National Repository of Grey Literature 71 records found  previous11 - 20nextend  jump to record: Search took 0.00 seconds. 
Microfluidic models of cell membranes
Haluzová, Kateřina ; Dzik, Petr (referee) ; Pekař, Miloslav (advisor)
This work deals with artificial cellular membrane models, their various types, production and usage. It also summarises basic matherials for production of microfluidic chips. Experimental part is focused on optimalization of production of polydimethylsiloxane chip suitable for free-standing lipid bilayers. A preparation workflow was developed which includes casting on a silicon wafer, removing bubbles from the PDMS, curing it at 80 °C for 1 h, plasma bonding, annealing at 150 °C for 30 min and storage. Using fluorescence microscopy, the prepared chips were found to be strong and sealed.
Titanium dioxide blocking layers fabricated by material printing
Lásko, Ondřej ; Pospíšil, Jan (referee) ; Dzik, Petr (advisor)
In this theses TiO2 blocking layers were fabricated using material inkjet printing and spincoating methods. These layers were then analyzed using cyclic voltammetry to find any defects and to determine the type of those defects. We found that layers of over 120 nm made using ITO glass and spincoating method had the best blocking capabilities. Blocking layers prepared using FTO glass were underperforming greatly throughout the whole experiment. We also achieved good results with material ink jet printing. The best results out of all printed samples were achieved with DPI of 635, although these layers also had problem with the electrolyte rising through microscopic pores in the layer thus changing the results.
Studies towards the Preparation of Organic-Inorganic Hybrid Silica Fibers via Electrospinning
Koukolová, Anna ; Dzik, Petr (referee) ; Hüsing, Nicola (advisor)
Polyorganosilany spadají do skupiny hybridních materiálů třídy II, které nabízejí nové možnosti materiálových funkcí a jejich vlastností. Ačkoliv byly v této kategorii již některé materiály zkoumány a stejně tak i jejich aplikace, nebyly doposud vlákna na základě polyorganosilanu v mikro a nano rozměru popsány což bylo motivací pro tuto práci. Předkládaná diplomová práce se zabývá podrobným zkoumáním poly(vinylmethyldimethoxysilanu) jako možného prekurzoru pro elektrostatické zvlákňování. Za účelem přípravy polymeru na bázi vinylmethylsilanu byla provedena radikálová polymerace a podmínky reakce byly modifikovány se záměrem změny molekulové hmotnosti získaného polymeru. Stupeň polymerace byl upravován na základě změny koncentrace iniciátoru a byl stanovován dynamickým rozptylem světla v roztoku polymeru a spektroskopickou metodou nukleární magnetické rezonance. Elektrostatické zvlákňování je velkou měrou spojeno s vlastnostmi roztoku a důraz byl proto kladen právě na zjištění těchto vlastností. Na základě experimentů bylo zjištěno, že syntetizovaný polymer je na přípravu vláken vhodný. Nicméně byly získány i fragmenty vláken a to s využitím polymeru v roztoku methanolu. Předpokladem zvlákňování je dostatek propojení mezi polymerními řetězci. Tento přístup byl studován se zapojením sol-gel postupu a bylo zjištěno, že fáze sol-gel procesu je velmi významná s ohledem na tvorbu vláken. Dalším využitým postupem pro získání vláken bylo začlenění dalšího polymeru do směsi jako nosiče a tímto postupem byla získána vlákna s různým průměrem.
Optimalization of gel electrolyte for printed UV sensor based on photoelectrochemical cell
Vrbková, Kateřina ; Gemeiner,, Pavol (referee) ; Dzik, Petr (advisor)
This paper deals with the construction of photoelectrochemical cell, used for detection of ultraviolet radiation as a UV sensor. Photoelectrochemical cell consists of three layers, layer of photoactive semiconductor titanium dioxide, carbon electrodes and poly(vinyl alcohol) polymer electrolyte. The sensor layer enables the detection of UV radiation with the subsequent generation of photocurrent. Material printing techniques, such as screenprinting, pad printing and inkjet printing were used to produce the cell. Gel electrolyte was characterized by optical microscopy and rheometry. Sensor functionality was verified by use of electroanalytical techniques.
Photocatalytic layers of tungsten trioxide fabricated by material printing
Saňák, Tomáš ; Krystyník,, Pavel (referee) ; Dzik, Petr (advisor)
This diploma thesis deals with milling of dispersed particles of WO3 using low-cost wet ball milling. Thin layers of WO3 were formed from them. These layers were characterized by profilometry, turbidity measurements, XRD and SEM. The photocatalytic activity was studied by the electrocatalytic properties of these layers. Profilometric measurements showed declining trends with milling time. XRD measurements confirmed the milling process and revealed a change in the crystalline phase during this process. Electrophotocatalytic measurements confirmed the photocatalytic activity of these layers and revealed its trends.
