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The 234U/238U isotope ratio in waters near the uranium mineral deposits
Fanta, Martin ; Goliáš, Viktor (advisor) ; Strnad, Ladislav (referee)
Uranium has three natural isotopes: 238 U, 235 U and 234 U. Isotopes 238 U and 235 U are primordial, isotope 234 U is one of the daughter products of 238 U decay series. Genetically dependent uranium isotopes 238 and 234 are fractionated in nature. The main reason is the alpha recoil in solid (crystalline) phase, where there is a preferential settling subsidiary 234 U in a higher oxidation state (VI). The isotope 234 U is then more available at the recent geochemical processes: leaching and alteration. Water then usually has 234 U/238 U activity ratio higher than 1, while the activity ratio in solid residuum is smaller than unity. Isotopic ratio in water is dependent on many factors. The most important are the nature of source rocks, weathering rate, the dynamics of geochemical processes (e.g. fluid-flow velocity) or anthropogenic influence on geological environment at mining of uranium deposits. Identification of these fractionation factors is not easy. Differences in the isotope ratios in water may be used to identify the source of uranium and to evaluate the contribution of technogenic uranium.
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Lead isotopic composition of selected certified reference materials in three step extraction procedure.
Martinovský, Václav ; Mihaljevič, Martin (advisor) ; Strnad, Ladislav (referee)
This work deals with the issue of lead isotopic composition in reference materials. These reference materials were extracted by using method of sequential extraction analyses Isotopic composition of the lead was determined by ICP MS (Thermo scientific). The first part summarizes knowledge in the field of sequential extraction analyses; in the following section issue of using isotopic composition of lead in environmental sciences is discussed. Experimental part describes research methodology and presents results of the sequential extraction and the isotopic composition of lead contained in the analysed reference materials. Following reference materials were analysed: CRM BCR 483, CRM BCR 701, SRM NIST 2709a, SRM NIST 2710a, SRM NIST 2711a. Results of modified sequential extraction procedure BCR (three steps methodology created by Community Bureau of Reference, Belgium to harmonize technical procedure) measured in this work corresponds to the certified or indicative values. Isotopic composition expressed by isotopic ratios 206 Pb/207 Pb among fractions of BCR sequential extraction (fractions I - IV) was folloving: CRM BCR 483 (1,1168 - 1,1350); CRM BCR 701 (1,1583 - 1,1844); SRM NIST 2709a (1,1819 - 1,2118); SRM NIST 2710a (1,1583 - 1,1989); SRM NIST 2711a (1,1079 - 1,1284). Key words: lead isotopic...
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Vlivy působící na hmotnost jehňat ve 100 dnech u plemene texel
STRNAD, Ladislav
The aim of this diploma thesis is to evaluate the chosen influences which effects the weight of lambs in the age of 100 days of breed texel. The evalution was done from 2013 to 2016 and the basic data set is consisted of 1149 lambs. The observed effects were sex, litter size, month of birth, year of birth, mother's age, father's line, and mother's father line. There was found a statistically highly significant difference in the monitoring of sex influence in male lambs (34,69 kg). A statistically significant difference was found in singles (35,14 kg) when evaluating the influence of litter size. There was found a statistically significant differences between the lambs born in May (36,78 kg) and February (37,29 kg), according to the influence of the month of birth. There is also the influence of the year of birth, a statistically highly significant difference was found between 2016 and 2015. There wasn't found a statistically significant difference in the influence of the mother's age. The influence of the father's line proved a statistically highly significant differences in the TAXI line (36,81 kg) and TAYLOR (37,76 kg). The evaluating of the influence of the mother's father line didn´t show a statistically significant difference in the TRISK line (48,50 kg). There wasn´t found a statistically significant difference in interaction of mother's father line and litter size.
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Trace elements and Pb isotopes in selected bone samples
Bartoš, Jan ; Mihaljevič, Martin (advisor) ; Strnad, Ladislav (referee)
The aim of this work is briefly summarize the current theoretical knowledge about trace elements and their inputs into calcified body tissues in a form of search. Here are described mechanisms of their inputs and depositing into human body and principles, which allows maintenance of their optimal levels. In this paper are also described the properties of bones and teeth and simply explained concepts such as an essential and toxic trace elements. The next part of this work is mainly about trace elements, which have the biggest potential to be used in an archeological research, particularly in paleodietary research. These elements are mainly Sr, Ba and Zn. Lead and its isotopes are discussed more here in relation to the effect of Pb to Romans in the past and to the identifying sources of pollution by this element. In the same chapter are also described principles of post-mortem alteration processes, to which are bones after burial exposed and which they have to face during analyzing and interpretations of data related to the amount of trace elements in origin bones.
