National Repository of Grey Literature 26,339 records found  beginprevious26330 - 26339  jump to record: Search took 0.66 seconds. 

Biodiversity of standing floodplain waters and processes of its formation and preservation
Pithart, David
Water chemistry and planktic communities in the naturally eutrophic alluvial waters in the Lužnice floodplain have been studied. The floofplain waters are naturally eutrophic, with strong vertical physico-chemical gradients and oxygen depletions at the botom. Small pools and backwaters of this type have unique phytoplankton structure. Prevailing dominance of flegellates, namely Cryptophyceae, and low proportion of green chlorococcal algae and Diatoms, and almost absence of Cyanophyceae are very unusual for such eutrophic waters. Flagellate dominate thanks their ability to keep the vertical position in a permanently light limited conditions (resulted from poorly mixed water columns and intensive shading of water surface by vegetation). Floodplain geodiversity play crucial role, determining morphology and location of pools and backwaters, their exposition to flooding and inflows of underground water. Terrestial vegetation effects light exposition, leaf litter.

Determination of the lipid profile in biological material by the method HPLC-ELSD
Vaindlová, Petra ; Pacáková, Věra (advisor) ; Feltl, Ladislav (referee)
A method of high-performance liquid chromatography with evaporative light-scattering detector (HPLC-ELSD) has been optimalized for the determination of neutral and polar lipids. Column filled by silica with chemically bonded diol has been used as stationary phase. As mobile phase, a ternary gradient composed from A: hexan-tetrahydrofuran 99:1 (v/v), B: isopropanol-chloroform-acetic acid 82:20:0,01 (v/v/v), C: isopropanol-water-triethylamine 47:47:6 (v/v/v) was used. Calibration curves have been measured in the range 2-200 μg of the injected amount; for individual lipid classes, optimal interlay of experimental data corresponded to the following functions: triacylglycerols - third order polynom (R=0,998), cholesterol esters - exponential dependence (R=0,998), free cholesterol - third order polynom (R=0.9998), ceramid - exponential dependence (R=0,992), cardiolipin - square dependence (R=0,998), phosphatidylethanolamine - exponential dependence (R=0,999), phosphatidylcholine - square dependence (R=0,997), phosphatidylserine - third order polynom (R=0,9985), sphingomyelin - third order polynom (R=0,9997), lysophosphatidylcholine - exponential dependence (R=0,9986). Analysis of the synthetic control sample showed recovery in the range of 82-95%. On the basis od these measurements, concentration of...

Stability of Vitamins in Intralipid Emulsions and Degradation of Ascorbic Acid
Khýnová, Lucie ; Nováková, Lucie (referee) ; Solich, Petr (advisor)
Malnutrition is a state in which a deficiency of energy, protein and other nutrients causes measurable adverse effects on tissue, body form, composition, function or clinical outcome1 . Parenteral nutrition (PN) is an alternative method of providing nutritional support for patients via the intravenous route3 . PN admixtures consist of fats, carbohydrates, proteins, vitamins, trace elements, electrolytes and fluids. Vitamins are believed to be among the least stable ingredients in PN mixtures and should be added immediately before commencing infusion. The purpose of this thesis was to obtain more punctual information on stability of the vitamins in Intralipid® emulsion depending on different storage conditions and different time. Water-soluble vitamins and fat-soluble vitamins were investigated in the mixture of Intralipid® emulsion (Fresenius Kabi) with Solvitio® N (water-soluble vitamins) and Vitlipid® N (fat-soluble vitamins) Adult Injections. There were prepared six 50ml Luer- Lock Syringes in total. Each of them was filled with 47 ml of the Intralipid® mixture and closed by Multi-Ad Luer-Lock Syringe cap. Assessing the chemical and physical stability was carried out after: zero time, 7, 14 and 29 days in a refrigerator followed by 24 and 48 hours storage at ambient temperature and day-light...

Study of Factors Influencing the Development of "Water Bloom" in the Water Reservoir Seč
Forczek, Sándor ; Holík, Josef ; Rederer, L. ; Koza, V.
In this work, we monitored several parameters that influence the development of algal bloom on the\nwater reservoir Sec. Primarily climatic conditions belong to the monitored parameters that influence\nthe population dynamics of algae (air temperature and rainfall, incident light), temperature\nstratification of water, concentration of oxygen, concentrations of total phosphorus, phosphate,\nvarious forms of nitrogen and organic substances, turbidity and also diversity and frequency of\nphytoplankton and zooplankton species. Between 2012 and 2014 have not occurred massive algal\nblooms in the summer months, however the measured physical, chemical and biological data, can be\nused to assess the development of algal population. The population dynamic factors influencing algal\ngrowth must be understand to be able to predict formation and to attempt suppression of algal\nblooms.

Optimization of thin films of metal oxide materials
Vítek, Jiří ; Šimonová, Lucie (referee) ; Šubarda, Jiří (advisor)
This thesis is focused on the description of the method of reactive sputtering of thin films. Currently, there are many ways how to create thin films and there are many applications of thin films in various industrial sectors. In this paper at the first are listed the issue of thin films, followed by an overview of the deposition techniques and of the chemical analysis of deposited thin films. It also describes the four-point measurement method of sheet resistance, mechanical test of adhesion and optical properties. At the end of the theoretical part are described the material composition of the deposited films. The goal of the practical part is to optimize the deposition process of the mixed layer of indium tin oxide (In2O3: SnO2) and contribute to the overall understanding of the influence of annealing on the layer. There were created six series of samples with that applied layers. First, the work focused on examining of the influence of annealing on the throughput in the whole measuring range, and then comparing the series due to the transmittance in the visible light spectrum. Furthermore were compared the value of sheet resistance of unannealed and subsequently annealed samples.

