Results 51 to 60 of about 160,813 (191)
Journal of the Brazilian Chemical Society, 2006 A selective and rapid spectrophotometric method for the determination of nitrite is presented. It is based on the reaction of nitrite with p-nitroaniline in acid medium to form diazonium ion, which is coupled with ethoxyethylenemaleic ester or ...
Cherian Tom, Narayana Badiadka
doaj
Extraction of Traces of Copper as Tetra-Butylammonium Tetrathiocyanato Copper (II) and Its Spectrophotometric Determination Using Eriochrome Black T [PDF]
Iranian Journal of Chemistry & Chemical Engineering, 1993 An extraction-spectrophotometric method for the determination of traces of copper (II) is described. The method is based on the quantitative extraction of copper as tetrabutylammonium tetrathiocyanato copper (II) into methyl isobutyl ketone, followed by ...
Mojtaba Shamsipur, Ali Reza Fakhari
doaj
Spectrophotometry in Stellar Associations [PDF]
Symposium - International Astronomical Union, 1978 When analyzing the spectral energy distributions of early type stars as measured at Cerro Calán, we find that many of them have a feature which we have called ΔD (Gutiérrez-Morenoet al., 1968); the internal error of the measure of ΔD for a single star is ±0.02.
Hugo Moreno, A. Gutierrez-Moreno
openaire +2 more sources
Absolute Flux Calibration of the IRAC Instrument on the Spitzer Space Telescope using Hubble Space Telescope Flux Standards [PDF]
, 2011 The absolute flux calibration of the James Webb Space Telescope will be based on a set of stars observed by the Hubble and Spitzer Space Telescopes. In order to cross-calibrate the two facilities, several A, G, and white dwarf (WD) stars are observed ...
A. Noriega-Crespo +52 more
core +2 more sources
The Changing Fractions of Type Ia Supernova NUV-Optical Subclasses with Redshift [PDF]
, 2014 UV and optical photometry of Type Ia supernovae (SNe Ia) at low redshift have revealed the existence of two distinct color groups, NUV-red and NUV-blue events.
Brown, Peter J. +3 more
core +4 more sources
Spectrophotometry of comets [PDF]
Photoelectric spectrophotometric- and image tube equipped spectrographic-studies on comets are used to formulate a new model for the cometary nucleus that is physically similar to the icy-conglomerate.
Odell, C. R.
core +1 more source
Nitrogen Concentration Estimation in Tomato Leaves by VIS-NIR Non-Destructive Spectroscopy
Sensors, 2011 Nitrogen concentration in plants is normally determined by expensive and time consuming chemical analyses. As an alternative, chlorophyll meter readings and N-NO3 concentration determination in petiole sap were proposed, but these assays are not always ...
Paolo Menesatti +10 more
doaj +1 more source
Ultraviolet cometary spectrophotometry [PDF]
During the 13 shifts dedicated to observations of Comet Bradfield (including the two European shifts), five high dispersion exposures were obtained with the LWR camera, 27 low dispersion images with the LWR camera, and 36 low dispersion images with the ...
Ahearn, M. F.
core +1 more source
The expected performance of stellar parametrization with Gaia spectrophotometry
, 2012 Gaia will obtain astrometry and spectrophotometry for essentially all sources in the sky down to a broad band magnitude limit of G=20, an expected yield of 10^9 stars.
A. Vallenari +40 more
core +3 more sources
3D Spectrophotometry of Planetary Nebulae in the Bulge of M31 [PDF]
, 2003 We introduce crowded field integral field (3D) spectrophotometry as a useful technique for the study of resolved stellar populations in nearby galaxies. As a methodological test, we present a pilot study with selected extragalactic planetary nebulae (XPN)
Andreas Kelz +17 more
core +1 more source