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Conceptual Overview of Algorithms
Published in Jerry J. Battista, Introduction to Megavoltage X-Ray Dose Computation Algorithms, 2019
Knowledge of the relative magnitude of primary and secondary dose contributions is important because it sets priorities for improving the accuracy of dose calculations. Tissue inhomogeneities affect primary and secondary particles in a different way and span different spatial domains. In Chapter 2, we reviewed exponential attenuation of primary rays, and described the complex influence that a single voxel can have on its scattering amplitude and secondary attenuation of photon fluences passing through the voxel (Figure 2.20). Empirically, the primary and secondary dose contributions can be decoupled at depth in a large homogeneous medium as follows:
Biointerface: a nano-modulated way for biological transportation
Published in Journal of Drug Targeting, 2020
Pravin Shende, Varun S. Wakade
Percolation theory explains the transport mechanism assemblies appropriately with a large number of nanoparticles stating two adjacent metal nanoparticles with an electrostatic potential difference. Organic linkers include fumaric acid and propanedioic acid that separates the nanoparticle by a gap to support the scattering theory for calculating the electrical current between metal nanoparticles [38]. Percolation theory shows non-Arrhenius behaviour because of path selections at various temperatures to build less temperature condition for increasing the conductance [39]. The electrons in the form of free gases travel from left to right so that nanoparticles overcome the charge. In Orthodox theory, single-electron tunnelling contains tunnel resistance more than quantum strength for alkane dithiol linker, which possesses weak couple limits and is measured by the T-matrix theory or Wentzel–Kramers–Brillouin (WKB) theory [9]. Furthermore, nucleation theory demonstrates a multi-component system showing alterations in temperature and pressure with homogeneous mixing that leads to change in Gibbs free energy and separation of phases [8]. The concept of classical colloids shows monodispersity that increases monosubstrate concentration, where the reaction continues till new nuclei are formed. Crystallization, aggregation, nucleation, additive control and colloidal stability play a fundamental role in the nucleation theory [40]. SAX’s theory is applicable for biological as well as non-biological substances like stem cells [41], immunoglobulin, DNA products and drugs like ibuprofen, ranitidine. It includes numerous steps: (1) determination of number particle, (2) identification of vector scattering, (3) calculation of radial electron density, (4) estimation of scattering amplitude, (5) formation of fracture, (6) detection of disseminating intensity, (7) addition of profile intensity and particle intensity, (8) calculation of data and (9) comparison of theoretical and experimental values. Methods for SAX’s include Monte–Carlo sampling, Cubature formula, Zernike polynomials and 3D model [29,42–44].