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Struktura a vysokoteplotní mechanické vlastnosti ternárnch intermetalických slitin na bázi Fe-Al-Zr
Pavel Kejzlar; školitel Petr Kratochvíl
2013 - Czech
The present PhD work dials with a study of structure, mechanical properties and oxidation resistance of selected Fe-Al-Zr typu intermetallic alloys. The composition was selected to enable study of effect of bothm Zr and Al concentration. On the basis of light optical-and scanning electron microscolpy, energy-dispersive analysis, electron backscatter diffraction and X-ray diffraciton, the structure and phase composition in as cast and annealed state had been described.
Keywords:
aluminidy železa; slitiny; mechanické vlastnosti materiálů
Available to registered users in the Library of TUL
Struktura a vysokoteplotní mechanické vlastnosti ternárnch intermetalických slitin na bázi Fe-Al-Zr
The present PhD work dials with a study of structure, mechanical properties and oxidation resistance of selected Fe-Al-Zr typu intermetallic alloys. The composition was selected to enable study of ...
Analýza systému smyčkového dopriadania
Monika Hejnová; školitel Jaroslav Beran
2013 - Slovak
This thesis was dealing with the analysis of the loop spinning system. The focus of the thesis was to build mathematical models and their vertification. The experimental verification of the static model indicated a stgrong consensus of the modelling results with the real measurements. The doctor thesis proposed the next direction of the field of this spinning method at the end. Táto práca sa zaoberala analýzou systému smyčkového dopriadania. Sústredila sa na zostavenie matematických modelov a ich overenie. Stacionárny model vychádzal z pohybových rovníc zostavených v minulosti pre vol'ný balón. Základom pre dynamický model bol model navrhnutý pre simuláciu odvíjania priadze z valcovej cievky.
Keywords:
dopřádání; matematické modely; textilní stroje
Available to registered users in the Library of TUL
Analýza systému smyčkového dopriadania
This thesis was dealing with the analysis of the loop spinning system. The focus of the thesis was to build mathematical models and their vertification. The experimental verification of the static ...
Využití emisních měření k diagnostice vozidlového zážehového motoru
Zdeněk Krabs; školitel Celestýn Scholz
2013 - Czech
The postgradual disertation thesis deals with utilization of a test bench for diagnostic of the automobiles engine with the emission stress test. A test bench was used to increase the measurement objectivity of emission parts of ignition engine. Laboratory measuring devices and servicing tools were used for measurements. Results of differen methods measurements are compared. The thesis assesses the usability of service measurement technique for objective measurement of emission of spark ifnition piston engine by a stress test. The outcome of the thesis is a proposal of a new system of emission measurement in the emission measuring stations based on results of the experiment. Práce se zabývá využitím válcového dynamometru pro diagnostiku stavu automobilového motoru pomocí emisního zatěžovacího testu. Pro větší objektivitu měření jednotlivých složek emisí zážehového spalovacího motoru jsem použil válcový dynamometr. K měření jsou využívána laboratorní měřící zařízení a servisní přístroje. Výsledky měření různými metodami jsou porovnány. Práce hodnotí využitelnost servisní měřící techniky pro objektivní měření emisí zážehového pístového spalovacího motoru při zatěžovacím testu. Výstupem práce je návrh nového systému měření emisí ve stanicích měření emisí na základě výsledků experimentu.
Keywords:
zážehové motory; měření; emise znečišťujících látek; automobilové motory
Available to registered users in the Library of TUL
Využití emisních měření k diagnostice vozidlového zážehového motoru
The postgradual disertation thesis deals with utilization of a test bench for diagnostic of the automobiles engine with the emission stress test. A test bench was used to increase the measurement ...
Vlastnosti umělých pneumatických svalů
Zdeněk Varga; školitel Miroslav Olehla
2013 - Czech
This work is focused on the exploration of the properties of artificial pnematical muscles. For the research of a pneumatical muscles was chosen the fluidic muscle from FESTO company, which can be easily applied due to industrial execution what is the one of the main advantages of this muscle. In the work were done complete study of properties a pneumatical valve which were used for the producing testing stand, by which is lead course a pressure inside the pneumatic muscle. Study of the dynamical properties showed, then the selected valve VPPM isn´t suitable for leading fast dynamical process up 10 Hz. Práce je zaměřena na zkoumání vlastností umělých pneumatických svalů. Pro zkoumání pneumatických svalů byl vybrán fluidní sval FESTO, který díky průmyslovému provedení umožňuje snadnou a reálnou aplikaci, což je jednou z hlavních výhod tohoto svalu. V práci byl proveden důkladný rozbor vlastností pneumatického ventilu, který byl použit při výrobě zkušebního standu, kterým je řízen průběh tlaku uvnitř pneumatického svalu.
