Electrical engineers have responded to the increasing demand for circuit speed and functionality by reducing transistor feature size and increasing on-chip transistor density. Consequently, interconnect density, both on-chip and the system level is also increasing. Increasing circuit speed translates into shorter clock cycles and signals with faster edge rates, which have multi-GHz bandwidth. Densely packed parallel interconnects will cause signal integrity problems not only due to the increase in crosstalk noise but also due to the intrinsic low pass filter characteristics of the interconnects. The lossy nature of the interconnects is also going to increase due to metal surface roughness at higher frequencies, which will further degrade the signal quality at the receiver input. Embedded Patterned Layer (EPL), which is a patterned floating metal layer between a signal trace and its return path shows promise in reducing far-end crosstalk (FEXT). EPL also allows designers to modify the characteristic impedance of interconnects by varying the different physical parameters of the EPL. This dissertation analyzes the effect of EPL on conductor backed coplanar waveguides (CB-CPW). CB-CPWs excite higher order modes at high frequencies, so work was done to understand the effect of different ground via fence parameters in suppressing the higher modes which helps increase the interconnect bandwidth. A CB-CPW with ground via fence is called a grounded coplanar waveguide (GCPW). A very basic lumped element model transmission line model was developed to account for the effect of floating metals near a transmission line. This model was then used to explain the effect of EPL on a GCPW with large bandwidth. EPL reduces the characteristic impedance of the transmission line. Engineers can then design narrow high impedance transmission lines and use EPL to reduce the impedance to a desired value. This also allows reduction in crosstalk by increasing the spacing between the transmission lines. The EPL also reduced the differential impedance of a grounded conductor backed edge coupled coplanar waveguide, when it was used for differential signaling. Care must be taken to make sure that the EPL is symmetric to both the legs of the differential pair to avoid differential to common mode energy conversion, which can cause electromagnetic interference (EMI) problems. EPL reduced FEXT while increasing near-end crosstalk (NEXT), when the coupled transmission line system was used for single ended signaling. Finally, a statistical method for modeling transmission line metal surface roughness in three dimensional (3D) full wave electromagnetic solvers was developed to account for increased attenuation in transmission lines, at high frequencies, due to metal surface roughness.

This thesis looks at illegal public art produced on state built barrier walls. The focus is on the artist Ron English, and his artworks produced on the Berlin Wall, Israeli Barrier Wall, and Mexican Border Fence. I examine English’s works in their respective contexts of Cold War divisions, the Israeli/Palestinian conflict, and tensions at the border between United States and Mexico. I also situate English’s works in relation to other artworks produced on these barriers. I argue that English is doing something different from other barrier wall artists in his work in Palestine and Mexico, offering a framework for understanding the primary motivations and tactics behind barrier wall art and highlighting English’s unique contributions.

