Univerzita Karlova 1. lékařská fakulta Studijní program: Zobrazovací metody v lékařství (P5150) Studijní obor: Zobrazovací metody v lékařství (5103V000) MUDr. Adam Kopecký Změny na předním segmentu po 25G+ PPV Changes in the Anterior Segment after 25G+ PPV Abstract Vedoucí závěrečné práce/Školitel: doc. MUDr. Jiří Pašta, CSc., FEBO Praha, 2019 Abstract: Pars plana vitrectomy is a dominant surgical method in posterior segment surgery of the eye. The principle of this method is the surgical approach via the pars plana anatomical region. With this approach, surgeon performs the posterior segment surgery without directly affecting the anterior segment of the eye. Short-term effect of pars plana vitrectomy on the anterior segment of the eye has been repeatedly proven. That might be an important factor both in assessing the complications of this method and planning the surgery in complicated patients. Generally, it is presumed that we do not observe long-term effects on anterior segment after pars plana vitrectomy. The aim of our work is to evaluate the long-term changes in the anterior segment after the uncomplicated 25G + PPV with gas tamponde. The group of 20 patients was selected according to strict indication criteria. Using a series of examinations, we examined specific parameters such as: intraocular...

The Ph.D. thesis deals with one of the most important characteristics of hardened concrete; i.e. the modulus of elasticity. The thesis aims to describe and evaluate the important factors that affect the final value of concrete modulus of elasticity, especially those that can be influenced during construction. Another aim is to find ways to determine the static modulus of elasticity of concrete by non-destructive means (primarily ultrasonic pulse method, resonance method and use of electronic rebound hammers), thus to determine the possibility of creating calibration curve for NDT determination of the modulus of elasticity.

The diploma thesis deals with different methods of determining levels of degradation of concrete due to freezing, also considering the options of freeze thaw resistance determination in structure. At first the properties of concrete and possible mechanisms of concrete degradation are described – mainly the effects of freezing water in the inner structure and of the combination of freezing water and de-icing chemicals on the surface. Principle and properties of air-entrained concrete are also mentioned. An overview of the approaches that current standards use to determine the freeze-thaw resistance of concrete is listed, followed by description of the tests that are used on air-entrained concrete specimens in the main part of the thesis. A portion of the test specimens was made in moulds while the rest was obtained from structure (concrete block). The non-destructive tests used are evaluated in several different ways and their results are compared with the destructive tests. Comparison and evaluation of different approaches used to determine the freeze-thaw resistence of concrete are the main outcome of this thesis.

The diploma thesis deals with influence of the used adhesive to large format tiles properties after installation. Properties on large format tiles were monitored by ultrasonic pulse velocity method. Hydraulic setting adhesives were tested in second part. Strength and modulus of elasticity were tested. The development of shrinkage over time was also monitored. The results were summarized in tabular and graphical form and were examined by simple statistical analysis to determine resulting conclusions.

The thesis deals with both scheme and its implementation of water-level metering apparatus. This data are send wireless into 500 m distant station. Potential ways of solution are gradually studied and final design suggested. Detailed implementation methods are described in the following section. Ultrasonic sensors are employed for level measurement and controlling element is processor ATmega162, data are transmitted by transceiver RC1280HP. Apparatus is suggested with a view to the lowest power consumption considering it will be supplied only with a accumulator. Solving of accepting station is not a part of the thesis. Functional tested sample is understated in the execution section.

The main topic of this diploma thesis is the modeling of nonlinear effects in ultrasonic fields. The work deals with application of finite difference method (FDTD) on the Westervelt equation and the subsequent creation of the model of ultrasonic fields in MATLAB. This thesis also includes theoretical analysis of ultra-acoustic and technical aspects of diagnostic ultrasonography. In addition, this document includes verification of theoretical assumptions by using created model.

This master´s thesis deals with problem of reliability of technical device in general a so there is explained bathtub curve, defects and malfunctions of devices and then there is a brief outline of reliability system. This thesis further briefly describes technical diagnostic and then there is performed the vibrodiagnostic measurements of selected pumps and ventilators in in heating plant Červený mlýn in Brno. Evaluation of their condition is done according to relevant standards. Further there was done a diagnostic of the steam traps through the ultrasound diagnostic. The last part of my thesis deals with the reliability of selected specific pumps in foregoing rating plant. There are showed reliability curves of selected pumps and elaboration of data from their long-term vibrations measurement.

This master’s thesis deals with the determination of dynamic modulus of elasticity non-destructive methods of brick body. The test samples were laboratory-made from two types of brick earth and further were used cotouts from the full brick types clinker. For measuring were used ultrasonic impulse and resonant-impact method.

This master‘s thesis is focused on the study of the behavior of cement concrete at high temperatures with a focus on monitoring the impact of aggregate and cement type. This work describes the processes in aggregates and cement matrix at high temperatures. The theoretical part describes the selestion of a suitable aggregate and cement for the surroundings with potential exposure to high temperatures. In the experimental part is given design of composition of a concrete with two types of aggregates and four cements. It has been suggested 8 recipes. Changes were observed densities, compressive strength and tensile strength in bending, calculate the velocity of propagation of waves with ultrasonic pulsed method. Also evaluated the appearance of the surface samples after thermal load – cracks on the surface and measure the maximum crack width.

Předkládaná dizertační práce se zabývá využitím techniky vysoce rozlišovací ultrazvukové spektroskopie (HRUS) při analýze huminových látek, za účelem získání hlubšího vhledu do problematiky vztahu mezi jejich primárními charakteristikami (elementární složení a rozložení uhlíku ve funkčních skupinách) a agregačními vlastnostmi. V literární rešerši jsou shrnuty nejnovější poznatky z oblasti studia huminových látek a představeny základní principy HRUS. Dále jsou uvedeny základní informace z oblasti fraktální analýzy a její aplikace na data získaná pomocí různých metod při studiu huminových látek. První úkol experimentální části je zaměřen na výhodné využití HRUS pro výzkum huminových látek, zde reprezentovaných standardy Mezinárodní společnosti pro huminové látky (IHSS) a to sodnými solemi huminových a fulvinových kyselin. Fulvinové kyseliny v jejich protonované formě byly taktéž zkoumány a to z důvodu objasnění vlivu sodného kationu. Pro popis chování vzorků byla použita mocninná funkce, jejíž empirické parametry byly korelovány s primárními charakteristikami. Byla vytvořena metoda fraktální analýzy a následně byla aplikována na data získána ultrazvukovou spektroskopií. Data získaná pomocí ultrazvukové spektroskopie byla zpracována i alternativní metodou. Ta spočívala v globálním pohledu na závislost ultrazvukové rychlosti na koncentraci a využití lineární regrese. Druhým z cílů práce je získání informací o vlivu teploty na stabilitu agregátů HS (IHSS standardy). Byl zkoumán vliv teplotních gradientů na chování agregátů při čtyřech různých koncentracích. V třetí části práce pak byly zkoumány koncentrační závislosti u vzorků pocházejících především z lokalit příliš nezasažených lidskou činností. HRUS data byla proložena mocninnou funkcí a zkoumána pomocí fraktální analýzy. Takto získané parametry byly korelovány s primárními vlastnostmi. Ze znalosti hustoty při dané koncentraci mohly být stanoveny velikosti hydratačních obálek. Jak se v současné době ukazuje, informace o agregačním chování huminových biomolekul mohou být v budoucnu velmi důležité pro navrhování průmyslových aplikací huminových látek, zejména v zemědělství a v ochraně životního prostředí, ale také například v medicíně.