111 research outputs found
65/Detektory MOSFET jako narzędzie do weryfikowania dawek terapeutycznych wiązek elektronów w radioterapii
CelZastosowanie detektorów MOSFET (Metal – Oxide Semiconductor Field Effect Transistor) do pomiaru dawki in vivo wiązek elektronów w radioterapii.Metody i materiałyWykonano pomiary fantomowe polegające na zbadaniu zależności wskazań detektorów MOSFET od: – wartości dawki wiązek elektronów, – temperatury otoczenia detektorów, – kierunku padania wiązki elektronów na detektor, – wielkości napromienianego pola.Zbadano także zmianę czułości detektorów w zależności od skumulowanej dawki. Detektory, ze względu na bardzo małe wymiary, umieszczano w odpowiednio zaprojektowanych nakładkach aluminiowych – w celu zapewnienia równowagi elektronowej podczas pomiaru dawki. Wskazania detektorów porównywano do wskazańkomory jonizacyjnej typu Markus, posiadającej świadectwowzorcowania. Pomiary wykonano z użyciem wiązek elektronów o energii 6, 9, 12, 15, 18,21 MeV.WynikiZbadane zależności i określone na ich podstawie współczynniki korekcyjne umożliwiają zmierzyć dawkę wiązki elektronów z dokładnością ±2.5%.WniosekDetektory MOSFET są dobrym narzędziemdo weryfikowania dawki wejściowej w radioterapii wiązkami elektronów
Optical Coherence Tomography (OCT) for examination of artworks
Chapter in the book: Bastidas D., Cano E. (eds) Advanced Characterization Techniques, Diagnostic Tools and Evaluation Methods in Heritage Science. Springer, Cham, 2018, pp 49-59 , doi: 10.1007/978-3-319-75316-4, Authors’version after embargo periodOptical coherence tomography is a fast, non-invasive technique of structural analysis utilising near-infrared radiation. Examples of using OCT, for obtaining cross-sectional images of objects of craftsmanship and an easel painting have been shown. Issues regarding the technique of execution and destruction phenomena were resolved non-invasively. In some cases, the secondary alterations can be identified and localised within the object’s structure which helps in authentication of the artwork
Munch and optical coherence tomography: unravelling historical and artist applied varnish layers in painting collections
Surface and interface treatments on wooden artefacts: Potentialities and limits of a non-invasive multi-technique study
Wooden artefacts embrace wide-ranging types of objects, like paintings on panel, sculptures, musical instruments, and furniture. Generally, in the manufacturing process of an artwork, wood is firstly treated with organic and inorganic materials to make it nonporous and morphologically homogeneous, and, at last, the surface treatment consists of varnishes or coatings applied with the aims of conferring aesthetic properties and protecting wood from biological growth and external degradation agents, as well as mechanical damage. In this work, different wooden mock-ups were prepared by varying some parameters: concentration of filler and pigment, respectively, in the ground and paint layers, thickness of the protective varnish coat, and sequence of the layers. The mock-ups were subsequently exposed to time-varying artificial aging processes. The multi-analytical non-invasive approach involved spectroscopic (reflection FT-IR, Raman, and X-ray fluorescence), tomographic (optical coherence tomography) and colorimetric techniques. Data were interpreted using both univariate and multivariate methods. The aim was to evaluate potential and limits of each non-invasive technique into the study of different stratigraphies of wooden artworks. This approach was supported by microscopic observations of cross-sections obtained from selected mock-ups. The methodological approach proposed here would add valuable technical know-how and information about the non-invasive techniques applied to the study of wooden artworks
Surface and interface treatments on wooden artefacts: Potentialities and limits of a non-invasive multi-technique study
Wooden artefacts embrace wide-ranging types of objects, like paintings on panel, sculptures, musical instruments, and furniture. Generally, in the manufacturing process of an artwork, wood is firstly treated with organic and inorganic materials to make it nonporous and morphologically homogeneous, and, at last, the surface treatment consists of varnishes or coatings applied with the aims of conferring aesthetic properties and protecting wood from biological growth and external degradation agents, as well as mechanical damage. In this work, different wooden mock-ups were prepared by varying some parameters: concentration of filler and pigment, respectively, in the ground and paint layers, thickness of the protective varnish coat, and sequence of the layers. The mock-ups were subsequently exposed to time-varying artificial aging processes. The multi-analytical non-invasive approach involved spectroscopic (reflection FT-IR, Raman, and X-ray fluorescence), tomographic (optical coherence tomography) and colorimetric techniques. Data were interpreted using both univariate and multivariate methods. The aim was to evaluate potential and limits of each non-invasive technique into the study of different stratigraphies of wooden artworks. This approach was supported by microscopic observations of cross-sections obtained from selected mock-ups. The methodological approach proposed here would add valuable technical know-how and information about the non-invasive techniques applied to the study of wooden artworks
Surface and interface treatments on wooden artefacts: Potentialities and limits of a non-invasive multi-technique study
Non-invasive mobile technology to study the stratigraphy of ancient Cremonese violins: OCT, NMR-MOUSE and reflection FT-IR spectroscopy
Laser cleaning of paintings: in situ optimization of operative parameters through non-invasive assessment by optical coherence tomography (OCT), reflection FT-IR spectroscopy and laser induced fluorescence spectroscopy (LIF)
Laser cleaning of paintings: in situ optimization of operative parameters through non-invasive assessment by optical coherence tomography (OCT), reflection FT-IR spectroscopy and laser induced fluorescence spectroscopy (LIF)
6. The technique of total body irradiation applied in the St. Leszczyński Memorial Hospital in Katowice
At the St. Leszczyński Memorial Hospital in Katowice a modification of TBI technique was prepared. For this a special two variant of body frame – one for treatment planning and an another one for treatment delivery – was made. The total dose of 12 – 15 Gy (in lung not more than 9 Gy) was delivered in six fraction of 15 MV photons, produced in Primus linear accelerator, for 3 consecutive days. Patient was treated by a combination of fields: lateral – set at SSD of 330 cm and AP/PA – set at 135 cm. The dose-rate measured at 10 cm in a water phantom for lateral fields was 4,3 cGy/min., and for AP/PA fields 23,6 cGy/min. Lung shields were made from wood alloy and their shape was carried out from computerized tomograph scans (CT). For each patient a set of computerized tomograph scans was prepared. Patient during the CT was laying in supine position in the body frame made of 1 cm thick plexi plates. On the walls of that body frame a special marks of tin material were inserted. These marks allow to reproduce both – the same patient position during the irradiation and also in the treatment planning system HELAX. Position of shields before AP/PA fraction was determined by means of HELAX, and then shields were fastened to plexi trays inserted in the head of Primus. Lung was also shielded during one lateral fraction and the shape of the shield was carried out on a simulator. The volume between the patient and walls of the body frame was fulfilled by bolus (bags with rice) to get a homogenous dose distribution. The electron boost to the thorax wall (shielded for 15 MV photons) was delivered with a 6 or 9 MeV electron beam.The percentage deviation of dose, for all 9 irradiated patients, calculated at ten anatomical points representative of the body anatomy, was in the limit −0,4% to +13% (excluded in lung) from the dose delivered to PC (reference point: 1/2 AP and 1/2 lateral dimension at 1/2 of patient length in irradiation position). The in vivo measurements carried out by means of MOSFET detectors confirmed that accuracy
- …