<div>Due to the depletion of fossil fuel reserves and emission challenges associated with its usage, there is a need for alternative aviation fuels for future propulsion. The alternative fuels with handling, storage and combustion characteristics similar to conventional fuels can be used as “drop-in” fuels without significant changes to the existing aviation infrastructure. Fire safety characteristics of alternative aviation fuels have not been studied intensively and therefore research is needed to understand these characteristics. In this study, fire safety characteristics namely hot surface ignition (HSI) and flame spread phenomena are investigated for alternative aviation fuels. </div><div><br></div><div>HSI is defined as the process of a flammable liquid coming in contact with a hot surface and evaporating, mixing and reacting with the surrounding oxidizer with self-supporting heat release (combustion). If all the conditions are adequate, the fuel may completely turn into combustion products following the ignition process. This work presents results from more than 5000 ignition tests using a newly developed reproducible test apparatus. A uniform surface temperature stainless steel plate simulating the wall of a typical exhaust manifold of an aircraft engine is used as the hot surface. Ignition tests confirmed that the ignition event is transient and initiates at randomly distributed locations on the hot surface. The results show many significant differences and some similarities in the ignition characteristics and temperatures of the different fuels. In this work, hot surface ignition temperatures (HSITs) are measured for nine hydrocarbon liquids. Five of these fuels are piston engine based, three fuels are turbine-engine based and one fuel is a pure liquid, heptane. The piston engine based fuels are given by FAA and are confidential and hence labeled as test fuels A, B, C, D for this study. The HSITs of these fuels are measured and compared against a baseline fuel 100 LL aviation gasoline (100LL Avgas). HSITs of conventional turbine engine based fuels namely Jet-A, JP-8, and JP-5 are also measured. </div><div><br></div><div>Flame spread along liquid fuel has been one of the important combustion phenomena that still requires more in-depth research and analysis for the deep understanding of the chemical processes involved. Flame spread rate determines how fast the flame spreads along the fuel surface and it is an important parameter to study for fire safety purposes. For the flame spread rates study, a novel experimental apparatus is designed and fabricated. The experimental apparatus consists of a rectangular pan, a fuel heating system, an autonomous lid actuation system, a CO2 fire extinguisher system, and a laser ignition system. The flame spread phenomenon is studied for a conventional aviation fuel namely, Jet-A and three alternative aviation fuels namely, hydro-processed ester fatty acids (HEFA-50), Fischer-Tropsch – IPK (FT-IPK) and synthetic iso-paraffin (SIP). The experiments are conducted for a wide range of initial fuel temperatures ranging from 25°-100°C for Jet-A, HEFA-50, FT-IPK and from 80-140°C for SIP as the flash-point of SIP is 110°C and is ~3 times higher than that of other three fuels. The flame spread rate of all fuels increases exponentially with increasing fuel’s initial temperature. Flame spread rate is as low as ~5 cm/sec for Jet-A, HEFA-50, FT-IPK for 25°C initial fuel temperature and goes to as high as 160 cm/sec for 80°C initial fuel temperature. For SIP based jet fuel, flame spread rate is ~160 cm/sec for initial fuel temperature of 140°C. Additionally, it was also found that the flame propagation consists of two types of flames: a precursor blue flame located ahead of the main yellow flame. These flames are more evident over the fuels’ surface with initial fuel temperatures higher than their respective flash-points. The precursor blue flame propagates like a premixed flame and the main yellow flame propagates like diffusion combustion.</div><div><br></div><div>This dissertation includes eight chapters. Chapter 1 gives an overview of the work done until now in the field of hot surface ignition. Following this review, the experimental apparatus designed and fabricated for this study are discussed in Chapter 2. This chapter also talks about the test matrix, data acquisition tools and concludes with the data analysis method. In Chapter-3, HSITs of 3 turbine engine based fuels and 5 piston engine based fuels are reported. This chapter also discusses the effect of drop height and curvature (flat v/s cylindrical) for two fuels, Jet-A, and heptane. This concludes the work done in the field of HSI in this dissertation. Chapter 4 talks about the past work reported by various researchers in the field of flame spread phenomenon and key learnings from their work. Chapter 5 discusses the experimental apparatus designed and fabricated for flame spread phenomenon study. In chapter-6, flame spread rates of 4 alternative aviation fuels are reported. This chapter also discusses the flame spread mechanism associated with slower (liquid-phase controlled) and faster (gas-phase controlled) flame propagation. Chapter 7 discusses flame propagation which consists two types of flames: a precursor blue flame and a main yellow flame. Chapter 8 concludes the key findings of the hot surface ignition and flame spread phenomenon study in this research work </div><div><br></div>

