Source Model Research Articles

On the correction factors for small field dosimetry in 1.5T MR-linacs

Objective. Clinical dosimetry in the presence of a 1.5 T magnetic field is challenging, let alone in case small fields are involved. The scope of this study is to determine a set of relevant correction factors for a variety of MR-compatible detectors with emphasis on small fields. Two dosimetry formalisms adopted from the literature are considered.Approach. Six small-cavity ionization chambers (from three manufacturers), four active solid-state detectors and a thermoluminescence dosimeter microcube were modeled in the EGSnrc Monte Carlo code. Phase space files for field sizes down to 1 × 1 cm2of the Unity 1.5 T/7 MV MR-linac (Elekta, UK) were used as source models. Simulations were performed to calculate thekQB,QfB,f(also known askB,Q),kQmsrB,fmsrandkQclin,QmsrB,fclin,fmsrrelevant to two different dosimetry formalisms. Two detector orientations with respect to the magnetic field were considered. Moreover, the effect of the ionization chamber's stem length (a construction parameter) on the correction factor was investigated. Simulations were also carried out to determine whether correction factors obtained in water can be applied in dosimetry procedures involving water-equivalent solid phantoms.Main results. Under thekQB,QfB,f-based formalism, the required corrections to ionization chamber responses did not exceed 1.5% even for the smallest field size considered. A much wider range ofkQB,QfB,fvalues was obtained for the active solid-state detectors included in the simulations. This is the first study to reportkQclin,QmsrB,fclin,fmsrvalues for ionization chambers. The impact of the stem on correction factors is not significant for lengths ⩾0.75 cm. Correction factors determined in water are also valid in dosimetry protocols employing solid phantoms.Significance. This work substantially expands the range of available detectors that can be used in small field dosimetry, enabling more options for commissioning, beam modeling and quality assurance procedures in 1.5 T MR-Linacs. However, more studies are needed to establish a complete and reliable dataset.

The Impact of Healthcare Reforms on the Epidemiology Workforce in Kazakhstan: An Interrupted Time Series Analysis with Predictive Modeling of Nationwide Data Sources from 1998 to 2022

Background: Following its independence, Kazakhstan implemented several reforms, including the adoption of the Entrepreneurial Code in 2008. This study aims to evaluate the impact of these reforms on the number and per capita rates of epidemiologists, nurse epidemiologists, epidemiological surveillance centers, and infectious morbidity from 1998 to 2022. Such an evaluation is critical for informing policy decisions regarding the future of epidemiological services in Kazakhstan. Methods: An interrupted time series analysis using a best-fit epidemiological model was conducted to assess the impact of key interventions—specifically, the adoption of the Entrepreneurial Code of the Republic of Kazakhstan and subsequent legislation—on the number and per capita rates of epidemiologists, nurse epidemiologists, and epidemiological surveillance facilities with infectious morbidity across the country. Results: Infectious morbidity per million individuals ranged from 4698.14 to 2263.79, with a consistent downward trend observed throughout the study period. Over the study period, the per capita rates of urban epidemiologists exhibited a downward trend, whereas the rates of rural epidemiologists showed an upward trajectory. The per capita rate of epidemiological surveillance centers declined from 26.89 to 15.24 over the study period. Substantial disparities were observed between urban and rural areas, with the epidemiology workforce in urban settings being 3–4 times larger than that in rural areas. Conclusions: This evaluation is important for informing policy decisions regarding the future of epidemiological surveillance services in Kazakhstan.

Systematical Theoretical Study of the Nonpoint Source Effects in Nuclear Medicine Shielding Calculation

Abstract The objective of this note was to systematically study the effects from nonpoint radiation sources on the nuclear medicine imaging room or uptake room shielding design. The dose from a nonpoint source to a location at a certain distance to the center of the source was calculated. A correction factor could be applied to the dose calculated using a point source model with the same distance to compensate the nonpoint source effects. The correction factor was a function only depending on the source relative dimension, the ratio of the source’s geometric dimension to the distance. Theoretical and numerical calculation were performed to calculate the correction factor on a one-dimensional line source, two-dimensional circular disc source, three-dimensional sphere, and cylinder sources. Our study indicated that for large nuclear medicine imaging rooms, the point source model was a good approximation for shielding design. For a small uptake room, a nonpoint source correction may be considered to calculate the barrier thickness.

