National Repository of Grey Literature 85 records found  1 - 10nextend  jump to record: Search took 0.00 seconds. 
Generation of volatile zinc chelates from aqueous matrix
Kračmarová, Aneta ; Nováková, Eliška (advisor) ; Červený, Václav (referee)
The topic of this work was optimization of the conditions for the generation of volatile zinc chelates. The aim was to develop an alternative method for generating volatile Zn speciates to its reduction by sodium tetrahydridoborate. Detection was carried out by atomic absorption spectrometry. Optimization of the conditions of the chelation reaction itself included the selection of a suitable chelating agent and appropriate modifiers, pH adjustment, suitable reagent and carrier gas flow rates, and appropriate apparatus arrangement. The following method characteristics were obtained under optimal conditions: LOD 1.55 mg L-1 , LOQ 5.17 mg L-1 and sensitivity 0.245 s L mg-1 . The repeatability was 13,7 %. The addition of modifiers was then tested to increase the efficiency of generation of volatile zinc chelates. Potential modifiers included transition metals, organic solvents, heterocyclic organic compounds, compounds from the carbamate group and surfactants. The heterocyclic 1,10-phenanthroline and the carbamate NaPDC were included in the optimal conditions because without them it was not possible to distinguish the signal from noise. Acetonitrile proved to be the most effective modifier, increasing the efficiency to 1547 %. With the addition of acetonitrile, the LOD decreased to 0.191 mg L-1 , the...
Basic Statistical Data about the Activities of Cultural Facilities in the Czech Republic 2022. I. díl, Muzea, galerie, památky
Nováková, Eliška ; Lindnerová, Vladimíra ; Národní informační a poradenské středisko pro kulturu - Centrum informací a statistik kultury
Předmětem zjišťování je činnost muzeí, galerií, památníků a památkových objektů. Nejvýznamnější šetřené ukazatele se vztahují k rozsahu sbírek, návštěvnosti, pořádání výstav, expozic, vzdělávacích programů, odborných konferencí a seminářů a v neposlední řadě k zaměstnanosti a hospodářským výsledkům činnosti.
Fulltext: Download fulltextPDF
The pragmatic competency of students of Japanese - speech act of refusal
Nováková, Eliška ; Kanasugi, Petra (advisor) ; Tirala, Martin (referee)
(in English): This thesis focuses on pragmatic competence of Czech students of Japanese, specifically on the speech act of refusal. The aim is to find out how students differ in comparison to native speakers of Japanese. Another aim is to compare Japanese students based on the length of their stay in Japan, their Japanese proficiency, and the textbook used at the beginner level. The theoretical part describes pragmatic competence, politeness theory, the speech act of refusal and its specifics in Japanese. The practical part focuses at the analysis of refusals from the Discourse Completion Task (DCT) using semantic formulas. Usage of these formulas by native speakers and student are then compared. Found differences from the native speakers are further examined among students according to Japanese proficiency, length of their stay in Japan and textbook used at the begginer level. Finally, the results are summarized.
Determination of selected elements in cereal flours and their gluten-free alternatives
Venclová, Veronika ; Hraníček, Jakub (advisor) ; Nováková, Eliška (referee)
This study deals with the determination of calcium, magnesium, phosphorus, potassium, sodium, iron, zinc, copper, manganese and molybdenum in cereal gluten flours and its gluten-free alternatives. The flour samples were digested using a microwave device and the elements in solution were subsequently determined using an inductively coupled plasma mass spectrometer. Optimization of the digestion of the selected flours was performer prior to the actual determination of the elements. The aim of the work was to determine the above listed elements in the flour samples and to establish a basic overview of the elemental composition of the different flours. This overview and comparison of the different flours is intended to help the people with celiac disease to choose gluten-free alternatives to wheat flour. Keywords Inductively coupled plasma mass spectrometry, microwave digestion, calcium, magnesium, phosphorus, potassium, sodium, iron, zinc, copper, manganese, molybdenum, wheat flour, gluten-free flours, celiac disease
Significance of the Forum '88. Possibilities of Art in Space
Nováková, Eliška ; Klimešová, Marie (advisor) ; Prahl, Roman (referee)
The bachelor thesis deals with the unofficial exhibition Forum '88 with the subtitle Possibilities of Art in Space, which took place in the autumn of 1988 in hall 11 of former slaughterhouses and greengrocers in the area of the Prague Market. Thirty-four Czech and Slovak artists of the middle and older generations presented their installations, objects and environmental art, many of which were created specifically for this space and for this particular event. It summarizes the findings from the beginning of thinking about the exhibition, its organization, preparation, creation and course. Also of interest is the contemporary reflection, which was very lively on the art scene after its opening and provoked various discussions. A significant part is devoted to the generational tension of the time, which escalated in the second half of the 1980s and escalated into a generational conflict, which had been unnaturally suppressed in the previous decade. Following this, the formation of artistic generational groups is also interesting. These facts will explain the absence of the distinctive youngest generation of Tvrdohlaví (Hardheads) from the above- mentioned exhibition. The thesis highlights the significant role Forum '88 exhibition played on the art scene in the second half of the eighties of the 20th...
