Ethanol lock therapy is a novel technique that is being studied for its efficacy in eradicating catheter related bloodstream infections. A systematic review of interdisciplinary studies from CINAHL, Medline, Academic Search Premier, Biological Abstracts, and Web of Knowledge databases was performed. This meta-analysis examined the findings of thirty-five studies on ethanol lock therapy. Twenty-six of these studies compared ethanol to a placebo and nine studies performed a direct comparison of ethanol to other agents frequently used in antimicrobial lock technique. Ethanol lock therapy was shown to be effective as both a prophylactic therapy and as an active treatment in eradicating biofilms of organisms that frequently cause catheter-related blood stream infections, including Staphylococcus epidermis, Staphylococcus aureus, Klebsiella pneumonia, Pseudomonas aeruginosa, E. coli, and Candida albicans. Ethanol has been shown to have a synergistic effect with several other antimicrobial agents. The majority of studies examined in this thesis have found that ethanol has equal or greater efficacy to several antibiotic and antimicrobial agents used in practice and should therefore be considered for the treatment of catheter-related blood stream infections.

My research has been on the development of concurrent algorithms for shared memory systems that provide guarantees of progress. Research into such algorithms is important to developers implementing applications on mission critical and time sensitive systems. These guarantees of progress provide safety properties and freedom from many hazards, such as dead-lock, live-lock, and thread starvation. In addition to the safety concerns, the fine-grained synchronization used in implementing these algorithms promises to provide scalable performance in massively parallel systems. My research has resulted in the development of wait-free versions of the stack, hash map, ring buffer, vector, and a multi-word compare-and-swap algorithms. Through this experience, I have learned and developed new techniques and methodologies for implementing non-blocking and wait-free algorithms. I have worked with and refined existing techniques to improve their practicality and applicability. In the creation of the aforementioned algorithms, I have developed an association model for use with descriptor-based operations. This model, originally developed for the multi-word compare-and-swap algorithm, has been applied to the design of the vector and ring buffer algorithms. To unify these algorithms and techniques, I have released Tervel, a wait-free library of common algorithms and containers. This library includes a framework that simplifies and improves the design of non-blocking algorithms. I have reimplemented several algorithms using this framework and the resulting implementation exhibits less code duplication and fewer perceivable states. When reimplementing algorithms, I have adapted their Application Programming Interface (API) specification to remove ambiguity and non-deterministic behavior found when using a sequential API in a concurrent environment. To improve the performance of my algorithm implementations, I extended OVIS's Lightweight Distributed Metric Service (LDMS)'s data collection and transport system to support performance monitoring using perf_event and PAPI libraries. These libraries have provided me with deeper insights into the behavior of my algorithms, and I was able to use these insights to improve the design and performance of my algorithms.

Room temperature ionic liquids (ILs) are a unique class of solvents which are characterized by non-volatility, non-flammability, electrochemical stability and high ionic conductivity. These properties are highly desirable for ion-conducting electrolytes, and much work has focused on realizing their application in practical devices. In addition, hydrophilic and ionophilic polymers are generally miscible with ILs. The miscibility of ILs with ion-coordinating polymers makes ILs effective plasticizers for gel polymer electrolytes. Due to their unique properties, ILs present a means to realize the next generation of energy storage technology. In this dissertation, the fundamental interactions between poly(ethylene oxide) (PEO) and a variety of room temperature ILs were investigated. ILs with acidic protons were demonstrated to form a stronger interaction with PEO than ILs without such protons, suggesting that hydrogen bonding plays a dominant role for PEO miscibility with ILs. The hydrogen bonding interaction is selective for the PEO block of a PEO-b-PPO-b-PEO block copolymer (BCP). Therefore, blending these copolymers with the strongly interacting IL 1-butyl-3-methylimidazolium hexafluorophosphate ([BMI][PF6]) induced microphase separation into a well-ordered structure, whereas the neat copolymer is phase mixed. At sufficient quantities, the interaction between [BMI][PF6] and PEO suppresses PEO crystallinity entirely. In addition, the induced microphase separation may prove beneficial for ion conduction. Therefore, microphase separated copolymer/IL blends were investigated as potential gel polymer electrolytes. Cross-linkable block copolymers which microphase separate when blended with [BMI][PF6] were synthesized by modifying PPO-b-PEO-b-PPO copolymers with methacrylate end-groups. Cross-linking these copolymers while swollen with an IL generates ion gels with high ionic conductivities. The copolymer/IL blends vary from a well-ordered, strongly microphase separated state to a poorly ordered and weakly microphase separated state, depending upon the molecular weight. Stronger microphase separation results in higher mechanical strength upon cross-linking. However, this does not greatly affect ion conductivity. Nor is conductivity affected by forming gels from cross-linked PEO homopolymers when compared to BCPs. It was found that BCPs can be beneficial in producing gel electrolytes by allowing sequestration of phase selective cross-linkers away from the conducting block. Cross-linker molecules that are selective for the PPO blocks can be used to increase the mechanical strength of the gels with only a small effect on the conductivity. When cross-linkers that partition to the mixed PEO/IL block are used, the conductivity decreases by nearly a factor of 2. These studies show how ILs interact with PEO and how gel polymer electrolytes can be constructed with the IL [BMI][PF6]. While BCPs cannot directly be used to increase ion conductivity, they do allow for greater mechanical strength without sacrificing conductivity. This suggests many new approaches that may be used to simultaneously achieve high ionic conductivity and mechanical strength in solid and gel polymer electrolytes.