A Radiation-Based Analytical Model for the Computation of Temperature in the Arc Column of Submerged Arc Additive Manufacturing (SAAM) Process

Abstract Submerged Arc Additive Manufacturing (SAAM) is an advanced Wire Arc-based Additive Manufacturing (WAAM) technique known for its uniform deposition structure, high deposition rate, and superior surface finish. However, it is difficult and expensive to experimentally investigate the arc column in SAAM due to its submerged nature under flux. This paper presents an effective alternative: developing a radiation-based analytical model to predict the complex temperature distribution within the SAAM arc column. It focuses on the radiation heat transfer phenomenon since the temperatures attained inside the arc column are beyond the melting temperature of the material involved, and the presence of granular flux and slag intensifies the effect of the same. The model incorporates key input process parameters like wire diameter, stick-out length, current, voltage, and travel speed alongside design parameters like bead width, penetration depth, and material reinforcement. The double ellipsoidal heat source model is the foundation for generating the temperature profile. The predicted temperature profile resembles the double ellipsoid in other arc welding-based additive manufacturing techniques. The model's predictions showed a deviation of approximately 14% from experimental results, validating its effectiveness. Extensive parametric studies were carried out using the developed model. It was observed that longer stick-out lengths dampened temperature variations, while higher currents confined the affected zone further. Increased travel speed reduces the heating and cooling rate, while voltage behaves the opposite way. This analytical approach offers a cost-effective alternative for optimizing process parameters to achieve desired dimensions and deposition quality.

A Parametric study on the effects of winglet cant angle on wing aerodynamics and aeroacoustics

The use of winglet devices is an efficient technique for enhancing aerodynamic performance. This study investigates the effects of winglet cant angles on both the aerodynamics and aeroacoustics of a commercial wing, comparing them to other significant parameters using a parametric analysis. A Full Factorial Design method is employed to generate a matrix of experiments, facilitating a detailed exploration of flow physics, with lift-to-drag ratio (L/D) and the integral of Acoustic Power Level (APL) as the primary representatives of aerodynamic and acoustic performance, respectively. The RANS formulation, along with the Realizable model and the Broadband Noise Source (BNS) model, are utilized to accurately simulate subsonic flows numerically. The study begins by examining the pressure coefficient () and APL distributions at various cant angles near the wingtip and root areas. The matrix of experiments is then analyzed to identify the most influential parameters based on the main effects of inputs and their two-way interactions. The results demonstrate that variations in winglet cant angle significantly alter the distribution of and APL along the span, particularly near the wingtip, and that cant angle strongly impacts overall performance, at times even outweighing atmospheric parameters such as pressure and temperature.

Study of residual stress and residual deformation of T-joints by continuous simultaneous double-sided welding

This paper investigates both the magnitude and distribution of temperature field, residual stress and deformation of DH36 steel fillet welded T-joints through the numerical simulation method. A thermal elastic-plastic finite element analysis is performed to investigate the heat transfer and deformation mechanisms during the welding process, employing a DFLUX subroutine developed in ABAQUS based on the double-ellipsoidal heat source model. The effects of welding speed and power on residual stress and deformation are further investigated. The finite element simulation results show good agreement with experimental measures regarding temperature distribution, melt pool morphology, residual stress, and deformation distribution. The results show that welding speed and power significantly affected the temperature variation during the welding process, which further influence the distribution of residual stress and residual deformation. The results indicate that high power at low welding speeds producing high temperatures leads to bottom fusion, while low power at high welding speeds resulted in insufficient fusion depth. Therefore, selecting appropriate welding speed and power is crucial for ensuring weld quality.

Sustainable Coastal Energy Development: Integrated Modeling of Renewable Energy Sources for Optimal Economic and Environmental Performance

Sustainable Coastal Energy Development: Integrated Modeling of Renewable Energy Sources for Optimal Economic and Environmental Performance

Multi-Layer Ceramic Capacitor Source Model Application in Acoustic Noise Prediction

Multi-Layer Ceramic Capacitor Source Model Application in Acoustic Noise Prediction

A combined noise source model based on vertical coherence to quantify the proportions of two types of noise power.

