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Measuring RLC on the components of electrical circuits
Pokorný, Marek ; Vítek, Ondřej (referee) ; Veselka, František (advisor)
Aim those work is inform numerator about possibilities and features gauging apparatus 7600 Precision LCR undergrounds and further then about metering paramers R,L,C on components electric standing ,especially then on sliding contacts,with which this work acquaint and how are their characteristics important for correct functionality electrical machine whereof are site rated power.Warp work largely start from manual to apparatus 7600 Precision LCR undergrounds and further then out publication sliding contact in electrical machine - doc. Veselka, doc. Chmelik.
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Fluorescence study of hydrophilic domains of associating colloids
Londinová, Monika ; Knotková,, Kateřina (referee) ; Pekař, Miloslav (advisor)
The properties of the hyaluronan were investigated by using different fluorescence probes, because hyaluronan is a hopeful carrier of an active matter in medicine and cosmetics. Selected fluorescence probes were: cationic acridine orange, Nile Blue A, methylene blue, amphiphilic 4-Di-2-ASP and anionic fluorescein. Except from fluorescence and absorption spectra of the probes were observed electrostatic and hydrophobic interactions as well. The probes in solvents with different polarity (MeOH, EtOH, DMSO) showed the bathochromic shift in the emission maximum and quenching of the fluorescence with the increasing polarity of the solvents. The influence of the ionic strength on fluorescence properties of the probe acridine orange and 4-Di-2-ASP was investigated in aqueous solutions of chlorides. The formation of acridine orange dimer is inhibited with increasing ionic strength. CaCl2 increased the ionic strength the most, then prevented repulsion of carboxylate groups, so it means the expansion of hyaluronan cluster into the solution. However, the emission of the probe 4-Di-2-ASP was quenched with the addition of CaCl2 the most. The first additions of COO– groups cause the formation of dimers of AO shown as decreasing in extinction coefficient and fluorescence intensity. Next addition of the hyaluronan caused a depolymerization of formed dimers and the increase of the emission intensity. The repolymerization caused the decrease and then again the increase. In case of 4-Di-2-ASP was the pattern of the fluorescence (the intensity and the position of the emission) firstly the same, but at the concentration of 1 g dm-3 the emission intensity increased. The probes MB and F were used for spectroscopic studies of the interaction between methylene blue-fluorescein complex and anionic and cationic surfactants. The absorbance of separate MB and F changed only with the addition of surfactants with the opposite electric charge. Absorbance of the mixture MB-F changed with the addition of the CTAC surfactant, while the addition of SDS into the mixture caused only the change of MB absorption spectra.
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New aspects of MIG/MAG welding
Minich, Marek ; Hála, Michal (referee) ; Kubíček, Jaroslav (advisor)
The thesis discusses the welding method MIG/MAG and the methods based on it. These methods are CMT and CMT Advanced which are currently still being improved. In the work are described their principles, benefits, uses and devices that allow welding by those methods. The thesis deals with the issue of a joint of steel and aluminum which is no longer an obstacle in welding due to CMT. This is a huge benefit especially for the automotive and aerospace industries, for which the solid and fast connection between steel and aluminum is a very desired matter. Further, there are welds of thin sheets described and discussed and also a list of wide range of practical uses for these welding methods.
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Aggregation Behaviour of Polysaccharides in Aqueous Solutions
Mravec, Filip ; Valko, Marián (referee) ; Hrdlovič, Pavol (referee) ; Valko, Marián (referee) ; Pekař, Miloslav (advisor)
Tato práce je zaměřena na agregační chování nativního a hydrofobně modifikovaného hyaluronanu, v různých molekulových hmotnostech a stupních substituce, ve vodném prostředí. Pro studium bylo vybráno šest fluorescenčních sond s různými vlastnostmi (Pyren; Nilská červeň; Perylen; Akridinová oranž; 6-(p-Toluidino)-2-nafthalenesulfonová kyselina; PRODAN). a výsledky získané pomocí těchto sond byly porovnány s jednoduchým anionaktivním tenzidem (Dodecylsíran sodný). U všech použité sond byly testovány jejich spektrální vlastnosti v závislosti na polaritě okolí a/nebo na koncentraci. Pro stanovení vlastností nepolárního jádra hyaluronového agregátu byly vybrány dvě sondy (Pyren, Nilská červeň). U domén byly sledovány polarita a viskozita vnitřního prostředí a jejich závislost na iontové síle a teplotě. Pro modifikované hyaluronany bylo stanoveno, že jejich kritická agregační koncentrace klesá s rostoucí molekulovou hmotností a stupněm substituce. Pro vlastní doménu platí, že její kompaktnost roste s rostoucí iontovou silou, ale klesá s rostoucí teplotou.
