This study presents a comprehensive numerical investigation of thermoacoustics (TA) wave propagation in the time domain using the Finite Difference Time Domain (FDTD) method, with a comparative analysis against the k-space pseudospectral approach. The TA wave equation is modeled under the assumptions of homogeneous, lossless, and isotropic medium, incorporating a physically realistic source term. A Gaussian initial pressure distribution is employed as the primary excitation, and the resulting acoustic signals are recorded using point and multi-sensor configurations. The study systematically the influence of spatial grid resolution and the Courant-Friedrichs-Lewy (CFL) number on numerical stability and accuracy. It is observed that maintaining a constant CFL number ensures consistent wave propagation behavior across different grid resolutions, whereas variations in CFL lead to significant discrepancies in amplitude and phase of the propagated signals. In addition to Gausian sources, various realistic source geometries, including circular disk, Chebyshev polynomial-based, and asymmetric (rock-like) distributions, are investigated to analyze their impact on wavefield characteristics. The numerical results demonstrate strong agreement between the FDTD and k-space method in both time and frequency domains under stable conditions. However, deviations are observed at higher frequencies due to numerical dispersion effects, particularly in the FDTD scheme. Furthermore, it is shown that sharp discontinuities in binary image based sources introduce non-physical high-frequency components, resulting in spurious oscillations. This study highlights the importance of numerical parameter selection, particularly the CFL condition, and provides a detailed comparision of two widely used computational methods for TA wave simulation. The findings offer valuable insights into the role of source geometry and numerical schemes in accurately modeling acoustic wave propagation.
Hygrothermal transfers have a decisive influence on the thermo-hydraulic behavior and durability of building materials. They directly influence energy performance of buildings, thermal comfort of occupants, and longevity of structures. This study presents a comparative analysis of heat and mass transfer mechanisms in various commonly used building materials, such as concrete, cement blocks, compressed earth bricks (CEB), and cut laterite blocks (CLB). The analysis is based on the thermo-hydraulic properties of these materials, as well as on the coupled phenomena of thermal conduction and water vapor diffusion. The materials are assumed to be placed in air. We used a numerical method to solve the equations. This numerical method involved formulating the transport equations according to the Luikov model. These equations are solved using an implicit finite-difference scheme. A Fortran code combined with the Thomas algorithm for solving the equations was developed and validated using the literature. The results are presented as the spatiotemporal evolution of temperature and moisture content at the center of the materials. The results show that hygrothermal transfers depend on the temperature of the air in contact with the materials. When this air temperature increases, the temperature within the materials increases by 5%. However, this increase is more rapid in cementitious materials, where it can reach 10%. The moisture content decreases by 0.3% for most materials, except for cementitious materials, which decrease by 0.5%. Materials with low thermal conductivity conduct less heat and retain more moisture.
Laser-Induced Breakdown Spectroscopy (LIBS) has gained interest among analytical techniques the last few years, thanks to its relative simplicity of use: generate compositional information from a material with minimal sample preparation. However, accurate recognition of chemical species in complex mixtures typically requires expert interpretation or extensive calibration datasets, and usually can only be performed on selected chemical elements. To mitigate these limitations and enhance the analytical capability of LIBS, we propose a novel vector space model coupled with singular value decomposition (SVD) and demonstrate its potential for both qualitative and quantitative LIBS analysis. In this vector space based algorithm, each chemical element is encoded as a unit vector; the complete set of unit vectors constitutes a basis that spans the spectral space of any unknown sample. Synthetic spectra generated from the LIBS spectra database of the National Institute of Standards and Technology is used to construct a database of 16 elements and assess the relevance of our approach in the identification and quantification of alloys in LIBS spectra. The algorithm reliably identified all elemental components and estimated their proportions; quantitative precision was highest for simpler binary alloys and decreased with compositional complexity. This approach provides a promising foundation for automated and calibration-light LIBS analysis. The limits of this approach are also discussed and some ideas for improvement are proposed.
