In this thesis, MEMS switches actuated using electrostatic actuation is explored. MEMS switches that are lateral switches and clamped-clamped switches are designed, fabricated, and tested in this thesis. This thesis extensively explains the process by which the MEMS Switches were designed and fabricated. In addition, it explains the changes in the switches when issues called for a modification to devices. Contact resistances were extensively studied, in this thesis. There has been a trade-off between the reliability of switches and their contact resistances. Many actions were taken to mitigate this trade-off and to allow both reliable devices with low contact resistances. The efforts to do so ranged from thermal oxidation to reduce the scalloping on the sidewalls, to modifying the dry etching recipe, to modifying the sputtering recipe, to electroplating, and many more. However, reliability of the MEMS Lateral switches was accomplished independent to the contact resistances. In addition, low contact resistances were accomplished independent to reliability. A novel approach to designing clamped-clamped MEMS switches is also showcased in this thesis. These devices experienced unique challenges compared to those faced with lateral switches. Both lateral and clamped-clamped switches are discussed in-depth in this thesis. / Master of Science

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Metal-insulator-semiconductor switches (MISS), in which the T denotes some form of thin semi-insulating layer and the semiconductor part consists of a pn junction, are part of the general class of regenerative switching devices which includes the thyristor. The switching behaviour of the MISS derives from the ability of the MIS junction to exhibit current gain and to exist in two modes, deep depletion and inversion. In this thesis, a general model for the regenerative switching is proposed after investigating the properties of the MIS junction both theoretically and experimentally. Results from MIS diodes with tunnelling-thickness oxide Mayers indicate that interface states play a dominant role in their electrical behaviour and that the uniformity of the oxide is poor, giving rise to a large spread in the current-voltage characteristics. Subsequently, the epitaxial form of the MISS device is investigated and in particular the importance of isolation of the pn junction. It is concluded that spreading effects set a practical lower limit to the device dimensions, making the epitaxial form unsuitable for microelectronic applications. An alternative semi-insulator, 'silicon-rich oxide' (SRO) is introduced as an optional I-layer with possibly greater integrity than tunnel oxide. MIS diodes formed with SRO are shown to have very similar properties to tunnelling diodes. Large area devices fabricated using this material are surprisingly discovered to exhibit stable negative differential resistance (NDR). Although this discovery at first appears to be contrary to normal circuit stability criteria and to the regenerative feedback model itself, both of these points are resolved. It is shown that the frequency of oscillation of an unstable device is controlled by the external circuit. Then it is proposed that if this frequency is greater than the maximum frequency of operation of the regenerative mechanism, stable NDR is observed. In the final chapter, alternative lateral MISS structures which should overcome the geometrical limitations of epitaxial devices are discussed.

This thesis investigates the possibility to analyse a mobile network with sequences of UERC switches specific to each user equipment. An UERC is essentially a channel that carries information and a user equipment connects to different UERCs depending on whether they want to talk and/or send data with different qualities. As a major player in the mobile technology industry, Ericsson strives to optimise the use of the UERCs and are looking for an automated way to detect changes. The first task was to identify and retrieve the required events from the network log files in order to create the UERC sequences. As a way to test the thesis assumption, and give a proof of concept, two different data sets were analysed were changes had been made to the network settings that should have affected the UERC sequences. With the use of n-grams, Markov chains and Bayesian Estimation testing, the changes could be identified and the thesis assumption could be confirmed - UERC sequences provides a possible way of analysing a mobile network.

Tricyanofuran-type metastable-state photoacids, relative newcomers to the field of photochromism, outperform traditional light-controlled molecular switches in regards to applicability in biological systems. In a preliminary attempt to understand the underlying processes that govern these compounds, this thesis project establishes the isomeric identity of an unsubstituted tricyanofuran-type metastable-state photoacid, referred to as TCF 1 in this work. Two-dimensional nuclear magnetic resonance experiments are employed to experimentally determine the presence and identity of the open-form TCF 1 isomers. Electronic structure calculations are then used to provide quantitative insight into the experimental results. Experiment and theory show that four out of eight possible open-form isomers exist in solution. To validate the information obtained theoretically, the calculation methodologies are tested against experimental chemical shifts. The impressive agreement with the experiments gives credibility to the picture painted by the theoretical models.

ITC/USA 2007 Conference Proceedings / The Forty-Third Annual International Telemetering Conference and Technical Exhibition / October 22-25, 2007 / Riviera Hotel & Convention Center, Las Vegas, Nevada / Some of the first applications of network-based data acquisition systems have been for large aircraft. These systems contained numerous network nodes including data acquisition units, switches, recorders, network management units, and others. One of the desirable aspects of a networked-based system is the ability to scale such a system to meet increasing test requirements. Similarly, these systems lend themselves to scaling down, as well, to meet the testing needs of smaller test articles. These needs may include fewer nodes and/or physically smaller components. The testing of smaller vehicles places slightly different requirements on the testing process. In general, there is a greater need for real-time analysis, flexibility and ad-hoc testing. This paper will attempt to show how a small to medium sized test article can benefit from the same powerful, feature-rich network-based data acquisition and recording system as used on larger programs. The paper will also show how a smaller system can deliver on this promise without sacrificing performance and functionality.

