Theoretical measurement limits of parameters of commissioned heat pumps
Rimbala J.; Kyncl J.
2020 - anglický This paper analyzes the uncertainties of measuring the heat and cooling factors of compressor and absorption heat pumps. The article analyzes the uncertainties of measurement and, in two case studies, it is shown that without the use of laboratory calibrated measuring instruments, the cooling and heating factor plowing is considerably inaccurate and is better based on manufacturer data. Klíčová slova: Heat Pump; Compressor Heat Pump; Absorption Heat Pump; Heat Transfer; Measuring; Uncertainty; COP Plné texty jsou dostupné v digitálním repozitáři ČVUT. Theoretical measurement limits of parameters of commissioned heat pumps

This paper analyzes the uncertainties of measuring the heat and cooling factors of compressor and absorption heat pumps. The article analyzes the uncertainties of measurement and, in two case studies, ...

Rimbala J.; Kyncl J.
České vysoké učení technické v Praze, 2020

Critical infrastructure and the possibility of increasing its resilience in the context of the energy sector
Čerňan M.; Müller Z.; Tlustý J.; Halaška J.
2020 - anglický The paper focuses on critical infrastructure and its resilience. The introductory parts of the paper define the concepts of critical infrastructure and resilience of critical infrastructure and further define its legislative basis. Then follows the definition of typical critical states in the field of power engineering. To a large extent, attention is also focused on methods for critical infrastructure protection and methods for strengthening critical infrastructure resilience. Within the selected area, a survey of the possibilities of critical infrastructure was carried out, which was evaluated. Based on the results, several recommended steps were identified in the sub-areas to which further research will be devoted. Klíčová slova: Critical infrastructure; resilience; energy sector; power system restoration; blackout Plné texty jsou dostupné v digitálním repozitáři ČVUT. Critical infrastructure and the possibility of increasing its resilience in the context of the energy sector

The paper focuses on critical infrastructure and its resilience. The introductory parts of the paper define the concepts of critical infrastructure and resilience of critical infrastructure and ...

Čerňan M.; Müller Z.; Tlustý J.; Halaška J.
České vysoké učení technické v Praze, 2020

Bioenergy Electricity on Internet of Renewable Energy (IoRE) Framework for Sustainable Electricity Grid Integration in the European Union (EU)
Igbinovia F.O.; Krupka J.; Hajek P.; Müller Z.; Tlustý J.
2020 - anglický Climate change and the finite nature of traditional electricity production sources have resulted in the increasing utilization of renewable electricity sources in today's electricity grid architecture. Which is hoped to eventually lead to a hundred percent renewable electricity grid architecture. A purely renewable electricity grid will bring about the implementation of the Internet of Renewable Energy (IoRE). The European Union (EU) in an attempt to stimulate and strengthen the integration of electricity grid architecture of member states has set in motion several strategies. A great strategy should be a purely renewable electricity grid assets integration in the region. Besides hydro and wind energy, bioenergy is following on the listing of vital renewable energy sources consumed in the European electricity generation mix. Bioenergy electricity combined with other renewables on the IoRE framework will lead to a sustainable electricity grid integration in the EU. The anticipated utilization of IoRE technology in the short-term and long-term in the region will lead the way to assess a hundred percent renewable electricity product by consumers in each member country. It will as well bring about cleaner electricity product production in the EU. Klíčová slova: bioenergy; bioenergy electricity; Internet of Renewable Energy (IoRE); sustainable regional electricity; European Union (EU) Plné texty jsou dostupné v digitálním repozitáři ČVUT. Bioenergy Electricity on Internet of Renewable Energy (IoRE) Framework for Sustainable Electricity Grid Integration in the European Union (EU)

Climate change and the finite nature of traditional electricity production sources have resulted in the increasing utilization of renewable electricity sources in today's electricity grid ...

Igbinovia F.O.; Krupka J.; Hajek P.; Müller Z.; Tlustý J.
České vysoké učení technické v Praze, 2020

Development of Concrete Bridges in the Czech Republic
Vítek J.
2020 - anglický Reinforced concrete bridges, the arch bridges in particular, which were built even in the first half of the 20th century exhibited a reasonably good safety and durability provided good quality materials were used. Fast development of the technology of prestressed concrete suffered from some deficiencies due to a limited knowledge and experience with the material behaviour and with the technology itself. However, the contemporary prestressed structures may be considered as safe and durable, since mainly the protection of prestressing units improved significantly. Design criteria also changed and requirements on robustness should avoid severe damages in case of failure of a single element. Klíčová slova: arch; bridge; concrete; Durability; Prestressing; safety Plné texty jsou dostupné v digitálním repozitáři ČVUT. Development of Concrete Bridges in the Czech Republic

Reinforced concrete bridges, the arch bridges in particular, which were built even in the first half of the 20th century exhibited a reasonably good safety and durability provided good quality ...

