Design of Mixing Station for Alternative Gaseous Fuels

Úkolem diplomové práce je navrhnout potrubní rozvod plynů do směšovací stanice a následně i navrhnout samotnou směšovací stanici. V textové části je nejprve vytvořena rešerše týkající se využívání technických a topných plynů v praxi. Na tuto část postupně navazují specifikace plynů, které se budou dopravovat do směšovací stanice. Ve výpočtové části se práce prostřednictvím výpočtových vztahů zabývá složením směsného plynu, fyzikálními vlastnostmi jednotlivých plynů i samotného plynu směsného, přičemž jsou vypočteny a navrženy potrubní tratě jednotlivých plynů směřujících do směšovací stanice. Konstrukční část práce se zabývá návrhem směšovací stanice a směšovací komory, ve které se jednotlivé plyny mísí. Grafická část práce obsahuje schémata jednotlivých potrubních tratí a směšovací stanice, 3D model směšovací komory a výkres směšovací komory.The task of the diploma thesis is to design the pipeline distribution of gases to the mixing station and then design the mixing station itself. In the text part is first created a search regarding the use of technical and heating gases in practice. This part is followed by the gas specifications that will be transported to the mixing station. In the computational part, the work with the help of calculation relations deals with the composition of the mixed gas, the physical properties of the individual gases and the mixing gas itself, and the pipelines of the individual gases leading to the mixing station are calculated and designed. The construction part deals with the design of the mixing station and the mixing chamber, in which the individual gases are mixed. The graphical part of the thesis contains diagrams of individual pipeline lines and mixing stations, a 3D model of the mixing chamber and a drawing of the mixing chamber.361 - Katedra energetikyvýborn

Heat Exchanger for RAO Incineration Plant

Import 23/07/2015Úkolem diplomové práce je navrhnout projekční řešení trubkového výměníku spaliny – vzduch pro spalovnu radioaktivních odpadů. V textové části je rozebírán postup spalování nízko-aktivního pevného a kapalného radioaktivního odpadu. Ve výpočtové části je úkolem spočítat kombinované přestupy tepla ze spalin do vzduchu, včetně výpočtů aerodynamických tlakových ztrát. Grafická část obsahuje výkres navrženého výměníku a schéma spalovny radioaktivního odpadu.The task of this thesis is to propose design solutions pipe heat exchanger flue gas - air incinerator for radioactive waste. In the text part is analyzed combustion process of low-level solid and liquid radioactive waste. Part of the solutition is calculate the combined task transfers heat from flue gases into the air, including the calculation of aerodynamic pressure loss. Graphical part includes a drawing of desinged scheme of heat and incineration of radioactive waste.361 - Katedra energetikyvýborn

The piezoresistive highly elastic sensor based on carbon nanotubes for the detection of breath

Wearable electronic sensor was prepared on a light and flexible substrate. The breathing sensor has a broad assumption and great potential for portable devices in wearable technology. In the present work, the application of a flexible thermoplastic polyurethane/multiwalled carbon nanotubes (TPU/MWCNTs) strain sensor was demonstrated. This composite was prepared by a novel technique using a thermoplastic filtering membrane based on electrospinning technology. Aqueous dispersion of MWCNTs was filtered through membrane, dried and then welded directly on a T-shirt and encapsulated by a thin silicone layer. The sensing layer was also equipped by electrodes. A polymer composite sensor is capable of detecting a deformation by changing its electrical resistance. A T-shirt was capable of analyzing a type, frequency and intensity of human breathing. The sensitivity to the applied strain of the sensor was improved by the oxidation of MWCNTs by potassium permanganate (KMnO4) and also by subsequent application of the prestrain.Ministry of Education, Youth and Sports of the Czech Republic-Program NPU I [LO1504]; Operational Program Research and Development for Innovations; TBU in Zlin [IGA/CPS/2018/005, IGA/CPS/2019/010]; national budget of the Czech Republic, within project CPS-strengthening research capacity [CZ.1.05/2.1.00/19.0409]; European Regional Development Fund (ERDF)European Union (EU

