The Production of Cast Components from MoNiCr Alloy for Reactors of 4th Generation

Tato práce se zabývá materiály pro výrobu litých součástí pro reaktory chlazené roztavenými solemi. Nejprve je nastíněna historie jaderných reaktorů, zejména reaktorů IV. generace. Podrobněji je rozebrán reaktor chlazený roztavenými solemi. Na to navazuje rozbor materiálů, které jsou díky svým vlastnostem vhodné pro použití v prostředí roztavených fluoridových solí a neutronového toku. Mezi tyto materiály patří zejména niklové slitiny, které jsou blíže představeny a porovnány mezi sebou. Nedílnou součástí práce je praktická část, ve které je popsána výroba oběžného kola čerpadla ze slitiny MoNiCr.This thesis deals with materials to produce cast components for reactors cooled by molten salts. First, the history of nuclear reactors is outlined, especially reactors IV. generation. A reactor cooled by molten salts is discussed in more detail. This is followed by an analysis of materials which, due to their properties, are suitable for use in the environment of molten fluoride salts and neutron flux. These materials include nickel alloys, which are introduced in more detail and compared with each other. An integral part this thesis is the practical part, which describes the production of the pump impeller from MoNiCr alloy.618 - Katedra metalurgie a slévárenstvívýborn

Photochemistry of a 9-Dithianyl-Pyronin Derivative: A Cornucopia of Reaction Intermediates Lead to Common Photoproducts

Leaving groups attached to themeso-methyl position of many common dyes, such as xanthene, BODIPY, or pyronin derivatives, can be liberated upon irradiation with visible light. However, the course of phototransformations of such photoactivatable systems can be quite complex and the identification of reaction intermediates or even products is often neglected. This paper exemplifies the photochemistry of a 9-dithianyl-pyronin derivative, which undergoes an oxidative transformation at themeso-position to give a 3,6-diamino-9H-xanthen-9-one derivative, formic acid, and carbon monoxide as the main photoproducts. The course of this multi-photon multi-step reaction was studied under various conditions by steady-state and time-resolved optical spectroscopy, mass spectrometry and NMR spectroscopy to understand the effects of solvents and molecular oxygen on individual steps. Our analyses have revealed the existence of many intermediates and their interrelationships to provide a complete picture of the transformation, which can bring new inputs to a rational design of new photoactivatable pyronin or xanthene derivatives

Highly Chemoselective Catalytic Photooxidations by Using Solvent as a Sacrificial Electron Acceptor

Catalyst recovery is an integral part of photoredox catalysis. It is often solved by adding another component-a sacrificial agent-whose role is to convert the catalyst back into its original oxidation state. However, an additive may cause a side reaction thus decreasing the selectivity and overall efficiency. Herein, we present a novel approach towards chemoselective photooxidation reactions based on suitable solvent-acetonitrile acting simultaneously as an electron acceptor for catalyst recovery, and on anaerobic conditions. This is allowed by the unique properties of the catalyst, 7,8-dimethoxy-3-methyl-5-phenyl-5-deazaflavinium chloride existing in both strongly oxidizing and reducing forms, whose strength is increased by excitation with visible light. Usefulness of this system is demonstrated in chemoselective dehydrogenations of 4-methoxy- and 4-chlorobenzyl alcohols to aldehydes without over-oxidation to benzoic acids achieving yields up to 70 %. 4-Substituted 1-phenylethanols were oxidized to ketones with yields 80–100 % and, moreover, with yields 31-98 % in the presence of benzylic methyl group, diphenylmethane or thioanisole which are readily oxidized in the presence of oxygen but these were untouched with our system. Mechanistic studies based on UV-Vis spectro-electrochemistry, EPR and time-resolved spectroscopy measurements showed that the process involving an electron release from an excited deazaflavin radical to acetonitrile under formation of solvated electron is crucial for the catalyst recovery

An examination of pelvic floor activity folloving the application of special exercises

Title: An examination of pelvic floor activity following the application of special exercises Objectives: The aim of this thesis is to validate the usefulness of carrying out local pelvic floor muscle examinations as an indication and education for therapy. A second objective is for the women involved in the research to subjectively evaluate the examination methods and therapy. Furthermore, the thesis aims to establish an example of a comprehensive and detailed local examination of the pelvic floor muscles. Methods: We measured the pelvic floor activity per vaginam using an EMG biofeedback device on clients with a pelvic floor dysfunction and grade I stress incontinence symptoms. Based on the results of the examination, therapy using the vaginal device was recommended and in six weeks a follow-up examination was carried out. The changes in pelvic floor activity were evaluated by comparing the initial and follow-up examinations. Thus the usefulness of carrying out an examination of the local pelvic floor muscles before indicating a therapy was validated. At the end of the examination an interview with participating clients was conducted in order to subjectively evaluate the method. Results: All of the women participating in the research had previously undergone a different method of pelvic floor..