Lightfastness of digital color prints
Kulhánková, Michaela ; Jančovičová, Viera (referee) ; Dzik, Petr (advisor)
In this diploma thesis the current methods of color fastness evaluation of color digital prints were solved. The theoretical part provides basic information needed to understand the experiment. Samples of inkjet prints were subjected to accelerated and long-term lightfastness test. The long-term test took place in the spaces of the Faculty of Chemistry, Brno University of Technology, which fulfilled the condition of direct light in a closed room. For one year, samples were exposed and their reflection spectra were measured at monthly intervals. An accelerated lightfastness test was performed in a solar chamber with a xenon lamp. Only some samples were selected for this test because of the small space in the chambre and thw failure of the instrument. At regular intervals were measured again their reflection spectra from which the colorimetric values were calculated. After completion of the testing, the rate parameter was determined from the dependence of the loss of the normalized gamut volume on different doses of irradiation. In the case of long-term testing, it was based on data from the Hydrometeorological Institute, which gave values of direct outdoor solar radiation. In the accelerated test, the irradiation dose of the sample up to 800 nm was determined. Finally, the lightfastness of each sample was examined and compared with each other and the relevance of the accelerated test was assessed.
Printed photoelectrochemical sensor for blue light
Papák, Jiří ; Hatala,, Michal (referee) ; Dzik, Petr (advisor)
This diploma thesis focuses on electrochemical sensors to detect radiation in the blue region of the visible spectrum. As a semiconducting material for the manufacture of the sensor, a suspension of tungsten trioxide was found. The individual elements of the sensor were applied by pad printing techniques or screen printing. Using linear voltammetry and chronoamperometry, the magnitude of the generated current was measured and radiometric calibration was performed. The properties of the layers were characterized by profilometry, optical and electron microscopy.
Study of plasma effects on quinine solutions
Procházková, Michaela ; Dzik, Petr (referee) ; Kozáková, Zdenka (advisor)
This diploma thesis focuses on quinine solutions and quality of these solutions after applying plasma discharge. These electric discharges can be used to destroy some substances from the water. The theoretical part is focused on description of electric discharges in liquids and on the properties of quinine. In the experimental part, the properties of quinine solutions containing different electrolytes were analysed by UV-VIS spectrophotometer and fluorescence spectroscopy. Two different types of configurations of plasma discharges in liquids were used. Solutions were compared on the base of different concentration of quinine, different electrolytes, different configurations of plasma discharges and pH values of the solutions. Furthermore, the experimental work focuses on quinine solutions with the sodium nitrate. The time instability of the solutions was analysed. Also, the influence of the solution age and different types of the plasma discharge on the excitation and emission spectra of quinine were investigated.
Fabrication and characterization of tungsten trioxide photoanodes
Hesková, Helena ; Králová,, Marcela (referee) ; Dzik, Petr (advisor)
This work deals with the optimization of the preparation process of WO3 photoanodes nad their characterization. For compositions were prepared, which were applied to a substrate via spin-coating process and subsequently annealed at 450 °C. The length of milling of precursor particles contained in the coating formulations determined properties of deposited layers. were examined for. The additivity of the individual compositions was also observed. The structure of the layers was observed by optical microscopy and scanning electron microscopy (SEM), their composition by the X-ray diffraction (XRD) and their thickness and surface roughness was defined by contact profilometry. Photoelectrochemical properties of the prepared layers were also investigated by linear voltametry and chronoamperometry.
Electroassisted photocatalysis
Filipská, Markéta ; Pekárková, Jana (referee) ; Dzik, Petr (advisor)
This thesis is focused on fotoelectrochemical cells, where as photocathode is used titanium dioxide coated on conductive FTO glass and as counter electrode is used gold electrode. Thesis is also focused on relationship between intensity of irradiation and Faradaic efficiency and also influence of the overvoltage to the rate of degradation od the model pollutant, in this case Acid Orange 7. Electrical properties were measured by recording values of photocurrent. The aim of this thesis was to study influence material composition of photoanode and connection with intensity of irradiation, rate of degradation proces of model pollutant and current.

National Repository of Grey Literature : 71 records found   previous11 - 20nextend  jump to record:
See also: similar author names
1 Dzik, P.
Interested in being notified about new results for this query?
Subscribe to the RSS feed.