Accelerated shape forming and recovering, induction, and release of adhesiveness of conductive carbon nanotube/epoxy composites by joule heating

The versatile properties of a nanopaper consisting of a porous network of multi-walled carbon nanotubes were applied to enhance the mechanical and electrical properties of a thermosetting epoxy polymer. The embedded nanopaper proved useful both in the monitoring of the curing process of the epoxy resin by the self-regulating Joule heating and in the supervising of tensile deformations of the composite by detecting changes in its electrical resistance. When heated by Joule heating above its glass transition temperature, the embedded carbon nanotube nanopaper accelerated not only the modelling of the composites into various shapes, but also the shape recovery process, wherein the stress in the nanopaper was released and the shape of the composite reverted to its original configuration. Lastly, in comparison with its respective epoxy adhesive, the internally heated electro-conductive carbon nanotube nanopaper/epoxy composite not only substantially shortened curing time while retaining comparable strength of the adhesive bonding of the steel surfaces, but also enabled a release of such bonds by repeated application of DC current. © 2020 by the authors.Ministry of Education, Youth and Sports of the Czech Republic-Program NPU I [LO1504]; Operational Program Research and Development for Innovations - European Regional Development FundEuropean Union (EU); national budget of the Czech Republic [CZ.1.05/2.1.00/19.0409]; Fund of the Institute of Hydrodynamics [AV0Z20600510

Ethylene-octene-copolymer with embedded carbon and organic conductive nanostructures for thermoelectric applications

Hybrid thermoelectric composites consisting of organic ethylene-octene-copolymer matrices (EOC) and embedded inorganic pristine and functionalized multiwalled carbon nanotubes, carbon nanofibers or organic polyaniline and polypyrrole particles were used to form conductive nanostructures with thermoelectric properties, which at the same time had sufficient strength, elasticity, and stability. Oxygen doping of carbon nanotubes increased the concentration of carboxyl and C-O functional groups on the nanotube surfaces and enhanced the thermoelectric power of the respective composites by up to 150%. A thermocouple assembled from EOC composites generated electric current by heat supplied with a mere short touch of the finger. A practical application of this thermocouple was provided by a self-powered vapor sensor, for operation of which an electric current in the range of microvolts sufficed, and was readily induced by (waste) heat. The heat-induced energy ensured the functioning of this novel sensor device, which converted chemical signals elicited by the presence of heptane vapors to the electrical domain through the resistance changes of the comprising EOC composites. © 2020 by the authors.Operational Program Research and Development for Innovations - European Regional Development Fund (ERDF)European Union (EU); Operational Program Education for Competitiveness - European Social Fund (ESF); National Budget of the Czech Republic [CZ.1.05/2.1.00/03.0111, CZ.1.07/2.3.00/20.0104]; Fund of Institute of Hydrodynamics [AV0Z20600510

High sensitivity sensor development for Hexamethylphosphoramide by polyaniline coated polyurethane membrane using resistivity assessment technique

Hexamethylphosphoramide is considered as one of the harmful of all carcinogens. In the present work, detection of Hexamethylphosphoramide by using a polyaniline coated polyurethane membrane was carried out and device is constructed to show its practical application using resistivity assessment technique. Polyurethane nanofiber membrane was prepared by electrospinning process. A modified synthetic method used to coat polyaniline onto a polyurethane membrane found to be effective to prepare a uniform and electrically conductive coating and promising for sensing a carcinogen like Hexamethylphosphoramide. Sensing performance may be attributed to the large resistance change in polyaniline because of the deprotonation when exposed to the Hexamethylphosphoramide environment. However, it is interesting to know that the high sensitivity of polyaniline modified polyurethane membrane toward Hexamethylphosphoramide is used as a promising gas sensor for the detection of said carcinogen using resistivity assessment technique at room temperature. © 2016 Elsevier Ltd. All rights reserved.LO1504, MEYS, Ministry of Education, Youth and SportsMinistry of Education, Youth and Sports of the Czech Republic - Program NPU I [LO1504

Microstrip antenna from silver nanoparticles printed on a flexible polymer substrate

