The increment in the number of automobiles and the densification of the city has increased noise pollution rates. In addition, the lack of regulation in Chile regarding the acoustic insulation of façades is a problem of a growing concern. The main objective of the present study was to obtain a model of the Sound Insulation of housing, façades, stratified in Santiago, Chile, based on constructive variables. It is expected to serve as a basis for one future regulation for acoustic façades of houses. In the present study, tests based on the international ISO 140-5 standard were carried out in situ. An estimation model of the Standardized Level Difference Dls,2m,nT,w + C, was obtained based on the opening/façade proportion, and the type of glass used for the windows.
Cytostatic drugs have become one of the greatest environmental hazards. They exhibit toxic, carcinogenic, mutagenic and teratogenic effects on flora and fauna, including people. They are poorly eliminated in conventional wastewater treatment plants and their mixtures could possess higher ecotoxicity than individual drugs. Fungi are organisms with enormous potential for biodegradation of a variety of toxic chemical pollutants. The aim of this work was to estimate tolerance of five fungal strains to selected anticancer drugs, which will be useful to determine the potential for their possible use in cytostatics removal and may be significant in the context of wastewater treatment application. Test was conducted on Fomes fomentarius (CB13), Hypholoma fasciculare (CB15), Phyllotopsis nidulans (CB14), Pleurotus ostreatus (BWPH) and Trametes versicolor (CB8) and the chosen drugs were bleomycin and vincristine. Their ability to grow in the presence of selected cytostatics was evaluated in cultures conducted on two solid media which differed in the richness of nutrient compounds. Fungal strains tolerance was expressed as a half maximal effective concentration. Results showed that fungi display better tolerance to high cytostatics’ concentrations in the medium rich in carbon source. Regardless of the medium used, the differences in growth ability were lower for bleomycin (the tolerance was higher). The greatest tolerance for bleomycin was shown by Pleurotus ostreatus. Results suggest that more efficient elimination of bleomycin would be possible to obtain, strain BWPH seems to be the best fungal candidate for this drug degradation assay and, probably, in wastewater treatment application tests in a longer perspective.
The article presents the results of research concerning to AlCu4MgSi alloy ingots produced using horizontal continuous casting process. The presented research was focused on the precise determination of phase composition of the precipitates formed during the solidification of ingots and the analysis of their thermal stability. In order to assess the morphology of precipitates in the AlCu4MgSi alloy, data obtained by using a computer simulation of thermodynamic phenomena were compiled with results obtained using advanced research techniques, i.e. High-temperature X-ray diffraction (HT-XRD), SEM-EDS, Thermal and derivative analysis (TDA) and Glow discharge optical emission spectroscopy (GD OES). SEM observations and analysis of chemical composition in micro-areas showed that the precipitates are mainly intermetallic θ-Al2Cu and β-Mg2Si phases, and also presence of Al19Fe4MnSi2 intermetallic phase was confirmed by X-ray diffraction studies. Based on the prepared Thermo-Calc simulation data, high-temperature X-ray diffraction measurements were conducted.
The microstructure of Al-Si alloy has coarse silicon and this structure is known dangerous for mechanical properties due to its crack effect. Sr addition is preferred to modify the coarse silica during solidification. Additionally, bifilms (oxide structure) are known as a more dangerous defect which is frequently seen in light alloys. It is aimed at that negative effect of bifilms on the properties of the alloys tried to be removed by the degassing process and to regulate the microstructure of the alloy. In this study, the effect of degassing and Sr modification on the mechanical properties of AlSi12Fe alloy was investigated, extensively. Four different parameters (as-received, as-received + degassing, Sr addition, Sr addition + degassing) were studied under the same conditions environmentally. The microstructural analyses and mechanical tests were done on cast parts. All data obtained from the experimental study were analyzed statistically by using statistical analysis software. It was concluded from the results that Sr addition is very dangerous for AlSi12Fe alloy. It can be suggested that to reach high mechanical properties and low casting defects, the degassing process must be applied to all castings whereas Sr addition should not be preferred.
During a Polish Antarctic Expedition to Dobrowolski Station the astronomic co-ordinates of a main geodetic point have been determined. The observations were performed by Kavrajski's method. In result 26 pairs of bright stars were observed. Longitude and latitude were defined with an estimated accuracy about ± 1".
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