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Toxicity of selected nitramines
Papírek, Jan ; Fojt, Pavel (referee) ; Bednařík, Karel (advisor)
This Bachelor Thesis is focused on determination of toxicity of selected nitramines and nitrosoamines, which had to be synthesized soon. Out of total 10 prepared N-nitro and N- nitrosocompounds 4 were selected for testing their toxicity in test using Duckweed (Lemna Minor). Factor IC50 was determined for two compounds 3,7-dinitro-1,3,5,7-tetraazabicyclo [3.3.1]- nonane (DPT) and 3,7-dinitroso-1,3,5,7-tetraazabyciclo [3.3.1] nonane (DNPT), unfortunately factor for other compounds failed to determine, because conditions of test validity hadn’t been kept. In the end of the thesis is compared toxicity of N-nitro and N-nitrosocompounds based on results and observations.
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Biotransformation of nitro aromates
Tomeček, Jaromír ; Bednařík, Karel (referee) ; Friedl, Zdeněk (advisor)
Contamination by nitroaromatic compounds, such as explosives, pesticides or other nitroaromatic compounds, is worldwide environmental problem. This text focuses on contamination by compounds from military and ammunition industry, most especially 2,4,6-trinitrotoluene (TNT), 1,3,5-trinitro-1,3,5-triazinane (RDX) and 1,3,5,7-tetranitro-1,3,5,7-tetrazocane (HMX). First goal of this work is to provide the reader with a aerobic biodegradation and transformation processes of nitroaromatic compounds named above. The second goal is to compare the toxicity of initial nitroaromates and their transformation intermediates.
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Environmental Aspects of Pyrotechnic Mixtures.
Mešková, Michala ; Bednařík, Karel (referee) ; Friedl, Zdeněk (advisor)
The submitted bachelor thesis deals with the study of pyrotechnic compositions and their influence on the health and environment. It explains the nature and ingredients used in pyrotechnic compositions. During burning these compositions release different compounds, toxic or non-toxic into the atmosphere in large quantities. In this work the issue of toxicity of selected alkali, alkaline earth metals and the other harmful metals was explored. The pyrotechnic compositions containing Ba, As, Pb and Cd were investigated in more detail. When burning the pyrotechnic compositions release noxious substances into the air first. Then these substances reach due to wet or dry transport mechanism the other components of the environment and mix with them. These compounds have diverse negative effects both on humans and the environment and other animals.
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Toxicity of nitroderivatives of toluene and products of their transformations
Marcelová, Štěpánka ; Zlámalová Gargošová, Helena (referee) ; Bednařík, Karel (advisor)
This work is focused on verification of p-Nitrotoluenu toxicity and compounds resulting from the aerobic transformation, and methyl group oxidation and reduction of nitro. Some of these products are not commercially available and had to be made soon. Toxicity of the substances was determined by toxicity tests. Were tested root growth inhibition Sinapis alba, which resulted in an inhibitory concentration IC50; test inhibition duckweed Lemna minor , which was also the determination of IC50 inhibitory concentration, and acute toxicity test Artemia salina, which was observed in mortality and immobility organisms and the test result was an efficient concentration EC50 value. Results of tests are compared in the conclusion of the work and is made evaluation of the toxicity of individual substances.
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UTILIZATION OF ALTERNATIVE TESTS OF BIOTOXICITY FOR DETERMINATION INADVISABILITY OF EXISTING AND/OR POTENTIONAL POLUTANTS
Vašulková, Lucie ; Zlámalová Gargošová, Helena (referee) ; Bednařík, Karel (advisor)
This thesis is focused on attestation of ecotoxicity of octachlorstyrene (OCS), persistent organic pollutant (POP), by biological tests of toxicity. The toxicity of OCS was determined by using two kinds of alternative tests applied on fresh water organisms. First of them, Thamnotoxkit, is based on observation of mobility, immobilization or even killing of crustacean Thamnocephalus platyurus. The second one, Daphnotoxkit, applies crustacean Daphnia magna. For purposes of comparison, a standard test of toxicity – so called test of root growth inhibition of Sinapis alba and two fytotests – test of growth inhibition of Lemna minor and test of root growth inhibition of Allium cepa were performed as well.
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Modern detection methods of energetic materials
Šesták, Jozef ; Bednařík, Karel (referee) ; Friedl, Zdeněk (advisor)
The review of modern detection methods of explosives was composed. Firstly the thesis deals with the detection methods commonly used in forensics science such as gas chromatography, mass spectrometry, ion mobility spectrometry, Raman spectroscopy and mainly their innovations. Then the thesis is focused on simple but very sensitive methods using fluorescence and chemiluminescence. At the end a methods as the results of a latest research are mentioned. The main of them are micro cantilever sensors and differential reflectometry. Security and counterterrorist warfare is main point of thesis.
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Nitramide-based energetic materials
Křištof, Adam ; Bednařík, Karel (referee) ; Friedl, Zdeněk (advisor)
Homolytic dissociation of the N-NO2 bond represents primary fission process of energetic materials under the influence of heat, impact, vibration and electric spark. The fission of nitramide bonds is characterized by homolytic bond dissociation energy BDE(RCON-NO2) or disproportionation bond energy DISP(RCON-NO2), which is expressed by an isodesmic reaction RCON-NO2 + SCON-H › RCON-H + SCON NO2, where SCON NO2 is a standard nitramide (1-nitropiperidin-2-on, NPO). This kind of virtual chemical calculation cancels the effect of electron correlation, accompanying the theoretical calculations of free radicals. In this thesis, the homolytic dissociation bond energy BDE(RCON-NO2) and disproportionation bond energy DISP(RCON-NO2) were evaluated for 13 cyclic nitramides using the DFT B3LYP/6-311+G(d,p) method and at the same time the total charges of corresponding nitro groups Q(NO2) were calculated by DFT B3LYP/6-31G(d,p) method. The evaluated BDE and DISP energies were correlated with detonation parameters as squares of detonation velocities and detonation heats. The resulting relationships allow a more detailed description of dependence between the molecular structure of evaluated nitramides and their explosive properties.
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Chemistry of linear polynitramines
Teplá, Romana ; Bednařík, Karel (referee) ; Friedl, Zdeněk (advisor)
This work is focused on chemistry of linear polynitramines, their physical-chemical and explosive properties with regards to the possibility of their preparation and field of utilization as energetic plasticizers of solid propellants and smokeless powder. The use of linear polynitramines as plasticizers or energetic binders is influenced by melting temperature which increases with the number of C-N(NO2)-C units in molecule of energetic material. Linear polynitramines with lower melting temperature are utilized as plasticizers of solid propellants and smokeless powder additives. Linear polynitramines with longer chain and consequently with higher melting points could be used as binders or energetic components of rocket propellants.
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