Credit market frictions, captured by mortgage spreads, are potentially an equally important driver behind mortgage rate innovations as monetary policy. Possibly a significant driver of business cycles. Yet, the effect of such shocks on the economy has barely received any attention in empirical research. By estimating a SVAR for 12 EU countries, I find that mortgage spread shocks have a significant effect on GDP, consumption, residential investment and house prices. The magnitude of their effects is comparable to a monetary policy shock. I also find that the transmission mechanism of such shocks is influenced by mortgage market characteristics. A high mortgage debt-to-GDP ratio and widespread use of mortgage equity withdrawal, compared to a lower ratio and less or no use, potentially imply a stronger response in house prices and residential investment of 0.5 and 1 percent respectively.

Vybíralová, E. Identification of key factors of financial performance of mixed agricultural primary production concerns in connection with changes in production structure. Diploma thesis. Brno: Mendel University in Brno, 2019. Diploma thesis deals with the identification of key factors of financial performance of the Agricultural concern Olbramkostel in connection with changes in production structure. The results will be compared with the business environment based on a representative sample of agricultural concerns. The theoretical part focuses on gathering theoretical knowledge from the area of measuring financial performance and agricultural production. In the practical part, a financial analysis will be done using selected tools, ensuring the basic evaluation of the company and the business environment. Based on the results of the financial analysis, the Discussion will identify the key factors affecting financial performance and the scenarios will model the effects of structural change on the business environment.

The eruption of the financial crisis in 2008 caused immense widening of both domestic and cross currency basis spreads. Also, as a majority of all fixed income contracts are now collateralized the funding cost of a financial institution may deviate substantially from the domestic Libor. In this thesis, a framework for pricing of collateralized interest rate derivatives that accounts for the existence of non-negligible basis spreads is implemented. It is found that losses corresponding to several percent of the outstanding notional may arise as a consequence of not adapting to the new market conditions. / I samband med utbrottet av 2008 års finansiella kris vidgades många basisspreadar till ej tidigare skådade nivåer. Därtill krävs i dagsläget att säkerhet finns tillgänglig vid initieringen av en majoritet av alla räntekontrakt, vilket innebär att en banks finansieringskostnad kan avvika substantiellt från den inhemska interbankräntan. I detta examensarbete implementeras ett ramverk för prissättning av räntederivat som beaktar existensen av basisspreadar samt krav på säkerhet. Resultaten visar att förluster motsvarande flera procent av det nominella beloppet kan uppstå som konsekvens av att inte anpassa sig till det nya tillståndet på räntemarknaden.

The COVID-19 pandemic is ongoing and global. A difficult situation affecting health and economy in all parts of the world. The need for and demand of accurate, trustworthy and efficient communication has never been more important. Understanding the importance and impact that media has when it comes to conveying their messages to various target groups is critical. The ability of individuals taking responsibility for implementing political ambitions depends entirely on communication. The time period chosen was March 2020 to March 2021. The purpose of this study is to examine the debate on whether there has been a shift of responsibility from individuals to the government, when it comes to managing the spread of COVID-19. It specifically focusses on the media’s role and responsibility in conveying fact-based messages for a desired shift towards more individual responsibility in reducing the spread of the pandemic. Debate articles and editorials were the main research base in determining if a shift has taken place or not. The study combines quantitative and qualitative techniques by examining COVID-19 issues in five Swedish newspapers. The research was condensed to in depth studies of 54 articles. Focusing on three keywords, namely: covid, corona and spread, both quantitative and qualitative conclusions could be made. In conclusion, it is not possible to draw any general assumption to whether there has occurred a shift of responsibility or not.

