This thesis reports the fabrication of three dimensionally independent on-chip microchannels using a CMOS-compatible single mask deep reactive ion etching (DRIE) process for cooling 3D ICs. Three dimensionally independent microchannels are fabricated by utilizing the RIE lag effect. This allows complex microchannel configurations to be fabricated using a single mask and single silicon etch step. Furthermore, the microchannels are sealed in one step by low temperature oxide deposition. The micro-fin channels heat transfer characteristics are similar to previously published channel designs by being capable of removing 185 W/cm2 before the junction temperatures active elements exceed 85°C. To examine the heat transfer characteristics of this proposed on-chip cooler, different channel geometries were simulated using computational fluid dynamics. The channel designs were simulated using 20°C water at different flow rates to achieve a laminar flow regime with Reynolds numbers ranging from 200 to 500. The steady state simulations were performed using a heat flux of 100 W/cm2. Simulation results were verified using fabricated test chips. A micro-fin geometry showed to have the highest heat transfer capability and lowest simulated substrate temperatures. While operating with a Reynolds number of 400, a Nusselt number per input energy (Nu/Q) of 0.24 W-1 was achieved. The micro-fin geometry is also capable of cooling a substrate with a heat flux of 100W/cm2 to 45ºC with a Reynolds number of 525. These channels also have a lower thermal resistance compared to external heat sinks because there is no heat spreader or thermal interface material layer. / Master of Science

L’utilisation de molécules stimulatrices des défenses des plantes (SDP), également appelées inducteurs de résistance, constitue une alternative potentielle aux traitements fongicides conventionnels pour combattre les maladies dues à des champignons phytopathogènes. Trois SDPs, le tréhalose (TR), l’acide salicylique (SA) et l’heptanoyl d’acide salicylique (HSA), un dérivé fonctionnel du SA, protègent le blé (Triticum aestivum L.) contre l’oïdium (Blumeria graminis f.sp. tritici), lorsqu’ils sont utilisés de façon préventive. La protection obtenue n’est pas liée à un effet fongistatique direct sur la germination des spores du champignon, mais à l’induction chez le blé de défenses qui diminuent le développement de la maladie. Notre travail consistait à caractériser les mécanismes de défense mis en jeu après applications foliaires de TR, de HSA et de SA chez un cultivar de blé sensible à l’oïdium. Un suivi de l’expression de gènes marqueurs de défense, réalisé par RTqPCR, a été mené en cinétique,depuis le traitement par les SDPs jusqu'à 4 jours après infection. Les activités enzymatiques correspondantes ont été également mesurées, et l’influence indirecte des SPDs sur le processus infectieux a été observé en microscopie in planta. Ainsi, les réactions de défense déclenchées par le TR, le SA et le HSA ralentissent l’évolution de l’infection, jouant respectivement sur la germination des conidies, structures infectieuses de Bgt, sur la germination du tube germinatif appressorial (AGT) et sur la proportion d’AGTs qui parviennent à pénétrer dans les tissus foliaires. Le TR est à l’origine d’une augmentation de l’expression des gènes codant pour une lipoxygénase, une protéine de transfert des lipides et une phospholipase C, impliquées dans le métabolisme lipidique et la signalisation, et de gènes codant pour des protéines PR comme les chitinases et PR1, tous connus comme marqueurs de défense. Ainsi, les réactions déclenchées par le TR correspondent à un effet inducteur de défenseplutôt qu’à une réaction de stress osmotique. Le HSA modifie particulièrement le métabolisme lipidique, en induisant fortement et pendant toute la cinétique, l’expression du gène codant pour la LOX et l’activité correspondante, aussi bien hors contexte infectieux qu’en contexte infectieux. Cette augmentation de l’activité LOX n’est pas retrouvée chez des feuilles traitées au SA et caractérise donc le HSA. L’importance des réactions observées avec le TR, le SA et le HSA, hors contexte infectieux et en présence de Bgt amène à discuter les effets éliciteurs et potentialisateurs de ces 3 SDPs. / The use of plant elicitors, also known as resistance inducers, is an alternative to conventional fungicides to