An examination of pelvic floor activity folloving the application of special exercises

Title: An examination of pelvic floor activity following the application of special exercises Objectives: The aim of this thesis is to validate the usefulness of carrying out local pelvic floor muscle examinations as an indication and education for therapy. A second objective is for the women involved in the research to subjectively evaluate the examination methods and therapy. Furthermore, the thesis aims to establish an example of a comprehensive and detailed local examination of the pelvic floor muscles. Methods: We measured the pelvic floor activity per vaginam using an EMG biofeedback device on clients with a pelvic floor dysfunction and grade I stress incontinence symptoms. Based on the results of the examination, therapy using the vaginal device was recommended and in six weeks a follow-up examination was carried out. The changes in pelvic floor activity were evaluated by comparing the initial and follow-up examinations. Thus the usefulness of carrying out an examination of the local pelvic floor muscles before indicating a therapy was validated. At the end of the examination an interview with participating clients was conducted in order to subjectively evaluate the method. Results: All of the women participating in the research had previously undergone a different method of pelvic floor..

Therapeutic techniques in patients with Vertebral Algic Syndrome

FyzioterapieFaculty of Physical Education and SportFakulta tělesné výchovy a sport

Immune Response to Vaccinia Virus Recombinants Expressing Glycoproteins gE, gB, gH, and gL of Varicella-Zoster Virus

AbstractImmunogenicity of Varicella-zoster virus glycoproteins gE, gB, gH, and gL expressed by recombinant vaccinia viruses (VV) separately or simultaneously was determined in mice and guinea pigs by ELISA, Western blotting, radioimmunoprecipitation, plaque reduction assay, and skin test. Single VV-gE and VV-gB recombinants and double VV-gH/gL recombinant elicited specific antibodies with VZV neutralizing activity in mice. Co-expression of gE and gB by one recombinant VV resulted in an increased antibody response in comparison with immunization with single recombinants or their mixtures. Unlike anti-gB and anti-gH/gL antibodies, the gE-specific antibodies had no virus neutralizing activity in absence of complement, and when used alone, they even caused considerable increase of VZV infectious units. Moreover, immune sera containing anti-gE antibodies antagonized complement independent virus-neutralizing activity of anti-gB- and anti-gH/gL-positive sera. The ability to induce delayed hypersensitivity reaction to VZV antigens was observed after immunization of guinea pigs with gE- and/or gB-expressing VVs

Titania supported Co-Mn-Al oxide catalysts in total oxidation of ethanol

Catalytic activity of the Co–Mn–Al mixed oxide catalysts (Co:Mn:Al molar ratio of 4:1:1) supported over titania was examined in total oxidation of ethanol. The prepared catalysts were characterized by chemical analysis (AAS), surface area measurements, and temperature programmed techniques (TPR, TPD). In ethanol oxidation, the catalysts activity gradually increased with increasing active phase content. Low concentration of Co–Mn–Al oxides in the catalyst negatively affected formation of reaction byproducts: carbon monoxide production steeply increased when Co + Mn metals concentration were lower than 5 wt.%. On the other hand, formation of the second main reaction intermediate, acetaldehyde was limited, when acidity of the catalyst was not high, i.e. concentration of Co–Mn metals over titania was low.Web of Science179123823

Photochemistry of Common Xanthene Fluorescent Dyes as Efficient Visible-light Activatable CO-Releasing Molecules

Xanthene derivatives are organic dyes, some of which are routinely used in different chemical and biological applications, including human medicine. In this work, we investigated the photochemistry of some of the most common ones, fluorescein, eosin Y, and rose bengal, and major products of their photodegradation using optical spectroscopy, NMR, chromatography and mass spectroscopy techniques. These substances, usually considered (photo)chemically stable, were found to liberate carbon monoxide (CO) in 40–80% chemical yields upon extensive irradiation with visible light in aqueous solutions during their multistep concomitant degradation processes. In addition, a number of low-mass secondary photoproducts, such as phthalic and formic acids, were identified in the irradiated mixtures. We demonstrate that these common fluorescent dyes can also be considered as visible-light activatable carbon monoxide (CO)-releasing molecules (photoCORMs) under specific conditions with potential biological implications