CFD Prediction of Air Quality in the Area between Two City Vehicular Tunnels Considering Moving Cars

Concentration fields of different pollutants that spread outside two roadtunnels predicted with a CFD code will be presented. The solution domain represents the city area located between two tunnel outlets – tunnel Strahov and tunnel Mrazovka in Prague. The vicinity of both tunnels is a heavily built up area with tall buildings forming typical street canyons. The CFD modelling predicts the situation after the tunnel Mrazovka will be finished and traffic will increase considerably between both tunnels. Namely, an interest was given to the prediction of dispersion of emissions leaving both tunnel and the area touched by the traffic. For the CFD predictions, a method previously developed for moving vehicles was used. The method uses combination of Eulerian and Lagrangian approaches to moving objects and is capable of modeling different speeds and traffic rates of cars as well as traffic-induced turbulence. Influence of several meteorological parameters was studied, namely wind speed and direction and traffic parameters, like traffic rates and speed of cars. The method separates contributions from different sources to the total concentration field, namely from background, tunnel outlet and roadway. Results are presented in the form of horizontal and vertical concentration fields of NO_x.     

Effects of metal ions on Mg2+-ATPase activity in plasma membranes isolated from the rat uterus

In this study, we investigated the in vitro effects of metal ions on Mg²⁺-ATPase activity in isolated membranes from rat uterus. The effects of increasing concentrations of metal salts (CrCl₂, CuSO₄, HgCl₂ and ZnSO₄) show sigmoidal and almost complete inhibition relative to the control enzyme activity. According to the IC₅₀, the ATPase possesses greater sensibility to $ {\text{Zn}}^{{{\text{2}} + }} > {\text{Cu}}^{{{\text{2}} + }} \cong {\text{Cr}}^{{{\text{3}} + }} \cong {\text{Hg}}^{{{\text{2}} + }} ,$ {\text{Zn}}^{{{\text{2}} + }} > {\text{Cu}}^{{{\text{2}} + }} \cong {\text{Cr}}^{{{\text{3}} + }} \cong {\text{Hg}}^{{{\text{2}} + }} , while other metal salts exhibit the following inhibition: CdCl₂ 55%, CsCl 64.5% and SrCl₂ 58%. Here we demonstrated that the physico-chemical properties of these metals are of importance in defining possible mechanisms of binding and decrease of enzyme activity.     

Active biomonitoring with wet and dry moss: a case study in an urban area

Active biomonitoring of the air quality in Belgrade, Serbia, was performed using the moss Sphagnum girgensohnii. Moss bags were exposed in parallel with and without irrigation for 3 and 6 months, respectively, at three different sites. Twenty-nine elements were determined in the exposed moss samples by INAA. For all exposure periods, higher uptake in the irrigated moss bags was evident for Al, Cr, Fe, Zn and Sr. Elements such as Cl, K, Rb and Cs were depleted in the moss tissue during the time of exposure. For most of the elements the accumulation after 6 months exceeded that observed after 3 months.     

Indoor concentrations of carbon monoxide in selected urban microenvironments

CO concentrations were measured in five kindergartens, one children's hospital and two homes for aged, practically without indoor sources, all situated in the city centre, for ten random days in winter and ten in summer. The indoor CO concentrations were the result of the distance from and the traffic density in the nearest street, of general pollution level, seasonal differences, day-to-day variations and daily cycle of air pollution, the vicinity of traffic having a dominant influence. Therefore location of institutions for sensitive population groups in old city centres within a block of houses seems to be a suitable solution as far as exposure to CO is concerned.Revised version of a paper presented as poster at the VIth World Congress on Air Quality, Paris 1983.     

Economic impacts of soil fertility degradation by traces of iron from drinking water treatment

Environment, Development and Sustainability - The most common drinking water clarification technology worldwide is based on precipitation using the floccules of iron(III) oxide-hydroxide FeO(OH)....     

Quantifying the efficiency of soil sampling designs: A multivariate approach

The objective of this paper is to quantify and compare the loss functions of the standard two-stage design and its composite sample alternative in the context of multivariate soil sampling. The loss function is defined (conceptually) as the ratio of cost over information and measures design inefficiency. The efficiency of the design is the reciprocal of the loss function. The focus of this paper is twofold: (a) we define a measure of multivariate information using the Kullback–Leibler distance, and (b) we derive the variance-covariance structure for two soil sampling designs: a standard two-stage design and its composite sample counterpart. Randomness in the mass of soil samples is taken into account in both designs. A pilot study in Slovenia is used to demonstrate the calculations of the loss function and to compare the efficiency of the two designs. The results show that the composite sample design is more efficient than the two-stage design. The efficiency ratio is 1.3 for pH, 2.0 for C, 2.1 for N, and 2.5 for CEC. The multivariate efficiency ratio is 2.3. These ratios primarily reflect cost ratios; influence of the information is small.