Vítek J.
České vysoké učení technické v Praze, 2020

ANALYSIS, MANAGEMENT AND TRADE-OFF WITH RISKS OF TECHNICAL FACILITIES
Procházková D.; Procházka J.
2020 - anglický Submitted work “Analysis, management and trade-off with risk of technical facilities“ deals with the all type of risks associated with the technical facilities, particularly with the complex ones, with aim to ensure their safety. It demonstrates the ways of work with risks at phase of identification, analysis, assessment, management and putting under control aimed to the safety of both, the technical facilities and their surround-ings (i.e. their mutual coincidence), and simultaneously respecting the current knowledge that the risks are locally and time-specific. The safety is understood as a property on the level of the whole technical facility, which is determined by the quality of the file of anthropogenic measures and activi-ties aimed at the safe technical facility, and even at its critical conditions. Therefore, at safety make up, the publication proposes to monitor both, the public assets and the technical facility´ assets, and together to consider the diversity of their physical natures, vulnerabilities, and the constituent changes over time; which means contin-uously to solve emerging conflicts. procedures for the control and management of critical sit-uations. The publication “Analysis, management and trade-off with risks of technical facilities“ summarizes problems and shows methods and procedures for their solution based on system concept and present findings and experiences from practice obtained by detail research. It summarizes the results of specific research performed in project “Řízení rizik a bezpečnost složitých technologických objektů (RIRIZIBE)“ CZ.02.2.69/0.0/ 0.0/16_018/000”; detail data and results are in the Czech publication and in the CVUT archives. Klíčová slova: risk; safety; security; reliability; technical facility; management; risk management; satety management Plné texty jsou dostupné v digitálním repozitáři ČVUT. ANALYSIS, MANAGEMENT AND TRADE-OFF WITH RISKS OF TECHNICAL FACILITIES

Submitted work “Analysis, management and trade-off with risk of technical facilities“ deals with the all type of risks associated with the technical facilities, particularly with the complex ones, ...

Procházková D.; Procházka J.
České vysoké učení technické v Praze, 2020

Efficient Modelling and Reformulation of Planning Tasks
Chrpa, Lukáš
2020 - anglický Plné texty jsou dostupné v digitálním repozitáři ČVUT. Efficient Modelling and Reformulation of Planning Tasks

Chrpa, Lukáš
České vysoké učení technické v Praze, 2020

Development and Calibration of Elasto-Plasticity Models with Directional Distortional Hardening
Plešek Jiří; Parma Slavomír; Džugan Jan
2019 - anglický This thesis deals with the phenomenological modeling of the directional distortional hardening and the metal plasticity in general. A particular plasticity model is analytically integrated for the proportional multiaxial loading case. The integrated model is used to model the stress-strain curves, the hysteresis loops, and the cyclic stress-strain curves. Based on these curves, two calibration algorithms are developed. In the end, a sensitivity analysis of both calibration algorithms is done. A general aim of this thesis is to develop the procedures that would support an industrial application of advanced models with directional distortional hardening.Práce se zabývá fenomenologickým modelováním směrového deformačního zpevnění a obecně plasticity kovů. Konkrétní model je analyticky integrován pro případ víceosého proporcionálního zatěžování. Výsledná křivka je použita k modelování tahového diagramu, a dále k modelování hysterezních smyček a cyklických deformačních křivek. Na základě těchto analytických modelů jsou navrženy dva zcela nové algoritmy pro kalibraci parametrů modelu. V závěru je provedena citlivostní analýza obou kalibračních algoritmů. Obecným cílem práce je vývoj procedur pro průmyslovou aplikaci pokročilých modelů plasticity se směrovým deformačním zpevněním. Klíčová slova: plasticity,strain hardening,integration,calibration,finite element method; plasticita,deformační zpevnění,integrace,kalibrace,metoda konečných prvků Plné texty jsou dostupné v digitálním repozitáři ČVUT. Development and Calibration of Elasto-Plasticity Models with Directional Distortional Hardening

This thesis deals with the phenomenological modeling of the directional distortional hardening and the metal plasticity in general. A particular plasticity model is analytically integrated for the ...

Plešek Jiří; Parma Slavomír; Džugan Jan
České vysoké učení technické v Praze, 2019

