Optical Measuring Instruments
Mostrando 1-10 de 10 artigos, teses e dissertações.
-
1. Noncontact three-dimensional evaluation of surface alterations and wear in NiTi endodontic instruments
Abstract The aim of this study was to undertake a qualitative and quantitative assessment of nanoscale alterations and wear on the surfaces of nickel-titanium (NiTi) endodontic instruments, before and after use, through a high-resolution, noncontact, three-dimensional optical profiler, and to verify the accuracy of the evaluation method. Cutting blade surfac
Braz. oral res.. Publicado em: 09/10/2017
-
2. New electronic technique for temperature measurement with 0.5 mº C resolution using optical fiber bragg gratings / Nova tecnica eletronica para medida de temperatura com resolução de 0,5 mºC usando sensores de fibras opticas com grades de Bragg
Por serem eletricamente passivos e imunes à interferência eletromagnética, os sensores a fibra óptica estão se tornando uma excelente escolha para o sensoreamento em várias aplicações, como aeroespacial, distribuição e geração de energia elétrica, transportes ferroviários, e equipamentos de segurança militares. Entre outras vantagens está o f
Publicado em: 2009
-
3. Analise de aplicação e desempenho de uma esfera integradora em radiometros para calibração de medidores de potencia optica / Application analysis and performance of a integrating sphere in radiometers for optical power meters calibration
We have studied an integrating sphere and its properties for application as a reference standard in optical power measurement. This work shows the researches made in national and international laboratories. We have compared the measurements of a sphere with the standard optical power meter of a Brazilian calibration laboratory and with equipments of a Europe
Publicado em: 2007
-
4. Exposição ocupacional a poeiras em marmorarias: tamanhos de partículas caracteristicos
The main occupational hazards found in workplaces include dust exposure, facilitating the increase of respiratory diseases, of which silicosis is the most important. Due to the importance and gravity of the occupational exposure to dust and to the high number of workers exposed, the aim of this paper was to study the characteristics of this exposure in the o
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 01/09/2005
-
5. Estudo dos erros sistemáticos inerentes a um sensor de estrelas de cabeça fixa, quando à localização relativa de estrelas / Study of systematic errors inherent to fixed-head star trackers with respect to the relative position of stars
Sensores de estrelas são sensores de atitude usados em veículos espaciais capazes de fornecer sua atitude com precisão da ordem de segundos de arco. A atitude é determinada quando as coordenadas das estrelas, medidas pelo sensor em seu sistema de coordenadas, são comparadas com as direções conhecidas de estrelas obtidas em um catálogo de estrelas. Po
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 29/03/2005
-
6. AVALIAÇÃO METROLÓGICA DE ACELERÔMETRO ÓPTICO UTILIZANDO REDE DE BRAGG: APLICAÇÃO EM LINHAS DE TRANSMISSÃO DE ENERGIA ELÉTRICA / METROLOGICAL EVALUATION OF AN OPTICAL FIBER BRAGG GRATING ACCELEROMETER: APPLICATION IN OVERHEAD TRANSMISSION LINES
Overhead transmission lines play an important role on electric systems. Due to the high energy carried through those networks, failures on overhead lines can bring severe constraints on consumers supply, occasionally taking the form of blackouts in large geographic regions. Among the reasons of such failures is the breaking of electric cables caused by the f
Publicado em: 2005
-
7. Estudo dos erros sistemáticos inerentes a um sensor de estrelas de cabeça fixa, quando à localização relativa de estrelas / Study of systematic errors inherent to fixed-head star trackers with respect to the relative position of stars
Star trackers are attitude sensors used in spacecrafts capable of providing accurate attitude in arc-seconds range. The attitude information is provided when the star coordinates, measured by the sensor in its frame, are compared with known star directions obtained from a star catalog. Nevertheless, as in all measurement instruments, the measures are likely
Publicado em: 2005
-
8. Preliminary results of an instrument for measuring the optical aberrations of the human eye
The human eye, as our biological vision instrument, contains intrinsic optical defects, referred to as optical aberrations or ametropia. The immediate consequence of such aberrations is poor quality of images formed at the retina. With the advent of more precise pulsed lasers for eye surgery, the development of instrumentation to determine precisely the high
Brazilian Journal of Physics. Publicado em: 2003-03
-
9. METROLOGICAL EVALUATION OF OPTICAL EMITTERS AND DETECTORS APPLIED TO THE CHARACTERIZATION OF ATMOSPHERIC PARTICULATES POLLUTANTS / AVALIAÇÃO METROLÓGICA DE EMISSORES E DETECTORES ÓPTICOS APLICADOS À CARACTERIZAÇÃO DE POLUENTES PARTICULADOS ATMOSFÉRICOS
The atmospheric pollution is a latent world-wide problem, and it is harmful to the health, visibility and climate. For these factors, several studies and researches have been developed to characterize the chemical composition of the pollutants, concentration, size of particles, etc, with the objective of constructing adjusted instruments for the control of t
Publicado em: 2003
-
10. Measuring higher order optical aberrations of the human eye: techniques and applications
In the present paper we discuss the development of "wave-front", an instrument for determining the lower and higher optical aberrations of the human eye. We also discuss the advantages that such instrumentation and techniques might bring to the ophthalmology professional of the 21st century. By shining a small light spot on the retina of subjects and observi
Brazilian Journal of Medical and Biological Research. Publicado em: 2002-11