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Dissertations / Theses on the topic 'Pevnost v příčném tahu'
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1
Gottwaldová, Aneta. "Studium vlastností cementových kompozitů s rozptýlenou výztuží z anorganických vláken." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2019. http://www.nusl.cz/ntk/nusl-392335.
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Diploma thesis deals with study of properties of cementious composites with fiber reinforcement from glass and basalt inorganic fibers. Diploma thesis includes a theoretical and experimental part. The theoretical part deals with information about glass and basalt fibers, their durability and usage. In the experimental part we monitored properfies of cement composites with basalt and glass fibers. Fibers were exposed to an aggressive environment. The properties of composites with reference fibers were compared with composites with fibers affacted by the aggressive environment. The properties of composites were examined after 28 and 90 days. We monitored compresive strenght, bending tensile strenght, tensile strenght, surface layer strenght and SEM.
2
Alexa, Martin. "Vliv mnohonásobného zatěžování na vybrané parametry lehkého betonu." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2018. http://www.nusl.cz/ntk/nusl-371809.
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The diploma thesis deals with the observation of the values of selected parameters (especially the static modulus of elasticity) of light-weight concrete in compression before and after multiple cyclic loading. The deformation of test specimens during multiple cyclic loading were measured with resistive strain gauges. Test specimens (cylinders with a diameter of 150 mm and height of a 300 mm) were cyclically loaded and up to 4 500 loading cycles were performed. The aim of this thesis is assessment changes in the values of static modulus of elasticity depending on the number of loading cycles.
3
Mikulíková, Petra. "Nestmelené a stmelené směsi z betonového recyklátu dálnice D1." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2014. http://www.nusl.cz/ntk/nusl-226617.
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The work is divided into two parts. The first part deals with the description of unbound and bound base layers and their comparison. Furthermore is presented the description of the recycled concrete, its properties, production, improvement and issues. International experiences with recycled concrete technology are described as well. The practical part is focused on laboratory testing of concrete recycled material taken from the highway D1. The aim of this part is to determine whether the concrete can be recycled back into unbound or bound base layers and concrete casing.
4
Ševc, Jan. "Studené asfaltové směsi s R-materiálem." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2016. http://www.nusl.cz/ntk/nusl-240090.
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The thesis is focused on the use of R-material into cold asphalt mixtures. It deals with cold recycling and with input materials for this technology. It verifies properties of R-material and residues of bituminous binder. It also verifies properties of designed cold asphalt mixtures by the probative controls (indirect tensile strenght and water resistance). Furthermore is focused on the experimental measurement of selected mixtures to ensure more characteristics. The amount of homogenity of R-material, quantity and quality of residues bituminous binder is essential for positive results.
5
Pokluda, Radim. "Stavební recykláty pro stmelené směsi vozovek." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2013. http://www.nusl.cz/ntk/nusl-226040.
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In the theoretical part of the thesis are generally characterized hydraulically bound mixtures, their types, classification systems, manufacturing technology and the laying. There are also described experiences from abroad with the use secondary and recycled materials in hydraulically bound mixtures. The practical part deals with the experimental verification of the possibility of the use of secondary materials in hydraulically bound mixtures in construction of road infrastructure. In road laboratory Institute of road structures Brno university of technology was the five proposed mixtures, an assessment of their parameters with regard to the possibility of using these mixtures in the road sub-base layers. The work is also aimed at comparison of results elasticity modules reached laboratory testing and experimental measurements on road polygon.
6
Chloupek, Adam. "Využití nestandardního drobného kameniva do stmelených směsí podkladních vrstev vozovek." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2019. http://www.nusl.cz/ntk/nusl-391995.
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The works deals with the possibilities of using non-standard fraction of fine crushed aggregate in route base layers. Goal of my thesis is research of using material from specific location. Theoretical part summarizes basic knowledge regarding bound mixtures and their normative requirements. Practical part of my thesis describes my various mixture design and following testing and determination of design properties by official and experimental tests. The conclusion summarizes the researched outputs and findings, which confirm the future possibilities of using this material in base layers.
7
Stavař, Tomáš. "Změna trvanlivosti betonu z recyklovaného betonu variantní adicí silikátových příměsí." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2013. http://www.nusl.cz/ntk/nusl-225883.
