2,215 research outputs found
Nonlinear integrated optical waveguides in chalcogenide glasses
No full textY. Ruan, B. Luther-Davies, W. Li, A. Rode, and M. Sa
Gigantic optical nonlinearity in laser-deposited gallium films on the verge of a structural phase transition
No full textGallium/silica interfaces prepared by ultrafast pulsed laser deposition have excellent optical qualities and structural stability. They show a gigantic optical nonlinearity in the visible and infrared, up to 1800 nm, which reaches χ3) ~ 1 esu
Low-loss waveguides in ultrafast laser-deposited As(2)S(3) chalcogenide films
No full textThis paper was published in Journal of the Optical Society of America B and is made available as an electronic reprint with the permission of OSA. The paper can be found at the following URL on the OSA website: http://www.opticsinfobase.org/abstract.cfm?URI=josab-20-9-1844. Systematic or multiple reproduction or distribution to multiple locations via electronic or other means is prohibited and is subject to penalties under law.A. Zakery, Y. Ruan, A. V. Rode, M. Samoc, and B. Luther-Davie
Sudden scene change detection in MPEG-2 video sequences
No full textContent based indexing and retrieval of video is becoming increasingly important in many applications. Identifying scene changes and special effects in a video scene is an essential pre-requisite for automatic indexing. This paper presents a real time algorithm, which can detect abrupt scene changes in the compressed domain. It is based on the number of interpolated macroblocks (MBs) for a given B-frame as the main feature since it expresses a measure of how strong the previous and future I or P (I/P) frames are correlated. Experimental results show that this algorithm can detect most abrupt scene changes in MPEG-2 compressed vide
Source identification of fine-grained suspended sediment in the Kharaa River basin, northern Mongolia
No full textFine sediment inputs into river systems can be a major source of nutrients and heavy metals and have a strong impact on water quality and ecosystem functions of rivers and lakes, including those in semiarid regions. However, little is known to date about the spatial distribution of sediment sources in most large scale river basins in Central Asia. Accordingly, a sediment source fingerprinting technique was used to assess the spatial sources of fine-grained (<10 ?m) sediment in the 15 000 km(2) Kharaa River basin in northern Mongolia. Variation in geochemical composition (e.g. in Ti, Sn, Mo, Mn, As, Sr, B, U, Ca and Sb) was used for sediment source discrimination with geochemical composite fingerprints based on Genetic Algorithm (GA)-driven Discriminant Function Analysis, the Kruskal-Wallis H-test and Principal Component Analysis. All composite fingerprints yielded a satisfactory GOF (>0.97) and were subsequently used for numerical mass balance modelling with uncertainty analysis. The contributions of the individual sub-catchment spatial sediment sources varied from 6.4% (the headwater sub-catchment of Sugnugur Gol) to 36.2% (the Kharaa II sub-catchment in the middle reaches of the study basin), generally showing higher contributions from the sub-catchments in the middle, rather than the upstream, portions of the study area. The importance of river bank erosion is shown to increase from upstream to midstream tributaries. The source tracing procedure provides results in reasonable accordance with previous findings in the study region and demonstrates the applicability and associated uncertainties of the approach for fine-grained sediment source investigation in large scale semi-arid catchments
Ultrafast optically induced reflectivity switching at a gallium-silica interface
No full textIt was reported recently that the reflectivity of a gallium-silica interface held close to, but below, the gallium melting point of 29.8 C can be changed significantly (>40%) by light over a very broad spectral range 400 - 1600 nm. The effect has been attributed to a surface-assisted phase transition from the stable α-gallium phase to a phase of metallic nature. In this paper we present the results on the ultrafast switching dynamics of a gallium-silica interface
Validation of the FACSCount AF system for determination of sperm concentration in boar semen
No full textA flow cytometric method has been developed for rapid determination of sperm concentration in semen from various mammalian species.* All cells containing DNA are stained with SYBR-14 or propidium iodide (PI) and sperm concentration is determined in relation to an internal standard of fluorescent microspheres ( beads). Satisfactory staining can be achieved within 2-3 min and the following flow cytometric analysis on the FACSCount AF System rapidly provides the user with a precise and accurate assessment of the sperm concentration. In this study, the FACSCount AF System and Sperm Counting Reagent ( BD Biosciences) was compared with microscopic counting using a Burker-Turk haemocytometer. In addition, sperm concentration was determined using the Corning 254 spectrophotometer which is used routinely by Danish artificial insemination stations for boars. The results show that the agreement between flow cytometry and microscopic counting is very high. The slope for the regression line was 1.12 (SE = 0.03) with an estimated intercept with the Y-axis of 22 x 10(6) sperm/ml (SE = 10 x 10(6) sperm/ml) and an estimated error of the model of 10 x 10(6) sperm/ml. For the spectrophotometer, the slope of the regression line was 1.09 (SE = 0.07) with an estimated intercept of 137 x 10(6) sperm/ml (SE = 25 x 10(6) sperm/ml). The average error made by the spectrophotometer was 55 x 10(6) sperm/ml. In addition, the results obtained using flow cytometry was highly repeatable ( CV = 2.7%) in comparison with the spectrophotometric method ( CV = 6.3%). These results indicate that the FACSCount AF System is a valuable tool for precise and accurate assessment of sperm concentration in boar semen and that use of this system may lead to production of more uniform insemination doses containing a specific number of sperm per dose
EQUITABLE DISTRIBUTION OF DRINKING WATER SUPPLY IN MUNICIPAL CORPORATIONS IN THANE DISTRICT
No full textDue to higher urbanization, water demand in six Municipal Corporations of Thane district is continuously increasing. The growth of the population, small and large industries, health and educational institutions, commercial units are the responsible factors. The demand of drinking water is continuously increasing but supply is not matching with increasing demand. Municipal Corporations have not made the provision of drinking water to the growing population on 24*7 basis. The alternative policies of rainwater harvesting, reducing leakages and wastage, more provision of funds for water supply projects, revision of tariff structure and private sector participation in distribution of drinking water supply will yield the better results in terms of growing demand of water supply.water supply, water demand
Dynamics of light-induced reflectivity switching in gallium films deposited on silica by pulsed laser ablation (errata)
No full textIn our Letter [Optics Letters* (2001) Vol.26(7) pp.441-443], the references to silica (e.g., Ga–silica interface, Ga–silica structures, silica substrates) were incorrectly changed to Si. Silica or SiO2 should have been used throughout the Letter.*http://eprints.soton.ac.uk/?<br/
Fabrication of high-Q chalcogenide photonic crystal resonators by e-beam lithography
No full textThe authors report design, fabrication, and characterization of photonic crystal nanocavities in nonlinear chalcogenide glass using e-beam lithography and chemically assisted ion beam etching. The design indicated that three-hole missing cavities with simultaneously modified side hole position and radii showed the maximum quality factor of 14 000, which was insensitive to the fabrication error of side holes. The fabricated cavities presented coupling dips of −2.6dB at the wavelength of 1550nm and quality factors up to 10 000 when excited with the evanescent field from a tapered optical fiber.</jats:p
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