Observations of attenuation at 20.6, 31.65 and 90.0 GHz: Preliminary results from Wallops Island, VA

Ground based radiometric observations of atmospheric attenuation at 20.6, 31.65, and 90.0 GHz were made at Wallops Island, Virginia during April and May 1989. Early results from the analysis of the data set are compared with previous observations from California and Colorado. The relative attenuation ratios observed at each frequency during clear, cloudy, and rainy conditions are shown. Plans for complete analysis of the data are described

Optical particle counter measurement of marine aerosol hygroscopic growth

International audienceA technique is developed for the determination of the hygroscopic growth factor of dry particles with diameter between 0.3 and 0.6 ?m and is applied to measurements made during the second Dynamics and Chemistry of Marine Stratocumulus experiment (DYCOMS-II). Two optical particle counters are utilized, one measures the aerosol size spectrum at ambient relative humidity and the other simultaneously dries the aerosol prior to light scattering detection. Growth factors are based on measurements made in the region of the Mie scattering curve where scattered light intensity increases monotonically with dry and wet particle diameter, i.e. D<0.9 ?m. Factors influencing the accuracy of the measurement are evaluated, including particle drying, refractive index and shape. Growth factors at 90±3% ambient relative humidity in marine airmasses 400 km west of San Diego, California range between 1.5 and 1.8. This suggests that a significant fraction of the particle mass, between 40 and 70%, is either non-hygroscopic or weakly hygroscopic

Recent Extreme Ultraviolet Solar Spectra and Spectroheliograms

Extreme ultraviolet solar spectra and spectroheliogram analyse

The Jus Ad Bellum and the 1998 Initiation of the Eritrean-Ethopian War

From May 1998 to December 2000, Eritrea and Ethiopia engaged in an armed conflict that cost the lives of thousands of individuals, injured thousands more, and displaced tens of thousands of men, women, and children from their homes. In December 2000, the two sides concluded a comprehensive agreement that ended the war. Among other things, the agreement established the Eritrea-Ethiopia Claims Commission. Consisting of five arbitrators, the Commission’s mandate was to “decide through binding arbitration all claims for loss, damage or injury by one Government against the other” that were “related to the conflict” and that “resulted from violations of international humanitarian law, including the 1949 Geneva Conventions, or other violations of international law.” The two countries filed claims with the Commission in December 2001 and from that time until August 2009, the Commission issued seventeen arbitral awards and eight decisions, covering a broad array of claims, including inhumane treatment of prisoners of war and civilian internees, abuse of enemy aliens in a belligerent’s territory or in occupied territory, wrongful seizure of the enemy’s public or private property, indiscriminate battlefield conduct or aerial bombing, harassment of diplomats and seizure of diplomatic property, and many other matters. The book LITIGATING WAR: ARBITRATION OF CIVIL INJURY BY THE ERITREA-ETHIOPIA CLAIMS COMMISSION seeks to integrate in discrete chapters the Commission’s findings on key topics, with each chapter organized into sub-sections that deal with the principal elements of that topic. The guiding emphasis is not on who-filed-what claim but is instead on what kinds of violations were addressed by the Commission, what kinds of evidence were relevant in establishing or defending against such violations, what legal conclusions emerged in addressing those violations, and what levels of compensation were deemed appropriate when a violation was found.The dominant area of international law upon which claims before the Eritrea-Ethiopia Claims Commission were based was the jus in bello, or the law operating as between two belligerents after an armed conflict has arisen. One type of claim filed before the Commission, however, was quite different, in that it concerned an alleged violation of the jus ad bellum, or the law on when a state may resort to a use of military force against another state. As one of the most important norms for the international legal system, the Commission’s treatment of the jus ad bellum claim is of particular interest, and is addressed in the book’s Chapter IV on “Initiation of War.

Radiometric observations of atmospheric attenuation at 20.6 and 31.65 GHz: The Wave Propagation Laboratory data base

The National Oceanic and Atmospheric Administration (NOAA) Wave Propagation Laboratory (WPL) presently operates five dual-channel microwave radiometers, one triple-channel microwave radiometer, and one six-channel microwave radiometer. The dual-channel radiometers operate at frequencies of 20.6 or 23.87 GHz and 31.4 or 31.65 GHz. The triple-channel radiometer operates at 20.6, 31.65, and 90.0 GHz. The six-channel radiometer operates at frequencies of 20.6, 31.65, 52.85, 53.85, 55.45, and 58.8 GHz. Recent brightness temperature measurements and attenuation values from some of the above radiometers are presented. These radiometric measurements, taken in different locations throughout the world, have given WPL a diverse set of measurements under a variety of atmospheric conditions. We propose to do a more complete attenuation analysis on these measurements in the future. In addition, a new spinning reflector was installed recently for the dual-channel radiometer at the Platteville, Colorado site. This reflector will extend our measurement capabilities during precipating conditions. Locating the three-channel and portable dual-channel radiometers at or near Greeley, Colorado to support the Advanced Communications Technology Satellite (ACTS) program is discussed

Effect of Aerosol Size on Glass Transition Temperature

The amorphous phase state of suspended nanoparticles affects their atmospheric lifetimes and environmental impact. Influence of relative humidity and chemical composition on the glass-to-liquid transition is well-known. However, the influence of the particle size on the phase transition remains uncertain. Here we show experimental data that probe the amorphous phase transition of suspended sucrose particles as a function of particle size. The depression in glass-transition temperature follows the Gibbs-Thomson or Keesom-Laplace predicted proportionality of ΔTg ∝ D-1 for particles 100-700 nm in diameter, but the proportionality changes to ΔTg ∝ D-1/2 for smaller sizes. Literature data for glass-transition temperature depression in thin films and nanoconfined compounds show similar and strong deviations from the expected D-1 behavior. While the observed proportionalities remain incompletely understood, the results here provide evidence that the deviation from ΔTg ∝ D-1 is not attributable to substrate effects

Comparison of OLYMPUS beacon and radiometric attenuation measurements at Blacksburg, Virginia

Measurements of attenuation of the 20 and 30 GHz beacons onboard the OLYMPUS satellite are compared to simultaneous observations of atmospheric attenuation by a multichannel microwave radiometer along the same path. Departures from high correlation between the two measurements are believed to be related to differences in antenna beamwidths. Mean equivalent zenith attenuations derived from the slant path data are compared to zenith observations made at previous locations

Dynamical realization of breaking of exchanged degeneracy and violation of Zweig's rule

A multiperipheral model that implements part of the Veneziano topological expansion and in which the cylinder correction breaks exchange degeneracy and produces Zweig's rule violation as well as a Pomeron above one is presented. In the negative charge conjugation channel the model is identical to the 0 meson model of Freund and Nambu if continued to a spin one pole on the daughter of the Pomeron. (auth