Keywords:
pneumatické mechanismy
Available to registered users in the Library of TUL
Vlastnosti umělých pneumatických svalů
This work is focused on the exploration of the properties of artificial pnematical muscles. For the research of a pneumatical muscles was chosen the fluidic muscle from FESTO company, which can be ...
Vývoj nanovlákenného nosiče pro hybridní bioreaktory s imobilizovanou biomasou a využití obrazové analýzy pro hodnocení biofilmových struktur
Lucie Křiklavová; školitel Tomáš Lederer
2013 - Czech
This dissertation covers the design, development, and validation of polymer nanofiber carriers for use in hybrid bioreactors with immobilized biomass. In developing the nanofiber carriers, special attention was paid to the supporting threads, which must meet exacting standards (e.g. mechanical, physical, and chemical stability; colonization possibility; high surface area). Two basic types of nanofiber carriers were developed based on the final version of the threads: a fluidized bed carrier (carrier flows with the surrounding liquid) and a fixed bed carrier (liquid flows through a firmly attached carrier). Nanofiber carriers provide many significant advantages, such as their large specific surface area, high biofilm resistance against external toxic effects and speed of carrier incorporation. The basic technological parameters of the nanofiber carrier were verified in the laboratory, using both real and model wastewater, and technological limits identified (e.g. minimum wastewater residence time; maximum and minimum temperature and salinity; respiration assessment). At the same time, nanofiber carrier performance was compared with a commercial carrier (AnoxKaldnes). The latest image analysis methods were used to evaluate immobilized-bacteria biofilm (bacterial biofilm incorporation and formation on the carrier), its growth, and development of biofilm structure. A comprehensive non-invasive methodology was developed for the evaluation of immobilized microbial structures on base materials (i.e. on a biomass carrier). This methodology has been successfully correlated with gravimetric determination of dry matter. Předkládaná práce se zabývá návrhem, vývojem a ověřením polymerního nanovlákenného nosiče, který může být prakticky využíván v hybridních bioreaktorech s imobilizovanou biomasou. v rámci vývoje nanovlákenného nosiče byla pozornost věnována především nosné niti, která musí splňovat náročná hlediska (mechanická, fyzikální a chemická stabilita, kolonizovatelnost, vysoký měrný povrch aj.). Z finální verze nosné nitě byly vytvořeny dva základní typy nanovlákenných nosičů-nosič pro fluidní lože (proudící společně s okolní kapalinou), nosič pro fixní lože (kapalina proudí skrze pevně uchycený nosič). Nanovlákenný nosič poskytuje mnohé výrazné výhody, jakými jsou především jejich velký specifický měrný povrch, vyšší resistence biofilmu vůči vnějšímu toxickému působení a zejména rychlost zapracování nosiče. Laboratorní ověřování vyvíjeného nanovlákenného nosiče probíhalo na reálných a modelových odpadních vodách. Za přesně stanovených podmínek byly ověřovány základní technologické parametry a identifikovány byly limitní stavy (minimáílní doba zdržení odpadní vody, maximální a minimální teplota, rozpětí pH, sanility, hodnocení respirace systému aj.(. Paralelně jsou vyvíjené nanovlákenné nosiče porovnávány s komerčním nosičem AnoxKaldnes. K hodnocení procesů upoutávání bakteriálního biofilmu na nosič bylo v disertační práci využito moderní metody obrazového hodnocení. Stanoven byl růst a vývoj biomasy a hodnoceny byly výsledné biofilmové struktury.V rámci práce byla vytvořena ucelená neinvazní metodika jhodnocení imobilizovaného mikrobiálních struktur na podkladovém materiálu (obecně na libovolnéh nosiči biomasy). Vytvořená merodika byla úspěšně korelována s gravimetrickým stanovením sušiny.
Keywords:
biologické čištění odpadních vod; biomasa
Available to registered users in the Library of TUL
Vývoj nanovlákenného nosiče pro hybridní bioreaktory s imobilizovanou biomasou a využití obrazové analýzy pro hodnocení biofilmových struktur
This dissertation covers the design, development, and validation of polymer nanofiber carriers for use in hybrid bioreactors with immobilized biomass. In developing the nanofiber carriers, special ...
