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Traffic Shaping in High Speed Networks in DPDK
Doležal, Pavel ; Fukač, Tomáš (referee) ; Vrána, Roman (advisor)
This bachelor thesis is focused on traffic shaping in high speed networks. It presents framework DPDK, which can be used for fast packet processing. General traffic shaping mechanisms are described as well as traffic shaping in Linux using program tc. It also introduces a design and implementation of traffic shaper using DPDK framework for networks with 10 Gbps bandwidth. The traffic shaper uses a complex mechanism of hierarchical token bucket. The system was tested using high speed traffic generator Spirent.
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Materials of football shoes
Ponížil, Ondřej ; Doležal, Pavel (referee) ; Molliková, Eva (advisor)
This thesis is about materials of football boots and possibilities of their technological process. The thesis is divided into three main parts. The introduction part contains the basic facts about football and there is also a description of historical development of the football boots which includes advantages and disadvantages of the structure at that time. The second part presents permeable, flexible and durable materials which can be used to produce the upper part of the boots. In this part there are described attributes of the most common technological process which produces synthetic leathers. The final part is about polyamides and thermoplastics elastomers from which the football soles are made.
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Propsective surface treatments of magnesium alloys
Drábiková, Juliána ; Doležal, Pavel (referee) ; Zmrzlý, Martin (advisor)
The aim of this bachelor thesis is to summarize the methods of surface treatment of magnesium alloys and discussion of theireffectiveness of corrosion protection. In contrast to other metallic material used in technical practice, magnesium alloys have the lowest corrosion resistance, which can be increased by alloying or by use of surface treatments. The introduction part of the thesis deals with general knowledge about magnesium, its alloys AZ31, AZ91 and their corrosion processes. The recherché includes actual results of research about these alloys. Emphasizedare fluoride conversion coatings and composite coatings based on nickel, where their preparation is described and attention is focused on their properties in the sense of corrosion protection. Concluding the work, we give a critical assessment of the pros and cons of corrosion protective coatings on Mg alloys. Finally, there are suggested some convenient experiments to prove the repeatability of results published in the recherché literature.
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Evaluation of Surface Layers of Ball and Sliding Bearings Components
Šafář, Martin ; Hutařová, Simona (referee) ; Doležal, Pavel (advisor)
This bachelo’s thesis solve the problems abrasion film bearing. The purpose of this thesis was used four type film, ISOFLON, Xylan 1010, DLC a PTFE + Niborit 5P.By one of tendenci is specifi coefficient friction over tribological test. On the next tendenci was size film for and after a tribological test find, elese size abrasion. Was make chemical analyse of all film.To elements interaction study light microscopy, scanning electron microscopy equipped by energy dispersive mikroanalyses.
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Research and Development of Technology for Surface Layers of Roll and Sliding Bearings Components
Němcová, Aneta ; Klakurková, Lenka (referee) ; Doležal, Pavel (advisor)
To increase of bearing steels properties are research and development of surface modifications well above dedicated, in present. Basic requirements to the surface modifications are high wear resistance and good temperature resistance (origin by friction). Surface modifications can not negatively influence properties of bearing steels as a substrate. One of the possibilities can be used surface modifications used for high temperature applications. These are based on saturation of substrate surface layer by Al (and Si) elements. This work deals with preparing of Al and Al-Si diffusion layers from slurries on 100Cr6 bearing steel surface and study of elements interaction between coating and bearing steel as a substrate during proceeding of protective layers at high temperatures. To elements interaction study light microscopy, scanning electron microscopy equipped by energy dispersive microanalyses, glow discharge optical emission spectrometry and microhardness measurement methods were used. To the evaluation of layer thickness image analyses was used.
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Element analysis of magnesium alloys using laser induced breakdown spectrometry
Veis, Samuel ; Fintová, Stanislava (referee) ; Doležal, Pavel (advisor)
Bachelor‘s thesis is aimed at assessing the possibilities of trace elements detection in magnesium alloys using laser induced breakdown spectroscopy with a focus on rare earth elements. Base materials were wrought magnesium alloy sheet ZE10 with thickness of 1,6 mm and ZE41 with thickness of 2 mm produced using Direct Chill casting method. Qualitative and quantitative ways of LIBS spectra evaluation were described in the work. Qualitative analysis confirmed the presence of La, Ce, Nd and Pr in ZE41, and La with Ce in ZE10. These informations confirm results of EDS analysis. For a demonstration, quantitative analysis of ZE10 was made, which confirmed the possibility of using LIBS for detection of REE in Mg alloys.