control diseases caused by phytopathogenic fungi. Three resistance inducers, trehalose (TR), salicylic acid (SA) and heptanoyl salicylic acid (HSA), a functional derivative of SA, protect wheat (Triticum aestivum L.) against powdery mildew (Blumeria graminis f . sp. tritici) when applied prior to infection. The protection obtained is not linked to any direct fungistatic effect on the fungal spore germination, but to the induction of wheat defences that impair the development of the disease. Our work aimed at characterizing the defence mechanisms triggered after foliar applications of TR, HSA and SA in a wheat cultivar susceptible to powdery mildew. Monitoring of defence markers genes expression by RTqPCR was conducted during a time-course experiment from the treatment time until 4 days after infection. Corresponding enzyme activities were also measured, and the indirect influence of elicitors on the infectious process was observed by microscopy in planta. Thus, defence responses triggered by TR, SA and HSA slow the progression of the infection, respectively altering the germination of infectious structures such as conidia, the differentiation of appressorial germ tube (AGT) and the proportion of AGTs that manage to penetrate the epidermis. TR causes an increase in the expression of genes encoding a lipoxygenase, a lipid transfer protein and a phospholipase C, which are involved in lipid metabolism and signaling, and genes encoding for PR-proteins such as chitinases and PR1, all known as markers of defence. Thus, the reactions triggered by TR match with the ones triggered during induced defence rather than during osmotic stress response. HSA specifically targeted lipid metabolism, inducing strongly and throughout the time-course, the expression ofthe gene encoding LOX and the corresponding enzyme activity, both in infectious and non-infectious contexts. This increase in LOX activity was not found in leaves treated with SA and thus characterizes HSA mode of action. The importance of the reactions observed with TR, SA and HSA, in non-infectious conditions and in the presence of Bgt have to be considered regarding either elicitation or potentiation.

The international technology roadmap for semiconductors (ITRS) 2012 report foresees the use of porous dielectric materials with a low dielectric constant in conjunction with copper interconnects as a way to reduce the resistive-capacitive (RC) delay in microelectronic applications. However, the introduction of pores in the dielectric not only serves as stress raisers but also diminishes the structural strength of the material. The challenge therefore with the implementation of low-k dielectrics for high-performance flip-chip packages is to create a reliable die to organic substrate interconnect solution which induces low stresses on the die to prevent the cohesive cracking and the interfacial delamination of the dielectric material. Potential interconnect solutions that meet this challenge are MEMS-like compliant freestanding micro-structures. These structures are designed to work as spring-like elements which allow the free lateral and out-of-plane motion between the silicon die and the organic substrate under assembly conditions as well as under thermal or power cycling. Thus, the focus of this research is to design, fabricate, and characterize electrically and mechanically an innovative compliant interconnect approach that addresses these challenges. The proposed interconnect is scalable in dimensions and pitch, and consists multiple electrical paths which will provide redundancy against interconnect failure. The multi-path design employs parallel electrical paths which effectively split a larger cross-sectional area into several smaller areas making the overall design more compliant than otherwise. This research proposes wafer-level, high-yield, CMOS-compatible fabrication procedure using sequential photolithography and copper electroplating. The proposed interconnects are symmetric and are amenable to easy reflow assembly to substrates. The mechanical compliance of the fabricated structures is studied through nano-indentation, while the electrical characteristics are assessed through fabricated prototypes. The xvi thermo-mechanical reliability of compliant interconnects is also demonstrated. Lastly, the dimensional scalability of the interconnects is also demonstrated.