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The master thesis dealing with problematic about durability of concrete, with use of recycled concrete and addition of silica additions. Predominant for resistance of concrete constructions is surface layer, through which aggressive gasses and liquids penetrate from surrounding environment. The most important indicator of concrete durability is ability of surface layer transmissions of aggressive substants. In experimental part will be defined the actual state of surface layer by normal testing methods. The transmissions of surface layer will be tested on concrete cubes. Tests for transmissions of air (method TORRENT), of water (method ISAT), of acid gases (dept of carbonation by quick test in 98% CO2) will be carried out and also strength tests. Assessment of positive or negative influence of additions and amount of cement on durability and mechanical properties of concrete will be discussed in conclusion.
8
Růžička, Martin. "Závislost mezi pevností v tahu a tvrdostí hliníkových slitin." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2020. http://www.nusl.cz/ntk/nusl-417516.
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This thesis deals with relationship between tensile strength and hardness of aluminium alloys. The introduction provides an overview of aluminum aloys and their properties. In the following section there is an analysis of the processing of aluminum alloys. A large part is devoted to the course of precipitation hardening. The second part of the thesis contains a practical part, which describes the methodology of measuring hardness and tensile strength. The measurement process is described below. At the end, the measured data are processed into various graphs and their results are evaluated.
9
Habrová, Karolína. "Vlastnosti lepených spojů plněných mikročásticovým plnivem." Master's thesis, Česká zemědělská univerzita v Praze, 2016. http://www.nusl.cz/ntk/nusl-256971.
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This thesis deals with the measuring of adhesive and cohesive characteristics of composite systems filled with microparticles of glass powder.
The theoretical part describes in detail composites from their historical development
to the present, also their characteristics, general properties, distribution and types of fibers
and matrices. Emphasis is placed on composites filled with particulate filler and current researches in the field of composites with glass filler. Furthermore, the adhesion and cohesion of filled systems is described.
The experimental part of this thesis includes a methodology, which describes in detail
the used materials, methods of preparation of mechanical testing and statistical analysis. The results of mechanical tests for all three composite mixtures and evaluation of cost savings are appended to this thesis.
10
Wasserbauer, Jaromír. "Lokální zkoušky mechanických vlastností materiálů." Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2009. http://www.nusl.cz/ntk/nusl-216510.
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This thesis deals with measurement of hardness and microhardness in relation to structure of homogeneous and heterogeneous materials. In the introduction basic theoretical background is commented, i.e. definitions, terminology, principles of measuring techniques for estimation of hardness, microhardness, tensile strength, compressive strength and bending strength. Follows a brief review of present research results focused on use of described principles in materials engineering. Then the experimental equipment and sample preparation is described. The crucial part of the thesis is summary of achieved results of original measurement and discussion of their relations to each other. Finally, the groundbreaking estimation is described, showing the correlation of chemical composition gradient and mechanical properties in interfacial zone of geopolymeric material.
11
Vinter, Václav. "Latexy modifikované cementové materiály." Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2008. http://www.nusl.cz/ntk/nusl-216351.
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In this thesis, the development of mechanical properties and structure of latex modified cementious materials during hydration was studied. Latex modified materials are composites of inorganic cement (portland cement) and organic polymer latex. Preparation, processing and fabrication of the polymer cement material based on portland cement was optimized with aim to reach the most compact structure of the product with the finest mechanical characters. The experimental part was pointed to observe influence of the type and amount of polymer latex with focus on mechanical characters and hydration kinetics with given filling as well as without it. In presented work, the possibility of compaction of the material by high-shear mixing within twin-roll mixer (the prototype for production of MDF composite) was verified. The second part of the labor was aimed to analysis of prepared polymer-cementitious material. For determination of influence of batching of added polymer latex on hydration of cement paste the thermal analysis (DTA/TGA) and infrared spectroscopy of composite was done. At last the microscopic observation by optical microscope was carried.
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Nedbalová, Radka. "Příprava a vlastnosti pěnových materiálů na bázi Bioskla." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2014. http://www.nusl.cz/ntk/nusl-231661.
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The work deals with the preparation and mechanical properties of coated Bioglass® 45S5 based foam materials with open porosity. The samples have been fabricated applying the replication method with use of polyurethane foam. Furthermore, these samples were coated in order to increase the strength characteristics and crack resistance. Polyvinylalcohol and PVA with cellulose microfibrils have been used as coating. Besides microstructural parameters of investigated materials using the SEM images strength characteristics in compression and in tension were also quantified.
13
Myšičková, Lucie. "Vývoj a zkoušení vysokohodnotných betonů pro subtilní konstrukce." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2014. http://www.nusl.cz/ntk/nusl-226971.
