• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 10
  • 5
  • 2
  • 1
  • 1
  • Tagged with
  • 24
  • 5
  • 5
  • 5
  • 5
  • 4
  • 4
  • 4
  • 4
  • 4
  • 4
  • 4
  • 4
  • 4
  • 4
  • 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.
21

Dodávka energie pro skleníkovou produkci / Energy supply for greenhouse production

Najbrtová, Zuzana January 2021 (has links)
The import of the vegetable has prevailed in the long run over the own production. In connection with this reality and increasing demand for the food with higher quality the production greenhouse is more often built. The providing heat, cold and electricity for the year-round operation is related to the construction and working of these objects. The theoretical part of this theses describes possible ways how to cover energy consumption for the model greenhouse in Kožichovice, Třebíč region. The heat losses and the year-round heat consumption were stated for the selected model and compared with the exact values from Kožichovice. The following method of energy supply was selected based on the calculated energy consumption - the separate cogeneration unit, cooperation of several cogeneration units, a biogas station, a heat pump and central heating system. These methods of energy supply were subjected to technical and economical comparison.
22

Simulation and growth of cadmium zinc telluride from small seeds by the travelling heater method

Roszmann, Jordan Douglas 08 June 2017 (has links)
The semiconducting compounds CdTe and CdZnTe have important applications in high-energy radiation detectors and as substrates for infrared devices. The materials offer large band gaps, high resistivity, and excellent charge transport properties; however all of these properties rely on very precise control of the material composition. Growing bulk crystals by the travelling heater method (THM) offers excellent compositional control and fewer defects compared to gradient freezing, but it is also much slower and more expensive. A particular challenge is the current need to grow new crystals onto existing seeds of similar size and quality. Simulations and experiments are used in this work to investigate the feasibility of growing these materials by THM without the use of large seed crystals. A new fixed-grid, multiphase finite element model was developed based on the level set method and used to calculate the mass transport regime and interface shapes inside the growth ampoule. The diffusivity of CdTe in liquid tellurium was measured through dissolution experiments, which also served to validate the model. Simulations of tapered THM growth find conditions similar to untapered growth with interface shapes that are sensitive to strong thermosolutal convection. Favourable growth conditions are achievable only if convection can be controlled. In preliminary experiments, tapered GaSb crystals were successfully grown by THM and large CdTe grains were produced by gradient freezing. Beginning with this seed material, 25 mm diameter CdTe and CdZnTe crystals were grown on 10 mm diameter seeds, and 65 mm diameter CdTe on 25 mm seeds. Unseeded THM growth was also investigated, as well as ampoule rotation and a range of thermal conditions and ampoule surface coatings. Outward growth beyond one or two centimeters was achieved only at small diameters and included secondary grains and twin defects; however, limited outward growth of larger seeds and agreement between experimental and numerical results suggest that tapered growth may be achievable in the future. This would require active temperature control at the base of the crystal and reduction of convection through thermal design or by rotation of the ampoule or applied magnetic fields. / Graduate / 0346 / 0794 / 0548 / jordan.roszmann@gmail.com
23

Autosalon se servisem / Car showroom with service

Pavlíček, Jiří Unknown Date (has links)
The subject of this master thesis is the elaboration of project documentation for the construction of a car showroom & service. This building is located in Brno, cadastral area of city Brno: Královo Pole. It is a detached building without a basement built on a trapezoid shaped area with a flat terrain. Object is divided into two functional parts: the car showroom and the car service. These two parts are constructionally and operationally connected. The car showroom is designed as a two-storey object, which serves as car exhibition, technical and hygienic facilities and mainly the administrative parts of both objects. The car service is designed as a single-storey object without a basement, which serves as a workspace of the car service and a warehouse. The load-bearing structural system of the car showroom is made of reinforced concrete pillars with ceramic masonry. The load-bearing structural system of the car service is made of reinforced concrete pillars with light sandwich panels. The foundation slab consists of prefabricated stepped foundation pad, prefabricated reinforced concrete grade beam and concrete strip footing. Insulation system of the building is made of insulation boards from basalt wool cladding by ventilated facades with perforated steel panels. Insolation in the car showroom is secured by glass curtain wall in combination with plastic windows and doors. Ceiling structures are designed as prestressed ceiling panels Spiroll. Roofing structure of both objects is supported by prestressed reinforced concrete roof girder in combination with trapezoidal sheet and insulation boards from basalt wool and PIR boards. The roof of the objects is flat with ordinary layer order with waterproof layer from softened PVC.
24

Návrh soustavy CZT a tepelných zdrojů / Design of district heating system and heat sources

Kluzová, Ivana January 2018 (has links)
District heating, heat sources, cogeneration, boiler, biomass

Page generated in 0.0216 seconds