With the vigorous development of maritime trade, the frequency band from 100 to 1500 Hz of shallow-sea ambient noise is not only affected by surface wind-induced noise but also the contribution of ship noise. Shallow-sea ambient noise can be described by a linear combination of surface wind-induced noise sources and ship noise sources. By using the correspondence between the real part of the vertical coherence and vertical energy flux, this work establishes a combined noise source model based on vertical coherence. A 64-element vertical array is used to measure the ocean ambient noise 103 m deep in an area of the South China Sea. Two scenarios, one dominated by surface wind-induced noise and one dominated by wind-induced noise and ship noise, are selected for investigation. By comparing the theoretical and measured values, the accuracy of the model proposed in this paper and its ability to remove the ship noise reliably are verified. This approach can be used to quantify the proportion of ship noise power in shallow-sea low-frequency environments and evaluate the contributions of wind-induced noise and ship noise at different times.

Kinematic source rupture on listric faults for the 2024 Noto Peninsula, Japan, earthquake (Mw 7.5) estimated from near-field strong-motion waveforms

On January 1, 2024, an Mw 7.5 reverse-fault earthquake occurred along the submarine active faults just offshore of the Noto Peninsula in central Japan. This earthquake is one of the largest inland crustal earthquakes that ever recorded in Japan. We performed inversions of near-field strong-motion waveforms (0.05–0.25 Hz) to investigate the kinematic rupture process of this earthquake. For the inversions, we assumed listric fault planes, where the dip angles are steeper near the seafloor and become gentler with increased depth, based on the location of the submarine fault offsets, the structure at shallow depths revealed by seismic reflection surveys, and the relocated aftershock distribution at deep depths. To constrain our kinematic source model, we also utilized geodetic information published by the Geospatial Information Authority of Japan. We identified that the rupture process had three phases. The first phase was the initial rupture with a small slip of ~ 2 m around the rupture initiation area. After several seconds, the second and third phases, which were the main ruptures, propagated in the southwest and northeast directions, respectively. During the second and third phases, five large slip areas with average slips of 5–6 m significantly contributed to the strong-motion waveforms. By forward-simulating the geodetic data, we found that the rupture at shallow depths included an oblique component close to a right-lateral component and that, in the eastern part of the source region, the rupture transferred from a southeastward-dipping fault to a northwestward-dipping fault. The listric fault with high dip angles at shallow depths is better than a planar fault with a single dip angle for accurately modeling the fault slip near the surface and the coseismic displacement close to the fault trace during the reverse-fault earthquake.Graphical abstract

Dimensional Analysis and Validity of Uniaxial Residual Stress Distribution for Welded Box Sections

This paper investigates the residual stresses induced by metal inert/active gas (MIG/MAG) welding in normal strength steel box sections, focusing on the validity of uniaxial residual stress assumption. Advanced manufacturing simulations are conducted using deterministic uncoupled transient thermomechanical analysis with a double-ellipsoidal heat source model, employing 8-node solid elements and material models calibrated for extreme temperatures per EN 1993-1-2. A comprehensive parametric analysis investigates the effects of primary welding variables, such as heat source power and welding speed, alongside geometric parameters of the heat source model using random Latin hypercube sampling technique in the analyzed parameter set. The relationship between the size and shape of the characteristic isotherms, i.e., the aspect ratio and the Rosenthal number, underscores that the analyzed welding heat sources are in the fast regime with the validity of uniaxial residual stresses based on the analytical assumption (minimal values are AR = 9.94 and Ro = 30.47). The validity and limitations of uniaxial residual stress assumptions for 59 welded and 51 heated box sections are critically evaluated by using the finite element model-based stress triaxiality parameter. Results confirm that longitudinal residual stresses dominate typical MIG/MAG welding applications, supporting the application of uniaxial residual stress models in advanced structural design by neglecting in-plane and through-thickness residual stresses. Conversely, three-dimensional residual stress state dominates under conditions such as preheating or thermal straightening.

Evaluating Neural Network Performance in Predicting Disease Status and Tissue Source of JC Polyomavirus from Patient Isolates Based on the Hypervariable Region of the Viral Genome

JC polyomavirus (JCPyV) establishes a persistent, asymptomatic kidney infection in most of the population. However, JCPyV can reactivate in immunocompromised individuals and cause progressive multifocal leukoencephalopathy (PML), a fatal demyelinating disease with no approved treatment. Mutations in the hypervariable non-coding control region (NCCR) of the JCPyV genome have been linked to disease outcomes and neuropathogenesis, yet few metanalyses document these associations. Many online sequence entries, including those on NCBI databases, lack sufficient sample information, limiting large-scale analyses of NCCR sequences. Machine learning techniques, however, can augment available data for analysis. This study employs a previously compiled dataset of 989 JCPyV NCCR sequences from GenBank with associated patient PML status and viral tissue source to train multilayer perceptrons for predicting missing information within the dataset. The PML status and tissue source models were 100% and 87.8% accurate, respectively. Within the dataset, 348 samples had an unconfirmed PML status, where 259 were predicted as No PML and 89 as PML sequences. Of the 63 sequences with unconfirmed tissue sources, eight samples were predicted as urine, 13 as blood, and 42 as cerebrospinal fluid. These models can improve viral sequence identification and provide insights into viral mutations and pathogenesis.