Befolkningsökningen och urbaniseringsprocessen gör att fler bostäder och andra byggnader måste uppföras i städerna. Stadsförtätning är en planeringsstrategi där påbyggnad av befintliga byggnader är en lösning. Vid påbyggnad måste nya laster bäras av en befintlig konstruktion och beroende på påbyggnadens omfattning och materialval används olika förstärkningsmetoder. Syftet med denna studie är att undersöka en förstärkningsmetod genom breddning av pelarfundament. Konsekvenserna inom två teknikområden: geoteknik och byggnads-konstruktion, har studerats. Frågeställningarna har varit likartade: vilka undersökningar måste göras och vilken bärförmåga har en konstruktion som pålastas före och efter förstärkning av pelarfundamentet? Parallellt med studier av litteratur har intervjuer med konstruktör och geotekniker utförts, för att skapa en tydlig inriktning på arbetet.  Några metoder för förstärkning av pelarfundament presenteras. Förutom specialiserad litteratur, rapporter och uppsatser som utgör den största delen av teoriavsnittet i denna studie, har Eurokoderna utgjort referens, främst vid konstruktionsberäkningar men också för det avsnitt som berör geoteknik. För att kunna utföra relevanta beräkningar har ett fiktivt fall tagits fram. Utifrån bygghandlingar och uppmätningar i ett befintligt parkeringshus i Lund, har de vertikala lasterna före och efter påbyggnad beräknats. Den befintliga byggnaden var grundlagd på grov- och mellansand men placerades i det fiktiva fallet i Malmö och grundlades på lermorän. Utifrån de stipulerade förutsättningarna har en dimensionering vid förstärkning av det befintliga pelarfundamentet redovisats i form av beräkningskontroller samt ritningar. Vid dimensionering av pelarfundamentet har olika beräkningsmodeller använts. Flera avgränsningar har gjorts; exempelvis att horisontella laster inte beaktats och vertikala laster verkar centriskt, i syfte att ge en överskådlig bild av de vanligast förekommande beräkningarna och kontrollerna som måste göras vid fundamentförstärkning. I det aktuella fallet var sidan på det kvadratiska pelarfundamentet 2,8 m lång och dess tjocklek 0,6 m. De vertikala lasterna före påbyggnad uppskattades till 2242 kN och ökade till 3894 kN efter påbyggnad. Jorden blev då belastad nära maximal tillåten spänning och den befintliga betongkonstruktionen hade inte kapacitet för att bära de nya lasterna. En ökning av plattans breddmått med 0,45 m på samtliga sidor beräknades nödvändig för att behålla samma spänning i jorden. För att uppnå en godtagbar kapacitet antogs en pågjutning à 0,2 m också vara nödvändig. Även en breddning av den rektangulära pelaren antogs. Beräkningskontrollerna godkände de nya dimensionerna samt fastställde kvantiteten av nytt armeringsjärn som skulle användas, dels för att förlänga den befintliga armeringen, dels för att förbättra vidhäftningen mellan den gamla och den nya betongen. Val av förstärkningsmetod är förknippad med flera faktorer såsom läget inom byggnadskonstruktionen, geokonstruktionens skick, markförhållanden, mm. Därför är inte en metod bättre än en annan; lämplig metod måste bestämmas från fall till fall. Som studien visar skall en arbetsmetodik följas med undersökningar och relevanta beräkningar. Slutsatserna är att studiens resultat bedöms rimliga, men noggrannare dimensionering skulle kunna utföras med FEM-program. / The increase in population and the urbanization process means that more buildings must be built in the cities. Extension of existing buildings is a solution to increase housing capacity, but the existing structure must be strengthened to be able to carry the new loads.  The purpose of this study is to investigate a strengthening method of spread footing in two technical fields: geotechnics and building construction. The questions were: what investigations must be made and what load-bearing capacity has a structure that is loaded before and after enlargement of the spread footing? In addition to specialized literature, reports and essays, the Eurocodes have been a reference. Some methods for enlargement of spread footing are presented. A fictitious case has been developed based on construction documents and measurements in an existing parking garage that was placed in Malmö and founded on clay till. A dimensioning for enlargement of the existing spread footing has been reported in the form of calculation checks and drawings. The vertical loads before the extension were estimated at 2242 kN and increased to 3894 kN after the extension. An increase in the width of the footing by 0.45 m on all sides was calculated necessary to maintain the same tension in the ground. In order to achieve an acceptable capacity, an overlay of 0.2 m was also assumed to be necessary. The calculation controls approved the new dimensions and determined the quantity of new dowels to be used, partly to extend the existing reinforcement, partly to improve the adhesion between the old and the new concrete. The choice of enlargement method is associated with several factors therefore, one method is not better than another. The appropriate method must be determined on a case-by-case basis with a working methodology with surveys and relevant calculations. The conclusions are that the results of the study are considered reasonable, but more accurate dimensioning could be performed with FEM-programs.

