Results 41 to 50 of about 1,018,273 (298)

The fundamental parameters of the roAp star HD 24712 [PDF]

Astronomy & Astrophysics, 2016
Context. There is still a debate about the nature of the mechanism that causes the pulsation excitation of the rapidly oscillating Ap stars that oscillate above the highest theoretically acoustic frequency. HD 24712 is a good test case for such a study because it is bright, its parallax accurately determined, and its frequency spectrum is well known ...
Perraut, K., Brandao, Ines, Cunha, M., Shulyak, D., Mourard, D., Nardetto, N., ten Brummelaar, Theo A.   +6 more
openaire   +2 more sources

Dynamical Ne K Edge and Line Variations in the X-Ray Spectrum of the Ultra-compact Binary 4U 0614+091 [PDF]

, 2010
We observed the ultra-compact binary candidate 4U 0614+091 for a total of 200 ksec with the high-energy transmission gratings onboard the \chandra X-ray Observatory. The source is found at various intensity levels with spectral variations present.
Bayless, Boroson, Brandt, Brandt, C. R. Canizares, D. Chakrabarty, Ford, Ji, Ji, Jimenez-Garate, Jimenez-Garate, Juett, Juett, Juett, Juett, Krauss, Liedahl, Linares, M. A. Nowak, Mendez, Migliari, N. S. Schulz, Paerels, Piraino, Schulz, Schulz, Schulz, Schulz, Schulz, Schulz, Swank, Ueda, van Straaten, Verbunt, Wilms   +34 more
core   +2 more sources

A Recursive Bayesian Approach To Describe Retinal Vasculature Geometry [PDF]

, 2017
Demographic studies suggest that changes in the retinal vasculature geometry, especially in vessel width, are associated with the incidence or progression of eye-related or systemic diseases. To date, the main information source for width estimation from
Bharath, Anil Anthony, Uslu, Fatmatulzehra   +1 more
core   +2 more sources

Potato Late Blight Detection at the Leaf and Canopy Levels Based in the Red and Red-Edge Spectral Regions

Remote Sensing, 2020
Potato late blight, caused by Phytophthora infestans, is a major disease worldwide that has a significant economic impact on potato crops, and remote sensing might help to detect the disease in early stages.
Claudio Ignacio Fernández, Brigitte Leblon, Ata Haddadi, Keri Wang, Jinfei Wang   +4 more
doaj   +1 more source

Comparative Relationships between Some Red Edge Parameters and Seasonal Leaf Chlorophyll Concentrations

Canadian Journal of Remote Sensing, 1995
RESUMEDes donnees sur la reflectance spectrale des feuilles de certains arbres forestiers communs et des donnees botaniques ont ete recueillies chaque semaine au cours d'une saison de croissance. Les donnees botaniques comprennent des estimations sur les taux de chlorophylle a et b et sur le taux total, ainsi que sur la teneur totale en eau et sur le ...
M.J. Belanger, J.R. Miller, M.G. Boyer
openaire   +1 more source

Camera System Performance Derived from Natural Scenes [PDF]

, 2020
The Modulation Transfer Function (MTF) is a well-established measure of camera system performance, commonly employed to characterize optical and image capture systems. It is a measure based on Linear System Theory; thus, its use relies on the assumption
Jenkin, R., Jenkin, R., Psarrou, A., Psarrou, A., Triantaphillidou, S., Triantaphillidou, S., Van Zwanenberg, O., Van Zwanenberg, O.   +7 more
core   +1 more source

On some varieties associated with trees [PDF]

, 2014
This article considers some affine algebraic varieties attached to finite trees and closely related to cluster algebras. Their definition involves a canonical coloring of vertices of trees into three colors. These varieties are proved to be smooth and to
Chapoton, Frédéric
core   +2 more sources

Estimation of Canopy Structure of Field Crops Using Sentinel-2 Bands with Vegetation Indices and Machine Learning Algorithms

Remote Sensing, 2022
Leaf angle distribution (LAD), or the leaf mean tilt angle (MTA) capturing its central value, is used to quantify the direction of the leaf surface in a canopy and is one of the most important canopy structuraltraits.
Xiaochen Zou, Sunan Zhu, Matti Mõttus
doaj   +1 more source

Ground Hyper-Spectral Remote-Sensing Monitoring of Wheat Water Stress during Different Growing Stages

Agronomy, 2022
Monitoring agricultural drought via ground hyper-spectral remote sensing has always been a hot topic in the fields of agriculture and meteorology.
Qiang Li, Maofang Gao, Zhao-Liang Li
doaj   +1 more source

Temperature dependence of the band gap shrinkage due to electron-phonon interaction in undoped n-type GaN

, 2005
The photoluminescence spectra of band-edge transitions in GaN is studied as a function of temperature. The parameters that describe the temperature dependence red-shift of the band-edge transition energy and the broadening of emission line are evaluated ...
Adachi S, Gibart P, Newmann H, Niladri Sarkar, Subhasis Ghosh, Weisbuch C   +5 more
core   +1 more source