The Aharonov-Bohm (AB) effect fundamentally demonstrates that electromagnetic potentials, rather than strictly classical fields, play a foundational, observable role in quantum mechanics. While standard quantum theory successfully accommodates this phenomenon via the axiomatic insertion of the minimal coupling principle, a purely geometric interpretation of the gauge potential has historically remained elusive. Building on a previously established complex spacetime framework—where conventional spacetime coordinates are extended into real and imaginary domains—this paper proposes a novel, localized geometric origin for the AB effect. We postulate that the imaginary spatial derivative of the complex wavefunction is physically equivalent to the electromagnetic gauge potential, thereby deriving the minimal coupling prescription directly from spacetime geometry rather than treating it as an independent axiom. Under this framework, the topological phase shift experienced by a charged particle in a field-free region arises naturally from its local evolution through the imaginary dimensions of complex spacetime. Furthermore, by treating the gauge potential as an affine connection or cross-metric term that links real and imaginary dimensions, we successfully redefine the complex metric tensor. This allows the classical electromagnetic field tensor to emerge naturally as the Riemann curvature of the complexified space. This approach provides a unified geometric foundation for both gauge potentials and quantum interference phenomena, resolving previous field-tensor metric limitations while offering a promising mathematical framework for future integrations into relativistic quantum mechanics and cosmic geometry.
Electricity losses are a fundamental indicator of the performance of transmission and distribution networks. In developing countries, they represent a major technical, economic, and strategic challenge, as they directly affect the stability of the electricity system, the quality of service, and the profitability of operators. This study assesses technical and non-technical losses in the High Voltage A (HTA) and High Voltage B (HTB) networks of the National Electricity Company in N'Djamena, the capital of Chad. The analysis is based on the use of energy injection data at source stations and billing data collected over a continuous 12-month period. The methodology adopted consists of comparing the energy injected into the networks with the energy actually billed to subscribers in order to determine the overall loss rate, then distinguishing between technical and non-technical losses. Technical losses are mainly related to physical phenomena inherent in the transmission and distribution of electricity, including Joule losses in conductors, losses in transformers, and load imbalances. Non-technical losses are mainly due to metering system failures, fraud, illegal connections, and meter reading errors. The results show that losses recorded on the HTB network remain relatively moderate, with an estimated rate of between 3% and 5%, which is in line with the standards generally observed for transmission networks. On the other hand, the HTA network has significantly higher losses, ranging from 15% to 20%. This difference can be explained by the length of the HTA feeders, the obsolescence of certain equipment, the overload of distribution transformers, and a sometimes insufficient power factor. The study also highlights the significant impact of non-technical losses, which contribute significantly to the overall energy imbalance. Based on these results, several technical and organizational recommendations are proposed. These include optimizing conductor sizing, compensating for reactive energy to improve the power factor, strengthening preventive maintenance programs, modernizing transformer stations, and deploying smart meters to reduce non-technical losses. Improving the overall efficiency of the electricity grid in N'Djamena is therefore an essential lever for increasing the energy performance and economic viability of the national electricity sector.
This article presents a conservative phenomenological framework for discussing the free-neutron lifetime discrepancy in terms of possible geometry-dependent transport and storage contributions superposed on a common intrinsic time scale. The purpose is not to replace the standard weak-decay description, but to formulate an experimentally testable discriminator capable of separating predominantly velocity-dependent from configuration-dependent effects in the extraction of the neutron lifetime. As a starting point, a compact intrinsic-scale layer is used to introduce a working reference value τ₀ ≈ 877.77s. On top of this baseline, two effective correction channels are added. The first is a weak transport or alignment term for a straight tube geometry, suppressed in first approximation approximately as 1/v2. The second is a configuration-mixing term associated with storage or bottle setups, isotropization, and wall-induced scrambling. This leads to a direct and testable expectation: in one and the same straight decay-tube geometry, measurements across a broad speed interval should show either near constancy or only a weak residual speed dependence, whereas larger deviations would point more naturally to storage-specific mixing effects. The formulation is intentionally moderate. It is not presented as derived from QED, nor as a replacement for the standard theory of beta decay. Instead, it is proposed as an effective test framework written in notation-compatible form with respect to the standard operator language and directed toward a concrete straight-tube experiment.
