Sunday, February 22, 2015



Soy un nuevo usuario

Olvidé mi contraseña

Entrada usuarios

Lógica Matemáticas Astronomía y Astrofísica Física Química Ciencias de la Vida
Ciencias de la Tierra y Espacio Ciencias Agrarias Ciencias Médicas Ciencias Tecnológicas Antropología Demografía
Ciencias Económicas Geografía Historia Ciencias Jurídicas y Derecho Lingüística Pedagogía
Ciencia Política Psicología Artes y Letras Sociología Ética Filosofía

rss_1.0 Clasificación por Disciplina

Nomenclatura Unesco > (22) Física > (2209) Óptica
(2209.01) Espectroscopía de absorción (2209.02) Cinematografía
(2209.03) Colorimetría (2209.04) Espectroscopía de emisión
(2209.05) Fibras ópticas (2209.06) Óptica geométrica
(2209.07) Holografía (2209.08) Iluminación
(2209.09) Radiación infrarroja (2209.10) Láseres
(2209.11) Luz (2209.12) Microscopios
(2209.13) Óptica no lineal (2209.14) Propiedades ópticas de los sólidos
(2209.15) Optometría (2209.16) Instrumentos fotográficos
(2209.17) Fotografía (2209.18) Fotometría
(2209.19) Óptica física (2209.20) Radiometría
(2209.21) Espectroscopía (2209.22) Radiación ultravioleta
(2209.23) Radiación visible (2209.24) Física de la visión
(2209.90) Tratamiento digital. Imágenes (2209.99) Otras (especificar)

Categorías relacionadas:
(3311.11) Instrumentos ópticos

Mostrando recursos 1 - 20 de 26,042

1. Fossil group origins IV. Characterization of the sample and observational properties of fossil systems - Zarattini, S.; Barrena, R.; Girardi, M.; Castro Rodríguez, N.; Boschin, W.; Aguerri, J. A. L.; Mendéz Abreu, J.; Sánchez Janssen, R.; Catalán Torrecilla, Cristina; Corsini, E. M.; Burgo, C. del; D'Onghia, E.; Herrera Ruiz, N.; Iglesias Páramo, J.; Jiménez Bailón, E.; Lozada Muñoz, M.; Napolitano, N.; Vilchez, J. M.
Context. Virialized halos grow by the accretion of smaller ones in the cold dark matter scenario. The rate of accretion depends on the different properties of the host halo. Those halos for which this accretion rate was very fast and efficient resulted in systems dominated by a central galaxy surrounded by smaller galaxies that were at least two magnitudes fainter. These galaxy systems are called fossil systems, and they can be the fossil relics of ancient galaxy structures. Aims. We started an extensive observational program to characterize a sample of 34 fossil group candidates spanning a broad range of physical...

2. Papel de la colonografía por tomografía computerizada en el carcinoma colorrectal - Gómez de las Heras, Cristina
El cáncer colorrectal (CCR) es una de las neoplasias más frecuentes en los países occidentales, siendo la segunda neoplasia más frecuente en ambos sexos en Andalucía, detrás del cáncer de pulmón en el hombre y de mama en la mujer. A pesar del avance experimentado en los últimos años en relación a su tratamiento, constituye la segunda causa más frecuente de muerte por cáncer. Es, además, la neoplasi maligna más frecuente del aparato digestivo y el riesgo se incrementa a partir de los 50 años. Este hecho, junto con el establecimiento de la secuencia adenoma-carcinoma (el 85-90% de los CCR...

3. Nanometer-scale InGaAs Field-Effect Transistors for THz and CMOS technologies - del Alamo, Jesus A.
Integrated circuits based on InGaAs Field Effect Transistors are currently in wide use in the RF front-ends of smart phones and other mobile platforms, wireless LANs, high data rate fiber-optic links and many defense and space communication systems. InGaAs ICs are also under intense research for new millimeter-wave applications such as collision avoidance radar and gigabit WLANs. InGaAs FET scaling has nearly reached the end of the road and further progress to propel this technology to the THz regime will require significant device innovations. Separately, as Si CMOS faces mounting difficulties to maintain its historical density scaling path, InGaAs-channel MOSFETs...

4. Clinical features of
the congenital vitreoretinopathies AO Edwards The inherited vitreoretinal degenerations or vitreoretinopathies are characterized by congenital and acquired disorders of the eye including early onset cataract, anomalies of the vitreous manifesting as optically empty vitreous, course fibrils, and membranes, and retinal detachment. These diseases include Stickler syndrome types I (STL1) and II (STL2), usually caused by mutations in COL2A1 and COL11A1 respectively. Wagner syndrome (WGN1) is associated with mutations in versican (CSPG2) and snowflake vitreoretinal degeneration (SVD) with a mutation in a potassium channel (KCNJ13). The cataract is often cortical and may be wedge-shaped, but does not distinguish between the different...