Nanotechnology in the intensive care: Intravascular biocompatibility of carbon nanomaterials-effect of carbon nanotubes on blood platelets
Šemberová, Jana ; Straňák, Zbyněk (advisor) ; Dyr, Jan (referee) ; Hubálek Kalbáčová, Marie (referee)
Nanotechnology in the intensive care: Intravascular biocompatibility of carbon nanomaterials - effect of carbon nanotubes on blood platelets. EFFECT OF CARBON NANOTUBES ON BLOOD PLATELETS Carbon nanotubes (CNTs) are among the principal materials currently used in biomedical nanotechnologies. CNTs possess superior mechanical and chemical characteristics including enormous tensile strength, elasticity and conductivity. As a result they are very popular and attractive for use in various biomedical applications. Many of these applications may lead ultimately to contact of carbon nanomaterials and blood. Furthermore, CNTs may also be present intravascularly as a result of environmental or occupational exposure. Therefore, the investigation of the intravascular biocompatibility of CNTs is a critical safety issue. We studied the effects of structurally different purified CNT materials from different manufacturers on human platelets and compared their effects to amorphous carbon black nanoparticles (ACB), fullerene C60, fullerenol C60(OH)24 and NIST standard polystyrene nanobeads (PNBs). Using light transmission aggregometry of human platelet rich plasma, we found that various CNTs induce PLT aggregation and this occurs in a concentration dependent manner. In contrast to CNTs, ball-like shaped fullerene...

Noční motýli jako indikátory kvality zemědělské krajiny a úrovně biodiverzity při různém režimu hospodaření
Šafář, Jaroslav
This work deals with a research of moth species diversity in selected vineyards of southern Moravia that are often located in the vicinity of specially protected areas and often directly linked to them. When using sound agricultural practices, vineyards can provide a kind of stepping stones for a large number of endangered and rare species in their path to find suitable habitats to survive, or the environment of vineyards may be partially or even permanently colonized. During 2010 and 2011 in six vineyards and two forest-steppe areas, 8,061 specimens belonging to 309 species (12 families) of moths were collected using portable light traps. Based on some ecological indices, DCA, RDA, CCA analysis, Spearman's correlation coefficient, etc., the relationship between moths and the influence of farming in the vineyards (conventional, integrated, organic) in terms of agro-technical practices and the influence of natural and semi-natural habitats in intermediate vineyards surrounding on the moth communities of the monitored localities was evaluated. The results show that species diversity increases with vineyards having cover crop in the absence of application of chemical insecticides and especially with maintaining selffloristic succession in vineyard alleyways with cover crop. In RDA and CCA analysis, certain species responded significantly to the influence of studied factors of vineyard farm management, and for some species there was a significant effect of habitats in the immediate vicinity of monitored areas, but this effect did not reach statistical significance such as vineyard management factors examined.

Spatial distribution of water bugs (Heteroptera: Nepomorpha) in fishponds: estimation and comparison based on results reached by classic method (netting) and method of light traps.
ČELOUDOVÁ, Monika
The aim of this methodically oriented thesis was to find spatial distribution of water bugs in fishpond by parallelly used two different sampling methods - classic method (netting) and light traps as well as to find, if sampling method can influence a result of ecological study by substantial way. Study was realized in the one locality - fishpond Polepšil (region: Vysočina: Moravskobudějovicko) in years 2007 and 2008. Spaces {--} transects for sampling were difined. Efficiency of water bug sampling by nett is conspicuously less than sampling by light traps. More species and individuals (in total sum of samples and in samples from individual transects too) were sampled by light traps under comparable conditions. Chemical yelow-green light of light traps was more attractive for water bugs than the pink one. Spatial preferences of some corixid species and their developmental stages were noted by application of light trap method of sampling. Light trap method of samplings brings more complete and valuable data for ecological studies of water bug communities.

Performance of Continuous Micro Photo Reactor – Comparison with Batch Process
Drhová, Magdalena ; Hejda, S. ; Křišťál, Jiří ; Klusoň, Petr
Utilization of the flow chemistry as well as microreactors belongs to the latest trends in chemical engineering. Continuous microreactors of various kinds can be found in the literature, for example the micromixers, micro packed beds, or micro photo reactors. In order to evaluate the benefits of microtechnology application for the given process, the performance of a particular microreactor needs to be compared with the conventional setup. This contribution presents the performance of a continuous micro photo reactor in comparison with a batch process. Two model reactions were selected: the catalyzed photooxidation of 4-chlorophenol (4-CP) and the singlet oxygen chemical quencher 9,10-dimethylanthracene (DMA) in dimethylformamide. The tests were carried out using advanced opto-chemical apparatus with a well-defined light filter corresponding to the absorption bands of the used photo catalysts.
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Chemical Wet Synthesis and Characterization of Copper-Silver Nanoparticles
Zobač, O. ; Sopoušek, J. ; Vykoukal, V. ; Buršík, Jiří ; Roupcová, Pavla
AgCu nanoparticles (NPs) of near-eutectic composition were prepared by various route of wet synthesis. Nanoparticles suspended in nonpolar solvents were synthesized by solvothermal synthesis from metalloorganic precursors. AgCu colloids in aqueous solution were obtained by the hydride reduction of Ag and Cu nitrates under action of different stabilization agents. Chemical characterizations of as-synthesized AgCu NPs were done using inductively-coupled plasma-optical emission spectrometry (ICP-OES). The optical properties of nanoparticles were monitored using UV-Vis spectrophotometer. The size of colloid nanoparticles were measured by both dynamic light scattering (DLS) and small angle X-ray scattering (SAXS) method in some extra cases.