Dans certaines simulations numériques exigeantes de mécanique des fluides, ilest nécessaire de simuler des écoulements multiphasiques impliquant de nombreuses contraintes simultanées : nombre de fluides important, évolutions compressibles à la fois isentropes et fortement choquées, équations d’états variables et contrastées, déformations importantes et transport surdes longues distances. Afin de remplir ces objectifs de manière robuste, il est nécessaire que la cohérence thermodynamique du schéma numérique soit vérifiée.Dans le premier chapitre, un schéma de type Lagrange plus projection est proposé pour la simulation d’écoulements diphasiques avec un modèle squelette à six équations et sans termes de dissipation. L’importance de la propriété de préservation des écoulements isentropiques est mise en évidence à l’aide d’une comparaison avec des résultats issus de la littérature pour le test deRansom. Ce chapitre souligne aussi certaines limitations de l’approche Lagrange plus projection pour simuler des modèles multiphasiques.Afin de pallier à ces limitations, une nouvelle procédure de dérivation est proposée afin de construire un schéma mimétique pour la simulation d’écoulements instationnaires compressibles dans un formalisme ALE direct (Arbitrary Lagrangian–Eulerian). La possibilité de choisir a prioriles degrés de liberté permet de s’inscrire dans une continuité avec les schémas historiques décalés, tout en imposant les conservations au niveau discret. L’équation de quantité de mouvement discrèteest obtenue par application d’un principe variationnel, assurant par construction la cohérence thermodynamique des efforts de pression. Cette approche est appliquée au cas d’écoulements monofluides comme preuve de concept au Chapitre 3, puis elle est étendue au cas d’écoulements à Nphasescompressibles au Chapitre 4. Des tests mono et multiphasiques montrent un comportement satisfaisant en terme de conservativité, versatilité aux mouvements de grilles et robustesse. / In some highly demanding fluid dynamics simulations, it appears necessary tosimulate multiphase flows involving numerous constraints at the same time : large numbers of fluids, both isentropic and strongly shocked compressible evolution, highly variable and contrasted equations of state, large deformations, and transport over large distances. Fulfilling such a challengein a robust and tractable way demands that thermodynamic consistency of the numerical scheme be carefully ensured.In the first chapter, a Lagrange plus remap scheme is proposed for the simulation of two-phase flows with a dissipation-free six-equation bakcbone model. The importance of the property of isentropic flow preservation is highlighted with a comparison with Ransom test results fromthe literature. This chapter also also point out certain limitations of the Lagrange plus remap approach for multiphase simulations.In order to overcome these limitations, a novel derivation procedure is proposed to construct a mimetic scheme for the simulation of unsteady and compressible flows in a direct ALE (ArbitraryLagrangian-Eulerian) formalism. The possibility to choose a priori the degrees of freedom allows to obtain a continuity with historical staggered scheme, while imposing conservativity at discretelevel. The discrete momentum evolution equation is obtained by application of a variational principle, thus natively ensuring the thermodynamic consistency of pressure efforts. This approach is applied to single-fluid flows as a proof of concept in Chapter 3, then it is extended to N-phasecompressible flows in Chapter 4. Single- and multi-phase tests show satisfactory behavior in terms on conservation, versatility to grid motions, and robustness.

Most robotic systems reported for MRI-guided prostate interventions use manual needle insertion, based on a previously acquired image, which requires withdrawing the patient from the scanner multiple times during the procedure. This makes the intervention longer, more expensive and elongating the discomfort to patient and, most importantly, less accurate due to the virtually inevitable motion of the target. As a remedy, automated needle placement methods were proposed, putting human supervision out of the control loop. This thesis presents the development of enabling technologies for human-operated in-room master-slave needle placement under real-time MRI guidance, while the patient is kept in the scanner and having the process of needle placement under continuos control of the physician. The feasibility of teleoperated needle insertion was demonstrated by developing a 1-DOF (degree of freedom) MRI-compatible master-slave system, which was integrated with a 4-DOF robot for transperineal prostate biopsy and brachytherapy. An accuracy study was conducted on a robotic system for MRI-guided prostate needle placement. Different error sources were identified and quantified. This study concluded that errors occurring during needle insertion have the most significant contribution to needle placement error. In order to compensate for these errors, teleoperated needle steering under real-time MRI guidance was proposed. A 2-DOF piezo-actuated MRI-compatible needle steering module was developed and integrated with the aforementioned 4-DOF transperineal robot, yielding a fully actuated 6-DOF (x, y, z, yaw, pitch, roll) robotic platform for MRI-guided prostate interventions. A novel MRI-compatible master robot was also developed to enable teleoperated needle steering inside the MRI room. MRI-compatible controller hardware and software were developed. A novel MRI-compatible force/torque sensor was devised using Fiber Bragg Grating for force measurement in MRI room. Phantom experiments proved the feasibility iii of teleoperated needle steering under real-time MRI guidance. A system was also developed for real-time 3D shape tracking of a bevel-tip needle with Fiber Bragg Grating sensors embedded along the needle shaft. The needle profile was overlaid on the real-time MR image, yielding real time navigation with accuracy better than 0.5 mm. The experimental system is presently being refitted for clinical safety and feasibility trials on real patients. / Thesis (Ph.D, Mechanical and Materials Engineering) -- Queen's University, 2013-05-30 12:26:18.732

