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Physical-chemical property characterisation of thin reflective layers on polymer substrates
Stružínský, Ondřej ; Dzik, Petr (referee) ; Krčma, František (advisor)
This work deals generally with surface diagnostic and optical properties of thin layers which are created by plasma polymerization of hexamethyldisiloxane monomer. The influence of oxygen adittion on thin layers properties was studied, too. This polymer layers are commercially made to protect reflective layers in the headlights. Thin layers were made in deposition chamber AluMet 1800V at Zlin Precision Company. Teoretical part of this work deals with methods which are used for deposition of thin layers, mainly physical (PVD) and chemical (PECVD, CVD) depositions. The conditions which influenced plasma polymerization itself are discussed as well as, monomers which are used for plasma polymerization and stability of thin polymer layers. Also there are mentioned the most frequent plasma processes diagnostic methods applicable during the deposition (optical emission spectroscopy) and methods for thin layers diagnostic (wettability, UV-VIS and infrared spectroscopy). Spectrometer Jobin Yvon Triax 320 was used for emission spectra acquisition during the plasma deposition. There were analyzed only two spectra created at same conditions as power at 3 kW and monomer flow rate at 100 sccm; the first one was in pure monomer, the second was obtained with oxygen addition of 150 sccm into the monomer flow. There was not found any essential differences between these spectra in the range 300 nm to 800 nm. Besides the thin layers analyzes after their formation, the samples were exposed to common aging conditions with respect to their use. One third of the prepared samples was exposed by ultraviolet radiation for 48 hours (exposure power of 0.68 W.m-2 at 340 nm) and the other part of samples was inserted for four days into NaCl solution of 50 g.l-1. The surface properties of layers were studied by their contact angle with three liquids (water, diiodmethane, and glycerol) that allowed their surface energy calculation. Results of this measuring are as following: Oxygen addition decreased contact angle of water after exposure of UV radiation. If the highest flow rate of monomer was used and oxygen was added, NaCl degradation did not have any significant influence on contact angle to water. Optical properties of prepared thin films were characterized by UV-VIS spectroscopy. Optical properties were measured only for samples after deposition and samples that were exposed by ultraviolet radiation. Results showed that oxygen addition into the reacting mixture increased the light absorption in UV-VIS (300-800 nm). The absorption was significantly increased after exposure of ultraviolet radiation. With respect to the application of these thin layers is necessary to say that this influence is undesirable. On the other hand, absorption of thin layers deposited at 2 kW, without oxygen addition and flow rate of monomer at 125 sccm a 150 sccm was decreased. Results of this work can be useful for investigation and study of deposited thin layers. The most useful can be with another work which deals with plasma diagnostics during the deposition even more closely. Then it will be possible to adjust and predict properties of deposited layers.
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Comparison of pulse oximeters
Karafiátová, Pavla ; Harabiš, Vratislav (referee) ; Kolář, Radim (advisor)
This work deals with the pulse oximetres. The thesis describes the methods of measuring oxygen in blood and basic parts of pulse oximeter. It follows introduction to light absorbancy based on Beer’s law and its usage in pulse oximetry. The thesis also describes different probes and its properties and also algorithms for signal processing. Measuring and evauating on tester SECULIFE and volunteers is part of this thesis.
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Application of spectrophotometers
Klimešová, Marie ; Čmiel, Vratislav (referee) ; Kolář, Radim (advisor)
The work deals with the important analytical method - spectrometry. It is based on measurement of absorption of radiation in a wavelength range. On this principle can determine the absorbance and transmittance of the measured samples. The thesis also describes events related to the excitation of molecules. These include absorption, vibrational relaxation, internal conversion, inter-system crossing, fluorescence, phosphorescence and delayed fluorescence. The practical part includes three experimental measurements. The first measurement is the concentrations of potassium permanganate solution. In a second experiment, verifying the validity of Lambert-Beer law. In the third experiment, the fluorescence measurement of fluorescein and detection of fluorophore concentration dependence on fluorescence intensity. Measurement is performed in an environment SpectraSuite with the use of school spectrometers USB2000 + and USB650 Red Tide.