The thesis presents a systematic experimental and numerical study on the interactions among porous fence, airflow, and windblown snowdrifts, a knowledge that will contribute to optimize the performance of porous wind shielding system in Cold Regions. A comprehensive review of the concepts, theories, techniques, and key findings associated with the research work has been undertaken. The key technical parameters influencing fence performance have been systematically studied by means of wind tunnel experimental investigations and Computational Fluid Dynamics (CFD) simulations. The study has found that porosity is the most influential structural parameter affecting the performance of porous fences in many aspects. Fence height stands a significant positive position in terms of its performance. It was found that fence performance is not sensitive to the changes of approaching atmospheric airflow velocity. Nevertheless, a bottom gap can improve snow fence trap efficiency. All of those findings agree with most of the findings of other researchers, which affirms that the research methodology adopted in this research is sound. Physical experimental work was performed to assess the reliability and credibility of the numerical models. Those models have been intentionally simplified, which made them easier to construct and quicker to obtain numerical solutions at a lower computational cost. Furthermore, the numerical models demonstrate the level of competence acquired through this research that is implemented in the optimisation of fence design. Special attention has been paid to the issues where elaborate research work has not been systematically reached in the open literature, this includes areas such as the effects of arrangement of porous holes, fence surface shear, and directions of wind load with respect to the fence, etc. Correlation between the reattachment length, the shelter distance, and the creation and distribution of fence surface shear is reported, to the author's knowledge, for the first time in the open literature. General guidelines for the design of shelters based on porous fences have been established through this study. For example, the desirable size of hole range should be identified beforehand, and porous holes with sharp angular corners should usually be avoided in the fence design. It is recommended to place the fence within an angle of 30° to the wind load, where the effective shelter distance can be estimated in a linearized equation, and the normal drag coefficient can be described as a function of cos2θ. Optimal design of the arrangement of porous holes will maximize the fence performance, especially when the close fence environment is of concern. Although the definition of fence effective zone is still vague in the research field, the key factors influencing the fence effective zone have been investigated by evaluating the reduction of wind velocity leeward of the fence in this thesis. It is found that the fence effective zone is not sensitive to the change of approaching airflow velocity, and that increasing fence height will increase the physical size of the fence effective zone, but not in a proportional manner. It is also concluded that fence effective zone will be significantly reduced when the non-normal wind load is inclined at an angle greater than 30° to the fence. The effective zone increases effectively when the fence porosity is optimal. In contrast to the majority of published research work, the transient snow transport model presented in this work considers the snow transport rate as a whole without distinguishing the rate in saltation and suspension layer. The numerical study indicated that the position of the snow crest is mainly determined by the fence height, while porosity and bottom gap mainly affect the downwind deposition length. The optimal porosity for snow fences is in the range of 0.4 to 0.5, which is greater than the one for wind fences, which lies in the range from 0.25 to 0.35. Two snow crests have been observed leeward the fence at the onset of snow deposition, when the fence was placed without a bottom gap to the snow ground. This finding has not been encountered in any of the reported research work. Wind tunnel simulations of snowdrift around the fences have marginally under-predicted the sizes of snow deposition. The numerical predictions were quantitatively and qualitatively in good agreement with the field observations. This incompetence of wind tunnel experiments on porous fences implies that numerical modelling can play a more important role in snow fence research.

The purpose of the study was to find alternatives to fences by comparing the frequency of damages on different configurations of chemical treated, mechanically protected and untreated hybrid aspen seedlings, planted on agricultural land. The study also explored whether anthropogenic disturbance (proximity to roads and buildings) had any effect on the frequency of seedlings damages. The study was conducted as a quantitative study with field measurements over the course of a year, in two sample plots with hybrid aspen seedlings planted in May 2016 in Vimmerby kommun, Kalmar län. The field data was compiled into Excel and compared for differences between treatments and proximity to anthropogenic disturbance. The result showed that seedlings closer to anthropogenic disturbance showed a lower frequency of damage. There was no significant difference between the mechanical (Taimitassu) and chemical (Arbinol B) seedling protection. The highest frequency of damages occurred in the summer, peaking in July. In conclusion, when choosing a place to plant hybrid aspen, there should be anthropogenic disturbance to minimize the frequency of browsing.

Les architectures modernes avec des processeurs multicœurs, ainsi que les langages de programmation modernes, ont des mémoires faiblement consistantes. Leur comportement est formalisé par le modèle mémoire de l'architecture ou du langage de programmation ; il définit précisément quelle valeur peut être lue par chaque lecture dans la mémoire partagée. Ce n'est pas toujours celle écrite par la dernière écriture dans la même variable, à cause d'optimisation dans les processeurs, telle que l'exécution spéculative d'instructions, des effets complexes des caches, et des optimisations dans les compilateurs. Dans cette thèse, nous nous concentrons sur le modèle mémoire C11 qui est défini par l'édition 2011 du standard C. Nos contributions suivent trois axes. Tout d'abord, nous avons regardé la théorie autour du modèle C11, étudiant de façon formelle quelles optimisations il autorise les compilateurs à faire. Nous montrons que de nombreuses optimisations courantes sont permises, mais, surprenamment, d'autres, importantes, sont interdites. Dans un second temps, nous avons développé une méthode à base de tests aléatoires pour détecter quand des compilateurs largement utilisés tels que GCC et Clang réalisent des optimisations invalides dans le modèle mémoire C11. Nous avons trouvés plusieurs bugs dans GCC, qui furent tous rapidement fixés. Nous avons aussi implémenté une nouvelle passez d'optimisation dans LLVM, qui recherchent des instructions des instructions spéciales qui limitent les optimisations faites par le processeur - appelées instructions barrières - et élimine celles qui ne sont pas utiles. Finalement, nous avons développé un ordonnanceur en mode utilisateur pour des threads légers communicants via des canaux premier entré-premier sorti à un seul producteur et un seul consommateur. Ce modèle de programmation est connu sous le nom de réseau de Kahn, et nous montrons comment l'implémenter efficacement, via les primitives désynchronisation de C11. Ceci démontre qu'en dépit de ses problèmes, C11 peut être utilisé en pratique. / Modern multiprocessors architectures and programming languages exhibit weakly consistent memories. Their behaviour is formalised by the memory model of the architecture or programming language; it precisely defines which write operation can be returned by each shared memory read. This is not always the latest store to the same variable, because of optimisations in the processors such as speculative execution of instructions, the complex effects of caches, and optimisations in the compilers. In this thesis we focus on the C11 memory model that is defined by the 2011 edition of the C standard. Our contributions are threefold. First, we focused on the theory surrounding the C11 model, formally studying which compiler optimisations it enables. We show that many common compiler optimisations are allowed, but, surprisingly, some important ones are forbidden. Secondly, building on our results, we developed a random testing methodology for detecting when mainstream compilers such as GCC or Clang perform an incorrect optimisation with respect to the memory model. We found several bugs in GCC, all promptly fixed. We also implemented a novel optimisation pass in LLVM, that looks for special instructions that restrict processor optimisations - called fence instructions - and eliminates the redundant ones. Finally, we developed a user-level scheduler for lightweight threads communicating through first-in first-out single-producer single-consumer queues. This programming model is known as Kahn process networks, and we show how to efficiently implement it, using C11 synchronisation primitives. This shows that despite its flaws, C11 can be usable in practice.