The diploma thesis deals with the analysis of impact on the economic crisis from 2008 on tourism, focused on accommodation in the Czech republic. The basis for this analysis are data obtained from the Amadeus database. The theoretical part is related to the economic importance of tourism and the history of economic crises in the context to the 2008 crisis. In practical part is analysed the economic indicator of the effectiveness of INFA Spread. Graphical analysis is further complemented by correlation analysis, ANOVA analysis and trend analysis by LOESS. Finally, the results are summarized, compared and discussed with developments in times of crisis in European countries.

abstract: State-of-the-art automotive radars use multi-chip Frequency Modulated Continuous Wave (FMCW) radars to sense the environment around the car. FMCW radars are prone to interference as they operate over a narrow baseband bandwidth and use similar radio frequency (RF) chirps among them. Phase Modulated Continuous Wave radars (PMCW) are robust and insensitive to interference as they transmit signals over a wider bandwidth using spread spectrum technique. As more and more cars are equipped with FMCW radars illuminate the same environment, interference would soon become a serious issue. PMCW radars can be an effective solution to interference in the noisy FMCW radar environment. PMCW radars can be implemented in silicon as System-on-a-chip (SoC), suitable for Multiple-Input-Multiple-Output (MIMO) implementation and is highly programmable. PMCW radars do not require highly linear high frequency chirping oscillators thus reducing the size of the final solution. This thesis aims to present a behavior model for this promising Digitally modulated radar (DMR) transceiver in Simulink/Matlab. The goal of this work is to create a model for the electronic system level framework that simulates the entire system with non-idealities. This model includes a Top Down Design methodology to understand the requirements of the individual modules’ performance and thus derive the specifications for implementing the real chip. Back annotation of the actual electrical modules’ performance to the model closes the design process loop. Using Simulink’s toolboxes, a passband and equivalent baseband model of the system is built for the transceiver with non-idealities of the components built in along with signal processing routines in Matlab. This model provides a platform for system evaluation and simulation for various system scenarios and use-cases of sensing using the environment around a moving car. / Dissertation/Thesis / Masters Thesis Engineering 2019

Methicillin-resistant Staphylococcus aureus (MRSA) is a major nosocomial pathogen that has spread into the community since the 90s. In general, the community-associated (CA- MRSA) strains are more virulent, but less resistant to antimicrobials than the hospital- acquired strains (HA-MRSA). Some lineages of MRSA such as sequence type 8 have been transmitted more successfully around the world than others and there are situations where a dominant lineage has been replaced by a new one. The factors that are crucial for the selection of dominant lineage are often not clear. As part of this thesis, a longitudinal study of MRSA epidemiology in the Motol University Hospital during the period of 2018-2020 was performed and the occurrence of MRSA clonal complexes was characterized. A multicenter study of the epidemiological situation of MRSA in Slovakia during the period of January - April 2020 was also performed concomitantly. Moreover, several isolates from dominant lineages were further characterized by their phenotype. In the Motol University Hospital study, it was found that the HA-MRSA of the clonal complex 5 dominates and is represented mainly by spa-type t586; a finding that concurs with recent studies from the Czech Republic. In Slovakia, similar to the Czech Republic, MRSA lineages from clonal...

京都大学 / 0048 / 新制・課程博士 / 博士(農学) / 甲第17901号 / 農博第2024号 / 新制||農||1017(附属図書館) / 学位論文||H25||N4797(農学部図書室) / 30721 / 京都大学大学院農学研究科地域環境科学専攻 / (主査)教授 近藤 直, 准教授 小川 雄一, 教授 飯田 訓久 / 学位規則第4条第1項該当 / Doctor of Agricultural Science / Kyoto University / DFAM