Validating ECMWF forecasts for the occurrence of ice supersaturation using visual observations of persistent contrails and radiosonde measurements over England

2010 ◽  
Vol 136 (652) ◽  
pp. 1723-1732 ◽  
Author(s):  
Gaby Rädel ◽  
Keith P. Shine
Keyword(s):  
Visual Observations

The mechanism of formation of 2,7-dimethyl-2,6-octadiene in the synthesis of 3-methylene-7-methyl-1,6-octadiene

1983 ◽  
Vol 48 (7) ◽  
pp. 1864-1866
Author(s):  
Jan Bartoň ◽  
Ivan Kmínek
Keyword(s):  
Mass Spectrometry ◽  
Nmr Spectroscopy ◽  
Alkali Metal ◽  
Chromatographic Analysis ◽  
Solid Phase ◽  
Reaction Pathway ◽  
Mechanism Of Formation ◽  
Gas Chromatographic Analysis ◽  
C Nmr ◽  
Visual Observations

2,7-Dimethyl-2,6-octadiene is formed in the catalytic solution for the dimerization of 2-methyl-1,3-butadiene to β-myrcene (3-methylene-7-methyl-1,6-octadiene), as revealed by mass spectrometry and 13C NMR spectroscopy. Visual observations together with the results of gas chromatographic analysis of the catalytic solution suggest that the formation of 2,7-dimethyl-2,6-octadiene is associated with the transition of the alkali metal (sodium) from the solid phase into the solution. A reaction pathway is suggested accounting for the formation of 2,7-dimethyl-2,6-octadiene in the system.

scholarly journals PSX-28 Using estrus detection patches or a ram wearing a marking harness to monitor estrus in synchronized hair sheep ewes

2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 460-460
Author(s):  
Robert W Godfrey ◽  
Sue A Lakos
Keyword(s):  
Artificial Insemination ◽  
Post Partum ◽  
Hair Sheep ◽  
Cumulative Percentage ◽  
Estrous Synchronization ◽  
Estrus Detection ◽  
Visual Observations

Abstract Determining when a ewe is in estrus is important when using estrous synchronization and artificial insemination in sheep. This study was conducted to compare the efficacy of estrus detection patches (Estrotect™) and rams wearing marking harnesses for monitoring estrus in synchronized hair sheep ewes. St. Croix White (STX) ewes (3.5 ± 0.3 y of age, 89.7 ± 2.2 d post-partum) were synchronized using progesterone releasing inserts (Eazi-Breed™ CIDR) for 12 d. On the day of CIDR removal (d 1) ewes were administered prostaglandin (Lutalyse®; 15 mg i.m.) and placed with fertile STX rams in 0.55 ha pastures. One group of ewes (n =10; MH) was placed with a ram wearing a marking harness and a second group (n = 16; EP) had estrus detection patches placed on their rumps before being placed with a ram without a harness. Estrus detection was conducted using visual observations twice a day through d 7. A ewe was considered to be in estrus when crayon marks were observed on the rump or the patch was activated, based on product guidelines. Cumulative percentage of ewes in estrus was analyzed using the CATMOD procedure with treatment, day and the interaction in the model. All patches stayed in place on the EP ewes through d 7. By d 4 90% of MH ewes and 75% of EP ewes had been observed in estrus (P < 0.05). By d 7 90% of MH ewes and 81.25% of EP ewes had been observed in estrus (P < 0.05). With costs of $1.33 per patch or $29.33 for one harness and crayon the patches may be more economical when dealing with up to 21 ewes per ram. Estrus detection patches can be used on hair sheep ewes to detect estrus just as effectively as a ram with a marking harness.