Magnetic solitons in quasi-one-dimensional anisotropic Heisenberg magnets are stable nonlinear excitations that can transport spin, energy, and information over long distances. This paper develops a practical theory for neutron (inelastic) scattering from such solitons and clarifies how quantum and thermal fluctuations control the observable spectrum. Starting from an easy-axis Heisenberg ferromagnet with nearest-neighbor exchange and uniaxial anisotropy, a single soliton is treated as a particle-like mode characterized by conserved quantities that may be interpreted as the number of magnons bound in the soliton and the soliton quasi-momentum. Exploiting the integrability of the model and the possibility of separating kinetic and potential energies in action-angle variables, the soliton contribution to the dynamic structure factor S(q, ω) and to the double-differential scattering cross section is derived. The derivation adapts the Kawasaki-type approach used in earlier soliton scattering studies, but is reformulated here in a simplified and transparent way that yields a general working formula without cumbersome intermediate steps. The resulting response naturally splits into quasi-elastic and inelastic parts. Soliton translation produces a pronounced quasi-elastic intensity and can generate central-peak behavior through the soliton’s response to external perturbations. Thermal averaging leads to explicit conditions under which the quasi-elastic component reduces to a Gaussian form; the analysis also delineates when this approximation fails, in particular for “massive” solitons with large bound-magnon number. At larger energy transfers, scattering into excited soliton states becomes possible, providing access to internal soliton modes and to dissipation mechanisms in real materials. The obtained expressions connect measurable line shapes and spectral weights to soliton width, effective mass, stability, and transport characteristics. Overall, the work provides a concrete basis for interpreting neutron-scattering signatures of solitonic states in quasi-one-dimensional magnets and for designing experiments that isolate their contribution, with relevance to nonlinear magnetic dynamics, spin-transport phenomena, and prospective quantum-technology applications.
This study investigates the complex mechanisms of coupled heat and mass transfer within a fired porous clay plate optimized for evaporative cooling in hot and dry climates. The primary objective was to model and experimentally validate the material's ability to lower air temperature through capillary evaporation. Local results highlight a pronounced leading-edge effect, where a maximum evaporation flux of 0.78 g/m² induces rapid cooling within the first few centimeters of the plate. Under nominal conditions of 40°C and 20% relative humidity (RH), the outlet air temperature drops significantly to 25.38°C, corresponding to a thermal gain of nearly 15°C. The theoretical validity of the model is confirmed by the perfect superposition of local Nusselt (Nu x ) and Sherwood (Sh x ) numbers, demonstrating the consistency of the Chilton-Colburn analogy. Parametric analysis reveals that system efficiency is highly dependent on residence time and hygrometric potential: a moderate air velocity of 1.5 m/s combined with low initial humidity (10%) optimizes the process, achieving a record cooling of 17.4°C. Despite some simplifying assumptions (adiabatic walls, uniform saturation), comparison with experimental data shows excellent agreement, with an average relative error of 6% to 7% and a root mean square error (RMSE) of approximately 2°C. The research demonstrates that fired clay, owing to its porous structure that promotes capillary transport, constitutes an efficient passive heat exchanger and a sustainable alternative to energy-intensive air conditioning systems.
