This paper reviewed over 100 articles on the subject of the mechanism of catalyst layer (CL) degradation and the effect of various contaminations in the polymer electrolyte membrane fuel cell (PEMFC). Also the recovery of PEMFC via different types of methods, the causes and fundamental mechanisms of cell degradation and their influence on long- term performance of PEM fuel cell were discussed i...

the effective parameters of (5, 0) and (5, 5) single-wall carbon nanotubes during the interaction with carbon dioxide as sensors are determined. the interaction of carbon dioxide  molecules with internal and external walls of the nanotubes is studied using gaussian 03 coding by density functional theory (dft) at the b3lyp/6-311g level of theory. co2 rotation around tube axles vertically and par...

STUDY OBJECTIVE Assess associations between short-term exposure to gaseous pollutants and asthma hospitalisation among boys and girls 6 to12 years of age. DESIGN A bi-directional case-crossover analysis was used. Conditional logistic regression models were fitted to the data for boys and girls separately. Exposures averaged over periods ranging from one to seven days were used to assess the e...

The precipitation response to radiative forcing (RF) can be decomposed into a fast precipitation response (FPR), which depends on the atmospheric component of RF, and a slow response, which depends on surface temperature change. We present the first detailed climate model study of the FPR due to tropospheric and stratospheric ozone changes. The FPR depends strongly on the altitude of ozone chan...

The combined effects of ozone and nitrogen dioxide were assessed in an in vitro test system utilizing human red cells. In general, these two pollutants had additive effects on the parameters measured which included osmotic fragility, acetylcholinesterase activity, lipid peroxidation, reduced glutathione and methemoglobin levels. However, at lower pollutant doses a synergistic increase in lipid ...

Ozone is one of the main air pollutants with harmful influence over human health. Therefore, predicting the ozone concentration and informing the population when the air quality standards have been exceeded is an important task. In this paper, firstand high-order Gaussian process models for 1-hour ahead prediction of ozone concentration in the air of Bourgas, Bulgaria are identified and verifie...

There is no evidence in the literature that nitrogen pentoxide (N205), the highest known oxide of nitrogen, has ever been the subject of a toxicological investigation. This gas rapidly breaks down to give nitrogen dioxide and oxygen, but is known to be stabilized by the presence of ozone, and several investigators (Schumacher and Sprenger, 1929; Johnston, 1951) have studied the complex system o...

background: patients undergone mechanical ventilation need rapid and reliable evaluation of their respiratory status. monitoring of end-tidal carbon dioxide (etco2) as a surrogate, noninvasive measurement of arterial carbon dioxide (paco2) is one of the methods used for this purpose in intubated patients. objectives: the aim of the present trial was to study the relationship between end-tidal c...