Numerical Implementation of Distortional Hardening Models
Plešek Jiří; Marek René; Halama Radim
2019 - anglický The presented thesis describes the formulation of two new constitutive models of metal plasticity within the realm of small strains, both featuring directional distortional hardening. New yield functions have been proposed with distortion and cross-effect control. The models feature new kinematic hardening rule that builds on the premise of multisurface plasticity while keeping the amount of internal variables low. The models’ intended use is the study of multiaxial ratcheting–the cumulation of plastic deformation in combined loading, and ways of its calibration. Their possible real application lies in cyclic multiaxial operational loading present in pressurized piping systems and in some very specific applications. The models have been implemented into a UMAT subroutine for FE-system Abaqus.Předložená práce popisuje formulaci dvou nových konstitutivních modelů plasticity se směrovým zpevněním pro oblast malých deformací. Pro modely byly navrženy nové funkce plasticity s řízením distorze a příčného rozměru. Modely mají zcela nový zákon kinematického zpevnění, který vychází z principu mnohaplochové plasticity, avšak zachovává malé množství vnitřních pro-měnných. Zamýšleným použitím modelů je studie víceosé kumulativní deformace a způsoby kalibrace. Jejich možné praktické uplatnění spočívá v cyklickém víceosém provozním zatížení v tlakových potrubních systémech a v některých velmi specifických aplikacích. Modely byly implementovány ve formě subroutin UMAT pro MKP-systém Abaqus. Klíčová slova: metal plasticity,directional distortional hardening,constitutive model,combined loading,ratcheting,implementation,convexity,FEM; plasticita kovů,směrové zpevnění,konstitutivní model,kombinované namáhání,cyklické zpevnění,implementace,konvexita,MKP Plné texty jsou dostupné v digitálním repozitáři ČVUT. Numerical Implementation of Distortional Hardening Models

The presented thesis describes the formulation of two new constitutive models of metal plasticity within the realm of small strains, both featuring directional distortional hardening. New yield ...

Plešek Jiří; Marek René; Halama Radim
České vysoké učení technické v Praze, 2019

Optimalizace výkonových MOSFET součástek vhodných pro integrované obvody
Husák Miroslav; Vacula Patrik; Musil Vladislav
2019 - anglický Táto doktorská práca sa zaoberá návrhom laterálnych výkonových tranzistorov s nízkym špecifickým odporom pri zapnutom stave, vhodných pre integráciu do Integrovaných Obvodov.This doctoral thesis deals with the design of lateral power transistor with lower specific on-resistance for integration into IC.The new model of MOSFET with waffle gate pattern is there described. For first, time the conformal transformation the Schwarz-Christoffel mapping has been used for the description of nonhomogeneous current distribution in the channel area of MOSFET with waffle gate pattern. In addition base on the figure of merit definition Area Increment (AI) the topological theoretical limit of MOSFET with waffle gate pattern has been a first time defined. Klíčová slova: výkonový MOSFET,GaN HEMT,mriežkový vzor,integrovaný obvod,fyzický návrh analógových a zmiešaných obvodov; power MOSFET,GaN HEMT,waffle pattern,integrated circuit,physical design of analog and mixed-signal circuits Plné texty jsou dostupné v digitálním repozitáři ČVUT. Optimalizace výkonových MOSFET součástek vhodných pro integrované obvody

Táto doktorská práca sa zaoberá návrhom laterálnych výkonových tranzistorov s nízkym špecifickým odporom pri zapnutom stave, vhodných pre integráciu do Integrovaných Obvodov.This doctoral thesis deals ...

Husák Miroslav; Vacula Patrik; Musil Vladislav
České vysoké učení technické v Praze, 2019

Spektroskopická speciační studie U(VI) ve vodných roztocích
Vetešník Aleš; Višňák Jakub; Bouř Petr
2019 - anglický Experimentální část práce zahrnuje speciační studie systému UO2(2+) - XO4(2-) - H2O (X = S, Se) a analýzu přírodních vzorků obsahujících U(VI) s dominantními species MnUO2(CO3)3 (M = Ca, Mg) pomocí spektroskopických metod (TRLFS a UV-VIS). Získané spektroskopické parametry mají přímý chemicko-fyzikální význam. Teoretická část se zabývá výpočtem luminiscenčních spekter pomocí molekulové dynamiky a kvantové chemie.The experimental part covers speciation studies of the UO2(2+) - XO4(2-) - H2O (X = S, Se) system and analysis of natural water samples containing U(VI) – with MnUO2(CO3)3 (M = Ca, Mg) as dominant species systems by spectroscopic means (TRLFS and UV-VIS). The obtained spectroscopic parameters have a direct chemical-physical meaning. Theoretical part includes luminescence spectra computation using Molecular Dynamics and Quantum Chemistry. Klíčová slova: uranyl,speciace,luminiscenční spektroskopie,TRLFS,spektrofotometrie,multilineární analýza,chemometrie,vibronické přechody,kvantová chemie,Diracova rovnice,Franck-Condonovy faktory,modelování spekter; Uranyl,speciation,luminescence spectroscopy,TRLFS,spectrophotometry,multilinear analysis,chemometrics,vibronic transitions,quantum chemistry,Dirac equation,Franck-Condon factors,Spectral Plné texty jsou dostupné na jednotlivých katedrách ČVUT. Spektroskopická speciační studie U(VI) ve vodných roztocích

Experimentální část práce zahrnuje speciační studie systému UO2(2+) - XO4(2-) - H2O (X = S, Se) a analýzu přírodních vzorků obsahujících U(VI) s dominantními species MnUO2(CO3)3 (M = Ca, Mg) pomocí ...

Vetešník Aleš; Višňák Jakub; Bouř Petr
České vysoké učení technické v Praze, 2019