Taylor-vortex instability and annulus-length effects

1976 ◽  
Vol 75 (1) ◽  
pp. 1-15 ◽  
Author(s):  
J. A. Cole
Keyword(s):  
Critical Speed ◽  
Taylor Vortex ◽  
Vortex Instability ◽  
Critical Speeds ◽  
Taylor Vortices ◽  
Torque Measurements ◽  
Concentric Cylinders ◽  
Theoretical Predictions ◽  
Range Of Values ◽  
Visual Observations

Critical speeds for the onset of Taylor vortices and for the later development of wavy vortices have been determined from torque measurements and visual observations on concentric cylinders of radius ratios R1/R2 = 0·894–0·954 for a range of values of the clearance c and length L: c/R1 = 0·0478–0·119 and L/c = 1–107. Effectively zero variation of the Taylor critical speed with annulus length was observed. The speed at the onset of wavy vortices was found to increase considerably as the annulus length was reduced and theoretical predictions are realistic only for L/c values exceeding say 40. The results were similar for all four clearance ratios examined. Preliminary measurements on eccentrically positioned cylinders with c/R1 = 0·119 showed corresponding effects.

scholarly journals Meteorite Orbits from Observations by Camera Networks

1983 ◽  
Vol 6 ◽  
pp. 399-404 ◽  
Author(s):  
Ian Halliday ◽  
Arthur A. Griffin ◽  
Alan T. Blackwell
Keyword(s):  
Current Knowledge ◽  
Great Difficulty ◽  
Camera Networks ◽  
Significant Group ◽  
Lost City ◽  
Knowledge Based ◽  
Alternative Approach ◽  
Physically Identical ◽  
Review Current ◽  
Visual Observations

Camera networks for the study of bright fireballs now have a history approaching two decades• It was hoped that the networks would produce a statistically significant group of recovered meteorites with accurate orbits. Due to the great difficulty in locating the meteorites from a photographed event, there are still only three meteorites with orbits determined from suitable photographs; Pribram, Lost City and Innisfree (Ceplecha I96I, McCrosky et al. 1971, Halliday et al. 1978, respectively). Networks do, however, provide an alternative approach to the problem. Instead of determining approximate orbits from visual observations of recovered meteorite falls, it is now preferable to use reliable orbits from the camera networks for fireballs which are believed to have dropped meteorites that could not be located, or, that are believed to have been physically identical to meteorites, although no appreciable mass survived the atmospheric flight. This paper will review current knowledge based on this approach to the problem.

Ecological aspects of deformed chaetognaths and visual observations of their periphytes

1985 ◽  
Vol 87 (1) ◽  
pp. 67-75 ◽  
Author(s):  
S. Nagasawa ◽  
U. Simidu ◽  
T. Nemoto
Keyword(s):  
Ecological Aspects ◽  
Visual Observations

LONG DURATION ECHOES FROM AURORA, METEORS, AND IONOSPHERIC BACK-SCATTER

1953 ◽  
Vol 31 (2) ◽  
pp. 171-181 ◽  
Author(s):  
D. W. R. McKinley ◽  
Peter M. Millman
Keyword(s):  
Long Range ◽  
High Frequency ◽  
The Other ◽  
Very High Frequency ◽  
Long Duration ◽  
E Region ◽  
Very High ◽  
Visual Observations

In the course of the Ottawa meteor program some unusual echoes have been detected on 33 Mc. Echoes from the aurora are discussed and correlated with visual observations. Two mechanisms of radio reflections from the aurora have been proposed but the data here presented are insufficient to favor one over the other. On Aug. 4, 1948, six extremely long duration meteor echoes were observed which may have been due to abnormal ionospheric conditions. From time to time since August, 1948, a weak semipermanent echo has been recorded, usually appearing at a range of about 80 km., and enduring up to an hour. It is suggested that this echo is due to back-scatter from the same sources in the lower E-region that are presumed to be responsible for long-range very high frequency propagation.

scholarly journals Whirlwinds and Hairpins in the Atmospheric Surface Layer

2016 ◽  
Vol 73 (12) ◽  
pp. 4927-4943 ◽  
Author(s):  
Steven P. Oncley ◽  
Oscar Hartogensis ◽  
Chenning Tong
Keyword(s):  
Surface Layer ◽  
Atmospheric Surface Layer ◽  
Dust Devils ◽  
Hairpin Vortices ◽  
Structure And Dynamics ◽  
Fixed Array ◽  
Visual Observations

Abstract Vortices in the atmospheric surface layer are characterized using observations at unprecedented resolution from a fixed array of 31 turbulence sensors. During the day, these vortices likely are dust devils, though no visual observations are available for confirmation. At night, hairpin vortices appear to have been observed. The structure and dynamics of several types of vortices are described and related to other vortex investigations, including tornadoes and hurricanes.

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