Termomechanické vlastnosti PET/ PEN vláken a jejich vyhodnocování pomocí metodiky Six Sigma
Miroslava Znojilová; školitel Jiří Militký
2013 - Czech
Polyester fibres belong to the most important polymer fibres and their scope of use and its importance continue to grow up. The polyester fibres are very often modificated and treated by purpose of application. In this work have been used special nondrawn PET fibers with variation of PEN present within the range of 0 to 20 percent. For this fibres has been predicted better thermal and mechanical characteristics. For the purpose of use and requested characteristics has been tested following thermal characteristic - Melting temperature, Glass transition temperature and temperature of Crystallization, mechanical characteristics - elongation at break, strength and completed of fibers density. This work is divided into five chapters, in literary research are described as contemporary knowledge about material, structure, behavior, measurement methods and Six Sigma methodic. In Experimental part were used measurement method and equipment, For this experiment was provided - apparature Vibrodyn/ Vibroskop, TMA, DSC and DMA. Obtained data are registered in chapter - Measurement results - and their evaluation is described in next chapter. For evaluation has been used Six Sigma method and whole work is introduce there as development project. Summary of results and finished evaluation is in final chapter. Polyesterová vlákna patří k nejdůležitějším syntetickým vláknům a jejich použití a význam stále roste. Velmi často jsou tato vlákna různě modifikována a upravována podle jejich použití. v této práci byla použita speciální PET vlákna s různým procentuálním zastoupením PEN složky a to v rozmězí od 0% až po 20%. U těchto vláken byly předpokládány zlepšené termické a mechanické vlastnosti. Dle účelu použití a vzhledem k požadovaným vlastnostem byly zkoumány následující termické vlastnosti-teplota tání, zeskelnění a krystalizace a mechanické charakteristiky, tažnost a pevnost vláken doplněné ještě o hodnoty jemnosti. Práce je členěna do pěti kapitol, kde v průzkumu jsou popsány dosavadní poznatky o daném materiálu, struktuře, vlastnostech, měřících metodách a metodice Six Sigma. V kapitole Experimentální část jsou zmíněny použité metody a zařízení na kterých byl experiment prováěn-aparatura Vibrodyn/Vibroskop, TMA, DSC a DMA. Získané hodnoty jsou zaznamenány v kapitole " Výsledky měření" a jejich vyhodnocení a je popsáno v následující části, kde k hodnocení byla použita metodika Six Sigma a celá práce je zde představena jako projekt na vývoj nového výrobku. Shrnutí výsledků a vyhodnocení úspěšnosti projektu je popsáno v závěrečné kapitole.
Keywords:
vlastnosti materiálů; textilní vlákna
Available to registered users in the Library of TUL
Termomechanické vlastnosti PET/ PEN vláken a jejich vyhodnocování pomocí metodiky Six Sigma
Polyester fibres belong to the most important polymer fibres and their scope of use and its importance continue to grow up. The polyester fibres are very often modificated and treated by purpose of ...
Renewable Nanoscale Reinforcement of Biodegradable Polymers
Vijaykumar Narayandas Baheti; školitel Jiří Militký
2013 - English
Textile industry generate significant amount of waste fibers in form of short lengths during mechanical processing. However these short fibers possess excellent properties suitable for many other applications. The objective of this work was to use them for the preparation of nanoparticles/nanofibrils, as fillers in biodegradable composite applications such as food packaging, agriculture mulch films, automotive plastics, etc. In the present study, waste jute fibers generated in textile industries, were wet pulverized to the scale of nanofibrils of 50 nm diameter using high energy planetary ball milling for three hours.The rate of refinement of uncleaned jute fibers having non-cellulosic contents was found slower than the cleaned jute fibers. This tendency is attributed to the strong holding of fiber bundles by non-cellulosic contents which offered resistance to the defibrillation during wet milling. In addition, the presence of water during wet pulverization found to reduce the rising temperature of mill, which prevented sticking of nanofibrils on the mill wall and resulted in unimodal size distribution. In the subsequent stage, 1 wt %, 5 wt % and 10 wt % of jute nanofibrils were incorporated in poly lactic acid (PLA) matrix to prepare nanocomposite films by solvent casting. The reinforcement of nanofibrils was investigated from the improvements in mechanical properties based on tensile tests, dynamic mechanical analysis and differential scanning calorimetry. The maximum improvement was observed in case of 5 wt % nanocomposite film where initial modulus and tensile strength increased by 217.30 % and 170.59 % respectively compared to neat PLA film. These improvements are attributed to the increased interaction between nanofibrils and matrix as well as to the increased crystallinity of PLA in composites. The improvements in load bearing capacity of nanocomposite films were significant at 60oC than 35oC, which showed ability of jute nanofibrils to improve the softening temperature of PLA matrix. In the end, experimental results of Initial modulus were compared with predicted modulus of mechanical models. A good level of agreement was observed up to 5 wt % loading of jute nanofibrils.
Keywords:
vlastnosti materiálů; polymery
Available to registered users in the Library of TUL
Renewable Nanoscale Reinforcement of Biodegradable Polymers
Textile industry generate significant amount of waste fibers in form of short lengths during mechanical processing. However these short fibers possess excellent properties suitable for many other ...