Background: The unification of General Relativity and Quantum Mechanics represents a fundamental challenge in theoretical physics due to their mutually exclusive conceptual foundations: continuous deterministic geometry versus probabilistic wave functions. While the de Broglie-Bohm pilot-wave theory offers a deterministic, trajectory-based alternative to the standard probabilistic framework, it introduces a non-local, ad-hoc "Quantum Potential" (Q) to account for phenomena such as interference and non-locality. The lack of a geometric origin for Q in standard spacetime remains a significant conceptual barrier to a fully unified theory. Purpose: This paper aims to resolve this interpretational crisis by proposing that the Quantum Potential is not a fundamental or mysterious external force, but rather a derived geometric artifact. We postulate that the physical universe is fundamentally a 4-dimensional Complex Manifold (ℂ4), extending the standard Riemannian spacetime manifold to include imaginary coordinates. Methods: To establish this geometric basis, we treat the quantum wave function not as an abstract probabilistic amplitude, but as a physical, holomorphic map describing a particle's deterministic trajectory through this complex spacetime. Utilizing the Cauchy-Riemann conditions, we demonstrate that the Bohmian amplitude (R) is strictly coupled to the particle's location in the imaginary dimension. We then analyze the dynamics of particles following geodesics within ℂ4. By projecting the complex geodesic equation of motion onto the observable real slice (ℝ4), we separate the real and imaginary components of the complex 4-velocity to observe the energy balance. Conclusions: Our derivation reveals that the Quantum Potential (Q) emerges naturally and is mathematically identical to the kinetic energy component associated with a particle's hidden motion in these imaginary dimensions. This formulation successfully recovers the predictions of the Schrödinger equation while removing the ad-hoc nature of Bohmian mechanics. Furthermore, it interprets quantum non-locality—such as the interference observed in the double-slit experiment—as purely local, deterministic geodesic motion around topological singularities in a curved complex manifold. Ultimately, this framework provides a unified geometric description wherein gravity is the curvature of real coordinates, electromagnetism is the torsion of imaginary coordinates, and quantum mechanics is inertial motion through this complex geometry.
The article discusses the study of the impact of the magnetic field (B) on the performance of a series vertical junction solar cell operating in static conditions and under polychromatic illumination. These solar cells consist of several non-monolithic junctions connected in series and illuminated from the edges. The theoretical approach is based on solving the continuity equation for excess minority charge carriers in the base (p-zone). This equation explicitly incorporates the influence of the magnetic field via the diffusion coefficient (D (B)), which is inversely proportional to 1+(μ. B) 2 (magnetoresistance phenomenon). The solution to the continuity equation is used to derive expressions for photocurrent (Jph), photovoltage (Vph), power (Pmax), form factor (FF), and conversion efficiency (η). The results clearly show that maximum power (Pmax) and conversion efficiency (η) decrease as the magnetic field increases (B). This effect is attributed to the Lorentz force, which deflects the trajectory of photogenerated carriers, significantly increasing their recombination rate before they reach the junction, thereby reducing the photocurrent. The study mainly shows that the optimum thickness (Hopt) of the base offering maximum power decreases as the magnetic field increases. This decrease is due to the fact that the magnetic field deflects the trajectory of minority carriers (electrons) towards the lateral faces of the cell. Therefore, for better carrier collection, the thickness of the base must be much thinner. The form factor (FF) is only very slightly affected by the magnetic field.
Background: The reconciliation of General Relativity with Quantum Mechanics remains the primary challenge in modern theoretical physics. Traditional approaches often assume a fixed background geometry, yet recent developments in string theory and loop quantum gravity suggest that spacetime is not fundamental but emergent. Specifically, the Holographic Principle implies that the information defining the bulk universe is encoded on a lower-dimensional boundary, raising the question of how a singular, classical reality arises from a quantum superposition of geometries. Purpose: This paper proposes a novel model of quantum cosmology where the observed spacetime is defined not as a pre-existing manifold, but as a macroscopic "ensemble average" of all possible spacetime fabrics. We aim to demonstrate that the perception of a unique physical reality is a result of holographic projection rather than intrinsic geometric properties. Methods: We utilize the AdS/CFT correspondence to model the universe as a holographic projection arising from a single, universal quantum state. By applying Feynman’s Path Integral formulation to the "superspace" of all possible metrics, we calculate the sum over histories for these geometric projections. We treat the emergence of classical spacetime as a process of constructive interference among infinite holographic realizations, filtering out unstable geometries through environmental decoherence.
