2,154 research outputs found
Growth and Characterization of Fe0.95Se0.6Te0.4 Single Crystal
In this paper we present the single crystal growth of Fe0.95Se0.6Te0.4 high
TC superconducting sample by the modified Bridgman technique. The x-ray
diffraction pattern shows the single crystal nature of the sample, as only
(00l) peaks are detectable. The stoichiometric composition has been verified by
energy dispersive x-ray analysis. The superconducting transition temperature at
14 K was confirmed through DC magnetization (ZFC-FC) and resistivity
measurements. By analyzing the isothermal M-H curves, we determined the value
of H_c1 (0) ~360 Oe by extrapolating the data. The temperature coefficient of
resistivity obtained using the power law fitting was found to be 0.6. The
obtained Raman spectra at room temperature can be interpreted with the
tetragonal crystal structure and space group P4/nmm.Comment: conference pape
High Power, Continuous-wave Supercontinuum Generation in Highly Nonlinear Fibers Pumped with High Order, Cascaded Raman Fiber Amplifiers
A novel method for efficient generation of high power, equalized
continuous-wave supercontinuum source in an all conventional silica fiber
architecture is demonstrated. Highly nonlinear fiber (HNLF) is pumped in its
anomalous dispersion region using a novel, high power, L-band laser. The L-band
laser encompasses a 6th order cascaded Raman amplifier which is pumped with a
high power Ytterbium doped fiber laser and amplifies a low-power, tunable
L-band seed source. The supercontinuum generated 35W of power with ~40%
efficiency. The Supercontinuum spectrum was measured to have a high degree of
flatness of better than 5 dB over 400 nm of bandwidth (1.3 - 1.7 micron,
limited by spectrum analyzer range) and a power spectral density in this region
of >50 mW/nm. The extent of the SC spectrum is estimated to be upto 2 micronComment: 6 pages, 5 figure
Study of Histamine Forming Bacteria in Commercial fish samples of Kalyan city
Histamine food poisoning is found to be associated with consumption of scombroid fish containing unusually high levels of histamine. Fish belonging to non-scombroid group may also cause histamine poisoning. In this study, histamine forming bacteria in the commercial fish samples of local markets of Kalyan region were investigated. Among 54 isolates 24 were found to be prominent histamine producers. A simple and rapid colorimetric method for the quantification of histamine in fish was used. Histamine level in fresh mackerel samples was found to be around 20 mg/100 g, which was much above the defect action level (5 mg/100 g) given by FDA indicating potential risk for histamine poisoning. The study suggest that practice of more hygienic and sanitary conditions during handling and processing of fish are required to minimize the contamination of such histamine producing bacteri
Goal Directed Visual Search Based on Color Cues: Co-operative Effectes of Top-Down & Bottom-Up Visual Attention
Focus of Attention plays an important role in perception of the visual environment. Certain objects stand out in the scene irrespective of observers\u27 goals. This form of attention capture, in which stimulus feature saliency captures our attention, is of a bottom-up nature. Often prior knowledge about objects and scenes can influence our attention. This form of attention capture, which is influenced by higher level knowledge about the objects, is called top-down attention. Top-down attention acts as a feedback mechanism for the feed-forward bottom-up attention. Visual search is a result of a combined effort of the top-down (cognitive cue) system and bottom-up (low level feature saliency) system. In my thesis I investigate the process of goal directed visual search based on color cue, which is a process of searching for objects of a certain color. The computational model generates saliency maps that predict the locations of interest during a visual search. Comparison between the model-generated saliency maps and the results of psychophysical human eye -tracking experiments was conducted. The analysis provides a measure of how well the human eye movements correspond with the predicted locations of the saliency maps. Eye tracking equipment in the Visual Perceptual Laboratory in the Center for Imaging Science was used to conduct the experiments
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