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Rio de Janeiro, Brazil

Soares F.A.A.,Federal University of Santa Maria | Dalla Corte C.L.,Federal University of Santa Maria | Andrade E.R.,Brazilian Army Technological Center | Marina R.,Autonomous University of Chile | And 2 more authors.
Nutricion Hospitalaria | Year: 2014

The aim of this work was to test the hypothesis that a moderate intake of organic purple grape juice shows a positive radiomodifier effect over early behavioural damage following acute X-irradiation in mice. Anxiety-, locomotion-, and feeding-related responses to 6 Gy total body X-irradiation (TBI) were studied via open field, Rotarod, and feeding/drinking recording. Thirty-two male mice weighing 25-30 g were grouped according grape juice (J) or water (W) ad libitum drinking and either non-irradiated (N) or irradiated (R). 24 h post-TBI the access frequency to the center and corners of the open field was decreased, and the total stay in the corners increased, in RW vs. NW mice. Anxiety-related parameters decreased in RJ vs. RW mice. Rotarod latency times increased 72 h post-TBI in RJ vs RW mice. No overall changes in food and drink intake were observed along the experimental period. On the irradiation day, bout number was increased and bout duration was decreased in RW mice. The changes were reversed by purple grape juice intake. Grape juice intake before and after TBI can overcome several radiation-induced changes in behaviour within 24-72 hours after sub-lethal X-irradiation. This beneficial effect on short-term anxiety and mobility-related activities could probably be included in the list of flavonoid bio-effects. The present findings could be relevant in designing preventive interventions aimed to enhance body defense mechanisms against short-term irradiation damage.

Pereira I.M.,Brazilian Army Technological Center | Pereira I.M.,Federal University of Minas Gerais | Pereira I.M.,Ghent University | Axisa F.,Ghent University | And 3 more authors.
Journal of Biomedical Materials Research - Part B Applied Biomaterials | Year: 2011

In this work, we propose the use of shape-memory polymer as an anchoring system for a bladder sensor. The anchoring system was designed from a biomedical biodegradable water-based poly(ester-urethane) produced in an aqueous environment by using isophorone diisocyanate/hydrazine (hard segment) and poly(caprolactone diol)/2,2-bis (hydroxymethyl) propionic acid (soft segment) as the main reagents. Tensile strength and elongation-at-break deterioration upon degradation in synthetic urine were investigated. In-body shape recovery was simulated and measured in synthetic urine. Results indicated that shape recovery can occur at body temperature and expulsion of the sensor by the body along with urine may occur through the combined effect of urine hydrolytic attack and compression exerted by the bladder walls. © 2010 Wiley Periodicals, Inc.

Rita V.A.F.S.,Brazilian Army Technological Center
2015 IEEE Radar Conference - Proceedings | Year: 2015

This work presents a mode S secondary surveillance radar (SSR) architecture that enables signal processing to be done all in software. It avoids a widely implemented architecture approach with a first step of processing with a filter in hardware, normally implemented in FPGA. This proposed architecture replaces the hardware filter with a highly customized filter in software implemented in C language running as an operating system process executed with high priority. The filter in software keeps extracting preambles and payload from noise as hardware counterpart but on a CPU. The further processing steps of the mode S logic was implemented in high level language, simplifying project complexity and maintainability. To validate the architecture, a simulator was implemented with realistic constraints, and was tested with real data in the reception channel. © 2015 IEEE.

Bittencourt T.D.M.G.,Brazilian Army Technological Center | Gonzaga A.,University of Sao Paulo
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2012

The digital image processing of uncooled LWIR thermal detectors is one of the main steps in the research and development of thermal cameras. The study of this technology is a strategic issue for military and civil areas, considering that thermal imaging equipment have dual application. This paper aims to design and develop a pipeline of all processing steps required to obtain high performance images with low noise and high contrast. In addition to the digital processing algorithms, this paper presents some results of electro-optical characterization on the assembled system, indicating the main figures of merit that guide the study of this technology. © 2012 SPIE.

Pralon L.,Grenoble Institute of Technology | Pompeo B.,Brazilian Army Technological Center | Fortes J.M.,Pontifical Catholic University of Rio de Janeiro
IEEE Transactions on Aerospace and Electronic Systems | Year: 2015

Noise radars are electromagnetic systems that use random signals for detecting and locating reflecting objects. Besides high performance against external interferences (intentional or not), the stochastic nature of the transmitted waveforms may lead to the suppression of range ambiguity in the detection of targets and low range sidelobes, if systems parameters are properly chosen. This paper addresses a probabilistic analysis to derive mathematical expressions for the signal-to-noise ratios, the peak-to-sidelobe ratios and the signal-to-interference ratios (due to ambiguous targets) throughout a typical receiver processing chain of a pulsed FM noise radar. A receiver that employs matched filtering and pulse integration prior to detection was considered. Pulse compression and integration gains (in signal-to-noise and signal-to-interference, due to ambiguous targets, ratios) are also derived. The analysis provides closed-form expressions relating the precise dependence of sidelobe levels as well as interference levels due to ambiguous targets to the integration time, the transmit signal bandwidth, and the number of integrated pulses. © 2015 IEEE.

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