The effect of selected compounds on determination of antimony by atomic fluorescence spectrometry with UV-photochemical generation of volatile compounds
Jelínková, Klára ; Červený, Václav (advisor) ; Nováková, Eliška (referee)
5 Abstract This bachelor thesis is focused on the investigation of the influence of selected chemical individuals on the determination of antimony by UV-photochemical generation of volatile compounds with atomic fluorescence spectrometry detection (UV-PVG-AFS). Antimony, as a toxic semimetal occurring mainly in the trivalent and pentavalent oxidation state, plays an important role in many industries. Its determination is of importance not only from the point of view of analytical chemistry but also for monitoring of its environmental effects and for human health. For the interference studies with Sb5+ , the inorganic ions Br− , Cr2O7 2− , I− , CO3 2− , K+ , Cr3+ , Cd2+ , Co2+ , Cu2+ , Ni2+ , Na+ , Zn2+ , the organic solvents acetonitrile, ethanol and methanol, as well as the extraction reagents L-cysteine and 2-mercaptoethanol were chosen. Br− , Cr2O7 2− , I− , CO3 2− , K+ , Cr3+ , Cd2+ , Na+ and Zn2+ were chosen as possible interferents in the determination of Sb3+ . Solutions of the interferents were prepared in a medium of acetic acid (35%v/v) and 50 g l−1 Sb3+ or Sb5+ . The detection limit of the determination of Sb3+ in the flow injection mode analysis was 3.7 g l−1 for peak area and 1.9 g l−1 for peak height evaluation. For Sb5+ determination, the detection limit was 3.6 g l−1 for peak area and...
Compatibility of determination of antimony by UV-photochemical generation of volatile compounds and atomic fluorescence spectrometry with potential matrix components
Klečková, Adéla ; Červený, Václav (advisor) ; Nováková, Eliška (referee)
The root of this bachelor work is UV-photochemical generation (UV-PVG) of volatile substances of antimony. Problematics, with which we deal, are potential interferences, which can affect measurement. As model interferents when considering future speciation analysis of antimony using HPLC-UV-PVG-AFS were chosen acetonitrile, methanol, ethanol, L-cysteine and 2-mercaptoethanol. Detection was progressed using atomic fluorescence spectrometry (AFS). L-cysteine muffled the response. Methanol and ethanol were behaving alike. They were increasing and lowering the peaks in waves, when only at the highest concentration they completely disappeared. Acetonitrile was proved to be the most interesting one thanks to its specifical behaviour, which started to show off in higher concentration. 2-mercaptoethanol had in smaller amount similar interference properties as acetonitrile.
Reduction of polyatomic interferences in As and Se determination by ICP-MS
Vajnahij, Volodymyr ; Nováková, Eliška (advisor) ; Hraníček, Jakub (referee)
This bachelor thesis was focused on the eliminationof polyatomic interferences in the determination of As and Se using inductively coupled plasma mass spectrometry. For this purpose, the collision-reaction cell technique was employed. The collision-reaction cell was filled with either collision gas or collision-reaction gas, namely pure He and H2, at different flow rates.In the case of the determinationof arsenic,which is monoisotopic and therefore no isotope other than 75 As can be selected, one of the main polyatomic interferences is 40 Ar35 Cl+ , which has the same mass-to-charge ratio m/z = 75 as 75 As. In the case of selenium determination, there are isobaric interferences due to 40 Ar38 Ar+ , 40 Ar40 Ar+ and 38 Ar40 Ca+ affecting the measurement of 78 Se and 80 Se. When 78 Se was determined in the He mode with 5 ml ∙ min-1 , a 300-fold decrease in BEC was observed. At the same time, this collision gas flow rate is higher than the routinely used one and thus able to remove more polyatomic interferences caused by 40 Ar38 Ar+ and 38 Ar40 Ca+ , respectively.Aslight improvement in some parameters was also achieved by using the H2 mode, which is more effective in reducing polyatomic interferences in the determination of Se than the He mode. With the removal of argide interference, H2 reaction...
Determination of elements in human hair
Gazda, Vojtěch ; Nováková, Eliška (advisor) ; Červený, Václav (referee)
The bachelor thesis is focused on the determination of selected elements in human hair. For the determination of 13 samples, a procedure for their digestion with concentrated HNO3 and elemental analysis using inductively coupled plasma mass spectrometry ICP-MS was proposed. The results were compared with other sources, if the cited works reported the geographical origin of the sample, the differences in our population are compared with the population in another country. The concentrations of heavy metals that were determined were not particularly different from the others, with the exception of Pb, here it was found that in the area where the samples were taken the concentration of Pb in hair is low and this finding shows that the people from whom the samples come are not exposed to Pb from the environment and work environment and from food and water. Subsequently, the samples were found to contain more Mg, Sr, Ni, Ba and Au compared to others reported in the literature. The next objective was to determine if the concentrations differed between the sexes. Men were found to have higher concentrations of K than women, while women's hair was found to contain almost 12 times more Ca and Mg than men's hair. Therefore, in order to prove whether there was a statistical difference between the...
Comparison of detection cells for chemiluminescent determination of cobalt ions
Dospělová, Veronika ; Hraníček, Jakub (advisor) ; Nováková, Eliška (referee)
In this thesis, a method for the determination of cobalt ions by sequential injection analysis was developed and optimized. The chemiluminescent reaction of luminol was used for the determination of cobalt ions, where its oxidation by hydrogen peroxide is catalysed by cobalt ions in a basic medium. The reaction is accompanied by the emission of radiation in the form of chemiluminescence, which is detected at a peak wavelength of 425 nm. The determination was carried out in several experimental setups with different types of detection cells. For each setup, the measurement conditions were optimized to achieve the highest and at the same time stable signal of the chemiluminescent radiation intensity. Subsequently, under the optimized conditions, the individual calibration dependencies were measured, and the basic measurement characteristics were determined. Based on these characteristics, the most suitable layout and type of detection cell were selected for which interference studies of selected major cations were measured. The developed method was applied to the determination of vitamin B12 samples. The vitamin molecule contains just one cobalt atom, which was released by different types of decomposition prior to determination. Keywords Sequential injection analysis Chemiluminescence Luminol Cobalt...

National Repository of Grey Literature : 85 records found   1 - 10nextend  jump to record:
Interested in being notified about new results for this query?
Subscribe to the RSS feed.