Gully erosion is a global problem that degrades land and reduces its utility for agriculture, development, and water quality. Quantification of sediment yield and control of sediment sources is essential for environmental protection. Five methods to evaluate erosion rates and sediment yield on an east Tennessee, USA, hillslope were compared: (1) physical measurement by removal of accumulated sediment using 10 L buckets; (2) repeated measurement of erosion pins in gully (erosional) and delta (depositional) areas; (3) geometric model using a combination trapezoidal prism-cylinder segment; (4) geometric model using a series of trapezoidal pyramids; and (5) 3D solid computer modeling. The 3D solid model created in SolidWorks was selected as the reference model and all other methods overestimated sediment yield to varying degrees. Erosion pin methods overestimated sediment yield by 368% in deltas and 123% in gullies. Volumetric measurement of sediment using buckets overestimated sediment yield by 160% due to void space in the buckets. The trapezoidal prism-cylinder segment model overestimated sediment yield by 66% and the trapezoidal pyramids method overestimated sediment yield by 5.7%. For estimation of sediment trapped behind an elliptical or circular silt fence dam, use of the trapezoidal pyramid method provides a good approximation comparable to 3D solid computer modeling.

Public land management agencies, conservation organizations, and landowners are interested in expanding the diversity of plant species used in rangeland restoration seedings. While the restoration of native grasses and shrubs in the Great Basin has become increasingly successful, restoration of native forbs continues to be problematic. In the Great Basin, soil water availability and soil fungal pathogens are thought to limit to restoration success. During the course of two years, we conducted two field experiments at three sites in the Great Basin that spanned a latitudinal gradient encompassing different precipitation and temperature patterns. In the first experiment, we evaluated two treatments for enhancing native forb restoration – snow fences and N-sulate fabric. In addition, we tested whether multiple fungicide and hydrophobic seed coatings could reduce seed and seedling mortality from soil fungal pathogens. To quantify the effectiveness of treatments, we tracked the fate of sown seeds over four life stages: germination, seedling emergence, establishment, and second-year survival. We found that snow fences and N-sulate fabric had varying degrees of success for increasing seedling emergence or establishment but ultimately did not increase second-year survival. Seed coatings increased seedling emergence but did not increase establishment or second-year survival. In the second experiment, we replicated the first experiment and also measured soil water availability to better understand how snow fences and N-sulate fabric alter soil water availability, and if differences in soil water availability can explain restoration outcomes. While we found that our treatments can increase soil water availability, increased soil water did not consistently result in better restoration outcomes. Snow fences did not benefit any life stage at any site while N-sulate fabric had positive and negative effects on forb restoration depending on the site. Seed coatings increased seedling emergence and establishment at all sites, warranting further research with other forb species. Results from both experiments provide insights for developing new treatments and techniques that can improve native forb restoration in the Great Basin and similar semiarid systems.

No description available.