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Thesis describes properties of HPC compared to concretes of normal and high strength. It further describes the input materials and the procedure for designing the composition of the mixture. It gives examples of already completed structures made of HPC. The experimental part describes the optimization of concrete mix and production of specimens. In the end results of testing the properties of the developed mixes from tests of dynamic and static modulus of elasticity, compressive strength and tensile strength by bending are described.
14
Hanuš, Petr. "Experimentální ověření vlivu typu vláken na chování vláknobetonů." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2019. http://www.nusl.cz/ntk/nusl-392039.
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This diploma thesis deals with the comparison of different properties of fibre-reinforced concrete according to the type of fibres. The main monitored property is flexural strength, tested on prisms with a cross section of 150x150 mm and a length of 600 mm. Four concretes of natural aggregate and four concrete of lightweight aggregate were prepared for the experiment. There were 2 reference concrete and 6 fibre-reinforced concrete. Three types of fibres were used: steel, polypropylene and glass. More than 2500 kg of concrete was produced. The aim of the thesis is to assess the influence of fibres on the flexural strength and other characteristics of fibre-reinforced concrete.
15
Procházková, Lenka. "Využití dynamických nedestruktivních metod pro zjišťování pevností cementů z cementárny Hranice." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2017. http://www.nusl.cz/ntk/nusl-265287.
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Nondestructive testing methods are employed as a tool for evaluation of parameters of building materials, especially to ascertain strength properties and to determine alteration occured during durability tests. An ultrasonic pulse velocity method is one of the most used nondestructive methods. A resonance method is employed among the nondestructive methods less. The aim of this work is to establish the calibration relationships between parameters of nondestructive testing and compressive strength value and flexural tensile strength value, respectively. Moreover, applicability of the calibration relationships is also discussed.
16
Sáček, Josef. "Vysokohodnotné betony na bázi druhotných surovin." Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2008. http://www.nusl.cz/ntk/nusl-216352.
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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.
17
Dvořák, Richard. "Studium efektu aplikace celulózových vláken v cementových kompozitech." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2016. http://www.nusl.cz/ntk/nusl-240420.
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This diploma thesis is focused on composition and processing of cellulose fibers and their usage in cementitious composites. It describes key attributes of cellulose fibers, which has to be acquired for effective use in cement composites. There are stated effects of cellulose fibers on concrete properties, such as workability, physical and mechanic attributes and freeze-thaw resistance. In experimental part is designed a mixture with portion of cellulose fibers. There has been performed various tests to define the effect of cellulose fibers. There was designed experiment to determine its alkali resistance for fibers itself, and possible changes in microstructure of fibers were analyzed by optic and electron scanning microscope.
18
Žižlavský, Tomáš. "Vliv použitého kameniva na vlastnosti vápenných malt." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2017. http://www.nusl.cz/ntk/nusl-265681.
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The thesis is focused on the comparison of the role of different types of aggregates and the binder-aggregate ratio on the properties of lime mortars. The theoretical part of the thesis deals with the effect of properties of aggregate, a binder-aggregate ratio and a use of calcareous aggregate, especially limestone, on the properties of mortars. It also deals with the utilization of limestone as aggregate in a history of masonry. In the practical part of the thesis there is a comparison of physically-mechanical and microstructural properties of mortars prepared with different type of aggregate (siliceous sand and limestone aggregate), with varying binder-aggregate ratio and also with a partial substitution of the aggregate by limestone fines. It was found that the usage of limestone instead of quartz sand produces the mortar of comparable properties. The partial substitution of the aggregate with limestone fines caused noticeable growth of strength, especially in mortars with higher binder-aggregate ratio.
19
Láník, Jaromír. "Vliv rozptýlené výztuže na fyzikálně-mechanické parametry výsledného kompozitu." Doctoral thesis, Vysoké učení technické v Brně. Fakulta stavební, 2015. http://www.nusl.cz/ntk/nusl-234541.
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The dissertation is focused on the issue of implementation and evaluation of the laboratory tests fiber reinforced concrete. The issue of steel fiber is solved in terms of their physico-mechanical parameters, which are an important part of their design and reliable operation in the product design. The experimental part of the thesis is focused on laboratory tests of steel fiber of different strength classes and different weight benefits of steel fibers, the default reference mixture of plain concrete are certified mixtures commonly used as structural concrete in construction. The evaluation of the testing of samples produced steel fiber is made by three selected recommending regulations for the design and testing of structural steel fiber. In conclusion, the individual obtained experimental results are compared.