5. Multi-Wavclcnrth Mode-Locked Laser Arrays for WDM Applications - L. Davis; M. G. Young; D. Dougherty; S. Keo; R. Muller; P. Makcr
Multi-wavelength arrays of colliding pulse mode-locked (CPM) lasers have been demonstrated for wavelength division multiplexing (WDM) applications. Arrays with up to 9 wavelengths have been fabricated, operating at repetition rates of- 18 GHz with pulsewidths < 10 ps. Introduction: The need for increased bandwidth is driving the development of both increased speed in time division multiplexing (TDM) and more channels in WDM for fiber optic communication systems. While present WDM systems utilize discrete DFB lasers, future high speed systems would greatly benefit from an integrated, multi-wavelength source of optical pulses at very high repetition rates for WDM soliton communications. Mode-locked...

6. Kitthaweesin K: Optic neuritis caused by intraocular angiostrongyliasis - Kittisak Sawanyawisuth; Kitthisak Kitthaweesin
Abstract. A 21-year-old Thai man first presented with eosinophilic meningitis. One week later he developed visual impairment of the left eye with a visual acuity of 20/600. He had a Marcus Gunn pupil, constricted visual field, prolongation of visual evoked potential and the presence of inflammatory cells in the vitreous cavity of the affected eye. On funduscopic examination there was disc swelling with hyperemia of the left eye. These ocular findings are compatible with optic neuritis. The causative agent, Angiostrongylus cantonensis, was identified in the vitreous cavity. To our knowledge this is the first case of optic neuritis caused by...

7. On spiking units in the first optic chiasm of the blowfly III. The sustaining unit - N. M. Jansonius; J. H. Van Hateren
Abstract. We recorded from the spiking sustaining unit in the optic chiasm between lamina and medulla in the brain of the blowfly Calliphora vicina, and investigated both temporal and spatial properties of the light-adapted cell. The sustaining unit fails to follow the highest em-poral frequencies followed by the photoreceptor, but its temporal resolution is substantially better than that of the on-off unit. The sustaining unit does not display the fast temporal adaptation as previously described in the on-off unit. As compared with the on-off unit, the sustaining unit has a high sensitivity to small contrasts. Although the sustaining unit continues...

8. Equipo óptico de ajuste de color II PPS de 3M

9. Canal Segarra-Garrigues: Transformación de un territorio, transformación de las personas - del Estal Malillos, Javier
El regadío del Sistema Segarra-Garrigues transformará una superficie de más de 95.000 Ha de secano en regadío.Siempre nos fijamos en los números macros de una actuación como esta: inversión, incremento de producción, hm3 de agua consumida, municipios afectados, propietarios beneficiados, etc. Pero no reparamos en la visión de las personas que se ven envueltas, de una forma u otra, por el cambio que supone la llegada del agua de riego. A través de exponer una serie de experiencias personales pretendo aportar datos que ayuden a quien desee analizar el nuevo regadío del Segarra-Garrigues desde una perspectiva menos técnica o económica...

10. area SIS100 - Plotnikov A; Gsi Darmstadt
Investigation of life time of the electronics and the optic fiber inside the niche and the tunnel in the slow extraction

11. A simple laser system for atom interferometry - Merlet, Sébastien; Volodimer, Laurent; Lours, Michel; Pereira Dos Santos, Franck
We present here a simple laser system for a laser cooled atom interferometer, where all functions (laser cooling, interferometry and detection) are realized using only two extended cavity laser diodes, amplified by a common tapered amplifier. One laser is locked by frequency modulation transfer spectroscopy, the other being phase locked with an offset frequency determined by an Field-Programmable Gate Array (FPGA) controlled Direct Digital Synthesizer (DDS), which allows for efficient and versatile tuning of the laser frequency. Raman lasers are obtained with a double pass acousto-optic modulator. We demonstrate a gravimeter using this laser system, with performances close to the...

12. Correlative Compositional Analysis of Fiber-Optic Nanoparticles - Francois-Saint-Cyr, H; Martin, I; Blanc, W; Lecoustumer, P; Hombourger, C; Neuville, D; Larson, D.J.; Prosa, T.J.; Guillermier, C
International audience

13. Fiber Optic Dielectric Nanoparticles Characterization by Atom Probe Microscopy - Francois-Saint-Cyr, H; Martin, I; Blanc, W; Lecoustumer, P; Hombourger, C; Neuville, D; Larson, D.J.; Prosa, T.J.; Guillermier, C
International audience

14. Sand-assisted fluidization of large cylindrical and spherical biomass particles: Experiments and simulation - Fotovat, Farzam; Ansart, Renaud; Hemati, Mehrdji; Simonin, Olivier; Chaouki, Jamal
In this study, bubbling fluidization of a sand fluidized bed with different biomass loadings are investigated by means of the experiments and numerical simulation. The radioactive particle tracking (RPT) technique is employed to explore the impact of the particle shape factor on the biomass distribution and velocity profiles when it is fluidized in a 152 mm diameter bed with a 228 mm static height. Using a pair of fiber optic sensors, the bubbling characteristics of these mixtures at the upper half of the dense bed are determined at superficial gas velocities ranging from U=0.2 m/s to U=1.0 m/s. The experimental...