The new public library building needs to meet a lot of diverse demands. It has to be developed in conjunction with librarian's needs, it has to react on existing urban conditions and it needs to be self-defining and future oriented, so it will be able to cope with radical changes in the communications we experience nowadays. Our proposition is a reaction to the impulses of the site combined with our view of what a new library should represent. It is: communication, interaction, inspiration. We try to eliminate negative aspects of the selected site and on the other hand, use and develop existing potential. The building tries to terminate the big crossroads next to the site and on the contrary to create a nice quiet public space with the church. It also wants to be a new landmark and icon of the town. The solution we found is based on two main principles. A fence. And a hill. Fence as a guard and prevention from crossroads, as a closure of the urban block and public space with green and church building inside, as a boarder with the industrial part of the town, as a show-off wall, a allure to the world of wisdom and quiet public space behind... It is represented by double glass facade along the border of the site. Hill as an activator of the site, as an icon and a brand of the place, as a second hill in whole town, as an island and oasis, as a place for sport, play, as an open public reading room, as a natural amphitheatre... It consists of a simple green roof raising from the church towards the sky, covering the library buiding.

Ce travail décrit de nouveaux composés thérapeutiques anticancéreux traçables par imagerie optique appelés théranostiques optiques.Après un premier chapitre bibliographique décrivant le contexte de l’imagerie et la thérapie des cancers, un deuxième chapitre présente une première série de théranostiques BODIPY-phosphine-or dont la synthèse a été optimisée (diminution du nombre d’étapes, baisse du temps de réaction, compatibilité avec une augmentation d’échelle). Leur conjugaison à des biomolécules (glucose, peptide) a été réalisée par une méthode simple et efficace par couplage entre l’atome d’or de la sonde et la fonction thiol de la biomolécule (modifiée ou non), conduisant à une liaison or-soufre. Elle permet une biovectorisation pour rendre les composés plus sélectifs des cellules tumorales vis à vis des cellules saines. Les études photophysiques et biologiques réalisées ont démontré tout le potentiel de ces théranostiques dans le cadre d’un suivi de composé in vitro et l’impact que pouvait avoir le vecteur choisi.Le troisième chapitre présente deux autres séries de théranostiques et précurseurs visant deux objectifs distincts pour rendre la sonde plus compatible avec une imagerie optique in vivo. La modification structurale de la plateforme BODIPY par introduction de groupements augmentant la conjugaison permet d’obtenir des BODIPYs absorbant et émettant dans la « fenêtre thérapeutique » (650 900 nm, proche infrarouge). Des études préliminaires in vivo ainsi que des tests en imagerie photoacoustique ont donné des résultats prometteurs. Une deuxième modification structurale par introduction de groupements encombrants sur chaque face du BODIPY vise à empêcher l’agrégation des BODIPYs en milieu biologique (phénomène connu pour affecter leurs propriétés optiques). Cette approche « Picket-Fence » des porphyrines transposée en série BODIPY a permis d’appliquer pour la première fois en série BODIPY le concept d’atropoisomérie et d’atropoisomères interconvertibles. / This work describes new anticancer agents that could be detected by optical imaging, namely optical theranostics.After a first chapter describing the context of cancer imaging and therapy, a second chapter describes a first series of BODIPY-phosphine-gold theranostics, the synthesis of which has been optimized (less steps, shortening the reaction time, scale up). Their conjugation with biomolecules (glucose, peptide) has been achieved by developing a simple and efficient method that leads to the coupling between the gold atom of the probe and the thiol of the biomolecule (modified or not), leading to a gold sulfur bound. Hence, it makes the biovectorization of the probes possible in order to get selectivity against tumor cells compared with healthy cells. Subsequent photophysical and biological studies demonstrated the potential of such theranostics, such as in vitro monitoring, and the impact of a chosen biomolecule (vector).A third chapter presents two additional series of theranostics and precursors with two distinct objectives aimed at making the probe more suitable for in vivo optical imaging. A first structural modification of the BODIPY platform was achieved upon introducing chemical groups allowing an extention of the π conjugation. It leads to BODIPYs that absorb and emit in the « therapeutic window » (650 900 nm, NIR). Preliminary in vivo studies and preliminary photoacoustic imaging studies with such compounds led to promising results. A second structural modification upon introducing bulky groups on each face of the probe was aimed at preventing stacking of BODIPYs platforms in biological media (a phenomenon known to affect their optical properties). Hence, a porphyrin « Picket Fence » approach was successfully transposed to BODIPY together with the concept of atropisomery and atropisomer interconversion.