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Combination of modeling and experiment in analysis of partially disordered structures
Čapková, P. ; Repáková, J. ; Koudelka, B. ; Pospíšil, M. ; Trchová, Miroslava ; Weiss, Z. ; Zima, V. ; Ilavský, Michal
An overview of structures solved by this method will be presented, especially intercalates, liquid crystals and liquid crystalline polymers.
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Transport systems used in cosmetics
Škopová, Jitka ; Kramářová,, Daniela (referee) ; Zemanová, Jana (advisor)
Between transport systems in cosmetics belong liposomes, liquid crystals and also chosen substances, which speed under given conditions a transport of active compounds, so-called accelerators of trans-dermal penetration. Liposomes are used topically (i.e. directly onto the place of their action in surface structures of organism) in dermatological and cosmetic preparations, they facilitate the penetration of active substances into the deeper layers of the skin and make possible their more expressive treatment. Some properties of liquid crystals are similar to the properties of live organisms. Analogous to the vital cells are they sensitive to light, sound, warm, mechanical straining and chemical changes. And by contraries, some scientists mark vital cells as liquid crystals. Thanks to this similarity are liquid crystals characterized by their excellent ability to penetrate by the skin, which is probably comparable only with liposomes. Accelerators of trans-dermal penetration otherwise accelerators of penetration by the skin are substances, which change structure of the skin or derma to be more permeable for other compounds. The trans-dermal penetration of active substances is an important part of medical researches. Those results are however applied also in other branches as for example is cosmetic industry. From the point of view of the chemical texture of these materials form they a very heterogeneous group and an elucidating of mechanisms of their incidence is so far rather in beginnings.
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Magnetic nanostructures with application potential
Bittová, Barbara ; Holý, Václav (referee) ; Kalbáčová Vejpravová, Jana (advisor)
The thesis is mainly focused on the investigation of macroscopic and microscopic magnetic properties of selected nanomaterials containing cobalt and iron, and also the capability of our new device, scanning probe microscope Multimode V by Veeco, to directly visualise morphology and magnetic structure of these samples (Magnetic Force Miscroscopy, MFM). Investigated materials, such as CoFe2O4 nanoparticles and SiO2_Co_Si(111) thin films and multilayers are in general promising materials in many fields. In the medicine, the nanoparticles are used as the drug targets or contrast agents whereas in electronics, the (nano)granular thin films are the starting point in fabrication of high density storage media. The macroscopic magnetic properties of our samples are discusses in a view of superparamagnetic phenomena. The interactions in systems of nanoparticles are presented theoretically within the up-to date knowledge and also experimentally by demonstrating the behavior of the strongly-interacting, uper-spin-glass system. The thin films are studied in term of their granular structure and magnetic anisotropy. The morphology and the microscopic domain structure, respectively, are studied with use of the MFM. The first successful results obtained in our lab by this method are presented.
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Vliv tepelného namáhání na mechanické vlastnosti FeNiB amorfní slitiny
Zábranský, Karel ; Jirásková, Yvonna
An influence of thermal treatment in the temperature range of 150 - 350 °C on the structural and mechanical properties of an amorphous FeNiB alloy is investigated. The high tensile strength of 2200 MPa in the as-prepared amorphous state slightly decreases with increasing temperature of annealing up to approximately 200 °C in opposite to microhardness where an increase is observed. Above 200 °C a pronounced deterioration of both characteristics reflect the embrittlement of amorphous structure without any indications of crystallization.
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Analysis and modification of thin layers using ion beams
Jonner, Jakub ; Lörinčík, Jan (referee) ; Bábor, Petr (advisor)
This diploma thesis deals with analysis and modification of thin layers using ion beams. The first part of this diploma thesis deals with phenomena accompanying ion beam bombardment of solid matter. The second part of this diploma thesis is concerned with Secondary Ion Mass Spectroscopy (SIMS) and Low Energy Ion Scattering (LAIS). This work convey some basic information about these two techniques and it also deals with some benefits result in their connection into parallel depth profiling mode (such as better depth resolution of the LEIS profile, quantification of the SIMS). These benefits are demonstrated on MoSi film measurement. Within the framework of this thesis a new UHV manipulator was designed. This new UHV manipulator is equipped with precise stepper UHV motor and since the proportions are smaller, the manipulation with a sample in a space limited UHV chamber is much more comfortable and more precise. The third part of this diploma thesis deals with ion-beam induced transformation of epitaxially grown Fe films with thickness of 22 monolayer (ML) and 44 ML on Cu(100) single crystal at room temperature. Metastable Fe films of 22 ML thickness were prepared in CO pressure and 44 ML Fe films were prepared by co-evaporation of Fe with Fe64Ni36 (invar). Structural changes are analyzed by scanning tunneling microscopy and low-energy electron diffraction. The aim of this thesis is to discuss the influence of the sputtering parameters such as ion dose and ion energy on the nucleation of bcc nanocrystals, their growth, final shape and size. The influence of different Ni concentration on stability of 44 ML thick Fe films is also discussed.