20
Řezník, Bohuslav. "Geopolymery na bázi elektrárenských popílků a cihelného střepu." Doctoral thesis, Vysoké učení technické v Brně. Fakulta stavební, 2014. http://www.nusl.cz/ntk/nusl-390250.
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In line with the current focus on utilizing side products of various production processes, this dissertation thesis analyzes the process of alkali activation of particular side products: fly ash and brick fragments. This activation produces geopolymeric materials widely used in civil engineering. The thesis aims to optimize the geopolymerization process so that the resulting geopolymer is both ecologically and economically viable. To that end, the thesis studies the course of geopolymeric reaction between the alkali activator and fly ash from: (i) the Chvaletice power plant, (ii) the Dětmarovice power plant, and (iii) biomass combustion, as well as (iv) fluid fly ash from the Hodonín power plant. All experiments of geopolymeric reaction have focused on the factors influencing the synthesis of geopolymers—that is: composition of the alkali activator, the ratio of alumino-silicate to the activator, and the impact of temperature on structure of the synthesized geopolymer. Further, the thesis analyzed the synthesized polymer’s microstructure, phase composition, resistance against corrosive conditions, and compressive strength, as well as mechanical-fracture properties of selected fly-ash geopolymers. The thesis finds that the most suitable for geopolymeric synthesis appears to be the fly ash from the Chvaletice power plant in which case the obtained geopolymers showed best properties in the studied areas. The fly ash from the Dětmarovice power plant, biomass fly ash, and fluid fly ash have failed to reach acceptable properties. Separately, the thesis studies the geopolymerization of brick body that could be suitable input for alkali activation. The geopolymers synthesized from brick fragments resulted in materials of supperior mechanical strength. A mixed use of fly ash and brick fragments failed to show a synergetic effect. Properties of the resulting geopolymers have been inferior to the properties of geopolymers produced using just fly ash or just brick body.
21
Hlaváček, Jaroslav. "Příměsi ovlivňující tuhnutí portlandského cementu." Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2012. http://www.nusl.cz/ntk/nusl-216898.
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During the production of concrete is important the careful selection of raw materials. Nowadays, we are trying in the production to minimize the economic burden and to maximize the use of secondary raw materials. This work is focused on the use of secondary raw materials from the energy industry in construction for the preparation of hydraulic binders. As the main raw materials were used different power plant fly ash from fluidized combustion. The composition of these secondary materials is quite different from conventional high-temperature ash, due to mixing with water they solidify and harden. Experiments were performed with three lodge fly ash from electrostatic precipitators of the fluidized combustion and one high-temperature fly ash. This work is focused on the possibility of monitoring the use of these secondary materials in construction, especially when tests were evaluated characteristics of strength and speed of setting and hardening.
22
Panenková, Monika. "Reaktivní práškové kompozity a cementové kompozity bez makropórů." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2018. http://www.nusl.cz/ntk/nusl-372126.
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This diploma thesis deals with the design principles and manifacture of ultra performance concrete (UHPC), reactive powder composites (RPC) and other fine-grained materials, such as Macro defect free (MDF) or Densified systems with small particles (DSP). Theoretical part of this work is focused on the requirements of properties and composition UHPC and RPC and methodology of their design principles. Experimental part describes design principles RPC, manufacture of test specimens, testing of certain physical and mechanical properties, such as tensile strenght, bending strenght and compressive strenght and determination chemical character X-ray and thermal analysis.
23
Janoušek, Petr. "Vývoj kompozitů na bázi anorganických pojiv určených pro extrémní aplikace." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2013. http://www.nusl.cz/ntk/nusl-225913.
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The topic of this master's thesis is the development of composite materials based on inorganic binders for use in extreme conditions. It means especially geopolymeric or alkali activated materials (AAM) based composites. The theoretical part of this thesis summarizes knowledges about the development and use of alkali-activated materials, their structure and mechanisms of their formation. It also deals with the applicable raw materials for AAM and their exciters, which are in particular water glass and sodium hydroxide. There also have been a summary of the effects of high temperatures and chemicals on the mechanical properties of AAM and the requirements of standard EN 1504-3 for repairing materials. The task of the practical part was to develop a repair mortar for concrete structures based on AAM so that its production was as simple as possible, ie one-component materials. Gradually six recipes have been develeoped. Test specimens made from these recipes have been putted to selected tests according to the requirements of ČSN EN 1504-3.