Customer relationship management jako nástroj zvyšování konkurenceschopnosti podniků :
Jana Marková; vedoucí práce Jozefína Simová
2013 - Czech
The important changes of consumer behaviour, caused by economy recession, press on business subjects to explore new ways to get costumers. This is the time, when competitive advantage gets important role. This advantage could be appreciated by controlling relationships with customers, called Customer Relationship Management. Customer Relationship Management (CRM) is complex solution of communication among companies and costumers, also way to long and profitable business relationships. This system is not only database of useful information about costumers. This is company solution, which is born in effort to get or to hold costumer and which grows up to complex system of all processes in company. Outputs of this thesis are based on passed researches about CRM in Czech Republic, on interviews with CRM specialists and based new questionary research realized in June 2013. The knowledge of passed researches was used in interviews with CRM specialists, which helps to prepare questionary of research in region of Liberec among 117 companies. The data of research were analyzed by factor analysis. This research proves the utilising of CRM, mainly to get the customers. Saved data in CRM are sorted, because of next use in communication with costumers and use in segmentation. Saved data are used in way which helps to make costumers feeling of importance and uniqueness. Also the customer satisfaction is important information, which could improve relations with costumer and which could extend time of the business ? get competitive advantage.
Keywords:
konkurenceschopnost; management
Available to registered users in the Library of TUL
Customer relationship management jako nástroj zvyšování konkurenceschopnosti podniků :
The important changes of consumer behaviour, caused by economy recession, press on business subjects to explore new ways to get costumers. This is the time, when competitive advantage gets important ...
Mačkavost plošných textilií
Katarína Zelová; školitel Ludmila Fridrichová
2013 -
The dissertation thesis is dealing with the design of an innovative methodics of creasing for the study of the anisotropy of angle recovery. It also deals with the analysis of viscoelastic behaviour of textiles after creasing. The work is also discussing about the influence of structural parameters of textiles, finishes and material composition on the anisotropy and on the value of the immediate viscoelastic recovery, and even on the total creasing. The innovative method of evaluation is compared with classic methods of evaluation of creasing and with the method of wearing. For stating the predictive model, the statistic analysis of multidimensional data, is used. The designed linear regression model for the prediction of creasing of textiles came out of the analysis of mechanical properties of textiles measured by the system of KES. The obtained experimental process of recovery of the textile is modeled by means of composite rheological models. Of the basic rheological elements and models, such combinations are recommended as suitable, which are able to model elastic, viscoelastic and even plastic deformations. It has been proved that creasing is an anisotropic property and the proposed steps were justified and they contributed to a higher quality description of the real creasing of textiles.
Keywords:
mačkavost; hodnocení textilií; plošné textilie
Available to registered users in the Library of TUL
Mačkavost plošných textilií
The dissertation thesis is dealing with the design of an innovative methodics of creasing for the study of the anisotropy of angle recovery. It also deals with the analysis of viscoelastic behaviour ...
Investigation of Aggregation Models of Magnetic, Zero-valent Iron Nanoparticles
Dana Rosická; školitel Jan Šembera
2013 - English
This work focuses on an investigation into the aggregation mechanisms of unstable, nanoscale particles in flowing groundwater. A study and a description of the process of aggregation help to simulate the transport of unstable undissolved nanoparticles. This could be useful when one needs to know how the nanoparticles behave in transit. In the following example a knowledge of this process is helpful. Some contaminants, such as halogenated hydrocarbons, are remediable by zero-valent iron nanoparticles. These are very unstable particles but still have a high potential in remediation field. Thanks to their (nano)size, they can migrate through the ground and are able to decontaminate wide areas. However, they aggregate into microsized entities and lose their migratory ability. Simulation of the transport of iron nanoparticles and their aggregation could be useful in predicting the success of decontamination interventions. The mathematical derivation of iron nanoparticle aggregation is so complex and difficult that this work is focused mainly on them. This work is mainly theoretical. First, an aggregation model is described. The model is based on aggregation due to the heat fluctuation of nanoparticles and due to their different velocities during sedimentation and drifting in groundwater. This model is then extended to include the impact of repulsive electrostatic and attractive magnetic forces that affect the rate of aggregation of magnetic nanoparticles with non-zero surface charge. The coefficients of aggregation are recalculated in order to compute the aggregation not only between single nanoparticles, but also between aggregates of nanoparticles (more simply called "particles"). A study of the possible aggregate structures was performed to be able to compute their mutual reactions. Extended coefficients of aggregation between particles were converted to coefficients of aggregation between ''sections'' of nanoparticles with similar size and properties. This enabled the simulation of aggregation in real time. The subsequent part of this work is dedicated to the computational aspects of aggregation in order to make the computation faster, but with a small error. At the end of the work, simulations of aggregation and transport of different types of nanoparticles are presented.
Keywords:
nanočástice
Available to registered users in the Library of TUL
Investigation of Aggregation Models of Magnetic, Zero-valent Iron Nanoparticles
This work focuses on an investigation into the aggregation mechanisms of unstable, nanoscale particles in flowing groundwater. A study and a description of the process of aggregation help to simulate ...
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