Microwave applicator system design for the needs of animal experiments on mice

Diplomová práce Návrh systému mikrovlnného aplikátoru pro potřeby animálních experimentů pojednává o metodě léčby zhoubných novotvarů uložených hluboko pod povrchem těla. V úvodní kapitole jsou uvedeny základní biologické a fyzikální poznatky principu hypertermie. Hlavní složkou této práce je návrh, realizace a otestování modelu regionálního aplikátoru pracujícím na frekvenci 2450 MHz. Systém aplikátoru, který je tvořen čtyřmi budícími elementy, je schopen za předpokladu symetricky umístěných a buzených elementů fokusovat elektromagnetickou energii do válcového fantomu o průměru podstavy 5 cm. V závěrečné části této práce jsou uvedeny výsledky testování modelu anténního elementu na homogenním kvádrovém fantomu v porovnání s elementem rezonujícím při frekvenci 434 MHz, a to z hlediska parametru efektivní plochy pole (EFS). Dále pak na dielektrickém modelu myši testuji tyto regionální aplikátory z hlediska porovnání objemu myši, ve kterém nabývá hodnota SAR 25 % svého maxima. Anténní element o pracovní frekvenci 2450 MHz vykazuje značně menší plochu expozice.Master's thesis Microwave application system design for the needs of animal experiments on mice deals with method of curing malign tumors set deep under the body surface. Introduction contains basic biological and physical knowledge of the principles of hyperthermia. The main aims of this thesis are design, realization and testing of a regional applicator model resonating at frequency 2450 MHz. The system of applicator consisting of four antenna elements is capable of focusing electromagnetic energy into cylindrical phantom with 5cm base diameter, if systematically placed and elements are provided. Conclusion of this thesis delivers test results of diverse effects of two antennas with 434 and 2450 MHz frequencies on homogenous block phantom accordingly to parameter of effective field size (EFS). Subsequently, those same regional applicators are being tested on dialectical mouse model in order to compare mouse's volume in which SAR value reaches 25% of its maximum. The antenna element resonating at frequency 2450 MHz shows considerably smaller exposed area

Effectivity of cleaning methods in electrönics and classification inc. ecology

V práci jsou popsány čistící metody používané v elektronice a je vytvořen nástroj pro jejich hodnocení včetně ekologického hlediskaThis work deals with analyze of cleaning methods in electronics and there is designed valuation tool for its clasification including ecology

On the relationship between {1 1 2¯ 2} and {1 1 2¯ 6} conjugate twins and double extension twins in rolled pure Mg

This is an Accepted Manuscript of an article published by Taylor & Francis Group in Philosophical Magazine on February 2017, available online at: http://www.tandfonline.com/10.1080/14786435.2017.1290846The paper presents a new type of twin-like objects observed in rolled pure magnesium. They have {11¯26} and {11¯22} habit planes and their misorientations to the matrix are close to 56° and 63° about ¿10¯10¿ axis, respectively. The ad hoc performed theoretical analysis and atomic simulations allow to interpret the objects as {10¯12}-{10¯12} double twins formed by the simultaneous action of two twinning shears with completely re-twinned volume of primary twin. The observed inclinations from the ideal misorientations for such double twins can be explained by the compliance of the strain invariant condition in the twin boundary. It seems plausible that, once the double twin is formed, its twin boundaries are hard to move by glide of twinning disconnections. If so, these twins represent obstacles for the motion of crystal dislocations increasing the hardness of the metal.Peer ReviewedPostprint (author's final draft