Sm 3+ doped PbO–Sb 2 O 3 glasses containing varying concentrations of Sm 2 O 3 (0–1.0 mol%) were synthesized using the conventional melt-quenching technique to investigate their structural, optical, and luminescent properties. The prepared glass samples were characterized through density measurements, optical absorption spectroscopy, photoluminescence, and infrared spectral studies. Density analysis revealed a gradual increase with increasing Sm 3+ concentration, accompanied by a decrease in interionic distance and an increase in field strength, indicating significant modifications in the local glass structure. Optical absorption spectra exhibited several well-defined bands in the visible and near-infrared regions corresponding to the characteristic f–f transitions of Sm 3+ ions, with absorption intensity increasing systematically with dopant concentration. Photoluminescence studies under 401 nm excitation showed intense emission bands originating from the 4 G 5/2 excited state of Sm 3+ ions, and the luminescence intensity was found to enhance with increasing Sm 2 O 3 content. Infrared spectral analysis confirmed the presence of SbO 3 pyramidal structural units along with PbO 4 groups, suggesting that PbO plays a dual role as both a network former and a network modifier within the glass matrix. The combined structural and spectroscopic results demonstrate that Sm 3+ doped lead antimonate glasses possess favorable optical and luminescent characteristics, making them promising materials for photonic and luminescent device applications.
The standard interpretations of quantum mechanics, particularly the Copenhagen and Many-Worlds (MWI) views, fail to provide a satisfactory, physically localized mechanism for wave function collapse or the appearance of a single classical reality. This paper proposes the Emergent Universe from Many Unreal World Interpretation (MUWI), a novel framework that integrates concepts from the Feynman Path Integral Formulation (PIF), the Holographic Principle, and the concept of quantized spacetime. MUWI posits that reality emerges from a finite, pre-existent set of Unreal Spacetime Fabrics, each corresponding to a potential quantum state, or "address." We establish a formal equivalence between these unreal fabrics and the "sum over histories" in the Path Integral Formulation (PIF). The particle’s quantum state is the propagator, calculated as the collective interference of all potential states (shadows) across these fabrics. The critical distinction lies in the collapse mechanism: Measurement is not a branching event, but an irreversible, informational event-an "address change"-triggered by the interaction of a true particle with a shadow. This interaction enforces a new boundary condition, instantaneously collapsing the PIF to a single history (the observed outcome) and transferring the particle's quantum information across a non-local holographic plane. This approach proposes a localized, geometric mechanism for wave function collapse, offers a consistent explanation for the paradox of retrocausality in delayed-choice experiments, and suggests a fundamental link between the quantum wave and the emergent geometry of spacetime.
By considering a magnetized dusty plasma system which is composed of inertial negatively charged dust particles, positively charged warm ions, and inertia less κ-distributed electrons, the obliquely propagating dust ion acoustic solitary waves (DIASWs) are thoroughly examined. The shape of nonlinear electrostatic excitations is significantly altered by the external magnetic field. A Zakharov–Kuznetsov equation is derived by utilizing well known reductive perturbation method. The basic characteristics (amplitude, width, phase speed, etc.) that related to the DIASWs are examined. It is found that for the considered plasma system the fundamental features of DIASWs changes significantly. It is correspondingly analyzed that the amplitude of positive solitary waves changes significantly for different plasma parameters. The results of this work can be used to comprehend the properties of DIASWs and localized electrostatic structures in different astrophysical plasmas. Numerous physical parameters, including the temperature ratio, electron superthermality, and dust to ion mass ratio, have a substantial impact on the propagation characteristics of DIASWs. An increase in dust content enhances the overall mass loading, which tends to reduce phase speed and broaden the solitary structures, while also modifying the balance between dispersion and nonlinearity. A brief discussion is given of the implications of this work for laboratory plasmas and space.
We propose the General Theory of Relative Fabrics (GTRF), a unifying theoretical framework that posits that gravity does not arise primarily from spacetime curvature induced by mass–energy, but rather emerges from weak nonlocal entanglement between microscopic spacetime fabrics associated with each particle. This perspective replaces the classical dictum, "mass tells spacetime how to curve," with the foundational postulate: "Each mass carries its own spacetime, and gravity emerges when their fabrics entangle". In this model, each particle generates a localized micro-fabric of spacetime that interacts with others through a long-range, decaying entanglement field. This field, scaling as 1/r2 due to the geometric falloff of phase coherence in three dimensions, produces time dilation and curvature as emergent synchronization effects between these fabrics. The gradient in this temporal synchronization manifests macroscopically as the gravitational attraction described by Newtonian and General Relativity (GR). Building on earlier work regarding complex spacetime geometry and the Holographic Address Framework, the GTRF unifies GR and quantum entanglement under a single geometric–informational principle. Crucially, the GTRF framework accounts for dark matter phenomenology not as missing mass, but as the residual coherence of ancient spacetime fabrics. We demonstrate this by deriving modified field equations that incorporate an entanglement stress-energy tensor, which yields asymptotically flat galactic rotation curves without invoking unseen dark matter particles. We show that the weak-field limit of GTRF reduces to a Modified Poisson Equation that naturally generates the required asymptotic velocity profiles. Furthermore, the GTRF maintains consistency with high-precision Solar System tests, as demonstrated by the ability to tune the entanglement coupling functions to satisfy the stringent constraints on the Parameterized Post-Newtonian (PPN) parameters γ ≈ 1 and β≈ 1 and. Gravity, dark matter, and quantum entanglement are thus presented as different scales of the same underlying coherence principle.