This work describes the use of inkjet printing technology to fabricate a flexible microstrip antenna. The antenna is printed on a flexible PET foil (Polyethylene terephthalate) using silver nanoparticles. Silver nanoparticles were synthetized by the solvothermal precipitation technique. The diameter of the prepared silver nanoparticles ranges from 20 to 200 nm measured with the help of the SEM analysis. In addition, the ink formulation for printing of a homogenous and electrically conductive layer was further prepared using silver nanoparticles. The printed antenna operates in two frequency bands of 2.02 GHz (-16.02 db) and 2.3 GHz (-19.33 db). The antenna is flexible and weigh is only 0.208 g and is suitable for electronic devices of a very low weight, such as wearable electronic devices. © 2017 Elsevier Ltd.Ministry of Education, Youth and Sports of the Czech Republic - National Sustainability Program NPU I [LO1504]; Operational Program Research and Development for Innovations; European Regional Development Fund (ERDF); national budget of the Czech Republic [CZ.1.05/2.1.00/19.0409

Flexible microstrip antenna based on carbon nanotubes/(ethylene-octene copolymer) thin composite layer deposited on PET substrate

A most of portable devices, such as mobile phones, tablets, uses antennas made of cupper. In this paper we demonstrate possible use of electrically conductive polymer composite material for such antenna application. Here we describe the method of preparation and properties of the carbon nanotubes (CNTs)/(ethylene-octene copolymer) as flexible microstrip antenna. Carbon nanotubes dispersion in (ethylene-octene copolymer) toluene solution was prepared by ultrasound finally coating PET substrate by method of dip-coating. Main advantages of PET substrate are low weight and also flexibility. The final size of flexible microstrip antenna was 5 x 50 mm with thickness of 0.48 mm (PET substrate 0.25 mm) with the weight of only 0.402 g. Antenna operates at three frequencies 1.66 GHz (-6.51 dB), 2.3 GHz (-13 dB) and 2.98 GHz (-33.59 dB). © Published under licence by IOP Publishing Ltd

Deformation theory of an electro-conductive composite composed of entangled network of carbon nanotubes embedded in elastic polyurethane

A strain sensing polymer composite consisting of a network of entangled multi-walled carbon nanotubes in a thermoplastic polyurethane elastomer is tested by tensile and bending deformation. The composite is prepared by taking a non-woven polyurethane filter membrane, enmeshing it with carbon nanotubes and melding them together. The testing has shown that the material can be elongated as much as 400% during which the electrical resistance is increased more than 270 times. To describe the composite strain dependent resistance, a rheological model is proposed which takes into account a decrease of local contact forces between nanotubes as well as the reduction of number of contacts with deformation. The theory is used for description of sensing element deformation and resistance when simple elongation and repeated bending is exerted

Electro-mechanical transducer based on carbon nanotube network / polystyrene laminate for deformation detection

A new type of polystyrene (PS)/carbon nanotube (CNT) network laminate is introduced as an electrically conductive composite material; with favorable properties as electro-mechanical signal transducer capable to detect applied mechanical strain. In course of its fabrication a non-woven polystyrene membrane made by electro spinning was used as filtering mesh for CNT aqueous dispersion. Produced semi-product like filtering membrane with entrapped carbon nanotubes was stuck using solvent of PS on polystyrene test specimen. The electrical resistance of final laminate is sensitive to tensile strain when elongation leads to increase of macroscopic electrical resistance. Test specimens were then tested in the course of monotonic strain growth and also when loading/unloading cycles were imposed. Changes in resistance were found to be reversible, reproducible and deformation can by monitored in real time. Finally, sensitivity to strain can be quantified by means of a gauge factor, GF, which defines sensitivity of strain gauge as a relative resistance change divided by the applied strain. Measured GF for PS/CNT laminates reaches relatively high values, compared with ones of commonly used metallic strain gauges, serving for values of around 13 and applied tensile deformation in range 0.1-0.6 %. These experimental results are really promising serving for real practical application of this principle in course of polymeric based strain gauges or as an integrated PS/CNT units into polystyrene based constructions for their so called "health monitoring"