Cloud computing has changed how services are provided and supported through the computing infrastructure. It has the advantages such as flexibility , scalability , compatibility and availability . However, the current architecture design also brings in some troublesome problems, like the balance of cooperation benefits and privacy concerns between the cloud provider and the cloud users, and the balance of cooperation benefits and free-rider concerns between different cloud users. Theses two problems together form the incentive problem in cloud environment. The first conflict lies between the reliance of services and the concerns of secrets of cloud users. To solve it, we proposes a novel architecture, NeuCloud, to enable partially, trusted, transparently, accountably privacy manipulation and revelation. With the help of this architecture, the privacy-sensitive users can be more confident to move to public clouds. A trusted computing base is not enough, in order to stimulate incentive-compatible privacy trading, we present a theoretical framework and provide the guidelines for cloud provider to compensate the cloud user's privacy-risk-aversion. We implement the NeuCloud and evaluate it. Moreover, a improved model of NeuCloud is discussed. The second part of this thesis strives to solve the free-rider problem in cloud environment. For example, the VM-colocation attacks have become serious threats to cloud environment. We propose to construct an incentive-compatible moving-target-defense by periodically migrating VMs, making it much harder for adversaries to locate the target VMs. We developed theories about whether the migration of VMs is worthy and how the optimal migration interval can be determined. To the best of our knowledge, our work is the first effort to develop a formal and quantified model to guide the migration strategy of clouds to improve security. Our analysis shows that our placement based defense can significantly improve the security level of the cloud with acceptable costs. In summary, the main objective of this study is to provide an incentive-compatible to eliminate the cloud user's privacy or cooperative concerns. The proposed methodology can directly be applied in commercial cloud and help this new computing fashion go further in the history. The theoretical part of this work can be extended to other fields where privacy and free-rider concerns exist.

Coccolithophores are single-celled marine phytoplankton, which produce intricate calcium carbonate platelets or ‘coccoliths’. Emiliania huxleyi is the most abundant and widespread coccolithophore, and is one of the most productive calcifying species on earth, playing a key role in global carbon, carbonate and sulphur cycles. Despite much research into coccolithophore biology, the underlying function of their coccoliths is still unknown. The main aim of the research reported in this thesis was to examine the impact of calcification on metabolism in coccolithophores. Calcification is a significant global process, so it is important to discover what effect it has on the metabolism of cells. The major metabolites each have different costs and benefits to the cell, which will vary depending on the habitat and environmental conditions the cell is in. By comparing the metabolite profiles of different strains, including calcifying, non-calcifying, haploid and diploid cells, differences in metabolite composition and potential patterns related to cell type were investigated. Low molecular weight (LMW) metabolites were characterised using a combination of metabolomic techniques. In agreement with previous research, dimethylsulphoniopropionate (DMSP) was the most abundant compound, followed by mannitol and glycine betaine (GBT). Less abundant sugars, polyols and amino acids were also identified. Environmental factors were manipulated to investigate how the principal metabolites were affected by salinity, different light intensities and nutrient (phosphate and nitrate) limitation. The data revealed a striking difference between haploid and diploid cells of the same strain, with the haploid containing lower concentrations of most of the major metabolites. Thus it is proposed that haploid cells have a different osmoregulatory strategy from the diploid cells. A negative correlation was found between DMSP and mannitol, suggesting that mannitol has a dual function, not only as a major storage compound but also as a principal compatible solute. Untargeted metabolite profiling is becoming a popular tool to investigate phenotypes and varying environmental conditions. LC-ESI-QTOF-MS/MS analyses of a wide range of metabolites showed that it is an effective method to identify differences and similarities between E. huxleyi strains grown in different conditions. Strain and growth phase appear to be the more important factors in differentiating metabolite profiles. Surprisingly there were no obvious metabolite profiling differences between calcifying and non-calcifying cells. Untargeted analysis can, however, be used to identify the compounds that did display differences, and which may be important biomarkers, so warrant further investigation. A range of metabolite profiling techniques highlighted important differences between strains, which will hopefully lead onto further research into the metabolome of E. huxleyi, and the unravelling of important metabolic pathways. There has been little research into the LMW metabolites of E. huxleyi, and especially comparisons between strains. Thus the use of metabolomics is a novel way to investigate the difference between cell types and the possible functions of calcification.

