The pursuit for improved engine efficiency is driving the demand for accurate temperature measurement inside turbine engines. Accurate measurement can allow engines to be operated closer to their design limits to improve thermal efficiency. It can enable engineers to verify mechanical integrity, provide better prediction of component life, validate CFD and other design tools and aid the development for leaner more efficient engines. Unfortunately, experimentally measuring surface temperatures under harsh rotating conditions is challenging. This EngD study conducted by Ashiq Hussain Khalid at the University of Manchester and Rolls-Royce plc, reviews the rationale of using phosphor thermometry over existing methods, including thermocouples, pyrometry and thermal paints/melts, which lack detail, accuracy, or are too expensive for continuous testing. Although phosphor thermometry exhibits desirable characteristics, the high temperature and fast rotating engine environment presents some challenges that would need to be addressed before a successful measurement system can be implemented. Examples of such issues include: rising blackbody radiation, restricted optical access, fibre optic constraints and limited time period to collect data. These factors will impose measurement limits and greatly influence the design philosophy of the system, including phosphor choice, phosphor lifetime characteristics, bonding technique, excitation/detection methodologies and probe design. Taking these into consideration, the research focuses on the development of phosphor thermometry systems for use in development gas turbine engines, with measurement solutions for specific engine components. The high pressure turbine blade was given research priority. A number of phosphors including YAG:Tb, YAG:Tm. Y2O3:Eu and Mg3F2GeO4:Mn were investigated and characterised in terms of intensity and lifetime decay, with increasing temperature up to 1500oC. Spectral analysis and absolute intensity measurements established emission peaks and permitted comparative quantitative analysis to optimise system setup. The intensity of phosphor emission relative to Planck's blackbody radiation was also performed. YAG:Tm under 355nm illumination was found to exhibit the highest emission intensity at high temperatures, and because its spectral emission peak at 458nm was the lowest, its advantage in terms of blackbody radiation was further amplified. For rotating components, an upper temperature limit is reached based on the emission intensity at rising blackbody radiation levels and the system's ability to detect fast decays. A lower limit is reached based on the quenching temperature, probe design and rotational velocity. There are different methods to correct the distorted decay waveform as it traverses through the acceptance cone of the fibre. A phosphor selection criterion, taking into consideration these limitations, was successfully applied for various rotating engine components. The optical layout was setup and tested on stationary and rotating cases under laboratory conditions using similar design constraints, including fibre choice, maximum permissible lens size and target distances. A series of tests validated design methodologies and assumptions to enable testing on full scale rotating engine components. Mg3F2GeO4:Mn, using 355nm illumination, was found to be the most suitable phosphor for the HP drive cone. The estimated performance under the expected rotational speeds was found to be 624-812°C with a standard uncertainty of ±0.99%. YAG:Tm, illuminated with 355nm, was found to be the most promising phosphor for high pressure turbine blade measurements. The performance under the expected rotational speeds was found to be 1117-1375°C with a standard uncertainty of ±0.97%. This is better than other competing technologies that are currently available for temperature measurement of rotating turbine blades.