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New aspects of MIG/MAG welding
Minich, Marek ; Hála, Michal (referee) ; Kubíček, Jaroslav (advisor)
The thesis discusses the welding method MIG/MAG and the methods based on it. These methods are CMT and CMT Advanced which are currently still being improved. In the work are described their principles, benefits, uses and devices that allow welding by those methods. The thesis deals with the issue of a joint of steel and aluminum which is no longer an obstacle in welding due to CMT. This is a huge benefit especially for the automotive and aerospace industries, for which the solid and fast connection between steel and aluminum is a very desired matter. Further, there are welds of thin sheets described and discussed and also a list of wide range of practical uses for these welding methods.
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Aggregation Behaviour of Polysaccharides in Aqueous Solutions
Mravec, Filip ; Valko, Marián (referee) ; Hrdlovič, Pavol (referee) ; Valko, Marián (referee) ; Pekař, Miloslav (advisor)
Tato práce je zaměřena na agregační chování nativního a hydrofobně modifikovaného hyaluronanu, v různých molekulových hmotnostech a stupních substituce, ve vodném prostředí. Pro studium bylo vybráno šest fluorescenčních sond s různými vlastnostmi (Pyren; Nilská červeň; Perylen; Akridinová oranž; 6-(p-Toluidino)-2-nafthalenesulfonová kyselina; PRODAN). a výsledky získané pomocí těchto sond byly porovnány s jednoduchým anionaktivním tenzidem (Dodecylsíran sodný). U všech použité sond byly testovány jejich spektrální vlastnosti v závislosti na polaritě okolí a/nebo na koncentraci. Pro stanovení vlastností nepolárního jádra hyaluronového agregátu byly vybrány dvě sondy (Pyren, Nilská červeň). U domén byly sledovány polarita a viskozita vnitřního prostředí a jejich závislost na iontové síle a teplotě. Pro modifikované hyaluronany bylo stanoveno, že jejich kritická agregační koncentrace klesá s rostoucí molekulovou hmotností a stupněm substituce. Pro vlastní doménu platí, že její kompaktnost roste s rostoucí iontovou silou, ale klesá s rostoucí teplotou.
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Measuring RLC on the components of electrical circuits
Pokorný, Marek ; Vítek, Ondřej (referee) ; Veselka, František (advisor)
Aim those work is inform numerator about possibilities and features gauging apparatus 7600 Precision LCR undergrounds and further then about metering paramers R,L,C on components electric standing ,especially then on sliding contacts,with which this work acquaint and how are their characteristics important for correct functionality electrical machine whereof are site rated power.Warp work largely start from manual to apparatus 7600 Precision LCR undergrounds and further then out publication sliding contact in electrical machine - doc. Veselka, doc. Chmelik.
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|
Fluorescence study of hydrophilic domains of associating colloids
Londinová, Monika ; Knotková,, Kateřina (referee) ; Pekař, Miloslav (advisor)
The properties of the hyaluronan were investigated by using different fluorescence probes, because hyaluronan is a hopeful carrier of an active matter in medicine and cosmetics. Selected fluorescence probes were: cationic acridine orange, Nile Blue A, methylene blue, amphiphilic 4-Di-2-ASP and anionic fluorescein. Except from fluorescence and absorption spectra of the probes were observed electrostatic and hydrophobic interactions as well. The probes in solvents with different polarity (MeOH, EtOH, DMSO) showed the bathochromic shift in the emission maximum and quenching of the fluorescence with the increasing polarity of the solvents. The influence of the ionic strength on fluorescence properties of the probe acridine orange and 4-Di-2-ASP was investigated in aqueous solutions of chlorides. The formation of acridine orange dimer is inhibited with increasing ionic strength. CaCl2 increased the ionic strength the most, then prevented repulsion of carboxylate groups, so it means the expansion of hyaluronan cluster into the solution. However, the emission of the probe 4-Di-2-ASP was quenched with the addition of CaCl2 the most. The first additions of COO– groups cause the formation of dimers of AO shown as decreasing in extinction coefficient and fluorescence intensity. Next addition of the hyaluronan caused a depolymerization of formed dimers and the increase of the emission intensity. The repolymerization caused the decrease and then again the increase. In case of 4-Di-2-ASP was the pattern of the fluorescence (the intensity and the position of the emission) firstly the same, but at the concentration of 1 g dm-3 the emission intensity increased. The probes MB and F were used for spectroscopic studies of the interaction between methylene blue-fluorescein complex and anionic and cationic surfactants. The absorbance of separate MB and F changed only with the addition of surfactants with the opposite electric charge. Absorbance of the mixture MB-F changed with the addition of the CTAC surfactant, while the addition of SDS into the mixture caused only the change of MB absorption spectra.
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