Catalytic converters are used for minimizing the release of pollutants to the atmosphere. It is during the warm-up period that hydrocarbons are seen to be released in appreciable quantities from these converters. In this paper the conversion of a fast oxidizing hydrocarbon propylene is analysed using two numerical methods. The quasi steady state method assumes the accumulation terms to be negli...

During the warm early Pliocene (approximately 4.5 to 3.0 million years ago), the most recent interval with a climate warmer than today, the eastern Pacific thermocline was deep and the average west-to-east sea surface temperature difference across the equatorial Pacific was only 1.5 +/- 0.9 degrees C, much like it is during a modern El Niño event. Thus, the modern strong sea surface temperature...

BACKGROUND AND OBJECTIVES: The goal of this study is to evaluate in a time-series study the short-term effects of particulate matter-2.5exposure on respiratory emergency visits in six central-southern Chilean cities highly contaminated by wood smoke. METHODS: Association was assessed using both distributed lag linear and non-linear Poisson models constrai...

[1] Two aspects of the onset of a warm event in the Southern Oscillation are 1) the subtropical South Pacific High is weakened in early southern winter which weakens subtropical sea level pressure (SLP) gradients, and thus reduces the trade winds and upwelling along the equator, and 2) in the months that follow, and particularly during the mature phase of the warm event during southern summer, ...

[1] Three alternate China-wide temperature composites covering the last 2000 years were established by combining multiple paleoclimate proxy records obtained from ice cores, tree rings, lake sediments and historical documents. Five periods of temperature variation can be identified: a warm stage in AD 0–240, a cold interval between AD 240 and 800, a return to warm conditions from AD 800–1400, i...

Embryonic development of the common chameleon, Chamaeleo chamaeleon, was monitored from oviposition to hatching at a field site in southwestern Spain and in the laboratory under five experimental temperature regimes. Embryos were diapausing gastrulae at the time of oviposition; developmental arrest in the field continued as cold torpor during winter. Postarrest development in the field commence...