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Creative Destruction Within the Automotive and Energy Industry - Sustainable Electric Mobility as a Political-Economic Challenge for the EU
Vejbor, Jan ; Rovná, Lenka (advisor) ; Chatard, Benoit (referee)
The diploma thesis "Creative Destruction Within The Automotive and Energy Industry - Sustainable Electric Mobility As a Political And Economic Challenge for the EU" deals with the issue of the impacts on the political and economic area caused by technological innovations. The subject of the study is the personal motorised transport with its key elements: automotive industry, oil industry, energy industry and state administration. The goal is to introduce the reader the development of the personal motorised transport as a concept of "major innovation" of the Joseph Schumpeter's economic theory. The binding of the two innovations of (a) automobiles propelled by internal combustion engines with (b) the refined crude oil products gave way to a new economic cycle. The integral part of every economic cycle represents the "creative destruction", i.e. the fall of old structures and the rise of new ones. In the domain of personal transport, automobiles devoured not only the animal propelled transportation, but the successfully expanding market of electric vehicles, too. Mainly due to the ecological and supply problems of the fossil fuels, electric vehicles cars are currently witnessing a period of a strong publicity and technological success. Nevertheless, their accession on the market and hence a new economic cycle...
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Preparation of Fe2O3/SiO2 Nanocomposites from Molecular Precursor by Sol Gel Method and Doping of Iron(III) by Trivalent Metal Cations
Brázda, Petr ; Nižňanský, Daniel (advisor) ; Matějec, Vlastimil (referee) ; Grenéche, Jean-Marc (referee)
Přírodovědecká fakulta Univerzity Karlovy v Praze katedra anorganické chemie a Univerzita Štrasburk Department of Inorganic Chemistry, Faculty of Science, Charles University in Prague and Université de Strasbourg Příprava nanokompozitů Fezos/Sioz z moleku!árního prekurzoru metodou so! gel a dopování Že|ezitých kationtů jinými trojmocnými kationty Preparation of Fezos/Sioz Nanocomposites from Molecutar Precursor by sol Gel Method and Doping of lron(lll) by Trivalent Metal Cations Souhrn disertačnípráce Summary of Thesis Petr Brázda Šrotitete(Supervisors): RNDr. Danie| NiŽňanský, PhD' Dr. Jean-Luc Rehspringer Praha 2009 Y Abstract Iron (III) oxide fonns two well-known polymorphs - the maghemite (y-Fe2O3), which is in fact a metastable phase, and is transformed into the hematite (cr-Fe2O3) at higher temperatures. At certain conditions, elusive e-Fe2O3 can be obtained as an intermediate between these two phases. e-Fe2O3 crystallizes in orlhorhombic space group Pna\ with lattice constants a: 509.5, b = 87g.9 and c:943.7 pm and is isomophous with r-A12O3, e-Ga2O3, AIFeO: and GaFeO3. Oxygen atoms form close pseudohexagonal packing with layers ABAC. kon cations occupy four different sites, three of them are octahedrally and one is tetrahedrally coordinated. There is eight formula units in unit cell. Structure of...
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Intramolecular self-organised structures in amphiphilic (co)polymers
Košovan, Peter ; Procházka, Karel (advisor) ; Jungwirth, Pavel (referee) ; Cifra, Peter (referee)
59 ËÙÑÑ ÖÝ In this thesis we have presented results of our simulation studies concerning the intramolecular morphology of amphiphilic polymers. Amphiphilic polymers are those which contain two or more types of monomer units with different affinity for the solvent. Using the common terminology of polymer physics, we say that such polymers are in the selective solvent, i. e. such that it is poor for one type of units and good for the other type. In our definition of amphiphilic polymers we also include polyelectrolytes in which the good solvent conditions can be induced by the electrostatic repulsion among the charged monomer units. In our studies we have investigated both polyelectrolytes and neutral polymers of linear as well as branched topologies. While the poorly soluble monomer units have the tendency to collapse into compact globular structures, this tendency is counteracted by the excluded vol- ume repulsion among the well-soluble units. Equilibrium is attained when the two tendencies are balanced which often results in the so-called pearl-necklace confor- mation consisting of both collapsed domains (pearls) and stretched ones (strings). This behaviour has been first predicted for linear polyelectrolytes in poor solvents by Dobrynin and coworkers [8]. Later on similar structures have been predicted by...
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Applications of experimental mineralogy to Te containing systems: Crystal structures, phase relations
Laufek, František ; Rieder, Milan (advisor) ; Palatinus, Lukáš (referee) ; Johan, Zdeněk (referee)
This dissertation contributes to the crystal chemistry of Te. The primary goals of the thesis are synthesis and crystal structure analysis of new Te-bearing ternary phases. The first part of the thesis shows significance of experimental mineralogy in research of Te containing systems. It briefly describes a novel approach to the study of new mineral species - the possibility of using synthetic analogues for their detailed mineralogical characterization. The results of the experimental mineralogical study in the Ni-Sb-Te ternary system at 400řC are reported in the second part. According to the performed experiments, two solid solutions λ1- Ni(Sb1-xTex)1+y (0<x<1, where 109.09.0 ≤≤⇒≥≈∀ yx ) and λ2 - NiSb1-xTe2x (0.28<x<0.66) dominate the system at 400řC. A characteristic feature of most phases present in the Ni-Sb-Te system at 400řC is apparent tendency to the Sb - Te substitution. The third part deals with the characterisation of the new mineral pašavaite Pd3Pb2Te2, which was found at the Noril'sk-Talnakh Ni-Cu camp, Russia. The synthetic Pd3Pb2Te2 phase was used for thorough mineralogical characterization of this new mineral species. Pašavaite displays orthorhombic symmetry, space group Pmmn. The structural identity between natural grains and synthetic Pd3Pb2Te was supported by the EBSD study. The...
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