Cheung Wing Kin, Chong Kwok Kwong, Daniel. / Thesis (M.B.A.)--Chinese University of Hong Kong, 1990. / Bibliography: leaf 133. / ABSTRACT --- p.ii / TABLE OF CONTENTS --- p.iv / LIST OF FIGURES --- p.vii / LIST OF EXHIBITS --- p.viii / LIST OF TABLES --- p.ix / PREFACE --- p.xi / Chapter / Chapter I. --- INTRODUCTION --- p.1 / The World Market of LAN --- p.3 / Local Market of LAN in Hong Kong --- p.7 / The Research --- p.8 / The Significance of Study Findings --- p.9 / Chapter II. --- METHODOLOGY --- p.10 / Target Population --- p.10 / Unit of Analysis --- p.11 / Population Size --- p.12 / Sample Size --- p.14 / Data Collection --- p.15 / Objective --- p.15 / Selection of Data Collection Method --- p.15 / Questionnaires --- p.16 / Design --- p.16 / Contents --- p.18 / Despatch Methods --- p.18 / Research Aids --- p.20 / Summary --- p.20 / Chapter III. --- SURVEY FINDINGS --- p.21 / Despatch and Collection of Questionnaries --- p.21 / Company Data --- p.26 / Classification --- p.26 / Size in Terms of Number of Staff --- p.27 / Degree of Computerization --- p.27 / Number of PC in Use --- p.30 / PC LAN Installed --- p.32 / Hardware Particulars --- p.35 / Type of Computers in Use --- p.35 / PC LAN Hardware in Use --- p.35 / Length of Use of PC LAN --- p.37 / Assessment of Hardware in Use --- p.38 / Software Particulars --- p.39 / PC LAN Software in Use --- p.39 / Applications in Use --- p.39 / Assessment of Software in Use --- p.40 / Criteria in Choosing PC LANs --- p.41 / Job Function --- p.43 / Role in Purchasing --- p.43 / Report --- p.44 / Chapter IV. --- ANALYSIS AND INTERPRETATION OF FINDINGS --- p.45 / Response Rates --- p.45 / Company Data --- p.46 / Classification --- p.46 / Degree of Computerization --- p.48 / Size in Terms of Number of Staff --- p.50 / Number of PC in Use --- p.52 / PC LANs Installed --- p.54 / Hardware Particulars --- p.55 / Type of Computers in Use --- p.55 / PC LAN Hardware in Use --- p.55 / Length of Use of PC LAN --- p.57 / Assessment of Hardware in Use --- p.57 / Software Particulars --- p.57 / PC LAN Software in Use --- p.57 / Applications in Use --- p.59 / Assessment of Software in Use --- p.59 / Observation Relating to the Objectives of the Survey --- p.60 / Objective 1 : PC LAN Market Segment in Hong Kong --- p.60 / Objective 2 : Identify Market Characteristics --- p.63 / Objective 3 : Selection Criteria of LANs --- p.66 / Objective 4 : Gap between what are offered and what are needed --- p.66 / Objective 5 : Major Applications of PC LANs in Hong Kong --- p.71 / Job Function --- p.73 / Role in Purchasing --- p.73 / Report --- p.74 / Chapter V. --- CONCLUSION AND RECOMMENDATION --- p.75 / Conclusion --- p.75 / Extent of Usage of PC LANs in Hong Kong --- p.76 / PC LAN Market Segment in Hong Kong --- p.76 / PC LAN Market Characteristics in Hong Kong --- p.77 / Selection Criteria of PC LANs in Hong Kong --- p.78 / Gap Between what are offered and what are needed for PC LAN in Hong Kong --- p.78 / Major Applications of PC LANs in Hong Kong --- p.79 / Recommendation --- p.79 / Firms Already Installed PC LANs --- p.79 / Firms Not Yet Installed PC LANs --- p.81 / Marketeers --- p.82 / APPENDIX --- p.85 / BIBLIOGRAPHY --- p.133

Image guided surgery (IGS), which has been developing fast recently, benefits significantly from the superior accuracy of robots and magnetic resonance imaging (MRI) which is a great soft tissue imaging modality. Teleoperation is especially desired in the MRI because of the highly constrained space inside the closed-bore MRI and the lack of haptic feedback with the fully autonomous robotic systems. It also very well maintains the human in the loop that significantly enhances safety. This dissertation describes the development of teleoperation approaches and implementation on an example system for MRI with details of different key components. The dissertation firstly describes the general teleoperation architecture with modular software and hardware components. The MRI-compatible robot controller, driving technology as well as the robot navigation and control software are introduced. As a crucial step to determine the robot location inside the MRI, two methods of registration and tracking are discussed. The first method utilizes the existing Z shaped fiducial frame design but with a newly developed multi-image registration method which has higher accuracy with a smaller fiducial frame. The second method