New Areas of the Ultrasonic Application in Microelectronics Technology

Tato práce se zabývá depozicí speciálních tixotropních materiálů určených pro mikroelektronické technologie. Cílem práce je vývoj nové metody optimalizace dávkovacího procesu za účelem dosažení rozlišení tisku pod 100 µm. Práce obsahuje vývoj speciální dispensní hlavice (UZD) využívající působení ultrazvukové energie. Doložené výsledky dokumentují možnosti nově vyvinuté metody, která je schopna tisknout tixotropní materiály s rozlišením 65 µm. Oproti jiným metodám dosahuje těchto výsledků s běžně využívanými materiály pro tlustovrstvovou technologii s velikostí částic do 5 µm.Doctoral thesis deals with the deposition of special thixotropic materials for microelectronic technology. The aim of the work is the development of the new method optimizing the dosing process in order to achieve a print resolution of better than 100 microns. The work includes the development of a special dispensing head (UZD) using the influence of ultrasonic energy. These results demonstrate the possibility of a newly developed method that is able to print thixotropic materials with a resolution of 65 microns. Compared to other methods achieves these results with the commonly used materials for thick film technology with particle size up to 5 microns.

Stabilization of the high-spin state of Co3+^{3+} in LaCo1−x_{1-x}Rhx_{x}O3_3

The rhodium doping in the LaCo$_{1-x}$Rh$_{x}$O$_3$ perovskite series ($x=0.02-0.5$) has been studied by X-ray diffraction, electric transport and magnetization measurements, complemented by electronic structure GGA+U calculations in supercell for different concentration regimes. No charge transfer between Co$^{3+}$ and Rh$^{3+}$ is evidenced. The diamagnetic ground state of LaCoO$_3$, based on Co$^{3+}$ in low-spin (LS) state, is disturbed even by a small doping of Rh. The driving force is the elastic energy connected with incorporation of a large Rh$^{3+}$ cation into the matrix of small LS Co$^{3+}$ cations, which is relaxed by formation of large Co$^{3+}$ in high-spin (HS) state in the next-nearest sites to the inserted Rh atom. With increasing temperature, the population of Co$^{3+}$ in HS state increases through thermal excitation, and a saturated phase is obtained close to room temperature, consisting of a nearest-neighbor correlation of small (LS Co$^{3+}$) and large (HS Co$^{3+}$ and LS Rh$^{3+}$) cations in a kind of double perovskite structure. The stabilizing role of elastic and electronic energy contributions is demonstrated in supercell calculations for dilute Rh concentration compared to other dopants with various trivalent ionic radius.Comment: 8 pages, 8 figure

Vliv ICT na anglický jazyk

Vliv ICT na anglický jazyk - Abstrakt Tato bakalářská práce se snaží popsat, kterak výpočetní a komunikační technika, po vkročení do každodenního života, ovlivnila anglický jazyk. Důraz je kladen na komunikaci v anglickém jazyce, jelikož právě tento byl prvním jazykem světa počítačů. Práce vysvětluje, proč tomu tak je a dále podává přehled výhod a nevýhod počítačem zprostředkované komunikace a její dopad na angličtinu. Závěry jsou porovnány s výzkumem, který potvrzuje, že spíše než k degradaci jazyka došlo k jeho obohacení, a že nové prvky, které do jazyka pronikly, nezasahují negativně do jeho struktury.The impact of ICT on the English language - Abstract This B.A. Thesis is trying to present in what ways is the English language affected by information and communication technologies, as they entered our everyday lives. The focus is on communication in the English language, as it was the first language of the world of computers. The thesis explains, why is that and furthermore gives an overview of advantages and drawbacks of computer mediated communication and its impact on the English language. Conclusions are then compared with the research which confirms, that the language was rather enriched than degraded and that the new elements of the language are in now way harmful to its core.Katedra anglického jazyka a literaturyFaculty of EducationPedagogická fakult

