The analysis of the operational process of a complex fire alarm system used in transport facilities

A fire alarm system(FAS)is a system comprising signalling-alarm devices,which automatically detect and transmit information about fire,but also receivers of fire alarms and receivers for damage signals.Fire alarm systems function in different environmental conditions.During operation they should be in state of fitness.This is determined by the reliability of the assembled units and rational management of the operation process.Therefore a reliability and operational analysis of fire alarm systems as a whole is essential.This article presents an authorial model and an operational and reliability analysis of FAS,which is exploited in a transport building.It also demonstrates relationships occurring in the analysed system,where to an addressable fire alarm central unit with detection loops and control-monitoring loops alarm device lines(with monitored relay outputs for actuation of alarm-signalling devices)were connected.Research and analysis of results for representative FAS,which were exploited in similar environmental conditions,were conducted in order to determine operational and reliability parameters of the investigated system.FAS computer simulation was run during the time t=1 year of safety system operation.This led to the calculation of the probability value of the analysed FAS staying in the examined operational states.

Submicron particle-bound polycyclic aromatic hydrocarbons in the Polish teaching rooms： Concentrations, origin and health hazard

The goal of the work was to investigate the concentrations of the 16 US EPA priority polycyclic aromatic hydrocarbons（PAH） bound to submicrometer particles（particulate matter, PM1） suspended in the air of university teaching rooms and in the atmospheric air outside. Two teaching rooms were selected in two Polish cities, Gliwice, southern Poland,and Warsaw, central Poland, differing with regard to the ambient concentrations and major sources of PM and PAH. The variabilities of indoor and outdoor 24-hr concentrations of PM1-bound PAH, the ratio（I/O） of the indoor to outdoor 24-hr concentrations of PM1-bound PAH, probable sources of PAH and the level of the hazard from the mixture of the 16 PAH（ΣPAH） to humans at both sites were analyzed. In both Warsaw and Gliwice, the mean concentrations of PM1-bound ΣPAH were slightly higher in the atmospheric air than in the rooms. The indoor and outdoor concentrations of individual PAH in Gliwice were correlated,in Warsaw – they were not. Most probably, the lack of the correlations in Warsaw was due to the existence of an unidentified indoor source of gaseous PAH enriching PM1 in phenanthrene, fluorene, and pyrene. Although the ambient concentrations of PM1-bound PAH were low compared to the ones observed earlier at both sites, they were much higher than in other urbanized European areas. However, because of low mass share of heavy PAH in ΣPAH, the various indicators of the health hazard from the 16 PAH mixture were low compared to other regions.