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Tree rings as a Pb pollution archive
Šimeček, Martin ; Mihaljevič, Martin (advisor) ; Strnad, Ladislav (referee)
The Bachelor's thesis is written as a research talking about storing Pb in tree rings. The first part speaks about the basic characteristic of the pollutant, his natural and anthropogenic deposits. Following chapters are comparing the tree rings with the peat bogs, which are often used as a natural archive of the contamination by the metallic elements. Than I continue with the description of the transport of Pb into wood and subsequent radial distribution in tree rings. One of the chapters concludes the results of certain researches of tree rings. The main time sections of environmental pollution in the 20th century are shown by the results of researches on the concentrations and isotope ratios of Pb. These studies informe us also about sources causing this pollution. The thesis includes also a chapter about bark pockets, which can be used as another alternative to observe the movement of Pb in the environment. The last part describes the method ICP-MS usually used to determine Pb in natural materials.
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Determination of Pt metals in environmental samples
Kotková, Kristýna ; Mihaljevič, Martin (advisor) ; Strnad, Ladislav (referee)
Platinum group elements are increasingly used in various industries, and that generates their occurrence in many parts of the environment, including biota. The interest of scientists is currently focused on studying the behavior of Pt metals in the ecosystem because of the potential health risks of Pt metal compounds. There are used various techniques for this purpose, including analytical methods. This bachelor thesis deals with properties of PGE, their appearance and behavior in the environment. The aim of the bachelor thesis is to review the analytical methods used to determine the Pt metals in environmental samples. Key words: platinum group elements, determination, ICP-MS
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Variation of Pb-isotopic composition in coal basins
Čurda, Michal ; Strnad, Ladislav (advisor) ; Mihaljevič, Martin (referee)
This Bachelor Thesis is devided into three main parts. The first part has a character of a research and describes the presence of lead in coal, in deposits of ore, in peat bogs, or in lake and flood sediments. The second part briefly describes the analythic methods used to determine lead in natural material. The third - practical part is focused on measurement of samples taken from the sokolov brown coal basin. It describes the laboratory method of the preparation of the samples for the analysis of contents and isotope composition of lead using ICP - QMS.
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Lead isotopic ratio determination in soils
Kotrč, Vlastislav ; Mihaljevič, Martin (advisor) ; Strnad, Ladislav (referee)
This barchelor thesis deals with the issue of lead in the environment, with its main focus being on describing the right analytical method for determining the isotopic composition of lead in soil. First part this thesis summarizes the most important characteristics and properties of lead. Next part is concerned with the methodology of collection and preparation of soil samples for the analysis itself. The thesis then contains detailed description of the analytical method, which is being currently the most used for determining the isotopic composition of soil - mass spectrometry with inductively coupled plasma. Since this is not a research thesis, in the fifth part, results of studies from the Příbram region are presented, alongside other possible uses of this method. Key words: lead isotopic composition, soils
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Biogeochemical cycle of rare earth elements in the Lesní potok catchment
Dubroková, Jitka ; Mihaljevič, Martin (advisor) ; Strnad, Ladislav (referee) ; Chrastný, Vladislav (referee)
110 Summary The study of biogeochemical cycle of rare earth elements (REE) carried out in the Lesní potok catchment and its vicinity (located in the Nature State Reserve, Voděradské bučiny, 30 km SE of Prague) was focused on the monitoring of REE concentrations and distribution patterns in natural environment, their relationship with other analysed elements and compounds such as Al, Ca, Fe, K, Mg, Mn, Na, P, S, Si, F- , Cl- , NO3 - SO4 2- , HCO3 - and organic carbon, and its response to physicochemical conditions in various investigated ecosystem compartments. The samples of soil, stream sediment, stream and ground water, rainwater and throughfall in beech and spruce forest, samples of tree assimilatory organs, bark and stem wood of Norway spruce (Picea abies) and European beech (Fagus sylvatica) and lichens (Hypogymnia physodes) were collected in the catchment and its vicinity. Liquid samples were acidified with dilute nitric acid to prevent losses by adsorption, and filtered using a 0.45 µm membrane filter. Stream water samples sampled in months characterized by low and high discharge were processed by ion exchange chromatography and membrane dialyses. Solid samples were dried to constant weight (and sieved and homogenized in case of soil stream sediment samples) and decomposed in the microwave oven with...
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