Ultraviolet radiation and bottom-ice algae: Laboratory and field studies from McMurdo Sound, Antarctica

1994 ◽  
pp. 229-242 ◽  
Author(s):  
K. G. Ryan ◽  
D. Beaglehole
Keyword(s):  
Ultraviolet Radiation ◽  
Field Studies ◽  
Ice Algae ◽  
Mcmurdo Sound

scholarly journals Photophysiology and photoacclimation in surface sea ice algae from McMurdo Sound, Antarctica

1997 ◽  
Vol 147 ◽  
pp. 243-256 ◽  
Author(s):  
DH Robinson ◽  
Z Kolber ◽  
CW Sullivan
Keyword(s):  
Sea Ice ◽  
Ice Algae ◽  
Mcmurdo Sound ◽  
Sea Ice Algae

Method for Measurements of Terrestrial Ultraviolet Radiation on Inclined Surfaces in Personal Dosimetry Field Studies

2019 ◽  
Vol 95 (6) ◽  
pp. 1454-1460 ◽  
Author(s):  
Elena Corradi ◽  
Katarzyna A Baczynska ◽  
Marco Morelii ◽  
Danilo Giulietti ◽  
Marina Khazova
Keyword(s):  
Ultraviolet Radiation ◽  
Field Studies ◽  
Inclined Surfaces ◽  
Personal Dosimetry

Seasonal Variation of Paraquat Photodegradation Rate on Polyethylene Mulch

2006 ◽  
Vol 20 (2) ◽  
pp. 315-318 ◽  
Author(s):  
James P. Gilreath ◽  
Bielinski M. Santos ◽  
Steven J. Duranceau
Keyword(s):  
Seasonal Variation ◽  
Solar Radiation ◽  
Ultraviolet Radiation ◽  
Field Studies ◽  
Sunlight Exposure ◽  
The Other ◽  
Herbicide Application ◽  
Photodegradation Rate ◽  
The Difference ◽  
Polyethylene Mulch

Field studies were conducted to determine the effect of season of the year, sunlight exposure time, and mulch color on paraquat photodegradation rate on polyethylene mulch. Experiments were established in winter, spring, and summer, with white and black polyethylene mulch, and paraquat-applied films were exposed to sunlight for 1, 4, 8, 24, 30, 48, 72, or 96 h after herbicide application. There was significant effect of the season by mulch color by time of exposure interaction on paraquat concentration recovered from mulch eluants. Winter paraquat photodegradation was lower than during the other seasons. At 48 h of sunlight exposure, predicted photodegradation on white mulch was 67, 83, and 88%, during winter, spring, and summer, respectively, whereas these values were 66, 82, and 84% on black mulch. The difference in paraquat photodegradation in winter with respect to the other seasons may be attributed to reduced ultraviolet radiation in winter, when solar radiation has to penetrate a larger atmosphere mass. In practical terms, transplanting on paraquat-applied mulch requires a minimum of 96 h during the spring and summer seasons, when concentrations were 5% or less, whereas a longer waiting period might be necessary in the winter.

PHOTOPHYSIOLOGICAL EVIDENCE OF NUTRIENT LIMITATION OF PLATELET ICE ALGAE IN MCMURDO SOUND, ANTARCTICA

1998 ◽  
Vol 34 (5) ◽  
pp. 788-797 ◽  
Author(s):  
Dale H. Robinson ◽  
Kevin R. Arrigo ◽  
Zbigniew Kolber ◽  
Michel Gosselin ◽  
Cornelius W. Sullivan
Keyword(s):  
Nutrient Limitation ◽  
Ice Algae ◽  
Mcmurdo Sound ◽  
Platelet Ice

Applications of Photoelectron Microscopy

1976 ◽  
Vol 34 ◽  
pp. 506-507
Author(s):  
William J. Baxter
Keyword(s):  
Electron Microscopy ◽  
Thermal Decomposition ◽  
Chemical Composition ◽  
Ultraviolet Radiation ◽  
Thin Layer ◽  
Edge Effects ◽  
Electron Optics ◽  
Surface Layers ◽  
Crystalline Orientation ◽  
Fluorescent Screen

In this form of electron microscopy, photoelectrons emitted from a metal by ultraviolet radiation are accelerated and imaged onto a fluorescent screen by conventional electron optics. image contrast is determined by spatial variations in the intensity of the photoemission. The dominant source of contrast is due to changes in the photoelectric work function, between surfaces of different crystalline orientation, or different chemical composition. Topographical variations produce a relatively weak contrast due to shadowing and edge effects.Since the photoelectrons originate from the surface layers (e.g. ∼5-10 nm for metals), photoelectron microscopy is surface sensitive. Thus to see the microstructure of a metal the thin layer (∼3 nm) of surface oxide must be removed, either by ion bombardment or by thermal decomposition in the vacuum of the microscope.

803: Interactions Between Ultraviolet Radiation and Polymorphisms in the Vitamin D Receptor Gene Mediate Prostate Cancer Susceptibility

2006 ◽  
Vol 175 (4S) ◽  
pp. 260-260
Author(s):  
Nicholas J. Rukin ◽  
Samuel J. Moon ◽  
Dhaval Bodiwala ◽  
Christopher J. Luscombe ◽  
Mark F. Saxby ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Vitamin D ◽  
Ultraviolet Radiation ◽  
Vitamin D Receptor ◽  
Cancer Susceptibility ◽  
Receptor Gene ◽  
Vitamin D Receptor Gene ◽  
Prostate Cancer Susceptibility
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