When the copper production takes place, the pure rock smelting undergoes a sub-processcalled copper conversion. This process is a batch process, which means that the converterfurnace cools down before the next refill. Inside the converter ovens there is a masonrywear brick that is adversely affected when exposed to temperature variations. When thewearing brick cools down, a contraction occurs in the material, then when heated, anexpansion of the material occurs instead. The result of this is that tensions arise in thematerial, which increases the risk of cracking. To possibly make it possible to maintain amore even temperature in the converter furnace, this thesis will focus on developing a basisfor a construction of a heat-keeping lid for the mouth of the converter furnace. With a heatretention cap in place, it could possibly be possible to maintain a more even temperature,which could result in a longer lifespan of the masonry wear brick. If a warming cover were tobe placed on the mouth, it could also mean a reduced combustion of diesel oil via thewarming burners that are placed inside the converter furnace, which could also reduce theenergy requirement. In addition to the heat-keeping lid, a construction that will enable amovement of the heat-keeping lid to and from the mouth of the converter furnace will alsobe investigated. The design produced will be in a very harsh environment where corrosion isknown to be a concern, and therefore this is considered when choosing the material used inmanufacture. According to the results presented in the report, the heat-keeping burnersinside the converter oven should need to be used approx. 64% less than if the heat-keepinglid were not placed. / När kopparframställningen sker så genomgår skärstenssmältan en delprocess som kallaskopparkonvertering. Denna process är en batchprocess vilket innebär att konverterugnensvalnar av innan nästa påfyllnad. Invändigt i konverterugnarna finns det ett murat slittegelsom påverkas negativt när det utsätts för temperaturvariationer. När slitteglet svalnar av såsker det en kontraktion i materialet sedan vid uppvärmning sker i stället en expansion avmaterialet. Resultatet av detta är att spänningar i materialet uppstår vilket ökar risken försprickbildning. För att eventuellt kunna möjliggöra att hålla en jämnare temperatur ikonverterugnen så kommer detta examensarbete att rikta in sig på att ta fram ett underlagav en konstruktion på ett varmhållningslock till konverterugnens mynning. Med ettvarmhållningslock placerat så skulle det eventuellt kunna vara möjligt att bibehålla enjämnare temperatur vilket skulle kunna resultera i en längre livslängd på det muradeslitteglet. Om ett varmhållningslock skulle placeras på mynningen så skulle det också kunnainnebära en minskad förbränning av dieselolja via varmhållningsbrännarna som är placeradeinvändigt i konverterugnen, vilket också skulle kunna minska energibehovet. Utövervarmhållningslocket så kommer även en konstruktion som ska möjliggöra en förflyttning avvarmhållningslocket till och från mynningen på konverterugnen undersökas. Konstruktionensom tas fram kommer att befinna sig i en väldig påfrestande miljö där det är känt attkorrosion är ett bekymmer, och därför tas detta i beaktan vid val av det material somanvänds vid tillverkning. Enligt de resultat som tas fram i rapporten så börvarmhållningsbrännarna invändigt i konverterugnen behöva användas ca 64% mindre tillskillnad från att varmhållningslocket ej skulle vara placerat.