Relativity theory based on a single transformation law (STL) for 4-vectors and tensors under universal rotation matrix (URM) on a unit circle satisfies principle of relativity, conservation laws and new symmetry valid for vc. This model can be called as relativity theory for all velocities (RTAV). The framework of relativity theory under universal Lorentz transformation matrix (ULTM) on a unit hyperbola gave form invariance of spacetime laws of physics for vc such that spacetime as a whole remains same for all observers. We consider the transformation of electrodynamic laws consisting of electromagnetic field (EMF), Maxwell’s equations (ME) and conservation law in tensor components form. STL under URM gives rise to new symmetry of EMF, ME and conservation law along their diagonals. These terms constitute structure of zero-point electrodynamics (ZPE). Matrix method and Einstein’s summation convention method (ESCM) are employed. Both methods agree up to the transformation of EMF, ME but differ in the transformation of conservation law. Usual electrodynamics remains same for all observers without being affected by ZPE. Conservation law in matrix method holds as usual. In ESCM, zero-point conservation appears as 4D EM wave while conservation law itself becomes 7D EM wave. In quantum theory zero-point energy violates conservation law whereas in our model ZPE is necessary to validate form invariance of spacetime laws and conservation law. This model of relativity is equally valid for noninertial frame.
Doubly excited systems, particularly in heliumoid configurations, represent a complex area of research due to the strong interactions between the electrons. The diagonalization method is a powerful technique for studying these systems, simplifying the problem to a system of linear algebraic equations. This method makes it possible to obtain resonance parameters, such as energies E and partial widths Γ, with great precision. In the literature, there are no experimental measurements of the energies of doubly excited states in heliumoid systems, nor of the associated partial widths. The theoretical results available are few and often show inconsistencies. Moreover, even states have not yet been treated exhaustively using diagonalization or other theoretical methods. In this work, we focus on doubly excited resonances of 1,3Ge symmetry sublevels. Using a diagonalization method, we have performed robust numerical calculations to determine the resonance parameters (energies E and widths Γ) of the (3l1kl2) 1,3Ge states of the ion. The numerical advantages of the diagonalization method make it possible to obtain these resonance parameters simply and accurately. We report for the first time the resonance parameters of the 1,3Ge states, including E energies and Γ partial widths. The calculations have shown high accuracy, with results consistent with the few existing theoretical data. This study makes a significant contribution to our understanding of doubly excited states in heliumoid systems. These results fill a gap in the literature and provide a solid basis for future theoretical and experimental studies. The numerical advantages of the diagonalization method make it a technique of choice for the study of complex quantum systems. The results obtained pave the way for further investigations into other configurations and symmetries of doubly excited states. They also encourage the development of experimental measurements to validate theoretical predictions and improve our understanding of self-ionization processes in multi-electron ions.
