National Repository of Grey Literature 49 records found  1 - 10nextend  jump to record: Search took 0.01 seconds. 
Development of beverages containing lignans obtained from waste plant material (spruce knots)
Tříska, Jan ; Vrchotová, Naděžda
Development of beverages containing lignans obtained from waste plant material (spruce knots). Analyzes of lignans, in particular 7-hydroxymatairesinol, by chromatographic methods, especially by HPLC with DAD and FLD detectors. Some analyzes had to be confirmed by LC-MS.
Development of the extraction process of plant material (grapevine canes) and determination of resveratrol and its derivatives
Tříska, Jan ; Vrchotová, Naděžda
Development of the waste material extraction process (grapevine canes) and determination of resveratol and its derivatives. Analyzes of polyphenols and stilbenes, in particular catechin, epicatechin, resveratol, viniferin in grapevine canes extract, using chromatographic methods, especially HPLC with DAD and FLD detector. Some analyzes had to be confirmed by LC-MS. An interpretation of the results is also part of the analysis.\n\n
Utilization of sampling filters from the Kresin atmospheric station for further analysis
Vítková, Gabriela ; Kahoun, D. ; Strnadová, G. ; Hanuš, Vlastimil ; Petrov, M. ; Tříska, Jan ; Holoubek, Ivan
The Kresin At Pacov Atmospheric Station serves as a monitoring point for the occurrence and remote transmission of greenhouse gases, selected atmospheric pollutants and basic meteorological characteristics. The determination of the GHG concentration (CO2, CH4, N2O, CO) is carried out in air continuously sampled at 10, 50, 125 and 250 m heights. The analysis itself takes place at the foot of a high mast where the air is drawn through the tubes of Synflex 1300. lines and individual analyzers are protected from mechanical pollution by input filters that are changed at regular intervals as part of the routine maintenance of the device or earlier when unexpected clogging occurs. Analyzing these filters can provide additional information about the surrounding area. These are stainless filters (Swagelog „T“ filter) with a porosity of 40 μm. A sampling head is provided in front of them to protect them from rough dirt and water drops. The volume flow of the scrubbed air is about 15 l / min, the exchange interval is usually 3 months. The need to replace these filters has increased in recent months as the flow rate on the sampling lines has fallen. The question arises as to how long the filters remain fully passable and how well they serve their purpose without burdening the sampling system and lowering the measurement quality. The results of analyzes of polycyclic aromatic hydrocarbons (PAHs) carried out on filters at the Institute of Chemistry and Biochemistry of the Faculty of Science of South Bohemian University as well as images from the Scanning Electron Microscope (SEM) could be helpful in answering this question. On the basis of the preliminary results, we propose a more extensive study for the use of this waste material for the analysis of solid particles from the atmosphere in the surroundings of AS Křešín near Pacov and the optimization of the QA / QC sampling systems of greenhouse gas analyzers.
Creation and validation of chemistry worksheets for lower grades students of grammar school
Tříska, Jan ; Hybelbauerová, Simona (advisor) ; Teplá, Milada (referee)
Inclusion of learning exercises intended to acquisition of schoolwork is desirable in majority of science subjects. This diploma thesis deals with creation of chemistry worksheets for 8th and 9th grade pupils of secondary school and forpupils of corresponding grades of lower grammar schools. Research of contemporary literature mostly chosen workbooks and worksheets available on the Internet isincluded in the thesis. The main part of the thesis was creation of worksheets on diferent themes in chemisty education according to RVP ZV. Created worksheets were verified and evaluated at schools. The thesis brings new possibilities how to deal with teaching some of the chemistry topics using pre-prepared worksheets, which contain mostly exercises for acquiring new schoolwork.
Chemical thermodynamics in chemisty education at grammar schools
Tříska, Jan ; Teplý, Pavel (advisor) ; Šmejkal, Petr (referee)
This bachelor thesis is focused on teaching chemical thermodynamics at the four-year grammar school. The theoretical part of the thesis deals with the analysis of current curricula. Basic document is the Framework educational programme for grammar schools. Subsequently, in a few cases of the School educational programs my work present the scope of this topic at different grammar schools and inclusion in a school year. My thesis also includes reviews of the most widely used grammar school textbooks. Practical part of my thesis deals with creating my own textbooks of chemical thermodynamics for grammar schools. These textbooks should to be actually used in chemical thermodynamics education at grammar school in compulsory and optional chemistry subjects. These textbooks include a brief explanation of subject matter and teaching tasks encouraging pupils to be more active in class. They comprise all the essentials of secondary school textbooks and present all the grammar school matter of chemical thermodynamics and thermochemistry in detail. Both textbooks contain solutions of teaching tasks for teachers.
The relationships of soil CO2 flux with selected Norway spruce root parameters and sterol content in the soil
Holub, Filip ; Fabiánek, Tomáš ; Večeřová, Kristýna ; Moos, Martin ; Oravec, Michal ; Tříska, Jan ; Marková, I. ; Edwards, Magda ; Cudlín, Pavel
The flow of CO2 from the soil is a very important part of the carbon cycle in an ecosystem. The aim of our work was to determine how roots and rhizospheric fungi contribute to CO2 flux from the soil. Preliminary results from two years of research are presented. The research on how root biomass as well as ergosterol and phytosterol contents in roots and soil affected CO2 flux from the soil was conducted in a 108-year-old Norway spruce (Picea abies (L.) Karst.) forest in the Drahany Highlands during 2010 and 2011. CO2 flow was measured using a LI-8100 portable closed gasometric system (Li-Cor, USA). The dry weight and volume of individual root categories (< 1 mm, 1–2 mm, 2–5 mm, > 5 mm), C and N contents in the roots, as well as ergosterol, β-sitosterol, and campesterol contents in the soil and roots were determined from root-containing soil samples located in the circular measurement chamber. In addition, sterol content was determined in the soil only. Our soil respiration results correspond with the findings of Buchman (2000) who found respiration values between 5–7 μmol CO2 m−2 s−1 in a 111-year-old spruce forest. A significant influence on soil respiration was proven only for sitosterol content in the soil. The relationships among soil CO2 flux, root characteristics, and nitrogen and sterol contents in the roots and soil are discussed.
Occurence of lignans in environmental waters
Tříska, Jan ; Moos, Martin ; Marešová, I. ; Vrchotová, Naděžda
The content of lignans, especially hydroxymatairesinol (HMR) was investigated in different types of natural waters from the environment. Collected water samples were extracted with methyl tert. butylether, derivatized and analysed by means of GC-MS. HMR was found in different amount in all water samples beside the other lignans.
Metabolomic approach to the study of nanoparticles impact to barley plants
Večeřa, Zbyněk ; Večeřová, Kristýna ; Oravec, Michal ; Kozáčiková, Michaela ; Urban, Otmar ; Tříska, Jan
Barley plants in the pots after formation of second leaves were exposed in the special chamber to elevated concentration of CdO nanoparticles. After three weeks exposure the content of primary metabolites was measured using metabolomic approach and compared with the control.
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Ensolisation-silylation reaction study of selected steroids
Hehenberger, A. ; Kotas, Petr ; Tříska, Jan
For the purposes of trace analysis of 1,4-androstadiene-3,17-dione (ADD), 1,4-androstadiene-3-one-17β-ol (Boldenone) and 17-β-estradiol in water, waste water, soil and for the further phytosterols transformation studies the enolisation-silylation reaction was studied using MSTFA and BSTFA with different catalysts as derivatization reagents. The different reaction conditions and stability of the products was also studied using GC-MS technique.
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1 Tříska, Jakub
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