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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
61

Využití hydroformingu při vytváření strukturovaného povrchu solárního panelu / Utilization of hydroforming technology to create a structured surface of solar panel

Řiháček, Jan Unknown Date (has links)
The doctoral thesis deals with utilization of hydroforming technology for manufacturing of a new type of solar absorber, which has directly flow meandering structure and a structured surface consisting of pyramidal elements. Austenitic stainless steel X5CrNi18-10 is used as a material for absorbers production. At the beginning of the thesis, a literary research is performed, which is focused on particular methods of hydroforming technology, their applicability for this problem, forming limits determination and usability of numerical simulation. Based on the literature study, the production technology was developed by using parallel hydroforming technology and it was optimized by using a numerical simulation in the ANSYS software. Hydroforming parameters for two variants of the structured surface with pyramidal cavities with apex angle of 90° and 60° were determined from the calculations and the material tests.
62

Distribuce velikostně segregovaného aerosolu v mezni vrstvě atmosféry / Size segregated aerosol within atmospheric boundary layer

Traxmandlová, Nikola January 2017 (has links)
Phenomenon of industrial grounds placed near residential areas can be frequently detected in European cities, which may cause decrease of air quality in these areas. The aim of this diploma thesis is to determine level of concentration and size distribution of aerosol in the planetary boundary layer above the residential area and industrial complex of Škoda auto a.s. in Mladá Boleslav city by using remotely controlled airship. Thereby, the thesis extends terrestrial experiment realized in February and March 2013 which revealed no significant impact of industry and traffic on air quality. Size distribution and concentration of aerosol particles in range from 11.5nm to 10µm with integration time one second or one minute (depending on measure mode - SINGLE or SCAN) was measured by two aerosol spectrometers placed in dirigible gondola during 13 flights on February 11, 2015. SINGLE mode lead the airship in one stable flight level during one flight above residential area and industrial complex of Škoda auto a.s. Whereas SCAN mode changed flight level every two minutes during the flight of airship above sports fields in residential zone only. Exhausts of car painting halls and place of automobile loading were identified as the sources of nanoparticles, PM1 a PM2.5 and coarse aerosol in the industrial area...
63

Využití hydroformingu při vytváření strukturovaného povrchu solárního panelu / Utilization of Hydroforming Technology to Create a Structured Surface of Solar Panel

Řiháček, Jan January 2017 (has links)
The doctoral thesis deals with utilization of hydroforming technology for manufacturing of a new type of solar absorber, which has directly flow meandering structure and a structured surface consisting of pyramidal elements. Austenitic stainless steel X5CrNi18-10 is used as a material for absorbers production. At the beginning of the thesis, a literary research is performed, which is focused on particular methods of hydroforming technology, their applicability for this problem, forming limits determination and usability of numerical simulation. Based on the literature study, the production technology was developed by using parallel hydroforming technology and it was optimized by using a numerical simulation in the ANSYS software. Hydroforming parameters for two variants of the structured surface with pyramidal cavities with apex angle of 90° and 60° were determined from the calculations and the material tests.
64

Rekonstrukce zásobníku na slínek / Reconstruction of the cement component storage structure

Bažantová, Lenka January 2018 (has links)
The thesis is focused on the design of the reconstruction of the reinforced concrete pre-stressed construction of the clinker reservoir. The supporting system of the structure consists of a reinforced concrete wall on which a prestressing reinforcement is applied in the sprayed concrete layer. Preliminary research revealed disturbances that could disrupt static objects. The aim of this work is to propose a solution for the reinforcement of the supporting structure. The thesis contains two variants of the reconstruction solution. A static report is prepared for the selected option, including the impact of the construction, the construction procedure and the drawing documentation.
65

Aplikace dílčích součinitelů spolehlivosti při hodnocení bezpečnosti vodních děl / Application of partial reliability factors for safety assessment of dams