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Pulse Oxymeter in LabVIEW
Fojtík, Tomáš ; Rychtárik, Milan (referee) ; Čmiel, Vratislav (advisor)
Topic of bachelor thesis is the design and implementation of a system for measuring blood oxygen saturation and heart rate measurements. Is used for scanning optical probe is made by hand and amplifier made on a universal printed circuit board . The measurements used measuring NI USB card 6221. Custom design program is being implemented in the programming environment of LabVIEW Version 8.2
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Optical determination of the state of charge of vanadium flow battery cells
Šacl, Vojtěch ; Chladil, Ladislav (referee) ; Novák, Vítězslav (advisor)
The investigated subject for this diploma thesis is getting know properties of the vanadium redox battery (VRB), especially electrolyte. Specialization is applied to the state of charge of this cell and its measurements using the optical methods. Upon different state of charge is changed oxidation number of vanadium and resultant color of the electrolyte. Using spectrofotometry method that characteristic property is undergone measurement. The basic thing was learning to handle a measurement system. The first practical measurement was executed on example foils. Upon measurement of vanadium cell there was obtained the values of absorbation, which they were used for determination of state of charge.
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Spectrophotometry of ROS species with focus on hydrogen peroxide
Zhorný, Lukáš ; Hořavová, Lenka (referee) ; Provazník, Ivo (advisor)
The main theme of this work is spectrophotometry. The first chapter describes the theoretical problems of the topic, relevant units and formulas for calculating the absorbance of the solutions of given concentrations. Further disclosed herein is a spectrophotometer, its individual parts, and the principle on which the unit is based. The last chapter of the theoretical introduction to this work is focused on the production of ROS in living organisms and especially in plants, and then there are some spectrophotometric methods for determining the concentration of ROS. The practical part describes the method using TiCl4 and method using KI. Both methods were used to determine the hydrogen peroxide concentration and subsequent measurement of absorbance of solutions of standard hydrogen peroxide added interfering substances. Then, the statistical analysis of the measured data and the assessment of the impact of these interferents to measure absorbance. The first of these methods proved to be suitable for a given measurement.
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Rychlost růstu dominantních rybničních sinic
SYSLOVÁ, Petra
The bachelor thesis deals with the determination of cyanobacterial growth from ponds. The results are used to determine the growth potential in connection with eutrophication, i.e. increasing the concentrations of nutrients in water. Cultured strains of Cyanobium gracile A1 and Synechocystis sp. PCC7509 were used in the experiment. To determine their growth, static cultivation was used in culture plates with different well volumes of Thermo Scientific NunclonTM Delta Surface 96 Well and Cellstar 48 Well Cell Culture Plate, which were evaluated as the most suitable from the first part of the experiment. Cyanobacteria were cultured in concentrations from 0.06 to 30 mg P mg/l in Z medium. To measure the growth, a spectrophotometer measuring fluorescence and absorbance was set up at OD750 nm wavelength. At this wavelength cyanobacteria have negligible absorption and therefore turbidity was used to measure biomass. Growth curves were created from individual measurements and are shown in the form of graphs. The results show that the highest concentration used, 30 mg P/l, caused growth inhibition. Cyanobacteria in an environment with a concentration of 0.06 mg P/l showed acceptable growth values. However, at a concentration of 0.46 mg P/l, which is twice the current concentration of P in ponds, cyanobacteria showed much higher growth values. And even at a concentration of 15 mg P/l, cyanobacteria reached the highest growth values. It can therefore be expected that if the concentration of P in the ponds rises to the values of 15 mg P/l, a rapid development of cyanobacteria will take place in the pond. At the end of the experiment, I was supposed to measure the growth rate in the lighting gradient, but due to the announcement of the closure of universities due to the COVID - 19 virus, I was not able to fulfil that.
