Search results for "Physicist"
showing 10 items of 11 documents
Implementation of dosimetry equipment and phantoms at the MedAustron light ion beam therapy facility
2017
Purpose: To describe the implementation of dosimetry equipment and phantoms into clinical practice of light ion beam therapy facilities. This work covers standard dosimetry equipment such as computerized water scanners, films, 2D-array, thimble and plane parallel ionization chambers, but also dosimetry equipment specifically devoted to the pencil beam scanning delivery technique such as water columns, scintillating screens or multi-layer ionization chambers. Method: Advanced acceptance testing procedures developed at MedAustron and complementary to the standard acceptance procedures proposed by the manufacturer are presented. Detailed commissioning plans have been implemented for each piece…
[I062] The roles of radiographers in medical imaging and radiotherapy in Europe
2018
Very fast development of technologies in medical imaging and therapy has changed the role of radiographer in Europe. Over the past ten years education and necessary skills and competencies for radiographers has become more similar in most EU countries due to input of EFRS Educational Wing, but there are still rather significant differences in the roles of radiographers between countries. Role expansion is often initiated by external and internal factors that lead to advanced practice for radiographers. However, there is also a limiting factor that functions as a barrier for development of radiographer’s role and mainly that is connected to resistance when radiologists/medical physicists obj…
Mechanically interlocked calix[4]arene dimers display reversible bond breakage under force.
2009
The physics of nanoscopic systems is strongly governed by thermal fluctuations that produce significant deviations from the behaviour of large ensembles1,2. Stretching experiments of single molecules offer a unique way to study fundamental theories of statistical mechanics, as recently shown for the unzipping of RNA hairpins3. Here, we report a molecular design based on oligo calix[4]arene catenanes—calixarene dimers held together by 16 hydrogen bridges—in which loops within the molecules limit how far the calixarene nanocapsules can be separated. This mechanically locked structure tunes the energy landscape of dimers, thus permitting the reversible rupture and rejoining of the individual n…
TU-C-16A-01: Joint AAPM/SEFM/AMPR Educational Workshop On “Education of Radiotherapy Physicists”
2014
This workshop is jointly organized by the AAPM, the Spanish (SEFM) and the Russian (AMPR) Medical Physics Societies, as part of formal educational exchange agreements signed by the AAPM with each one of these two societies.With the rapid technological advances in radiation therapy both for treatment and imaging, it is challenging how physics is taught to medical physicists practicing in radiation therapy. The main Objectives: of this workshop is to bring forth current status, challenges and issues related to education of radiation therapy physicists here in the US, Spain and Russia. Medical physicists from each one of these countries will present educational requirements of international re…
Ultracold quantum gases in optical lattices
2005
Artificial crystals of light, consisting of hundreds of thousands of optical microtraps, are routinely created by interfering optical laser beams. These so-called optical lattices act as versatile potential landscapes to trap ultracold quantum gases of bosons and fermions. They form powerful model systems of quantum many-body systems in periodic potentials for probing nonlinear wave dynamics and strongly correlated quantum phases, building fundamental quantum gates or observing Fermi surfaces in periodic potentials. Optical lattices represent a fast-paced modern and interdisciplinary field of research.
Source strength determination in iridium-192 and cobalt-60 brachytherapy : A European survey on the level of agreement between clinical measurements …
2021
Background and purpose: Brachytherapy treatment outcomes depend on the accuracy of the delivered dose distribution, which is proportional to the reference air-kerma rate (RAKR). Current societal recommendations require the medical physicist to compare the measured RAKR values to the manufacturer source calibration certificate. The purpose of this work was to report agreement observed in current clinical practice in the European Union. Materials and methods: A European survey was performed for high- and pulsed-dose-rate (HDR and PDR) highenergy sources (Ir-192 and Co-60), to quantify observed RAKR differences. Medical physicists at eighteen hospitals from eight European countries were contac…
WE-C-141-01: Research and Relevance of Brachytherapy Dose Calculation Advancements
2013
Research and Relevance of Brachytherapy Dose Calculation Advancements Organizer: Mark J. Rivard Moderator: Geoffrey S. Ibbott Speakers: Facundo Ballester, Asa Carlsson Tedgren, Firas Mourtada Brachytherapy dosimetry is undergoing a renaissance with the scrutiny of the AAPM TG‐43 dose calculation formalism and comparisons with alternate approaches such as the Monte Carlo method, the grid‐based Boltzmann solvers, and the collapsed‐cone technique. Treatment planning systems (TPS) using these more advanced, model‐based dose calculation algorithms (MBDCAs) are now available for clinical use. However, their accuracy and the preferred method for their use have not been established. Thus, it is imp…
WHY IS IT NOT SO EASY FOR A PRESENT-DAY PHYSICIST TO BE GENUINELY A CHRISTIAN?
2021
A short description of the relationship between Physics, Philosophy and Theology is: Physics neglects or passes by Natural Realism, which is the origin of Philosophy. In turn, Natural Realism is backed up by Judeo-Christian revelation. Therefore, Physics neglects or passes by Theology. That relationship between Physics and Theology is widely used as a background for exercising an intense pressure on Theology. The defence of Theology should begin by pointing out certain shortcomings of Physics and formulating a philosophical control of these shortcomings. This is tantamount to turning Physics instead of Theology into a “site under construction”. Only a “controlled” Physics and Theology are a…
Colloidal and molecular electro-optics
2010
The Kerr effect, also known as the quadratic electro-optic effect, was discovered more than a hundred years ago by John Kerr, a Scottish physicist [1]. It describes the change in the refractive index of a material in response to an applied electric field. Around 1950 its application swayed from simple to complex fluids. A strong contribution was made through a number of seminal papers by the French polymer scientist H Benoit [2–4]. These and others initiated wide interest from researchers working on macromolecular solutions or colloidal dispersions. Experimental activities were further boosted by the advent of the laser and theoretical approaches strongly drew from growing computer power. U…
Fifty Years of Mössbauer Spectroscopy in Solid State Research - Remarkable Achievements, Future Perspectives
2011
Mossbauer spectroscopy was founded more than fifty years ago based on an outstanding discovery by the young German physicist Rudolf Ludwig Mossbauer while working on his Ph.D. thesis. He discovered the recoilless nuclear resonance fluorescence of gamma radiation and was awarded the Nobel Prize in Physics in 1961 as one of the youngest recipients of this most prestigious award. His discovery led to the development of a new technique for measurements of hyperfine interactions between nuclear moments and electromagnetic fields. This method, with highest sharpness of tuning of 10–13, yields information on valence state, symmetry, magnetic behavior, phase transition, lattice dynamics and other s…