Forward calculation of airborne gamma 3D radiation fields based on rapid coupling method of point kernel integrals.

Airborne gamma ray spectrum detection technology is an effective means to measure the concentration and spatial distribution of natural radionuclides in environmental media such as surface rocks and soil during aviation flight. Therefore, it is vital to fully explore the radiation information related to mineralization in airborne gamma spectrometry data and explore the dose distribution law of gamma radiation field of radionuclides in the detection area. This paper is based on the theoretical calculation model of ground-air interface gamma radiation field. After discretizing the equivalent surface source of the geological body with irregular and uniformly distributed radionuclides into a grid, it is divided into differential surface sources of uniform size, density, and isotropy. A theoretical calculation model for the spatial radiation field of differential surface sources at the ground-air interface has been derived. Finally, a rapid calculation program for the 3D radiation field of irregular surface sources coupled with point sources has been developed using the Qt framework. The accuracy and efficiency of the program were tested through three examples. For a single regular surface source, the rectangular surface source exhibited higher consistency at most detection points. The average relative deviation was 9.183%. In the case of a circular surface source, the dose rate values between the two methods deviated more significantly in the edge regions but less so in the central region. The average relative deviation was 12.765%. When comparing the calculation data of two irregular surface source models, the rapid calculation program was dozens of times faster than the SuperMC program. The maximum relative deviation was 38.245%, the minimum relative deviation was 5.416%, and the calculation accuracy was high. The average relative deviation was 21.912%. On several irregular surface source models, the relative deviations were relatively large. The maximum relative deviation reached 52.234%, the minimum was 12.305%, and the average relative deviation was 28.126%. This study can provide a certain theoretical reference for researchers in related fields, promoting the development and application of airborne gamma radiation field technology.

BioStructNet: Structure-Based Network with Transfer Learning for Predicting Biocatalyst Functions.

Enzyme-substrate interactions are essential to both biological processes and industrial applications. Advanced machine learning techniques have significantly accelerated biocatalysis research, revolutionizing the prediction of biocatalytic activities and facilitating the discovery of novel biocatalysts. However, the limited availability of data for specific enzyme functions, such as conversion efficiency and stereoselectivity, presents challenges for prediction accuracy. In this study, we developed BioStructNet, a structure-based deep learning network that integrates both protein and ligand structural data to capture the complexity of enzyme-substrate interactions. Benchmarking studies with different algorithms showed the enhanced predictive accuracy of BioStructNet. To further optimize the prediction accuracy for the small data set, we implemented transfer learning in the framework, training a source model on a large data set and fine-tuning it on a small, function-specific data set, using the CalB data set as a case study. The model performance was validated by comparing the attention heat maps generated by the BioStructNet interaction module with the enzyme-substrate interactions revealed from molecular dynamics simulations of enzyme-substrate complexes. BioStructNet would accelerate the discovery of functional enzymes for industrial use, particularly in cases where the training data sets for machine learning are small.