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Application of Surface Treatment on Hand Tools
Vraspírová, Eva ; Klakurková, Lenka (referee) ; Doležal, Pavel (advisor)
Bachelor's thesis deals with problems of materials, which are used to production of hand tools and implements. The theoretical part is focused on tool steels, their mechanical and technological characteristics and to their heat processing. Below there are well-arranged and described surface modification, which are applied to materials nowadays. The next part is focused on modern technology of surface modification, which are applied to hand tools. The research is mainly focused on technology of production of bits by company Wera Werk Ltd, which is deal with production and distribution of hand tightening tools, such as screwdrivers, angular keys, plug keys, bits and torque tools. Attention is also paid to technology of surface modification, e.g. based on zinc phosphate, nickel, nickel-gold and nickel-diamond-gold, used for these tools and to problems of painting. To elements interaction study light microscopy, the hardness measurement by Vickers and Brinell and scanning electron microscopy equipped by energy dispersive microanalyses.
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Processing of Mg-based powder materials by SPS method
Moleková, Kristína ; Pacal, Bohumil (referee) ; Doležal, Pavel (advisor)
Diploma thesis occupy with preparation of porous material from magnesium powder with a HAp admixture by cold pressing followed by spark plasma sintering (SPS). This thesis contain both preparation of bulk material, diffusion plot and charakterization of materials based on the compaction process conditions. On the basis of physical mechanical characteristics, the impact of the pressing process on the subsequent sintering and the resulting material properties are evaluated. Bulk material is characterized considering to structure and physical–mechanical properties. Properties of final metarial will serve to optimize conditions for process of bulk material preparation.
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Shape memory alloy
Sabela, Jakub ; Doležal, Pavel (referee) ; Němec, Karel (advisor)
The main aim is an overview of process in a shape memory metal-based materials. In the first part of the thesis, I commented on the issue of history and principle of shape memory materials. In the second part I have divided this materials by a structural point of view, dealing with the most widely used memory material in practice. I pointed out its advantages and disadvantages. Another part was devoted to the production, thermal and mechanical processing. Then I said the most used application in practice. Finally, I commented on the future shape memory materials.
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Structure and mechanical properties of magnesium materials processed by HPT
Poloprudský, Jakub ; Němec, Karel (referee) ; Doležal, Pavel (advisor)
This thesis is focused on processing of pure magnesium by high pressure torsion method (HPT). This process belongs to the group of intensive plastic deformation methods (SPD). SPD methods are in the centre of scientific interest for several decades. Theoretical part of this thesis puts an effort to summarize basic knowledge and principles of SPD methods with extra focus on method HPT. As theoretical part continues magnesium as technical material is presented. Influence of SPD on use and properties of pure magnesium is then presented. This trend is further developed in effort to describe the effect of individual HPT process variables on the properties of pure magnesium and its alloys. Focus of practical part of this thesis is in influence of number of revolutions. Samples were processed at 1/8, 1/4, 1/2, 1, 4 and 8 turns at room temperature. Speed of process was 1rpm and applied pressure was 6 GPa. The structure of commercially pure magnesium prepared by casting and moulding were observed with focus on differences caused by input material. The structure was observed by both light microscopy and back scattered electron diffraction (EBSD), focusing on structure development, grain size and grain orientation. Compared to other works on similar topic, the emphasis here is on observing the microhardness on the vertical edge of the sample. The hardness shows a steep increase right after 1/8 of a turn. With increasing number of turns gradual homogenization of microhardness is presented accompanied by slight decrease in microhardness. No trend in microhardness relative to the distance from anvil has occurred. Structure observed with EBSD shows a bimodal character with larger grains oriented in the same direction. The three-point bending test didn’t end up as expected, and the approach to evaluation of magnesium-based HPT needs to be re-evaluated for future work. A three-point bending test was designed for the initial assessment of the basic mechanical properties of the material.
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