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Dynamics of organic carbon in the ponds ecosystems
TOMKOVÁ, Iva
Ponds ecosystems are the most common type of lentic waterbodies in Czech Republic. In the last century, the quality of ponds water has been greatly influenced by intensive management in the catchment and ponds alone. As a result of the increasing concentration of nutrients, ponds lead to eutrophication. This is expressed as extensive primary production of phytoplankton and algal blooms. Decomposition of the accumulated organic matter affects the oxygen regime, pH and distribution of nutrients in the pond. Organic matter plays a key role in physical, chemical and biological processes in the ecosystem. The aim of the work was to describe the dynamics of organic carbon in the eutrophic ponds ecosystem with emphasis on its dissolved part (DOC). This study included evaluation of DOC concentration from 6 pond systems in the Třeboň region from 2010 to 2011 and a comparison with DOC concentrations from 2020. The relationship of DOC concentration to other chemical parameters of water was evaluated. It found that DOC concentration had no significant correlation with other parameters. The concentration of nutrients TN and TP had decreased over the last 10 years, while DOC concentration had increased. More detailed data from 5 ponds from 2008 to 2011 were evaluated in the same way. Optical methods such as absorbance and fluorescence were used to describe DOC dynamics. These methods were used to monitor 10 ponds from Třeboň and České Budějovice regions in 2017?2018. Data were compared between these regions because they differed in conductivity, but it had no differences in DOC concentration and other chemical parameters. The average value of DOC concentration was 14,8 mg l-1. The absorption characteristics of DOM such as spectral slope S275-295 and slope ratio SR suggested an autochthonous source of DOM. Specific absorbance values at 254 nm SUVA254 ranged from 1,4?3,0 l mgC-1 m-1 and indicates autochthonous substances with lower molecular weight and lower content of aromatics. SUVA254 values were higher in the Třeboň region, which indicates that there was a more allochthonous DOM with higher molecular weight and more aromatics in DOM in contrast to the České Budějovice region. Evaluation of seasonal changes in the composition of DOM using optical methods revealed that in the summer there were more autochthonous substances with lower molecular weight and lower aromatics DOM. SR values were negatively correlated to molecular weight and were higher in summer. FI and BIX values indicating autochthonous and microbial source DOM increased in summer. Optical methods were used for the first time to monitor the dynamics of organic matter in ponds.
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Estimating infiltration of quasi-ultrafine aerosol by the absorbance method: Air quality in schools
Stehlíková, Pavla ; Braniš, Martin (advisor) ; Hovorka, Jan (referee)
Estimating infiltration of quasi-ultrafine black carbon particles by an absorbance method: air quality in Pavla Stehlíková Abstract This diploma thesis focused on the estimating quasi-ultrafine particles amount in school gyms continue previous study researched air quality in schools. The size-segregated mass concentration of particulate matter was measured in three elementary school gyms in central part of Prague, on periphery of Prague and in a small settlement Černošice during twenty campaigns, from 2005 to 2009. The mass concentration of particulate matter were measured by 5-staged Sioutas impactor. For this thesis we have selected samples on filters with particle size <0,25µm. To evaluate carbonaceous particles amount we used reflectance. Reflectance was transformed into an absorption coefficient (m- 1 .10-5 ). The average levels of absorptions coeficients were higher outdoors (14,66 ± 8,93 m- 1 .10-5 ) than indoors (13,64 ± 8,08 m-1 .10-5 ). The correlations between absorption coeffitients outdoors and indoors were significant for all schools (Spearman's correlation coefficient at intervals 0,834-0,957, regression slope 0,759-1,007), suggesting a high outdoor-to-indoor penetration rate. The weak correlation between absorption coefficients and number of exercising pupils (correlation coefficient 0,059)...
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