Induction arrow spatial and temporal variations

The induction arrow C is a characteristic of the variable geomagnetic field at one observation point (x, y) for a certain period T of geomagnetic variations B. It visually describes the magnitude and direction of the deviation of the geomagnetic field vector from the horizontal plane. The induction arrow is nonzero only when the vertical component Bz appears. Bz appears in three cases: 1) electrical conductivity’s horizontal gradients under the surface of the globe; 2) incomplete compensation of the vertical component of the primary field of the ionosphere-magnetosphere source by the secondary field induced in the horizontally layered Earth. The degree of compensation systematically changes during the day, year..., leading to temporal variations in the induction arrow (source effect); 3) the appearance of not-removed noise or lithosphere emission containing Bz. This article presents the spatial and temporal variations of the induction arrows. Real (in-phase) and imaginary (out-of-phase) induction arrows (vertical response functions or tippers) were obtained for every day with proper observations from 1991 to 2014 years for five intervals of periods: 150—300 s, 300—600 s, 600—1200 s, 1200—2400 s, 2400—3600 s, calculated from three components of geomagnetic field recorded at 137 observatories of the global network INTERMAGNET. To reduce the scatter, the daily values were recalculated to monthly values. Such global material from +87° to –88° of geomagnetic latitude was obtained for the first time and its analysis yielded new scientific results. The annual variations (with a period one year) are visible at about 2/3 of the observatories (at the other observatories, they are below the background level of shorter period variations and/or noise). Its amplitude strongly depends on the geomagnetic latitude and sometimes reaches such a high value as 0.4—0.5 (peak-to-peak) at high (>65°) latitudes and varies within 0.01—0.15 at middle and low latitudes. Previous studies at middle latitudes discovered that the annual variations in the northern component Au is positive everywhere (maximum in June, minimum in December) and proposed, as a global source model for the annual variations explanation, the ring current at the height 3―6 Earth’s radii. We discovered that at high latitudes, Au is usually negative. We propose to explain all the observed features of the induction arrow’s annual variations by variations of the ionosphere currents in the aurora zone. 11-year variations are found at ≈30 % of observatories located at all latitudes but more frequently in aurora zones. At a few observatories, trends (monotonous changes in arrows) were found. The largest trend of magnitude 0.2 for all periods was found in southern Greenland, where glaciers have been melting rapidly over the past 30 years, which makes it possible to associate both trends with global warming. In a few aurora observatories of North America trends of magnitude ≈0.1 were noticed. In these same years, the North Magnetic Pole unusually rapidly migrated for 1100 km in 23 years. It can be assumed that these trends are related to changes in the aurora oval position. At geomagnetic latitudes from –78° to +78°, the main harmonic (24 hours=86400 s) of daily variations of the geomagnetic field is always accompanied by at least one higher order harmonic 24/n (n=1÷7). At higher latitudes >78° of both hemispheres only the fundamental 24-hour harmonic is visible. Induction arrow temporal variations create difficulties in determining its constant component used to study the electrical conductivity of the Earth’s crust and upper mantle but can be very useful for geodynamic processes study

Possibilities of Using a Virtual Source Model to Refine the Prediction of the Impact of Injurious Effects in Massive Releases of Toxic Gases

Massive leaks of toxic substances occur not only during accidents connected with the operation of industrial enterprises, but also during their transfers by the means of transport. These events pose a serious threat to both people and the environment. Particularly dangerous are situations where dense gas clouds are formed after the release of the given substance. These spread very quickly, while they tend to remain at the earth's surface for a relatively long time and flow into various depressions. In a few minutes, the toxic gas can reach a large area, as confirmed by the conclusions from the Jack Rabbit field tests. Knowledge of the behavior of heavy gas, as well as knowledge of events influencing its dispersion in real conditions, thus provide important information needed for effective management of the resulting accident. The key data is the extent of the harmful effects of the given hazardous substance, which can be obtained by simulating the predicted emergency situation using modeling software (e.g. ALOHA). However, the fundamental shortcoming of this approach is that these software usually generate overestimated results. The fact that dangerous concentrations in the real environment do not reach such distances from the source of leakage has been repeatedly proven by past accidents. The reason for this discrepancy is that the computer programs used do not allow to model with sufficient accuracy all the simultaneous physico-chemical processes that are applied during the dispersion of dense gas clouds. This task is far too complicated and only a part of it can be solved with the necessary precision. However, for the needs of emergency planning, these inaccuracies represent a relatively fundamental limitation. One way how to deal with this problem is to use a virtual resource (sometimes called a virtual point) model. It is successfully used in various areas where it is necessary to simplify the otherwise demanding physical modeling of the temporal and spatial distribution of matter emitted from a surface or volume source. The main idea of a virtual source is that the real primary emission source is approximated to an imaginary source that is located at a different location but acts and appears outwardly as if it were a real source of leakage. The key task of this solution is to determine the parameters of this source, because this is the only way to obtain results with significantly higher reliability during the subsequent simulation of the considered accident scenario.