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Plochý, Ondřej. "Vývoj sklobetonů s vysokými mechanickými vlastnostmi." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2018. http://www.nusl.cz/ntk/nusl-371943.
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This master thesis summarizes the current knowledge regarding the design and properties of glass fiber reinforced concrete products. It also deals with the design of a new concrete recipe for Dako spol. s.r.o company. There is verified effect of changes in input materials in real conditions the company to increase tensile bending strength above 20 MPa.In particular, verification of the use of building chemistry like superplasticizing additives, polymer-cement matrix or a change type or dose of glass fiber.
25
Černý, Miroslav. "Hybridní směsi na bázi recyklovaných plastů." Doctoral thesis, Vysoké učení technické v Brně. Fakulta chemická, 2017. http://www.nusl.cz/ntk/nusl-369742.
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Work describes the relationship between structure and mechanical properties in case of hybrid mixtures. They are composed from polyurethane matrices (eventually polyurethane-urea or polyurethane-inorganic filler mixtures), different rubber fractions as filler and eventually reinforcement made from PET monofilaments. Mechanical behaviour was studied by tensile testing. Studied mechanical properties include tensile modulus, ultimate strength and strain and also specific energy need neccessary for ultimate strength achievement. Prepared materials are naturally porous. Therefore their mechanical behaviour has to be described generally for porous composites. The porosity occurence means, that it is difficult to describe them by models valid for mechanical behaviour (mainly elastic modulus) of nonporous composites. Models are also based on idealized structures on microscopic level. In case of porous composites, it is very difficult to create any idealized structure. The structure is changed with modifications of composition (change of components or their rates). These conditions have lead to utilizing of different approach how to describe the relationship between structure and mentioned mechanical properties. The chosen approach comes from knewledge about structural parametres coming from porosity. Structural parameters describe the structure on macroscopic level. They include interspace volume (volume lying between filler particles), interspace filling (how the matrix fills the interspace volume) and matrix volume fraction. Proposed parameters are used in relations, where they are fitted by exponents to interlay values of chosen mechanical properties for composites containing discrete matrix and filler. Found exponents are then described by properties of matrices to obtain relations describing properties of filled porous materials. Very similar approach was chosen for description in the case of reinforced composites. Proposed relation are potentially valid for materials containing binding matrix, infinity count of fillers and one kind of reinforcement.
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Vorel, Pavel. "Vlastnosti betonů s přídavkem plazmatem upravených polypropylenových vláken." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2013. http://www.nusl.cz/ntk/nusl-225879.
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Master‘s thesis focuses on concrete combined with polypropylen fibres produced commercially, fibres without surface modifications and fibres modificated by plasma. Most important topic of the thesis is experimental verification of influence of plasma modificated fibres on attributes of fresh concrete and physical-mechanical attributes of solidified concrete. Based on the results of the tests perfomed on examin units compares results and anylyses applicability of different fibre surface modifications.
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Horák, Kryštof. "Posouzení vlivu odlišných technologických podmínek výroby na vlastnosti dřevěných briket." Master's thesis, 2011. http://www.nusl.cz/ntk/nusl-90857.
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Hromádka, Petr. "Pevnost lepeného spoje ve smyku materiálů na bázi dřeva v extrémních podmínkách." Master's thesis, 2014. http://www.nusl.cz/ntk/nusl-179324.
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This thesis deals with the issue of adhesive joints under extreme conditions. The aim of this work is to determine influence of temperatures -30 °C, +23°C, +70 °C on maximal tensile strength of adhesive joint and to determine which adhesive has the best results when used on specific agglomerated materials. Manufactured samples (chipboard, chipboard press-veneered by spruce, fibreboard, beech plywood board) were used in process of solving the task. These samples were used in accordance with standard ČSN EN 205. Data were processed by software and evaluation was accomplished by using statistical methods. As a result of a detailed research the adhesives appropriate for use in extreme conditions on Earth were determined. Contribution of this work is clarification of the impact of exposure temperature, type of adhesive and interaction between temperature of exposure and type of adhesive. Based on obtained results appropriate type of adhesive for given temperature during maximal tensile stress can be recommended.
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Hrabovský, Štěpán. "Vliv teploty na pevnost svařeného a lepeného spoje z materiálu Resysta®." Master's thesis, 2016. http://www.nusl.cz/ntk/nusl-362177.
