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Visar resultat 1 - 5 av 29 avhandlingar som matchar ovanstående sökkriterier.

1. 1. Heavy-ion transport codes for radiotherapy and radioprotection in space

   Författare :Davide Mancusi; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; charge-changing cross sections; transport codes; radiotherapy; Monte-Carlo codes; heavy ions; radioprotection in space;

   Sammanfattning : Simulation of the transport of heavy ions in matter is a field of nuclear science that has recently received attention in view of its importance for some relevant applications. Accelerated heavy ions can, for example, be used to treat cancers (heavy-ion radiotherapy) and show some superior qualities with respect to more conventional treatment systems, like photons (x-rays) or protons. LÄS MER

3. 2. Quantum transport and geometric integration for molecular systems

   Författare :Anders Odell; Anna Delin; Anders Niklasson; Michael Springborg; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; density functional theory; ab initio; first principles; electron transport; photoswitching; molecular dynamics; geometric integration; Condensed matter physics; Kondenserade materiens fysik; Computational physics; Beräkningsfysik;

   Sammanfattning : Molecular electronics is envisioned as a possible next step in device miniaturization. It is usually taken to mean the design and manufacturing of electronic devices and applications where organic molecules work as the fundamental functioning unit. LÄS MER

4. 3. Radiation and matter: how do they play with each other?

   Författare :Davide Mancusi; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; heavy ions; models; transport codes; Boltzmann equation; Monte Carlo; radioprotection in space; radiotherapy; nuclear reactions;

   Sammanfattning : The propagation of radiation is affected by the presence of matter; at the same time, the physicochemical properties of matter are modified by the passage of radiation. The interplay of radiation and matter is of crucial importance in many modern applications: accelerated heavy ions, in particular, can be used in radiotherapeutical treatments of some cancers; moreover, they are present in the space radiation environment and represent a serious threat to the health of spaceship crews and to the functionality of electronic equipment on board. LÄS MER

5. 4. Low-density parity-check codes : unequal error protection and reduction of clipping effects

   Författare :Sara Sandberg; David Declercq; Luleå tekniska universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Signalbehandling; Signal Processing;

   Sammanfattning : The invention of low-density parity-check (LDPC) codes made reliable communication possible at transmission rates very close to the theoretical limit predicted by Shannon. However, communication close to the Shannon limit requires very long codes and results in long delay and high encoder and decoder complexity. LÄS MER

7. 5. Monte Carlo particle transport codes for ion beam therapy treatment planning : Validation, development and applications

   Författare :Till Tobias Böhlen; Irena Gudowska; Oliver Jäkel; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Monte Carlo; ion beam therapy; treatment planning; cancer therapy; microdosimetry; Medical Radiation Physics; medicinsk strålningsfysik;

   Sammanfattning : External radiotherapy with proton and ion beams needs accurate tools for the dosimetric characterization of treatment fields. Monte Carlo (MC) particle transport codes, such as FLUKA and GEANT4, can be a valuable method to increase accuracy of dose calculations and to support various aspects of ion beam therapy (IBT), such as treatment planning and monitoring. LÄS MER