Transient Deformation in the Tatun Volcano Group, Taiwan: A Spatiotemporal GPS Analysis

AbstractThis study analyzed time series data from six GPS stations within the Tatun Volcano Group (TVG), a long‐dormant volcanic system in northern Taiwan, using multichannel singular spectrum analysis to search for potential spatiotemporally correlated transient deformations. A notable cycle of transient deformation was identified from 2015 to 2020, characterized by ground subsidence and uplift of up to 10 mm, accompanied by asymmetric horizontal motions directed inward and outward toward Dayoukeng, the largest fumarole and hydrothermal area in TVG. Evidence from earthquake focal mechanisms and gas composition, along with preliminary source modeling, suggest that these transient phases were likely caused by the pressure change of shallow hydrothermal systems beneath Dayoukeng. Further analysis of time series data from three long‐operating GPS stations revealed similar patterns of transient motion in the area from 2006 to 2015, indicating that TVG has experienced cyclical deformation, akin to many other volcanic systems worldwide.

Coseismic Shallow Slip Deficit Accounted for by Diffuse Off‐Fault Deformation

AbstractEarthquake ruptures produce fault slip and kilometer‐wide diffuse deformation of the host rocks. However, the origin of the diffuse deformation and its role in the rupture process are debated. We produce a refined slip model for the 2019 Ridgecrest, California, earthquakes, and analyze the relations between down‐dip rupture process, and surface diffuse deformation. We show that the decrease in coseismic slip toward the ground surface, also known as shallow slip deficit (SSD), correlates with the occurrence of diffuse deformation at the surface, which is not accounted for by models assuming elastic host rocks. Hence, we suggest that a significant part of the SSD in earthquake source models could be interpreted as a proxy for shallow diffuse inelastic deformation around faults. Revisiting earthquake source models for 28 continental earthquakes, we discuss the controlling parameters of the SSD and diffuse deformation, and propose a conceptual model of the near‐field coseismic surface deformation.

PREDICTION OF WELD-ABILITY CHARACTERISTICS OF DUAL-PHASE STEEL HCT600X BY NUMERICAL SIMULATION

Dual-phase (DP) steel plates are characterized by very good absorption capacity, so they are used in the automotive industry for body deformation zone parts. They are attached to the frame of the car-body by welding. Laser welding of dual-phase steels is gaining increasing importance in the automotive industry. In the present paper, the possibility of predicting the strength and deformation characteristics of laser-welded HCT600X steel sheets was analyzed based on experiments and numerical simulations. Butt joints were formed by YLS-5000 laser in two variants, which differ by laser power input and welding speed. The HCT600X- HCT600X with welded joint was analyzed based on microstructure and mechanical tests. The tensile strength and hardness of the welded joints were greater than those of the base material (BM). The microstructure of the weld metal (fusion zone) consisted of martensite, austenite and bainite, in the heat-affected zone it consisted of a mixture of martensite, bainite, ferrite and residual austenite. In numerical simulation, the finite-element mesh was created by linear volume elements refined in the weld region, and the Gauss model of the surface heat source was applied when modelling laser welding. The results of numerical simulation of the microstructure and selected mechanical properties were correlated with the experimental results.

DEVELOPING ELECTRICAL MODELS TO SIMULATE THE CONVERSION OF SOLAR RADIATION INTO ELECTRICAL AND THERMAL ENERGY

This article focuses on developing electrical models to investigate the conversion of solar radiation into both electrical and thermal energy. Our findings indicate that semiconductor converters are unable to harness the entire electromagnetic spectrum emitted by the sun. A substantial portion of solar radiation is transformed into heat. To achieve these results, we employed a corpuscular model to represent the solar radiation flow and a quantum mechanical framework to describe the energy associated with electromagnetic radiation and thermal processes within the crystal. To derive electrical modeling parameters, this study leveraged the principle of electrical and electrothermal analogies. We established a direct equivalence between the flow of solar photons and the flow of charge carriers represented by the electric current. Additionally, we demonstrated that the energy carried by photons is analogous to the voltage generated across the photovoltaic device. When modeling thermal energy using electrical circuits, we found that the electric current can be used to represent the flow of phonons, quasiparticles associated with thermal vibrations in the crystal, while the voltage corresponds to the energy of phonons. This study developed electrical models to simulate the conversion of solar radiation into both electrical and thermal energy. Current and voltage sources were employed to represent the energy conversion processes. It is shown that the internal resistances of energy sources in electrical models simulate the losses during the generation of electrical and thermal energy. It is noted that the proposed electrical model of a photovoltaic power source corresponds to the traditional equivalent circuit with a diode. The paper concludes by discussing the potential applications of the proposed modeling framework.