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This master thesis shortly deals with properties and usage of the Resysta material. The main objective of this thesis is to determine a temperature influence on tensile strength of welded and glued joints made from the material Resysta, for an usage such as an outdoor furniture, temperature influence analysis of the joints and to present the results of the analysis obtained by measurements. Further objectives are: tensile strength experiment of material Resysta and to determine influence of placing the pieces in a desk in different directions. Results will serve as a basis for a specific firm; as a basis for deciding between technology of gluing and a technology of welding and also for input for a custom made single purpose machine made for welding of material Resysta. Tests were performed in exposure temperatures -30 °C, 20 °C and 60 °C. We will perform two tests; first test will focus on the tensile strength of glued and welded joints and second one will try to test of tensile strength of Resysta material. Experiments were conducted according to standards ČSN EN 205 and ISO 527-1 on the Instron 3365 testing machine. Laboratory tests showed that values of tensile strength were decreased while increasing the exposure temperature and this was consistent in every test performed. A statistical significance was also confirmed in work piece direction influence on a board. There were higher values of the tensile strength in longitudinal direction than in the transverse.
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Falátek, Adam. "Pevnostní a ekonomické parametry strojově šitých švů v současné čalounické výrobě." Master's thesis, 2018. http://www.nusl.cz/ntk/nusl-428290.
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This thesis dealt with strength and economic parameters of machine-sewn seams in current upholstery production. It is focused on the determination of the tensile strength of the bound seams and the influence of the decorative seams and the various types of lining on it. In the economic part of the test, material and time consumption is measured. The result is the evaluation of the different types of seams and lining and taxation in connection with the consumption of time, materials and their cost.
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Polák, Vojtěch. "Analýza jakosti „Cold Metal Transfer“ svarů." Master's thesis, 2015. http://www.nusl.cz/ntk/nusl-250185.
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This diploma thesis is focused on overall research of the quality of joining steel and aluminum alloy using the CMT welding process. The theoretical part describes the principle and the technology of the welding system that allows joining dissimilar materials by an electric arc. Attention is also given to other modes such as CMT Advanced, CMT Pulse and CMT Advanced Pulse, which further improve the innovative process. These modifications include an efficient tandem method CMT Twin that uses two electric arcs in various combinations. The main aim of the experiment is assessment of the quality of created CMT joints. Individual tests are conducted to evaluate the corrosion resistance in an aggressive environment (salt fog). The testing subsequently evaluates mechanical properties by a destructive tensile test to determine the tensile strength. Part of the quality assessment is metallographic analysis including determining the elemental composition of the weld.
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Šmíd, Pavel. "Vliv modifikace na pevnost lepení buku." Master's thesis, 2019. http://www.nusl.cz/ntk/nusl-428635.
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This diploma thesis is focused on the influence of thermal modification on the strength of bonded joint in tension according to ČSN EN 205. For the purpose of this work was used beech wood. The thermal modification of the test samples was performed at temperatures of 160 °C, 180 °C and 200 °C. The selected bond strength adhesives were melamine-urea formaldehyde adhesives (MUF), phenol-resorcinol formaldehyde adhesives (PRF) and one-component polyurethane adhesives (PUR). In addition to the thermal modification the effect of plasma modification on bond strength is also determined. The test lamellas were plasma treated (DCSBD) prior to gluing and pressing. The result is the determination of the tensile strength of the bonded joint in all the above-mentioned modifications and comparation of the results.
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Hávová, Šárka. "Studium lisovacího procesu a vlastností tablet s hypromelosou a monohydrátem α-laktosy." Master's thesis, 2014. http://www.nusl.cz/ntk/nusl-337309.
Full textAbstract:
Charles University in Prague Faculty of Pharmacy in Hradec Králové Department of Pharmaceutical Technology Student: Šárka Hávová Supervisor: PharmDr. Jitka Mužíková, Ph.D. Title of diploma thesis: A study of compaction process and properties of tablets with hypromellose and α-lactose monohydrate Thesis studied the co-processed dry binder RetaLac® from the aspect of his compressibility and dissolution of the active ingredient from tablets. RetaLac® contains α-lactose monohydrate and hypromellose in the identical proportion. The same parameters were tested in the corresponding physical mixtures of FlowLac® 100 with various types of hypromellose (Metolose® 100 SR, Metolose® 4000 SR, Metolose® 100 000 SR) and compared with the substance RetaLac® . Compressibility was evaluated by means of the energy profile of compression and tensile strength of tablets. Salicylic acid was used as the model active ingredient. Dissolution testing was performed using the method of the rotating basket.