This thesis examines the design, synthesis and biological applications of a series of inhibitors which incorporate an azobenzene photoswitch, a peptidyl backbone and a trifluoromethyl ketone warhead. The photoswitch can be isomerised by irradiation with UV or visible light and has been employed to modulate the reactivity of the enzyme. Chapter one gives a brief outline of some of the important areas related to this work. Examples of previously utilised photoswitches as well as some background on serine protease and the uses of fluorine in medicine has been covered. Chapter two outlines the synthesis of the key trifluoromethyl carbinol 2.6 by two different methods. The condensation of a fluorinated aldehyde with a nitroalkane affords an α-nitro trifluoromethyl carbinol which can be reduced to give the desired amine 2.6. Treatment of oxazolones with trifluoroacetic anhydride via a modified Dakin-West reaction gives trifluoromethyl ketones which can be reduced to give trifluoromethyl carbinols. Chapter three investigate the synthesis of substituted stilbenes and phenanthrenes as alternative molecular switches to azobenzenes. Molecular modelling of phenanthrenes suggests they may be suitable mimics of E-azobenzenes. Chapter four outlines the synthesis of a series of mono and disubstituted azobenzenes by direct sulfonation of azobenzene or by condensation of nitroso arenes with aryl amines. The switches incorporate one or two peptidyl residues designed to improve specificity towards the enzyme. Chapter five examines the photoisomerisation of eight potential inhibitors by irradiating with UV or visible light. Irradiation with UV light enriches the sample to give 78-93 % of the Z-isomer. Irradiation with visible light gave photostationary states with 14-21 % Z-isomer. Ambient photostationary states are ca. 22 % Z-isomer. Chapter six looks at the testing of five trifluoromethyl ketones as potential inhibitors ofα-chymotrypsin. The inhibitors vary in substituents, substitution patterns and chain length. The inhibitors were tested at both ambient and Z-enriched photostationary states and were found to exhibit slow binding kinetics. In all cases the Z-enriched inhibitor solution was at least 3-fold more potent than the ambient solution. Chapter seven is an experimental chapter and outlines the synthesis of the compounds prepared in this thesis.

M.Ing. / High frequency magnetic components have significant advantages related to cost and physical size compared to their low frequency counterparts. The advent of high frequency power switch technology made the transformer frequency a variable and recent advances in this field have been ever pushing the switching frequency of higher power converters. Although high frequency inductors and transformers have been used and applied extensively to an increasingly broad range of applications over recent decades, analysis and design of these devices involves certain difficulties, related to extra losses due to eddy currents as well as smaller cooling surfaces,..

Entry into mitosis in eukaryotes depends on the activation of the Cyclin-dependent kinase 1 (Cdk1), which phosphorylates many mitotic protein substrates. Activation of Cdk1 requires formation of a complex with Cyclin B (CycB), which gradually rises in concentration during interphase. However, in most organisms Cdk1 activation is not gradual but switch-like, because phosphorylation of the Cdk1-CycB complex by the Wee1 kinase normally keeps Cdk1-CycB inactive during interphase. Mitotic entry is induced when rapid dephosphorylation of Cdk1-CycB by the Cdc25 phosphatase causes abrupt activation of Cdk1-CycB. Cdk1-CycB in turn phosphorylates both Wee1 and Cdc25 leading to Cdc25 activation and Wee1 inhibition. This regulation creates both a positive and a double-negative feedback loop in the system, which are thought to generate a sharp, bistable switch that controls mitotic entry. Bistability is known to require positive feedback and ultrasensitivity, however, how ultrasensitivity arises in the mitotic switch is subject to extensive research efforts both experimentally and theoretically. In this thesis I explore several possible sources of ultrasensitivity in the mitotic switch through mathematical modelling. Based on theoretical considerations and experimental evidence, I show that the existence of multiple positive feedback loops, multisite phosphorylation, and Cdk1-CycB-dependent regulation of Cdk1-counteracting phosphatase activity can all contribute to ultrasensitivity and bistability in the mitotic switch. I analyse models of the mitotic switch including these bistability-generating mechanisms, to simulate and explain experimental data and make testable predictions. I argue that it is unlikely that a single mechanism is responsible for ultrasensitivity in this system, and that bistability requires a combination of different sources, including the ones studied here and others such as enzyme saturation and sequestration effects. I also highlight the importance of network architecture and coherent regulation of opposing reactions in generating efficient biochemical switches. Finally, I draw on recent experimental evidence and ideas derived from this analysis to propose a revised network of the mitotic switch.

Context In the present world, there is an increase in the usage of the telecommunication networking services, as there is a need of efficient networking services in various fields which can be obtained by using the efficient networking components. For that purpose we have to know about the components parameters. One of the most important parameter is the energy usage of networking components. Therefore, there is a need in power profiling of the network switches. Objectives The objective of this research is to profile the power usage of different network components(Switches) for various load scenarios. Power measurements are done by using the open energy monitoring tool called emonpi. Methods The research method has been carried out by using an experimental test bed. In this research, we are going to conduct the experiments with different configurations to obtain different load conditions for sources and destinations which will be passed through DUT(Device Under Test). For that DUT’s we will measure power usage by monitoring tool called emonpi. Then the experiments are conducted for different load scenarios for different switches and results are discussed. Conclusion From the results obtained, the Power profiles of different DUT’s are tabulated and analyzed. These were done under different ports and load scenarios for Cisco2950, Cisco3560 and Netgear GS-724T. From the results and analysis it can be stated that the power usage of Cisco 2950 is having the maximum power usage in all the considered scenarios with respect to packet rate and also number of active ports. The Netgear-GS724T is having the minimum power usage from the three switches as it having the green switch characteristics in all scenarios. And the Cisco 3560 is in between the above two switches as it is having energy efficient management from Cisco. From this we have proposed a simple model for energy/power measurement.