Many devices in electronics are in the form of multilayered structures. These structures can fail catastrophically if they contain defects or cracks. Enhancing their fracture properties is therefore critical to improve the reliability of the systems. The interface-dominated fracture mechanics of multilayered structure was studied using experiments and finite element (FE) modeling by considering two examples: thin films on polymer substrates in flexible electronics and Cu leadframe/epoxy molding compound (EMC) in micro-electronics packaging. In the first example, aluminum-manganese (Al-Mn) thin films with Mn concentration up to 20.5 at.% were deposited on polyimide (PI) substrates. A variety of phases, including supersaturated fcc (5.2 at.% Mn), duplex fcc and amorphous (11.5 at.% Mn), and completely amorphous phase (20.5 at.% Mn) were obtained by adjusting alloying concentration in the film. In comparison with crystalline and dual phase counterparts, the amorphous thin film exhibits the highest fracture stress and fracture toughness, but limited elongation. Based on a fracture mechanism model, a multilayer scheme was adopted to optimize the ductility and the fracture properties of the amorphous film/PI system. Tensile deformation and subsequent fracture of strained Al-Mn films on PI were investigated experimentally and by FE simulations. It was found that by sandwiching the amorphous film (20.5 at.% Mn) between two ductile copper (Cu) layers, the elongation can be improved by more than ten times, and the interfacial fracture toughness by twenty four times with a limited sacrifice of the film's fracture toughness (less than 18%). This design provides important guidelines to obtain optimized mechanical properties of future flexible electronics devices. The reliability of amorphous brittle Al-Mn (20.5 at.% Mn) thin films deposited on PI substrates is strongly influenced by the film/substrate interface adhesion. Some strategies to improve the adhesion of the interface were conducted, including roughening the surface of the PI substrate, adding a buffer layer and then tuning its thickness. Tensile testing and FE analysis of amorphous Al-Mn thin films with and without buffer layers coated on intact and plasma etched rough PI were investigated. It was found that by adding a chromium buffer layer of 75 nm on a rough PI substrate, the interface adhesion of the film/substrate can increase by almost twenty times. The obtained results would thus shed light on the interfacial engineering strategies for improving interface adhesion for flexible electronics. In the second example, a systematic investigation and characterization of the interfacial fracture toughness of the bimaterial Cu leadframe/EMC was carried out. Experiments and FE simulations were used to investigate delamination and interfacial fracture toughness of the biomaterial system. Two dimensional simulations using computational fracture mechanics tools, such as virtual crack closure technique, virtual crack extension and J-integral proved to be computationally cheap and accurate to find the interfacial fracture toughness of the bimaterial structures. The effects of temperature, moisture diffusion and mode-mixity on the interfacial fracture toughness were investigated. Testing temperature and moisture exposure significantly reduce the interfacial fracture toughness, and its relationship with the mode-mixity was achieved by fitting the results with an analytic formula.

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Title: Martensite microstructures in thin films and monocrystals of Heusler alloys Ni-Mn-Ga Author: Kristýna Onderková Department: Department of Surface and Plasma Science Supervisor: Mgr. Ing. Oleg Heczko, Dr., Institute of Physics of the Czech Academy of Sciences Abstract: The submitted thesis examines mainly the first thin films from Ni-Mn-Ga Heusler alloy prepared by magnetron sputtering on the new equipment at Institute of Physics of Charles University. However, the work also analysed the thin films prepared in IFW Dresden and bulk material. The main focus of the work is primarily on the martensitic microstructures, because of the significant effect that their twin boundaries have on the magnetic shape memory phenomena. Microscopic techniques used for the research were mainly Scanning Electron Microscopy (SEM), but also Transmission Electron Microscopy (TEM) and Atomic Force Microscopy (AFM). As the Ni-Mn-Ga properties are stronly dependent on chemical composition, the composition was evaluated by two different methods (Electron Dispersive X-ray Spectroscopy and X-ray Fluorescence) and observed differences discussed. Finally the results were compared with X-ray diffraction (XRD) measurements and the films were further characterised by magnetic measurements using Vibrating Sample Magnetometer (VSM)....

