Air monitoring: Research needs.
Sampling and analyses difficulties encountered in the ambient, source and exposure monitoring areas of environmental data sampling of inorganic particulate matter, inorganic gases, organic particulate matter, and organic gases are discussed. Attention is given to instrumentation such as tunable lasers, ion chromatography, optical emission spectroscopy, fiber glass filters, dichotomous samplers, Teflon and other polymeric membrane filters, and electrostatic samplers. A lack of species-tailored devices is noted, as is a need to develop numerical and statistical models that will decrease the required sampling volume for reliable estimates. Finally, better characterizations of the effects that sampling has on the medium sampled are recommended. 8 references.
Interference effects in sampling particulate nitrate in ambient air
A laboratory and field study was conducted to evaluate artifact nitrate formation on filter media. The filter media evaluated included a cellulose acetate, a Teflon, a cellulose and five types of glass fiber filters covering a pH range from 4.6 to 9.4. Field studies employed simultaneous sampling using five high volume samplers and a low volume sampler system providing both a respirable (i.e. < 3.5 μm) fraction and a sample without size segregation. Laboratory studies evaluated interaction of clean filters with nitrogen dioxide and nitric acid as possible sources of artifact nitrate. The influences of temperature, relative humidity, sampling time, NH3, ozone and SO2 were determined. 
 
In 24-h field sampling in San Jose and Los Alamitos, California, mean nitrate values obtained with the filters studied differed by as much as a factor of 2.4. Of the filters studied only the Teflon filter (Fluoropore) provided collection of nitrate with negligible error due to interaction of the filter with the gaseous pollutants studied. A pH9.3 high volume glass fiber filter collected, on average, about 10 μg m−3 artifact nitrate compared with 8.5 μg m−3 of true particulate nitrate in 24h sampling. Laboratory studies suggest that collection of gaseous nitric acid is the dominant source of artifact nitrate. Nitrogen dioxide only became a substantial source of artifact nitrate in the presence of relatively high concentrations of ozone.
Politics of Judicial Independence and Judicial Accountability in Czechia: Bargaining in the Shadow of the Law between Court Presidents and the Ministry of Justice
Judicial independence – Judicial accountability – Court presidents – Judicial politics – Separation of powers – Court administration – Judicial councils – Selection of judges – Czechia – Central Europe