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Showing 1 to 16 of 16 for “"Photon transport"”.
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High-energy photon transport modeling for oil-well logging
… logging tools utilizing radioisotope sources of photons are used ubiquitously in oilfields throughout the world. Because of safety and security concerns, there is renewed interest in shifting to electronically-switchable accelerator sources. Investigation of accelerator sources opens up the …
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Diffuse photon transport in tissue-like media: Resolution limit for near-infrared imaging and an instrument for clinical spectroscopy of tissues
In this work I present the model for diffusive photon transport in tissue-like media along with solutions for a point source in infinite and semi-infinite media. Based on these solutions and experimental measurements, I consider the ultimate resolution of near-infrared based imaging of tissues …
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Anwendung der Monte-Carlo-Methoden zur Lösung spezieller Probleme des Photonentransports
Solutions were developed to solve the special photon transport problems. A respective Monte Carlo code were implemented. The photon transport calculations were made for simulation of light distribution in tissues, for 3D estimation of dosis brachytherapy source, for determination of scattering …
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Photon management in thermal and solar photovoltaics
… is a technology that directly converts photon energy into electrical energy. Depending on the photon source, photovoltaic systems can be categorized into two groups: solar photovoltaics (PV) and thermophotovoltaics (TPV). In solar photovoltaic systems, the photon source is the sun, …
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Scattering and Absorption of Photons in Emission Computed Tomography
… effects that the scattering and absorption of photons have on the ability to produce tomographic images of an internal gamma-ray source distribution. Computer simulations of the photon-transport process and the collimator-detector system are used in this study so that these scattering effects …
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Photon Path Lengths Distributions for Cloudy Skies : Their first and second-order moments inferred from high resolution oxygen A-Band spectroscopy
… is to achieve an improved understanding of photon transport inclouds. For this purpose, photon path length distributions are retrieved from spectroscopic oxygen A-band measurements (760-780 nm). An existing measurement method is improved and optimized. In comparison to former studies, it is …
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Optical dosimetry tools and Monte Carlo based methods for applications in image guided optical therapy in the brain
… the tools needed to quantify and verify photon fluence distribution in biological tissue. To accomplish this task, an optical dosimetry probe and Monte Carlo based simulation code were fabricated, calibrated and developed to predict light transport in heterogeneous tissue phantoms of the …
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Monte Carlo investigations of radiotherapy beams: studies of conventional, stereotactic and unflattened beams
… useful method of investigating the electron and photon transport in radiotherapy linear accelerators. The probability of interactions of the materials stored in the cross-section library is considered to be theoretically accurate. Calculations made by Monte Carlo techniques have many roles …
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Numerical Simulations of Oil Spills and Wind Turbine Flows for Applications in Offshore Environmental Sustainability
… spectral method for ocean waves, the Monte Carlo photon transport model for ocean radiative transfer, and the actuator disk model for wind turbines. The results show that the inherent properties of oil droplets including their size and rising velocity, under the background of cross flow, will …
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The design of an intense accelerator-based epithermal neutron beam prototype for BNCT using near-threshold reactions
… Monte Carlo (MCNP) simulations of neutron and photon transport in head phantoms. The theoretical and experimental determination of heat removal from a target backing with multiple fins, as well as numerical calculations of heat deposition profiles based on proton energy loss in target and …
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Measurement of neutron flux spectra in a Tungsten Benchmark by neutron foil activation method
… These depend on the knowledge of the neutron and photon flux spectra which is particularly important because it permits to anticipate the possible answers of the whole structure to phenomena such as nuclear heating, tritium breeding, atomic displacements, radiation shielding, power generation and …
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Inverse Problems In Structural Damage Identification, Structural Optimization, And Optical Medical Imaging Using Artificial Neural Networks
… the direct problems of structural dynamics and photon transport in opaque tissue, the finite element method was used. To solve transient problems, which include some of the problems addressed here, and are computationally intensive, the modal superposition and the modal acceleration methods were …
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GPU-Oriented Algorithms for Continuous Energy Monte Carlo Neutron Transport
… in continuous energy Monte Carlo (MC) neutron transport simulations. These simulations play a crucial role in designing fission, fusion, and security systems that may play a pivotal role in the transition to a decarbonized world. This work contributes to adapting continuous energy MC neutron …
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Detection and interpretation of fluorescence signals generated by excitable cells and tissues
… />Current interest in understanding light transport in cardiac tissue has been motivated in part by increased use of voltage-sensitive and Ca<em> i</em>2+-sensitive fluorescent probes to map electrical impulse propagation and Ca<em>i</em>2+-transients in the heart. The fluorescent signals …
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Topological Insulating States in Photonics and Acoustics
… systems might support dissipation-free boundary transport of electrons or zero dimensional localization of solid states.</p> <p>Topological insulators have not only attracted tremendous attentions from the communities of condensed matter, but also inspired various explorations in classical …