RESUMEN
THz pulse time delay was measured from ethylcellulose tablets having nominal porosities 13%, 22% and 30%. It is suggested that the observed pulse broadening of sample THz pulse is due to scattering and dispersion of the THz wave in a porous tablet. A parameter related to the pulse broadening is suggested as a sensitive measure for the porosity and porosity change of the tablet.
Asunto(s)
Celulosa/análogos & derivados , Comprimidos/química , Celulosa/química , Porosidad , Análisis Espectral/métodos , Tecnología FarmacéuticaRESUMEN
We demonstrate guided-mode resonance filters featuring an amorphous TiO(2) layer fabricated by atomic layer deposition on a polymeric substrate. The thermal properties of such filters are studied in detail by taking into account both thermal expansion of the structure and thermo-optic coefficients of the materials. We show both theoretically and experimentally that these two effects partially compensate for each other, leading to nearly athermal devices. The wavelength shift of the resonance reflectance peak (< 1 nm) is a small fraction of the peak width (~11 nm) up to temperatures exceeding the room temperature by tens of degrees centigrade.
Asunto(s)
Filtración/instrumentación , Polímeros/química , Refractometría/instrumentación , Resonancia por Plasmón de Superficie/instrumentación , Titanio/química , Diseño Asistido por Computadora , Diseño de Equipo , Análisis de Falla de EquipoRESUMEN
Bacteriorhodopsin (BR), a membrane protein of a microorganism Halobacterium salinarium has been studied since the 80's as a potential material for information technology. The information processing applications of BR employ either photochromic or photoelectric properties of the protein. In this study we discuss about design principles and describe our study of the use of bacteriorhodopsin as a sensor material for a color sensitive artificial retina. This retina includes low-level processing of input information. The design of a color sensitive matrix element, the self-organizing color adaptation algorithm and a system model for the retina are presented.
Asunto(s)
Órganos Artificiales , Bacteriorodopsinas/fisiología , Técnicas Biosensibles , Retina/fisiología , Percepción de Color , Ingeniería Genética , Humanos , Modelos BiológicosRESUMEN
We have studied opto-electric properties of wild type bacteriorhodopsin and its two artificial variants. We have measured opto-electric responses with respect to wavelength for all three proteins and we describe the use of the proteins for color detection. Opto-electric responses of proteins to set of colored lights were measured and it has been shown that bacteriorhodopsin and its variants can be used to recognize color. A simple equation for estimating opto-electric response to arbitrary spectrum is given.
Asunto(s)
Bacteriorodopsinas/química , Color , Reconocimiento de Normas Patrones Automatizadas , Bacteriorodopsinas/efectos de la radiación , Oscuridad , Electroquímica , Halobacterium salinarum , Luz , Óptica y Fotónica , Retinaldehído/análogos & derivados , Retinaldehído/química , Bases de Schiff , EspectrofotometríaRESUMEN
The reorientation of F(A)(II) centers in electrolytically colored KCl:Li crystals under ruby laser exposure was studied at room temperature. A prolonged series of laser pulses was applied over a period of three days to check the durability and possible fatiguing of the crystals.