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Wave Soldering Fluxes and Flux Residues
Kryll, Josef ; Dušek, Karel (referee) ; Starý, Jiří (advisor)
This work deals with issues of flux residues after wave Soldering. The general aim is to create methodology for measuring the surface insulation resistance values of flux residues after soldering and isothermal heating. Finding the ammount of ionic contamination by using conductometric method. Measurement of wettability of Cu wire by using wetting balance method for different fluxes. The aim is then to compare the measured values with the values dictated by the manufacturer.
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Relaxation, especially dielectric behaviour of polymer composites and liquid crystalline polymers
Neubert, Milan ; Nedbal, Jan (advisor) ; Dušek, Karel (referee) ; Starý, Vladimír (referee)
Title: Relaxation, especially dielectric behaviour of polymer composites and liquid crystalline polymers Author: Milan Neubert Department: Department of Macromolecular Physics Supervisor: doc. RNDr. Jan Nedbal, CSc., Department of Macromolecular Physics Abstract: The subject of the work was to study the relaxation electrical properties of polymer composites and liquid crystalline polymers. Work focused on till now not deeply explored new polymeric materials - on semi-aromatic poly (ester amides) and on composites of poly(vinyl alcohol) with polyaniline. In the case of poly(ester amides), we had three series with different aromatic groups and different length of the aliphatic chain, in the case of composite materials, we studied composites prepared as cryogels. Basic experimental method was dielectric spectroscopy, supplemented by approaches of electrochemical impedance spectroscopy. A noncontact measuring method based on eddy currents was newly developed, that is able to provide information about both the conductivity and permittivity of samples, and a measuring cell was constructed, later used to perform part of the experimental work. Keywords: permittivity, conductivity, dielectric spectroscopy, liquid crystalline polymers, conducting polymer composites
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Theoretical description and simulation of polymer network formation
Premus, Jan ; Šomvársky, Ján (advisor) ; Dušek, Karel (referee)
One of methods for description of formation and structure of polymer ne- tworks is used in the work - combination of chemical kinetics and theory of branching processes (TVP) with correlations to neighbors. Main output of this work is computer program, whose purpose is setting up of rooted fragments of given size, differential equations for their concentrations and calculation of se- lected structural parameters using TVP. Gel points for systems formed by three and fourfunctional monomer and combination of two and threefunctional mono- mer were computated in this way. Chemical simulation of molecules was used as reference value. Larger correlation distance (larger size of fragments) led to more accurate results. Calculation of system parameters using TVP allowed study of gel parameters, concentrations of elastically active chains for all studied systems is shown in the work. 1
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Relaxation, especially dielectric behaviour of polymer composites and liquid crystalline polymers
Neubert, Milan ; Nedbal, Jan (advisor) ; Dušek, Karel (referee) ; Starý, Vladimír (referee)
Title: Relaxation, especially dielectric behaviour of polymer composites and liquid crystalline polymers Author: Milan Neubert Department: Department of Macromolecular Physics Supervisor: doc. RNDr. Jan Nedbal, CSc., Department of Macromolecular Physics Abstract: The subject of the work was to study the relaxation electrical properties of polymer composites and liquid crystalline polymers. Work focused on till now not deeply explored new polymeric materials - on semi-aromatic poly (ester amides) and on composites of poly(vinyl alcohol) with polyaniline. In the case of poly(ester amides), we had three series with different aromatic groups and different length of the aliphatic chain, in the case of composite materials, we studied composites prepared as cryogels. Basic experimental method was dielectric spectroscopy, supplemented by approaches of electrochemical impedance spectroscopy. A noncontact measuring method based on eddy currents was newly developed, that is able to provide information about both the conductivity and permittivity of samples, and a measuring cell was constructed, later used to perform part of the experimental work. Keywords: permittivity, conductivity, dielectric spectroscopy, liquid crystalline polymers, conducting polymer composites
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Methodic handbook for conservtion of old landraces of herbaceous agricultural crops
Holubec, Vojtěch ; Dušek, Karel ; Dušková, Elena ; Doležalová, Ivana ; Hýbl, Miroslav ; Kopecký, Pavel ; Smékalová, Kateřina ; Stavělíková, Helena
The methodic handbook recommends management of basic cultivation practices for landraces of herbaceous crops in „on farm“ plantations. The materials were collected during field excursions of authors or gathered from germplasm collections. These materials have cultural-historical value and represent old habits and national identity of Czech inhabitants. Representative landraces were sellected for crop groups: Cereals, legumes, vegetables, condiments and medicinal plants.
Fulltext:  PDF
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Wave Soldering Fluxes and Flux Residues
Kryll, Josef ; Dušek, Karel (referee) ; Starý, Jiří (advisor)
This work deals with issues of flux residues after wave Soldering. The general aim is to create methodology for measuring the surface insulation resistance values of flux residues after soldering and isothermal heating. Finding the ammount of ionic contamination by using conductometric method. Measurement of wettability of Cu wire by using wetting balance method for different fluxes. The aim is then to compare the measured values with the values dictated by the manufacturer.
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