Der Hen´s Egg Test for Micronucleus-Induction (HET-MN) wurde bereits mehrfach als ein alternatives, versuchstierfreies Testsystem für in-vivo Mutagenitätstests am Nager unter Verwendung von angebrüteten Hühnereiern vorgestellt (Wolf and Luepke 1997; Wolf, Niehaus-Rolf et al. 2002; Wolf, Niehaus-Rolf et al. 2003; Wolf, Niehaus-Rolf et al. 2008). Während der häufig verwendete in-vivo Micronucleustest am Nager aufgrund seines komplexen in-vivo Stoffwechsel für die Bewertung von Mutagenen sehr gute Ergebnisse liefert (Wolf 2003), können Alternativen zur Testung am Tier, zum Beispiel in-vitro Micronucleustests, die Vorteile der in-vivo Testung nicht erreichen, weshalb sie häufig zu sensitiv sind. Gegenüber herkömmlichen in-vitro Tests stellt die Komplexität des angebrüteten Hühnereis, welches sowohl toxikodynamische als auch toxikokinetische Wirkungen der Prüfsubstanz aufzeigen kann, einen besonderen Vorteil dar, so dass der HET-MN unter anderem nicht nur direkte Mutagene sondern auch Promutagene detektieren kann. Mit Hilfe von zehn ausgewählten Substanzen wurde in dieser Arbeit die Prädiktivität des HET-MN weiter untersucht. Hierzu gehörten, neben den in-vitro und in-vivo negativen Stoffen Ephedrin-HCl und Ampicillin-Natrium und den in-vitro und in-vivo positiven Substanzen para-Chloranilin, Carbendazim und Vinorelbintartrat, auch die fünf so genannten irrelevant positiven Substanzen Isophoron, 2,4-Dichlorphenol, Phthalsäureanhydrid, Menthol und Malathion, für die uneinheitliche in-vivo und in-vitro Daten vorliegen, die aber aufgrund validierter Testverfahren als in-vivo negativ eingestuft werden. Die im HET-MN ermittelten Ergebnisse zeigen für alle zehn Substanzen, im Vergleich zu den gängigen Einstufungen auf Grundlage validierter Tests, eine vollständige Übereinstimmung und damit eine sehr hohe Prädiktivität des HET-MN. Die Ergebnisse stärken daher die Position des HET-MN als einen zuverlässigen in-vitro Test mit besonderen metabolischen Fähigkeiten, der darüber hinaus dazu beitragen kann, so genannte irrelevant positive Substanzen besser einzustufen.

京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第20365号 / 工博第4302号 / 新制||工||1667(附属図書館) / 京都大学大学院工学研究科材料工学専攻 / (主査)教授 辻 伸泰, 教授 田中 功, 教授 安田 秀幸 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM

京都大学 / 0048 / 新制・課程博士 / 博士(エネルギー科学) / 甲第20731号 / エネ博第359号 / 新制||エネ||70(附属図書館) / 京都大学大学院エネルギー科学研究科エネルギー応用科学専攻 / (主査)教授 大垣 英明, 教授 松田 一成, 教授 河瀬 元明 / 学位規則第4条第1項該当 / Doctor of Energy Science / Kyoto University / DFAM

<p>This thesis highlights the use and significance of surface enhanced Raman spectroscopy (SERS) for forensic applications. Two unique SERS substrates are developed for successful (1) forensic toxicological drug detection in human patient plasma and (2) trace explosive detection.  </p>

Mobile computing is becoming increasingly important, due to the rise in the number of portable computers and the desire to have continuous network connectivity to the Internet, irrespective of the physical location of the node. We have also seen a steady growth of the market for wireless communication devices. Such devices can only have the effect of increasing the options for making connections to the global Internet. The Internet infrastructure is built on top of a collection of protocols called the TCP/IP protocol suite. Transmission Control Protocol (TCP) and Internet Protocol (IP) are the core protocols in this suite. There are currently two standards: one to support the current IPv4 and one for the upcoming IPv6 [1]. IP requires the location of any node connected to the Internet to be uniquely identified by an assigned IP address. This raises one of the most important issues in mobility because, when a node moves to another physical location, it has to change its IP address. However, the higher-level protocols require the IP address of a node to be fixed for identifying connections. The Mobile Internet Protocol (Mobile IP) is an extension to the Internet Protocol proposed by the Internet Engineering Task Force (IETF) that addresses this issue. It enables mobile devices to stay connected to the Internet regardless of their locations, without changing their IP addresses and, therefore, an ongoing IP session will not be interrupted [2, 3, 4]. More precisely, Mobile IP is a standard protocol that builds on the Internet Protocol by making mobility transparent to applications and higher-level protocols like TCP. However, before Mobile IP can be broadly deployed, there are still several technical barriers, such as long handover periods and packet loss that have to be overcome, in addition to other technical obstacles, including handover performance, security issues and routing efficiency [7]. This study presents an investigation into developing new handover mechanisms based on link layer information in Mobile IP and fast handover in Mobile IPv6 environments. The main goal of the developed mechanisms is to improve the overall IP mobility performance by reducing packet loss, minimizing signalling overheads and reducing the handover processing time. These models include the development of a cross-layer handover scheme using link layer information and Mobile Node (MN) location information to improve the performance of the communication system by reducing transmission delay, packet loss and registration signalling overheads. Finally, the new schemes are developed, tested and validated through a set of experiments to demonstrate the relative merits and capabilities of these schemes.