This study aims to validate the simulation model of the GAMOS/ GEANT4 code for a 6 MV photon beam produced by the Elekta Synergy Agility linear accelerator installed at the International Cancer Center of Dakar (CICD), Senegal. The simulation encompasses all major components of the accelerator head: the target, primary collimator, flattening filter, ionization chamber, and X and Y jaws, using a homogeneous water phantom. The phase space was placed after the jaws, and for each angular distribution model studied: Tsai, Koch–Motz 2BS, and Koch–Motz 2BN, the dose distribution was evaluated. This includes depth dose curves for field sizes of 5 × 5 cm² and 10 × 10 cm² at a source-to-axis distance (SAD) of 100 cm, as well as dose profiles at depths of 5, 10, 15, and 20 cm in the phantom, with a source-to-surface distance (SSD) of 90 cm from the target. The three bremsstrahlung angular distribution models implemented in GAMOS were then compared with experimental measurements. Validation was performed using the gamma index, with an acceptance criterion of 3% for dose difference (DD) and 3 mm for distance to agreement (DTA). For the depth dose curves, a 94% agreement was observed between simulated and experimental data for the 5 × 5 cm² field, and 96% for the 10 × 10 cm² field, regardless of the model. Regarding the dose profiles, the three models: Koch–Motz 2BN, Koch–Motz 2BS, and Tsai, exhibit perfect agreement (100%) with measurements for the 5 × 5 cm² field size at all depths. For the 10 × 10 cm² field, the Koch–Motz 2BN model shows excellent agreement of 100% at 5 cm and 20 cm depths, followed by the Tsai model with 99% at 20 cm. At 10 cm depth, agreement reached 99% for Koch–Motz 2BN and 97% for Tsai. At 15 cm, Koch–Motz 2BN and Tsai achieved 98%, followed by Koch–Motz 2BS with 92%. At 20 cm, Koch–Motz 2BN maintained 100% agreement, followed by Tsai (99%) and Koch–Motz 2BS (94%). This study compares three bremsstrahlung angular distribution models in GAMOS with experimental values, assessing their respective performances in photon beam simulation. These results may guide radiotherapy practitioners in selecting the most appropriate model. In summary, this work contributes to the validation and enhancement of simulation techniques in radiotherapy, thereby improving treatment optimization and patient safety in cancer care.
The linear and spatial and temporal motions can all twin rotation and vibration. The entanglement of the former twins relies on the latter two, and entangles fundamental forces in sequence. The latter two entangle imaginary and gravitational particles sequentially, the comprehensive dimensionalities of their entanglements reveal various physical essences, hence it creates the resplendent world of matter and energy. These entanglements bring about the expansion of Special Relativity to General Relativity. These particles possess the differential and dimensional variabilities, which require to manipulate the differential variations (namely differential increment and domain) to maximally optimize differentiation, and govern the dimensional variations (videlicet dimensional exchange and involution) to timely replace integration, and eradicate the approximate estimation of limit theory to completely exterminate errors. The scientific analytical calculus emerges as these requirements, its integration embraces the extensive operations (e.g., summation, factorial, function, wavelet, etc.). The equations of these particles are confirmed by the theoretical inferences and experimental data and results. The evolutionary Euler's formula shines upon particle and wave as well as dimensionality of particle, the subtraction and addition of the analytical formula of quadratic difference in Einstein's linear motional corrective equation (namely high and low frequencies of wavelet) reveal rotation and vibration, the orbital radii and motions of the Earth and electron glimpse the gravitational constant, all of them demystify these particles from different perspectives.
Analytical expressions for the low-field mobility of the two dimensional electrons in mono layer graphene are obtained on base of quantum kinetic approach that is based on the one-particle density matrix and the model non-equilibrium distribution function in form of the shifted Fermi distribution. We consider the gated graphene with the Fermi level that is biased by applying an external voltage to the gate. In this case, the confining potential has the shape of a triangle well that can be written in terms of Airy functions. Screened acoustic, optic phonons and ionized impurities are considered as scattering mechanisms. Calculations show that in the semiconductors with Dirac spectrum of charge carriers mobility for scattering by acoustic phonons and ionized impurities does not depend on the electron effective mass. Both effective mass of electrons and scattering rate by non-polar optic phonons reach minimum for electron energy close to the Dirac point. A comparison of the temperature dependences of the calculated and experimental mobility data shows that in the temperature range under consideration, at T < 400 K mobility is determined by the scattering of electrons by ionized impurities. The acoustic and out-of-plane optical phonons (ZO phonons) determine the electron mobility at higher temperatures. Results of mobility calculations are compared with known experimental data.
