived from local resources to support sustainable biodiesel production.
Characterization of trusted masks on the market, physically
A study was conducted to physically characterize masks that have been accepted in Indonesian market. This was motivated by the importance of masks as part of public health measures, preventing droplets from the wearer from leaving the mask and from outside (other people) from entering the mask, while maintaining a comfortable breathing environment. The purpose of this study was to physically characterize the three layers (front, middle, and back) of the mask. The results of this study can serve as a reference for small businesses in producing masks that are suitable for use. The research method was carried out in three stages. Stage 1: Calibration of the red and green laser wavelengths used, using diffraction grating (250, 500, and 750 lines/mm). Stage 2: Randomly selected masks from several reputable brands on the market. The lattice constants of the front and back layers of the masks, as well as the water absorption of the middle layer, were measured. This was done (on single brand of mask) in new, used, and used condition with treatment (washing and ironing). Stage 3, checked the lattice constant value (distance between the front and back layer pores) which was seen with microscope (with a micrometer installed in it) at a magnification of 83,3 times. The results obtained were the lattice constant value of the front and back layers and water absorption in the middle layer respectively: (a) new mask: (3.1 0.1)x10-3 cm; (1.3 0.2)x10-3 cm, and (3 1)x10-1 g/minute; (b) used mask: (1.3 0.4)x10-3 cm, (1.2 0.4)x10-3 cm, and (3 1)x10-1 g/minute; (c) used mask with treatment: (1.4 0.4)x10-3 cm, (1.4 0.3)x10-3 cm, and (14 1)x10-1 g/minute. Visual observations using a microscope yielded a lattice constant equivalence to the laser diffraction method. These results indicate that, regardless of comfort, mask suitable for use do not have to be new but this also applies to used masks that have been treated.
Gamma passing rate evaluation for IMRT and VMAT techniques based on gantry angles
Introduction: The accuracy of radiation dose delivery in advanced techniques such as Intensity Modulated Radiation Therapy (IMRT) and Volumetric Modulated Arc Therapy (VMAT) is highly dependent on the consistency of gantry angle performance. This study aims to evaluate the effect of gantry angle variations on the gamma passing rate (GPR) in IMRT and VMAT treatment plans. Methods: IMRT and VMAT plans were created using the Monaco Treatment Planning System on a homogeneous slab phantom and delivered within a range of gantry angles, including 90°, 180°, 270°, and 360°. Measurements were performed using the 2D array PTW Octavius 1500 that delivered by Linac Elekta Synergy and analyzed with the Verisoft software, applying a 2%/2 mm gamma index with a 10% threshold and a 97% gamma passing rate criterion. Results: All plans achieved GPR above 97%. VMAT demonstrated higher GPR values than IMRT at gantry angles of 90°, 180°, 270°, with the largest difference of 0.8% observed at 270°. IMRT showed a slightly higher GRP value than VMAT at range gantry 360° with a difference of 0.1%. Conclusion: The higher GPR value observed in VMAT indicates greater stability in relation to gantry angle variations. Although, IMRT performed slightly better at 360°, the difference was minimal. In general, gantry angle dependence was observed in both techniques, but the variation was not clinically significant.
Mass spectra of quarkonium systems in the shifted generalized Cornell–inverse quadratic potential model
In this study, we present an application of the Shifted Generalized Cornell–Inverse Quadratic Potential (SG-CIQP) to heavy quarkonium systems. By solving the radial Schrödinger equation with the Pekeris-type approximation within the Nikiforov–Uvarov method, we derive closed-form expressions for both the energy eigenvalues and wave functions. This approach is applied to charmonium and bottomonium mesons, yielding mass spectra in excellent agreement with experimental data and established theoretical predictions. Notably, the S-wave states are reproduced with high precision, while the P-wave states are captured with quantitatively reliable accuracy, with minor deviations in the charmonium sector attributable to relativistic and coupled-channel effects. These results not only confirm the robustness of the SG-CIQP framework but also establish its potential as a versatile tool for extending quarkonium studies to spin-dependent interactions, relativistic corrections, and the spectroscopy of exotic hadronic states.
Modified time-dependent linear thermal expansion equation: using Inhomogeneous 1-D heat equation
The correction factor must be derived from the results of the linear thermal expansion experiment. We have two ways to address this problem: we use the form of polynomials for the linear thermal coefficient, and one must solve the one-dimensional heat diffusion equation. The temperature function that we obtained is the solution for the inhomogeneous differential equation. Using those two, then combine them into a modified linear thermal expansion equation, i.e., the infinitesimal form of the equation, so that we could find the expression for the time-dependent expansion for the metal rod, . We should attempt to reduce the higher-order terms by taking the approximation as our first step in this paper. Finally, the observer may choose a suitable boundary condition for the formula and use the resulting equation as the correction factor.