Raios-x: fascinação, medo e ciência

Lima, Rodrigo da Silva; Afonso, Júlio Carlos; Pimentel, Luiz Cláudio Ferreira

doi:10.1590/s0100-40422009000100044

Cited by 9 publications

(5 citation statements)

References 17 publications

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“…This risk increases with the number of exposures added over the life of the individual, since the radiation is cumulative. Thus, there is a medical concern to submit patients to as few X-ray exams as possible, always balancing it's cost and benefit [2]. Experts give a safe margin, considering tests done with well-calibrated equipment and trained professionals: up to five X-ray examinations per year [2].…”

Section: Introductionmentioning

confidence: 99%

Stereophotogrammetric Basic Framework for Postural Assessment

Fontes

Cagy

2019

IFMBE Proceedings

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Deviations of the vertebral column have become increasingly common. The follow-up of a spine deviation is performed every 2 or 3 months by routine visits and X-ray examinations. X-ray examination produces ionising radiation, which, over time, can cause cancer and is accumulative: this risk increases with the number of exposures. This work describes the conception and initial development of a simple and portable system based on stereoscopy capable of performing a topographic analysis of the patient's back, as well as 3D reconstruction, in order to subsequently allow postural assessment. The stereoscopic system was built and calibrated, then the images underwent a process of rectification and point matching to create a depth map, so that preliminary results point to adequate 3D reconstruction of the back of a plastic phantom. The advantage of this method is the minimization of parallax errors, low cost, easy implementation and portability.

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Section: Introductionmentioning

confidence: 99%

Stereophotogrammetric Basic Framework for Postural Assessment

Fontes

Cagy

2019

IFMBE Proceedings

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“…Röntgen observou que algumas emissões dos tubos de Crookes (formados por tubos de vidros selados e eletrodos) tinham a capacidade de viajar distâncias significativas e, mesmo atravessando alguns obstáculos, formavam imagens em placas fotográficas; chamou estas emissões de radiação X (BEREJKA et. al., 2014;LIMA et al, 2009). Becquerel realizou experimentos semelhantes ao de Röntgen, onde pôde observar que as emissões dos sais de urânio também podiam viajar distâncias através da matéria; tais materiais foram descritos como sendo radioativos (BEREJKA et.…”

Section: História Da Irradiação De Alimentosunclassified

Efeito da radiação gama nas propriedades nutricionais e bioativas de alimentos minimamente processados destinados a dietas especiais

Hirashima¹

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“…São denominados cintiladores os materiais sólidos, líquidos ou gasosos capazes de converter uma radiação de alta energia em radiação no espectro ultra violeta ou visível, ao absorver de maneira parcial ou total a radiação incidente [1,2]. A efetividade no uso de cintiladores só foi possível em função de avanços no desenvolvimento de dispositivos fotoelétricos, os quais tornaram possível amplificar a luminosidade produzida pelo cintilador e ainda convertê-la em sinais elétricos passiveis de serem contabilizados em conjunto com instrumentos eletrônicos apropriados [3,4,5].…”

Section: Detectores De Radiação E Cintiladoresunclassified

Otimização do crescimento de cristais cintiladores inorgânicos em matriz CsI dopada com lítio para uso como detectores de radiação

Tomaz¹

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TOMAZ, L. F. Optimization of growth of the inorganic scintillators crystals in CsI matrix doped with lithium for use as radiation detectors. 2019. 100 p. Dissertação (Mestrado em Tecnologia Nuclear)-Instituto de Pesquisas Energéticas e Nucleares-IPEN-CNEN/SP. São Paulo. Scintillators are solid, liquid or gaseous materials capable of efficiently converting high energy radiation into radiation in the ultraviolet or visible spectrum, by partially or totally absorbing the incident radiation. Regarding the investigation of scintillating crystals, the inorganics occupy considerable space in the group of scintillators used in the areas of work with radiation and they are applied as detectors. The objective of this work was to develop inorganic scintillation crystals in the CsI matrix using the lithium ion (Li +) as a doping element, in concentrations of 10-1 M, 10-2 M, 10-3 M and 10-4 M, by means of the Bridgman technique. The behavior of the crystals was studied by exciting them with different energy levels of alpha radiation, gamma radiation and also, with neutron radiation and the results were compared to the pure CsI matrix. The crystals were excited with gamma radiation in the energy range of 59 keV to 1333 keV, alpha radiation with energy 5.54 MeV and neutron radiation with energy of 1 MeV to 12 MeV. The CsI:Li crystals were, also, subjected to physical and chemical characterization, such as: optical transmittance, emission of luminescence, distribution of Li dopant along the growth axis and confirmation of the crystal structure. Lithium doped crystals showed better response to alpha radiation when compared to pure CsI crystal and sensitivity increases as the dopant Li concentration also increased, crystals CsI:Li with concentrations of 10-2 M and 10-3 M presented the best pulse height for gamma radiation. CsI: Li crystals showed sensitivity to neutron detection, with counts volume significantly higher than pure CsI crystal. The CsI:Li 10-3 M and 10-2 M crystals showed better neutron radiation detection in the Li doping concentration range studied. Addition of Li to the CsI matrix resulted in crystals with promising results for use as detectors, when excited with gamma, alpha and neutron radiation.

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Raios-x: fascinação, medo e ciência

Cited by 9 publications

References 17 publications

Stereophotogrammetric Basic Framework for Postural Assessment

Stereophotogrammetric Basic Framework for Postural Assessment

Efeito da radiação gama nas propriedades nutricionais e bioativas de alimentos minimamente processados destinados a dietas especiais

Otimização do crescimento de cristais cintiladores inorgânicos em matriz CsI dopada com lítio para uso como detectores de radiação

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