<p> A new radar tracking detector using fixed delay lines in place of continuously variable delay lines is described. The fixed delays are switched in and out depending on the output of a correlator. Results of a working system are shown using bang-bang feedback and analog-to-digital feedback, for tracking a time-varying delay. </p> / Thesis / Master of Engineering (MEngr)

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It has historically been the case that CPUs have run programs ever faster without significant intervention on the behalf of the programmer. However, this "free lunch" has largely ended due to the end of exponentially increasing core frequency and the current slow increase in instruction-level parallelism but continues to a degree in cache size improvements. But since Moore's law still largely continues "lunch", i.e. program performance, can still be bought at the price of rewriting code for multiple cores, which is enabled by the trend Moore's law describes. Multicore architectures cannot aid performance for problems whose solutions are necessarily sequential in nature and writing efficient and correct concurrent programs is not easy in all cases when using synchronization methods like fine-grained mutex locks. Transactional memory, and its implementation as hardware transactional memory, allow programmers to write concurrent applications without the attendant complexity of programming with mutex locks. This allows programmers to focus on optimizing the application for performance. Given that transactions can run two segments of code in parallel that a mutex lock would force to run sequentially and that transactions can abort, causing a program to do the same work more than once, whether transactions perform better or worse than mutex locks is dependent on the program's execution profile and the coarseness or fineness at which mutex locks are used. In this thesis the GNU C Library's futex implementation of mutex locks and Intel's Restricted Transactional Memory have been compared and the behavior of those transactions has been analyzed. This analysis includes a pathological behavior permitted by the GNU C Library's hardware transactional memory implementation of mutex locks. The tradeoffs between fine-grained and global locking implementations have been discussed, compared, and used in the context of fallback locks for hardware transactions. This thesis provides evidence to the effect that fine-grained locking is not critical for program performance and that in many cases global locking and hardware transactions can provide nearly equivalent performance without the programming difficulties. This work has shown that across the 23 applications examined, with relation to their original locking implementation, a global locking scheme without elision has a 0.96x speedup, Intel's Restricted Transactional Memory (RTM) with the application's original locks as a fallback has a 1.01x speedup and with global lock fallback RTM has a speedup of 0.97x. This work is supported in part by NAVSEA/NEEC under grant 3003279297. Any opinions, findings, and conclusions or recommendations expressed in this thesis are those of the author and do not necessarily reflect the views of NAVSEA. / Master of Science

Through the historic usage of fossil fuel, climate impacts have been severe and threaten to disrupt global economies and biological diversity. Hydrogen has emerged as a technology which can enable the productionand storage of renewable energy with no carbon emissions. However, energy transitions are complex as the sector is characterized by lock-in and path dependency due to co-evolution with infrastructure, policy and geography. The purpose of this study is to explore how hydrogen energy can overcome the lock-in and path dependency of fossil fuels. To achieve this, a qualitative single-case study of Sweden was conducted. The theoretical foundation consists of the Multi-Level Perspective and lock-in. The results indicate that in order for hydrogen technology to become large-scale and overcome lock-in, four criteria need to be fulfilled; hydrogen technology needs to be more cost-efficient, investments in infrastructure for hydrogen is required, a market needs to be established for the production of hydrogen and governments/institutions need to support hydrogen through regulation and investments. / Under decennier av fossil användning har klimatpåverkan blivit mer allvarlig och hotar att negativt påverka globala ekonomier och den biologiska mångfalden. Vätgas har framkommit som en teknik som möjliggör produktion och lagring av förnybar energi utan koldioxidutsläpp. Övergångar till nya energilösningar är dock svåra eftersom sektorn kännetecknas av “lock-in” och “path dependency”på grund av samutveckling med infrastruktur, politik och geografi. Syftet med denna studie är att undersöka hur vätgas kan övervinna “lock-in” och “path dependency” av fossila bränslen. För att uppnå detta genomfördes en kvalitativ fallstudie av Sverige. Den teoretiska grunden för studien består av Multi-Level Perspective och lock-in. Resultaten visar att fyra kriterier måste uppfyllas för att vätgas ska gå från en nisch innovation till att vara en del av dagens sociotekniska system. Vätgas måste bli mer kostnadseffektiv, investeringar i infrastruktur för vätgas krävs, en marknad måste skapas för produktion av vätgas och regeringar/institutioner behöver stödja vätgas genom föreskrifter.