Abstract
Organic scintillators have been promoted and widely used in scintillating fiber-optic dosimeters (SFOD) due to their tissue-equivalent characteristics, small sensitive volume combined with high spatial resolution, and emission of visible light proportional to the absorbed electron and gamma dose rate. In this paper we will present the validation of Monte Carlo simulations of dose measurements assisted by scintillating fiber optic dosimeters operating in the visible spectral range, in the context of the development of fiber optic dosimeters targeted to Brachytherapy. The Monte Carlo simulation results are compared to measurements performed with SFOD test probes, assembled with BCF-60 (Saint Gobain) samples of 1 mm diameter and 0.35 to 1.5 cm length, coupled to PMMA optical fiber. The optical signal resulting from scintillation and Cherenkov light is transmitted through an additional optical fiber link to a remote measuring device. For SFOD probes irradiation a dedicated PMMA phantom was used. The results were validated against measurements obtained with a properly calibrated pinpoint ionization chamber (PTW). The probes were positioned in a radial arrangement, with a radioactive source at its center point. The gamma-rays source is a Nucletron Microselectron-V2 Ir-192. The dose curves are obtained according to the different positions in the phantom with the SFOD dosimeters. The system is able to use a Fiber Optic Multiplexer (FOM) controlled with Labview software.

Abstract
The present context of women physicists in Portugal is discussed, updating our report for the 2002 IUPAP International Conference on Women in Physics, in which the 30 years prior to 2000 were analyzed.

Abstract

Abstract
Polyethylene terephthalate (PET) preforms are massively produced nowadays with the purpose of producing food and beverages packaging and liquid containers. Some varieties of these preforms are produced as multilayer structures, where very thin inner film(s) act as a barrier for nutrients leakage. The knowledge of the thickness of this thin inner layer is important in the production line. The quality control of preforms production requires a fast approach and normally the thickness control is performed by destructive means out of the production line. A spectral domain optical coherence tomography (SD-OCT) method was proposed to examine the thin layers in real time. This paper describes a non-destructive approach and all required signal processing steps to characterize the thin inner layers and also to improve the imaging speed and the signal to noise ratio. The algorithm was developed by using graphics processing unit (GPU) with computer unified device architecture (CUDA). This GPU-accelerated white light interferometry technique non-destructively assesses the samples and has high imaging speed advantage, overcoming the bottlenecks in PET performs quality control.

Abstract
A spectral calibration technique, a data processing method and the importance of calibration and re-sampling methods for the spectral domain optical coherence tomography system were numerically studied, targeted to optical coherence tomography (OCT) signal processing implementation under graphics processing unit (GPU) architecture. Accurately, assigning the wavelength to each pixel of the detector is of paramount importance to obtain high quality images and increase signal to noise ratio (SNR). High quality imaging can be achieved by proper calibration methods, here performed by phase calibration and interpolation. SNR was assessed employing two approaches, single spectrum moving window averaging and consecutive spectra data averaging, to investigate the optimized method and factor for background noise reduction. It was demonstrated that the consecutive spectra averaging had better SNR performance. © 2012 The Author(s).

Abstract
High-precision dosimeters are needed in brachytherapy treatments to ensure safe operation and adequate working conditions, to assess the correspondence between treatment planning and dose delivery, as well as to monitor the radiation dose received by patients. In this paper we present the development of a multi-sensor dosimeter platform targeted for brachytherapy environments. The performance of different scintillating materials response is assessed. The emission bands of most common scintillator materials used in ionizing radiation detection are typically below 550 nm, thus they may be prone to stem effect response. To avoid this effect we propose the use of scintillators with longer wavelength emission. Samples of neodymium doped glasses are evaluated as new infrared radioluminescent scintillators for real-time dosimeters, namely lithium lead boron silver (LLB4Ag) and lithium bismuth boron silver (LBiB4Ag) glasses. Their response is compared with the response of organic scintillator BCF-60 with a 530nm response.