• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 155
  • 139
  • 53
  • 35
  • 18
  • 14
  • 14
  • 10
  • 8
  • 5
  • 3
  • 3
  • 3
  • 3
  • 3
  • Tagged with
  • 524
  • 191
  • 134
  • 86
  • 86
  • 80
  • 73
  • 50
  • 48
  • 48
  • 46
  • 44
  • 40
  • 37
  • 37
  • 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.
471

Vysokohodnotné betony na bázi druhotných surovin / High-performance concretes based on the secondary raw materials

Sáček, Josef January 2008 (has links)
This work is devoted to study of physical-mechanical properties and structure of high performance concretes (HPC) based on portland cement. The attention is focused on possibility of substitution of economic high-cost components of concrete with utilization of secondary raw materials or cheaper components. Properties of raw materials and their influence on whole quality of concrete were tracked by various methods. Mechanical properties of prepared HPC samples were tested especially (compression and flexural strength) with further microscopic study of structure. Isoperibolic calorimetry and X-ray powder diffraction method were also used for concrete characterisation. These methods allowed to determine the influence of raw materials on prepared HPC and to carry out a certain optimization among price and quality of this material.
472

Využití některých velkoobjemově produkovaných druhotných surovin k přípravě pojiv a kompozitů na bázi geopolymerů / Utilization of some massive produced byproducts for preparation of geopolymer based binders and composites

Eckl, Ondřej January 2009 (has links)
Preparation of geopolymer composites from industrial wastes of energy power stations and metalurgy.
473

Prvková analýza anorganických materiálů / Elemental composition analysis of inorganic materials

Szmek, Václav January 2009 (has links)
This work deals with elemental analysis of inorganic materials, that are presented by blast furnace slag and geopolymeric material containing fly-ashes. In the theoretical part there are explained principles of elemental analysis of inorganic materials. Ways of dissolution of samples, optical emission spectroscopy and electron microscopy with energy dispersive x-ray analysis are commented. In experimental part the ICP analysis of oxide standards is described. The standards were used for estimation of EDS-correction factors. Then follow the preparation, proving and use of standards in analysis of blast furnace slag. The work is finished by exact analysis of concentration profiles of elements in interface of phases in geopolymeric material.
474

Možnosti využití odpadních písků z výroby vodního skla ve stavebnictví / Possibilities of the utilization of the waste sand from the water glass production in building industry

Bílek, Vlastimil January 2013 (has links)
Nowadays, the waste sands from the water glass production have no utilization and due to high alkali content are considered as a dangerous waste. So the aim of this thesis is to find and study some possibilities of their utilization in the building industry. First of all, some necessary analysis of these sands were performed and then some advantages and disadvantages of their application for production of materials based on portland cement and alkali activated materials were studied. Characteristics of fresh and hardened pastes, mortars and concretes containing these waste sands were determined. The most tested properties were their workability and their compressive and flexural strength. Close attention for the risks of alkali-silica reaction and for options of its suppressing by the mineral admixtures was paid.
475

Krematorium ve Žďáru nad Sázavou / Crematorium in Žďár nad Sázavou

Polnický, Vít January 2015 (has links)
The thesis deals with the design of the crematorium located in the municipal land registry of the city of Žďár nad Sázavou. The thesis contains design documentation, technical report, thermal technical appraisal, details of 2D technical field, fire technical report, structural analysis of reinforced concrete structure, heat recovery.The proposed project has two floors.The build-up area is 587 m2. The proposed project has green roof. The building is divided into three working parts.
476

Hydraulické posunovače / Hydraulic pullers

Kvasnica, Tomáš January 2009 (has links)
This Diploma thesis occupies with design of hydraulic puller. In work are mentioned possible types of construction. Choice construction of puller is disposed with parameters: maximum pushing force 50 kN, speed of piston rod 0,05 m/s. This work also contains FEM analysis by computer programme I-DEAS. The work also occupies with design of fluid drive.
477

Zvýšení efektivity při svařování pecních konstrukcí / The effectiveness of welding on furnace structures.

Rousová, Michaela January 2010 (has links)
This diploma thesis is resolving all the possibilities of enhancing the efficiency of furnace structures welding. Small batch production does not offer many possibilities for implementing mechanization or automation. On the other hand, when using a big batch production, efficiency can be enhanced by means of a robotic workstation. When the production batch is big enough, we will see a costs save after a short time, mainly in labor costs. This means the return of investments will be in short time period. In the LAC company there are three types of products made. At laboratory furnaces the efficiency can be enhance by using fixtures. At other standard and atypical furnaces is very difficult to design fixtures or positioners because of their different sizes. Big complication can be also a company location on second floor. The most suitable product regarding to welding efficiency enhancement is big batch production of heaters. For this type the welding time can be shortened by means of a robotic workstation.
478

Predikce koroze trubek pece s využitím provozních dat / Prediction of furnace tubes corrosion using operating data

Kolomazník, Milan January 2014 (has links)
The thesis deals with the modeling and prediction of corrosion of radiation tube snake in the heating furnace. Specifically it is focused on vertical cylindrical furnace which is included in the catalytic hydrocracking unit and serves for heating aggressive circulation gas which is the cause of high temperature corrosion. An important basis for the creation of computational models are available records about the operation of the furnace and about the corrosion and degradation mechanisms during the lifetime of the tube system in furnace. Such information enables the creation of a computational model which is based on the prediction of high-temperature corrosive damage of radiation tube snake. The computational model involving all relevant factors may serve as the basis for a predictive life management system of radiation snakes in the heating furnace.
479

Zařízení pro zásyp odpichového otvoru obloukové pece / Device for filling tap hole of arc furnace

Juda, Lukáš January 2015 (has links)
Diploma thesis describes design and function verification of device for filling tap hole of electric arc furnace with tap hole diameter from 190 mm to 250 mm. The theses includes drive design calculation of chute swinging movement and bearing calculations. Another part of the thesis deals with verification of device functions which it is completed with process description of creating DEM simulation in program YADE. The thesis also includes basic experiments for determination angle of internal friction, angle of repose, coefficient of restitution and angle of material friction on a steel surface. Drawing documentation of selected assemblies is part of the thesis.
480

Optimalizace složení betonů s využitím plniv z recyklovaných betonů / Optimization of the concrete composition with the use of recycled concrete aggregates

Skriňáková, Eva January 2016 (has links)
Concrete as a building material is subject to continuous innovation and thanks to advanced technology and quantum of research, its properties are still improved. It is logical that the more concrete we produce, the more waste it arises. The volume of this waste can not be stored in landfills endlessly, nowadays most of the waste economies in the world are trying to recycle concrete rubble. The recycling is not such a problem, the technology has been long verified but the quality of the recycled concrete aggregate is unquestionably one of the primary assumption which leads to accomplish required properties of concrete. In fact, the recycling process is „crushing“ the concrete into particles with an effort to eliminate the cement paste on the surface of the aggregate. An ideal solution would be create a resistant and firm coating that would adhere perfectly to the cement matrix. This diploma thesis is focused on the properties of recycled concrete aggregate and methods of improvement and optimization of the concrete mix composition.

Page generated in 0.0404 seconds