Search results for "Photo"
showing 9 items of 11789 documents
Hydrogels for Three-Dimensional Ionizing-Radiation Dosimetry
2021
Radiation-sensitive gels are among the most recent and promising developments for radiation therapy (RT) dosimetry. RT dosimetry has the twofold goal of ensuring the quality of the treatment and the radiation protection of the patient. Benchmark dosimetry for acceptance testing and commissioning of RT systems is still based on ionization chambers. However, even the smallest chambers cannot resolve the steep dose gradients of up to 30–50% per mm generated with the most advanced techniques. While a multitude of systems based, e.g., on luminescence, silicon diodes and radiochromic materials have been developed, they do not allow the truly continuous 3D dose measurements offered by radiation-se…
Innovative Approaches for Organizing an Inclusive Optics and Photonics Conference in Virtual Format
2023
The COVID pandemic is forcing the renewal of scientific conferences, offering opportunities to introduce technological and inclusive developments. Our analysis focuses on the implementation of inclusive practices for female and early-career researchers in a virtual scientific conference. This organization approach was applied in the XIII Spanish Optical Meeting (RNO2021), which was also characterized by avatars interacting in an online metaverse. The effectiveness of inclusive policies and novel technological tools was evaluated using the participation data and a post-conference survey. Our study reveals the high impact of inclusive actions and a strong interest in the scientific community …
Expérimentations techniques à Lavau : mécanisation, relevés et prélèvements
2022
Le site du Moutot à Lavau (Aube), fouillé sur 2 hectares par l’Inrap en 2014-2015, correspond à un complexe funéraire monumental occupé à plusieurs reprises, entre le Hallstatt A1 et la fin de l’Antiquité. Il se caractérise d’abord par sa stratigraphie, obligeant à un décapage délicat et au relevé de grandes longueurs de coupe. La conservation partielle de plusieurs élévations tumulaires a permis l’appréhension des pratiques et de l’architecture funéraires sur le temps long. De manière inattendue, la fouille a permis de documenter une exceptionnelle tombe princière du Ve siècle avant notre ère, dont l’étude a nécessité une adaptation technique et méthodologique constante. Fouille de longue …
Rubefacientu (mentola un niacīna) izraisīto mikrocirkulācijas reakciju novērtējums ādas dažādos dziļumos
2017
Ādai ir lokāla neiro-imuno-endokrīnā sistēma, kas lielā mērā atspoguļo organisma norises, kalpojot par sava veida „veselības indikatoru”. Īpaši pievilcīga un relatīvi pieejama ir ādas mikrocirkulācijas funkciju novērtēšana, ko var neinvazīvi veikt ar optiskām metodēm. Parasti praksē šādu reakciju novērtēšanai tiek lietoti standartizēti provokācijas testi, kā, piemēram, lokālas sildīšanas tests, vai acetilholīna jontoforēze. Taču bieži vien ādas sarežģītā mikrocirkulācija un liela regulācijas mehānismu daudzveidība apgrūtina rezultātu viennozīmīgu interpretāciju. Šajā kontekstā daudzsološa šķiet bispektrālā attēlveides fotopletizmogrāfija - optiska metode ar kuras palīdzību, izmantojot atšķi…
La séquence expérientielle à travers l'œnotourisme
2023
Le regard sur l’expérience touristique a considérablement évolué depuis les premiers travaux sur l’expérientiel. Le tourisme digital et l’utilisation des outils numériques expliquent en partie cette évolution. Dans ce contexte, la photographie prend une place majeure comme trace d’une expérience qui se conçoit avant, pendant et après l’activité touristique
New polysaccharide-polyaminoacid hydrogels: a suitable strategy for colon-specific drug delivery
2007
The aim of this study was to prepare and characterize novel hydrogels with polysaccharide–polyaminoacid structure, able to undergo an enzymatic hydrolysis in the colon and potentially useful for treating inflammatory bowel diseases (IBD). Starting materials were methacrylated dextran (DEX-MA) and methacrylated α,β-poly(N-2-hydroxyethyl)-DL-aspartamide (PHM). These polymers were photocrosslinked by exposure of their aqueous solutions at 313 nm without photoinitiators. Different samples, shaped as microparticles, were obtained as a function of polymer concentration and irradiation time. FT-IR analysis confirmed the occurrence of a co-crosslinking between DEX-MA and PHM in all experimental con…
Photoluminescence properties of S2 molecule trapped in Melanophlogite
2015
We studied the photoluminescence properties of a sample of SiO2-clathrate Melanophlogite, a crystalline microporous material which is found in nature as a rare mineral. Upon β irradiation, the material displays an intense light emission under near-UV illumination. We studied in detail this optical activity by steady-state and time-resolved photoluminescence measurements as a function of temperature. The spectroscopic properties we find can be ascribed to a population of quasi-free molecules trapped within each of the two different types of cage available in the structure of this clathrate, although the spectroscopic properties of the guest molecules are affected by their interactions with t…
Ground and first excited electronic state interaction of FAD with some β-carboline derivatives
1987
Abstract The spectrophotometric and thermodynamic properties of molecular complexes of flavine adenine dinucleotide (FAD) with some dihydro β-carboline derivatives have been investigated in aqueous solution. The molecular associations have been examined by means of electronic absorption spectra, since in each a new charge-transfer band has been located, and also the variation of the fluorescence emission of FAD on the solutions has been observed. The formation constants for the molecular complexes were determined from absorption data, using the Foster-Hammick-Wardley method. The quenching fluorescence phenomena observed in FAD is related to the concentration of the dihydro β-carboline deriv…
Study of the neutral pion and direct photon production in Au+Au collisions at √sNN = 39-200 GeV
2013
This thesis focuses on the study of the neutral pion and eta production in the Au+Au “low-energy”collisions at √sNN = 39 and 62.4 GeV.The η/π0 ratio was reconstructed in Au+Au minimum bias collisions at √sNN = 62.4 GeV up to pT < 7 GeV/c. The direct photons were reconstructed via the subtraction method using two different PID cuts up to pT < 10 GeV/c in Au+Au minimum bias collisions at √sNN = 62.4 GeV.