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An Experimental Assesment of Changes to the Size Distribution of Ammonium Nitrate Under Isothermal Conditioning
Talbot, Nicholas ; Ondráček, Jakub ; Ždímal, Vladimír
Results show that for 50nm ammonium nitrate particles, 70-80% losses were recorded through the evaporation chamber. The least volatile was found to be 200nm particulate at 15°C. Generally, at 25°C the greatest reactions were found as was expected from prior research, however an overall increase in particulate concentration at 100nm for all temperature regimes was surprising. Possible multiple physiochemical transformations during transportation through the evaporator, along with activation of impurities within the water could explain these particle gains. The lack of humidity data, inter- transportation temperature profiling and lateral gas measurements limit the effectiveness of this study.
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Plný tet: SKMBT_C22013101814592 - PDF
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Basamatikum - Combined Wide Size Range Aerosol Spectromeeter
Ondráček, Jakub ; Mašková, Ludmila ; Smolík, Jiří
Combined wide size range aerosol spectrometer Basamatikum allows to measure particle number size distribution in a range between 20 nm – 20 μm. The instrument separates the measured aerosol particles into 58 size bins. The instrument can automatically switch the scanning between two sampling points (e.g. indoors and outdoors). It consists basically from two aerosol spectrometers (UFPM and APS), electrically actuated ball valve, sampling tubing with isokinetic subsampling to both of the two spectrometers and two sampling lines. The overall control, data logging and saving to file, the switching between sampling lines and the user interface is provided by the means of the LACP-made (Laboratory of Aerosol Chemistry and Physics) software in LabVIEW programming environment.
Fulltext: content.csg - PDF
Plný tet: SKMBT_C22013101814582 - PDF
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Air Quality in Different Types of Archives
Mašková, Ludmila ; Smolík, Jiří ; Ondráček, Jakub
Particulate matter (PM) and gaseous pollutants in libraries and archives can be harmful for materials stored there. The study includes indoor/outdoor monitoring of air quality in 4 archives, which representing different outdoor environments: Zlatá Koruna (rural), Třeboň (small city), Teplice (industrial area), and Prague (large city with traffic). The aim of this study is to investigate concentrations and sources of airborne PM and gaseous pollutants in the indoor environment of the archives, and to establish the relationship between the indoor and outdoor environment. The results indicated outdoor air as the most probable source of particles in the indoor environment of naturally ventilated archives at Zlatá Koruna, Třeboň and Teplice. The concentrations in the indoor environment in Prague are relatively constant and low, because the archive is equipped with a sophisticated filtration systém.
Fulltext: content.csg - PDF
Plný tet: SKMBT_C22013101814590 - PDF
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Characterization of Filter Materials for Aerosol Research – Size Resolved Penetration
Ondráček, Jakub ; Zíková, Naděžda ; Ždímal, Vladimír
The comparison of penetrations for different types of filtration materials showed wide variety of penetration curves, MPPS and the maximum penetration. This study also confirmed our initial doubts about the standard filter efficiency testing method, regarding the used testing material, setting of MPPS and measuring only the total penetration of polydisperse aerosol. Therefore, such a study could serve also as a basis for improvements in the filter efficiency standard method, which seems to give insufficient and in some perspectives limited or even misleading information.
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Plný tet: SKMBT_C22013091913090 - PDF
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Generation of Pb/PbOx Nanoparticles for Inhalation Experiments
Moravec, Pavel ; Smolík, Jiří ; Ondráček, Jakub ; Vodička, Petr ; Fajgar, Radek
Health aspects of nanoparticles (NP′s) on living beings are considered to be important. However, the real data of the impact of NP′s inhalation are rather rare. A study of allocation of MnOx nanoparticles in organs of laboratory animals in inhalation chamber was presented by Večeřa and Mikuška (2012). For these experiments a source of continual generation of nanoparticles in duration of days or even weeks and in appropriate concentration is necessary. In this work a study of continual generation of Pb/PbOx nanoparticles in hot wall tube reactor are presented.
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Plný tet: SKMBT_C22013091912130 - PDF
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Ultrafine Particle Concentrations: Importance of Local Sources and New Particle Formation in Two Central European Cities
Wonaschuetz, A. ; Wagner, R. ; Aschauer, I. ; Haindl, R. ; Ludwig, W. ; Zecha, G. ; Ondráček, Jakub ; Vodička, Petr ; Zíková, Naděžda ; Ždímal, Vladimír ; Schwarz, Jaroslav ; Hitzenberger, R.
In this study, the importance of local primary sources and new particle formation as sources of fine and ultrafine particles is investigated for winter and summer in two central European cities. Particular attention is given to the impact of local meteorological characteristics: air mass origins play a large role in the characteristics of the background aerosol and the concentrations of trace gases associated with new particle formation and growth, and precipitation and thus the condensational sink.
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Plný tet: SKMBT_C22013091713550 - PDF
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Number Concentration and Modal Structure of Indoor/Outdoor Fine Particles in Four European Cities
Lazaridis, M. ; Eleftheriadis, K. ; Ždímal, Vladimír ; Schwarz, Jaroslav ; Wagner, Zdeněk ; Ondráček, Jakub ; Drossinos, Y. ; Glytsos, T. ; Vratolis, S. ; Torseth, K. ; Smolík, Jiří
Indoor/outdoor measurements campaigns were performed in naturally ventilated houses and offices in four European cities to investigate the relationship between indoor and outdoor particle number concentrations and aerosol modal structures. The measurements sites were located in Oslo (Norway), Prague (Czech Republic), Milan (Italy) and Athens (Greece). A number of ordinary indoor activities (cooking, smoking, candle burning, etc.) were performed during the measurements to quantify the contribution of particles emitted from indoor sources and the contribution of outdoor particles to the change of the indoor aerosol size spectra.
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Plný tet: SKMBT_C22013091712000 - PDF
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Diffusion Battery – The Renewed Aerosol Spectrometer for Nanoparticles
Holubová Šmejkalová, A. ; Ondráček, Jakub ; Zíková, Naděžda ; Ždímal, Vladimír
The aim of the experiments was to develop new control software for the diffusion battery model DB 3040, in order to optimize measurements with this device. The software allows for larger variability of key control parameters of the diffusion battery and re-opens its application beyond determination of activity size distributions. In comparison with the most widely used method of aerosol spectrometry based on electrical mobility of particles, the method of diffusion battery can be advantageous in situations where we need to measure aerosols of relatively low concentrations with size distributions peaking bellow 20 nanometers.
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Plný tet: SKMBT_C22013010916340 - PDF
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Penetration of Commercial Filter Materials in Detailed Study
Ondráček, Jakub ; Zíková, Naděžda ; Ždímal, Vladimír
Testing of various filter materials proved the functionality, good precision and reproducibility of a home-made filter tester. The measurements of penetration for standard commercial filter materials might be useful for many scientists and other users working with these materials. The comparison of penetration for different types of filtration materials showed wide variety of penetration curves, MPPS and the maximum penetration. This study also confirmed our initial doubts about the standard filter efficiency testing method, regarding the used testing material, setting of MPPS and measuring only the total penetration of a polydisperse aerosol. Therefore, such a study could serve also as a basis for improvements in the filter efficiency standard method, which seems to give insufficient and in some perspectives limited or even misleading information.
Fulltext: content.csg - PDF
Plný tet: SKMBT_C22012102615351 - PDF
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