15. Discrete Wavelet Analysis for Fast Optic Flow Computation - Christophe P. Bernard
This paper describes a new way to compute the optic flow, based on a discrete wavelet basis analysis. The optic flow is estimated locally by the projection of the differential optic flow equation onto wavelets. The resulting linear systems are small and of fixed size (3-5 equations). They are solved to find out the visual displacement. In this way, we circumvent the classical problems of time aliasing and aperture. Moreover, the coefficients of the systems can be computed with a set of wavelet transforms, and the resolution of these systems is of similar complexity. The algorithm has thus a complexity...

16. Dissolution Technologies | FEBRUARY 200822 Monitoring Dissolution Rate of Amiodarone Tablets by a Multiple Fiber-Optic Sensor System - Turghun Muhammad; Jide Wang; Mei Li-wan; Jian Chen
A fiber-optic dissolution testing (FODT) system for solid pharmaceutical formulations has been constructed. The system is based on a charge-coupled device (CCD) detector and includes six fiber-optic probes. Light is produced by a small deuterium arc lamp illuminating an optical fiber bundle. Six fiber-optic dipping probes were constructed with reflection geometry. The light passes back and forth through the flow-through cuvette backed by a coated aluminum mirror. The sampling interval was typically 30 sec for all probes. The system was tested for different tablet and capsule formulations. Amiodarone is a Class III anti-arrhythmic agent. It is used for treatment of...

17. Effects Of Pn Junction Position Depth On Output Current Of Solar Cell - S. H. Zaidi
Abstract:- The effect of position of pn junction on output current for both micro rectangular texturing and planer surface in solar cell has been investigated by ray tracing. This includes in geometric optic modeling and finding the effect of position of pn junction on improving the efficiency. By using ATLAS software show that the position of pn junction is very important when applying texturing to the surface of solar cells. Texturing improves the efficiency but the effectiveness increases with the depth of pn junction. A textured solar cell with 40 µm depth of pn junction has the efficiency 3 times...

18. Correspondence: - Estudio De; Los Parámetros; De La; Cabeza Del Nervio; Óptico En; Sujetos Normales; Hipertensos Oculares Y; Honrubia Fm; M. ª Aránzazu; Pérez Íñigo; Servicio De Oftalmología; Hospital Universitario; Miguel Servet
Objetivo: Comparar los parámetros del nervio ópti-co obtenidos mediante láser confocal en sujetos normales, hipertensos oculares y glaucomatosos y en los subgrupos de hipertensos clasificados según el aspecto papilar y la perimetría automatizada de longitud de onda corta (PALOC). Métodos: Se incluyeron 101 ojos de 101 sujetos normales, 247 ojos de 247 hipertensos oculares y 102 ojos de 102 glaucomatosos. Los sujetos fueron clasificados según la presión intraocular y resulta-dos de la perimetría automatizada (PA). Se clasifi-có a los hipertensos en hipertensos oculares y glau-comas preperimétricos, y en hipertensos oculares con PALOC normal e hipertensos con PALOC alte-rada. Se realizó...

19. AMONG ACADEMIC GLAUCOMA SUBSPECIALISTS IN ASSESSING OPTIC DISC - E. Gaasterl; Beth Blackwell; Scd (by Invitation; Leonard G. Dally; Msc (by Invitation
Purpose: An analysis of data from the Advanced Glaucoma Intervention Study (AGIS) has found eyes reported to have partial optic disc rim notching (not to the edge) at baseline to have less risk of subsequent visual field loss than eyes with no notching. Because this is counterintuitive and because classification of notching had not been defined in the AGIS protocol, we have assessed AGIS ophthalmologists interobserver and intraobserver agreement on notching. Methods: Fourteen glaucoma subspecialists classified notching in 26 pairs of stereoscopic disc photographs of eyes with mild to severe glaucomatous optic neuropathy. They classified images as showing either no...

20. Development/Plasticity/Repair L1/Laminin Modulation of Growth Cone Response to EphB Triggers Growth Pauses and Regulates the Microtubule - Destabilizing Protein Scg
During development, EphB proteins serve as axon guidance molecules for retinal ganglion cell axon pathfinding toward the optic nerve head and in midbrain targets. To better understand the mechanisms by which EphB proteins influence retinal growth cone behavior, we investigated how axon responses to EphB were modulated by laminin and L1, two guidance molecules that retinal axons encounter during in vivo pathfinding. Unlike EphB stimulation in the presence of laminin, which triggers typical growth cone collapse, growth cones co-stimulated by L1 did not respond to EphB. Moreover, EphB exposure in the presence of both laminin and L1 resulted in a...

Página de resultados:

Busque un recurso