Chemical Wet Synthesis and Characterization of Copper-Silver Nanoparticles

AgCu nanoparticles (NPs) of near-eutectic composition were prepared by various route of wet synthesis. Nanoparticles suspended in nonpolar solvents were prepared by solvothermal synthesis from metallo-organic precursors. AgCu colloids in aqueous solution were obtained by hydride reduction of Ag and Cu nitrates under action of different stabilization substances. The different surface stabilizing agents were used. Chemical characterisations of as-synthesized AgCu NPs were done using inductively-coupled plasma-optical emission spectrometry (ICP-OES). The optical properties of nanoparticles were monitored using UV-Vis spectrophotometer. The size of colloid nanoparticles was measured by both dynamic light scattering (DLS) and small angle X-ray scattering (SAXS) method in some extra cases. Zeta potential of AgCu colloids was measured by electrophoretic method. Size and shape of metal core of nanoparticles and morphology of aggregates were investigated by electron microscopy (SEM, TEM and HRTEM), the thermal properties of AgCu nanoparticles were evaluated by differential scanning calorimetry (DSC) and temperature controlled X-ray diffraction method (t-XRD). Mass loss under heating inside inert and air was monitored by thermo gravimetric analysis (TGA). The fraction of organic matter was deduced from ICP-OES analysis and compared to TGA mass loss. The adsorption maxima in UV-Vis region were occurred. Hydrodynamic size of AgCu NPs measured by DLS was compared with the metallic core size obtained by electron microscopy. The morphologies of aggregates were observed as well as the phase transformation (t-XRD) that undergoes at heating to liquid temperature (DSC). The obtained results were compared with respect to perspective use.Nanočástice AgCu (NPS)s téměř eutektickým složením byly připraveny různými způsoby mokré syntézy. Nanočástice suspendované v nepolárních rozpouštědlech byly připraveny solvothermal syntézou z prekurzorů organokovovů. AgCu koloidy ve vodném roztoku byly získány hydridovou redukcí dusičnanů Ag a Cu za přítomnosti různých stabilizačních látek. Chemická složení bylo stanoveno pomocí indukčně vázané emisní spektrometrie (ICP-OES). Optické vlastnosti nanočástic byly sledovány pomocí UV-VIS spektrofotometru. Velikost koloidních nanočástic byla měřena jak dynamickým rozptylem světla (DLS) tak i metodou sledování XDR malých úhlů (SAXS). Zeta potenciál AgCu NPs byl měřen elektroforetickou metodou.Velikost a tvar kovového jádra nanočástic a morfologie agregátů byly zkoumány elektronovým mikroskopem (SEM, TEM a HRTEM), tepelné vlastnosti AgCu nanočástic byly hodnoceny pomocí diferenční skenovací kalorimetrie (DSC), a rentgenové difrakční metody s řízenou změnou teploty (t -XRD). Úbytek hmotnosti při zahřívání v inertu a na vzduchu byl sledován pomocí termogravimetrické analýzy (TGA). Frakce organické hmoty byla odvozena z ICP-OES analýzy a srovnání s TGA. Hydrodynamická velikost AgCu NP měřená DLS byla porovnána s velikostí kovového jádra

Hard carbon films: Deposition and diagnostics

We studied the growth of microcrystalline diamond films on pre-treated Si and WC-Co substrates by microwave plasma chemical vapour deposition (MPCVD). The pre-treatment was varied and its effect on diamond film was studied

On thermal stability of nanocrystalline Ag–Cu-S powders

The nanocrystalline semiconducting compounds based on the AgCuS system are considered as low-cost candidates of thermoelectric materials with improved thermal stability. The nanocrystalline Ag–Cu—S powders were prepared from metal nitrates and sulphur powder in tetraethylene glycol (TEG) solvent by reductive agent NaBH4. The crystallite sizes of the observed phases were in the range between 60 and 80 nm. The chemical compositions of the as-received samples were analysed by the ICP-AES method and their phase compositions were evaluated by XRPD. The investigation was supplemented by DSC and in situ HTXRD thermal analysis. A more detailed in situ experiment was performed for a sample containing ternary phases. The nucleation and growth of silver micro-wires were first observed on the substrate involving ternary phases at isothermal heat treatment. The formation of silver wires and semi-conductive ternary thermoelectric phase (stromayerite τ3) is explained by observed phase transformation. The obtained results are complemented by microscopy (LM, SEM, TEM)