is a new fiducial design with a cylindrical shaped frame which is especially suitable for registration and tracking for needles. Alongside, a single-image based algorithm is developed to not only reach higher accuracy but also run faster. In addition, performance enhanced fiducial frame is also studied by integrating self-resonant coils. A surgical master-slave teleoperation system for the application of percutaneous interventional procedures under continuous MRI guidance is presented. The slave robot is a piezoelectric-actuated needle insertion robot with fiber optic force sensor integrated. The master robot is a pneumatic-driven haptic device which not only controls the position of the slave robot, but also renders the force associated with needle placement interventions to the surgeon. Both of master and slave robots mechanical design, kinematics, force sensing and feedback technologies are discussed. Force and position tracking results of the master-slave robot are demonstrated to validate the tracking performance of the integrated system. MRI compatibility is evaluated extensively. Teleoperated needle steering is also demonstrated under live MR imaging. A control system of a clinical grade MRI-compatible parallel 4-DOF surgical manipulator for minimally invasive in-bore prostate percutaneous interventions through the patient’s perineum is discussed in the end. The proposed manipulator takes advantage of four sliders actuated by piezoelectric motors and incremental rotary encoders, which are compatible with the MRI environment. Two generations of optical limit switches are designed to provide better safety features for real clinical use. The performance of both generations of the limit switch is tested. MRI guided accuracy and MRI-compatibility of whole robotic system is also evaluated. Two clinical prostate biopsy cases have been conducted with this assistive robot.

Intra-operative imaging is sometimes available to assist in needle biopsy, but typical open- loop insertion does not account for unmodeled needle deflection or target shift. Robotic closed-loop compensation for deviation from an initial straight-line trajectory can reduce the targeting error, using image-guidance for rotational control of an asymmetric bevel tip. By pairing closed-loop trajectory compensation with a hands-on cooperatively controlled needle insertion, a physician's control of the procedure can be maintained while incorporating benefits of robotic accuracy. Additionally, if puncture of a membrane can be detected, an enhanced haptic response can assist the physician in perceived anatomical localization of the needle tip. Functionality was implemented on a needle placement robot suitable for use in the MR environment and capable of holding a typical clinically used biopsy gun. The robot is configured for cooperatively controlled needle insertion with continuous closed-loop image- guided needle rotation. The robot and custom controller were tested for their effect on the Signal-to-Noise ratio (SNR) of MR images, and the results showed an approximate drop of only 12% in signal when the robot was present, and no additional signal drop when the robot was powered on or moving. The hardware and software subsystems were developed for clinical translation, and after each was validated in the lab they were integrated into the clinical environment to mimic the workflow of MRI-guided targeted biopsy. The full system was evaluated in-bore at Brigham and Women’s Hospital in Boston, MA where experiments for real-time puncture detection and MR image-guided targeted needle insertions under cooperative control were performed. Results showed overall targeting accuracy was 3.42mm RMS, improving accuracy by approximately 50% as compared to clinical trials of prostate biopsy using manual needle insertion. A cooperatively controlled robotic biopsy is more likely to gain acceptance by physicians over teleoperation due to maintaining proximity to the surgical site, but regulatory hurdles regarding robotic needle insertion still exist. The current robotic system framework is suitable for clinical use as it was fully validated in-bore, but some modifications could be made to increase the likelihood of regulatory approval. With these modifications the system could be ready for cadaver and pre- clinical animal trials within one year, and ready for in-human clinical trials in the next two to three years.