scholarly journals Physical parameters for the EXPORT sample. Rotational velocities and effective temperatures

2004 ◽  
Vol 202 ◽  
pp. 127-129
Author(s):  
E. Solano ◽  
B. Montesinos ◽  
A. Mora ◽  

The methods used to calculate projected rotational velocities and effective temperatures for the targets observed during the 1998-1999 La Palma International Time campaign are described here. This is part of a project whose main goal is to perform a detailed chemical analysis of these objects and to study their potential implications in the planetary formation phenomenon.

2003 ◽  
Vol 12 (4) ◽  
Author(s):  
A. Kazlauskas ◽  
V. Straižys ◽  
R. P. Boyle ◽  
A. G. Davis Philip ◽  
V. Laugalys ◽  
...  

AbstractA calibration of color indices of the Strömvil photometric system in terms of physical parameters of stars is presented. The calibration is based on photoelectric photometry of about 1000 stars with known effective temperatures, distances, gravities and metallicities. The observations were accomplished in 2000-2003 with the 1.5 meter telescope of the Steward Observatory. The distances were taken from the Hipparcos catalog, and T


The Copley Medal is awarded to Dr R. Hill, F. R. S., in recognition of his pioneering contributions to the understanding of the nature and mechanism of the main pathway of electron transport in photosynthesis. Almost fifty years ago Hill made the first important discovery that allowed detailed chemical analysis of the pathways of photosynthesis, when he demon­strated the light-driven oxidation of water by isolated chloroplasts, and this made it possible to study water oxidation separately from carbon-dioxide reduction. This was the starting point in the elucidation of the electron-transfer pathway in photosynthesis, and in 1951 Hill, with R. Scarisbrick, uncovered the first com­ponent in the chain when they discovered cytochrome and established its key properties. Subsequently, with H. E. Davenport, Hill discovered the second com­ponent of the chain, shown later by others to be ferredoxin. With F. Bendall he formulated the ‘Z-scheme’ to describe the mechanism of electron transfer in photosynthesis in chloroplasts, which showed the relation between the photochemically driven elements and conventional electron-transfer chains found in other biological systems. This proposal brought great clarity to the field and set the scene for further detailed elucidation of the mechanisms.


2008 ◽  
Vol 136 (2) ◽  
pp. 614-620 ◽  
Author(s):  
Marta Mottini ◽  
George Wallerstein ◽  
Andrew McWilliam

1999 ◽  
Vol 4 (2) ◽  
pp. 13 ◽  
Author(s):  
J.R.M. Thacker

A crude plant extract that was toxic to spider mites in a leaf dip bioassay was subjected to detailed chemical analysis using chromatographic and spectroscopic techniques, The analyses revealed that the major active chemical was probably fl-sitosterol-3-glucostdc, a known phytosterol. The literature indicates that this chemical has been identified in a number of plant species and that it has been tested for utility in a number of medical therapies. It has not so far been assayed for the control of arthropod posts, the data indicate that this compound may be of use in the control of pest species, especially spider mites.


1993 ◽  
Vol 138 ◽  
pp. 126-130 ◽  
Author(s):  
G.S.D. Babu ◽  
B.S. Shylaja

AbstractA comparison of various physical parameters of the normal A stars with those obtained by using the peculiarity-free zones of Ap stars indicate that the peculiar A stars may be treated as normal stars as far as their effective temperatures, radii, bolometric corrections and the mass range are concerned.


1997 ◽  
Vol 1997 ◽  
pp. 207-207
Author(s):  
S.J. Lister ◽  
R. Sanderson ◽  
A. Sargeant

The size of biological samples is often, by necessity, small and precludes a full and detailed chemical analysis of the material. Near infrared spectra are comprehensive records of the chemical structure and content of a substrate and are thus a rich source of information. To investigate diurnal changes in the chemical composition of duodenal digesta, NIR spectra and difference spectra were used to examine samples collected over a 24h period.


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