The influence of γ and X radiation on pulse characteristic of some commercial gas filled surge arresters

Cilj ovog rada je da se ispita uticaj gama i X zračenja na brzinu odziva komercijalnih CITEL i SIEMENS gasnih odvodnika prenapona. Pokazano je da oba tipa zračenja dovode do promene impulsne karakteristike odvodnika.. Dobijeni rezultati pokazuju da su u polju gama zračenja otporniji odvodnici firme CITEL, a u polju X zračenja SIEMENS odvodnici.The aim of this paper is to examine the influence of γ and X radiation to response time of some commercial gas filled surge arresters. We found that both radiations have significant influence on gas filled surge arresters pulse characteristic. The obtained results show that the optimal solution in gamma radiation field was CITEL components, while in X radiation field was better to use SIEMENS components.XXIV Simpozijum Društva za zaštitu od zračenja Srbije i Crne Gore, Zlatibor, 3-5. oktobar 2007

Occurrence, Source Apportionment, and Health Risk Assessment of Polycyclic Aromatic Hydrocarbons in Soil of Urban Parks in a Mid-Sized City

Public parks and open playgrounds are the most important compartments of the urban environment due to their role in sustaining the well-being of city residents, primarily through relaxation and recreation. To determine the occurrence, levels, and sources of 16 US Environmental Protection Agency (US EPA) priority polycyclic aromatic hydrocarbons (PAHs) and consequent human health risk, soil samples from 18 parks and playgrounds from Kruševac, a mid-sized city in Serbia, were collected and analyzed. The concentrations of PAHs were determined using gas chromatography-mass spectrometry. The total concentration of selected PAHs ranged from 14 to 121 µg kg−1, with a mean of 55 µg kg−1. The measured concentrations of individual PAHs were well below limits set by national legislation and were much lower than reported values for cities worldwide. Principal component analyses and positive matrix factorization were employed to identify possible PAH sources. Traffic emissions and coal, firewood, and natural gas combustion were identified as the main sources of PAHs in the analyzed soil. The most polluted soil samples were found in parks and playgrounds near busy roads and in the most densely populated city districts. A risk assessment procedure established by the US EPA showed no significant risk, either carcinogenic or non-carcinogenic, associated with exposure to PAHs in the soil for adults and children who use parks and open playgrounds for recreational purposes