Szarowski, Marcin January 2018 (has links)
The diploma thesis deals with an application of partial reliability coefficients of reliability in assessing the safety of water works. The reliability factors are the quantitative condition of the marginal equilibrium. A more detailed study of the methods of the marginal equilibrium method led to an assessment of the overall and local stability of the Vranov Dam. The baseline for the evaluation were the data provided by the Technical Surveillance (TBD) and available literature. The GeoStudio 2018 was used to calculate the loads on the Vranov waterworks. The model of the groundwater flow in the subsoil was calculated by the Seep/W module and the Sigma/W module was used to determine the local stresses. Subsequently, the selection of partial reliability coefficients and theirs subsequent application to the limit equilibrium conditions were performed. Stability assessments were complemented by calculations of safety factors. The results were compared with each other.
66

Tenkostěnný pravoúhlý přeliv bez bočního zúžení ovlivněný šířkou koryta / Full-width thin-plate rectangular weir influenced by channel width

Zmítko, Jakub January 2020 (has links)
The diploma thesis deals with the propagation of a weir (channel) width on the weir capacity. The influence rate is analyzed by laboratory measurements on models with a weir (channel) width of 0,02 m to a width of 0,50 m. Different heads are analyzed and different discharges that calculate the discharge coefficient. The results are compared with previous works, especially with the work of Kindsvater and Carter (1957) and of Schoder and Turner (1929), where the same procedures are used to calculate discharge coefficients. The thesis contains a theoretical introduction to the problem of thin-plate weirs and the problem of the formation of the boundary layer in the flow of liquid, following with the analytical part. In the analytical part, the results of measurements, their comparison, and evaluation are published. The work is completed with evaluation and recommendations.
67

Návrh nosné železobetonové konstrukce rodinného domu / Reinforced concrete structures of a family house

Bátrlová, Petra January 2019 (has links)
This diploma thesis concerns with a design of structure of a family house, garage and supporting wall. Design of these structures was accomplished id software SCIA Engineer, which uses finite element method and was veryfied by manual calculation. Design was ma-de in accordance with applicable standarts. The results are drawings of reinforcement of family house.
68

Návrh a kontrola parametrů zásobní smyčky linky pro zpracování plechu / Design and examination of parameters of the line stock loop for sheet metal processing

Novák, Tomáš January 2020 (has links)
Master thesis is focused on determination of stress and deformation state of metal sheet in stock loops of non-standard dimension. The main goal was creating numerical model and de-termination of maximal possible stock of metal sheet for all requested parameters. The problem was solved using Finite element methods in the software ANSYS. Results were handed to ŽĎAS, a.s. corporation, where they will be used for design of the lines for metal sheet proces-sing of non-standard dimension. Another goal was estimation, how the residual stress in metal sheet can effect the observed stress state.
69

Filtry vyšších řádů s proudovými zrcadly / Current mirror higher-order filters

Novotný, Matouš January 2010 (has links)
Submitted work engages in suggestion of frequency-selection filters with usage of more active elements of the MCMI (Multi-Output Current Mirror and inverter). The preamble of thesis is applied to theory of frequency-selection filters and possible usage of them. The projected circuit layouts with the active elements are discussed in terms of the impact of parasitic properties of the real models. The part of thesis is numerical suggestion of found solutions, their simulation in suitable program.
70

Řiditelné kmitočtové filtry s moderními aktivními prvky / Controllable Frequency Filters with Modern Active Elements

Preclík, Milan January 2010 (has links)
The work deals with design of transformation cells suitable for realization of higher orders frequency filters with possibility of cutoff frequency control. At first, there is a common description of frequency filters and active elements like current and voltage conveyors. Furthermore assumptions of cutoff frequency control are defined which result in a convenient characteristical equation. Phylosophy of synthetic elements DP , EP , DS , ES including a possibility of change of cutoff frequency is next in line. By exploitation of synthetic elements theory new circuit’s schemes of transformation cells are searched. The work continues with the choice of appropriate transformation cells for resulting circuit’s solutions of frequency filters with possibility of cutoff frequency control by using transfer coefficients of active elements or with help of passive elements. The work concludes with verification of its proper function based on a simulation executed in OrCAD and with practical implementation of choosen circuit’s solution.

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