Silicon-based nanostructures are essential building blocks for nanoelectronic devices and nano-electromechanical systems (NEMS). As the silicon device size continues to scale down, the surface to volume ratio becomes larger, rendering the properties of surfaces and interfaces more important for improving the properties of the nano-devices and systems. One of those properties is the friction, which is important in controlling the functionality and reliability of the nano-device and systems. The goal of this dissertation is to investigate the deformation and friction behaviors of single crystalline silicon nanolines (SiNLs) using nanoindentation techniques. Following an introduction and a summary of the theoretical background of contact friction in Chapters 1 and 2, the results of this thesis are presented in three chapters. In Chapter 3, the fabrication of the silicon nanolines is described. The fabrication method yielded high-quality single-crystals with line width ranging from 30nm to 90nm and height to width aspect ratio ranging from 10 to 25. These SiNL structures have properties and dimensions well suited for the study of the mechanical and friction behaviors at the nanoscale. In Chapter 4, we describe the study of the mechanical properties of SiNLs using the nanoindentation method. The loading-displacement curves show that the critical load to induce the buckling of the SiNLs can be correlated to the contact friction and geometry of SiNLs. A map was built as a guideline to describe the selection of buckling modes. The map was divided into three regions where different regions correlate to different buckling modes including Mode I, Mode II and slidingbending of SiNLs. In Chapter 5, we describe the study of the contact friction of the SiNL structures. The friction coefficient at the contact was extracted from the loaddisplacement curves. Subsequently, the frictional shear stress was evaluated. In addition, the effect of the interface between the indenter and SiNLs was investigated using SiNLs with surfaces coated by a thin silicon dioxide or chromium film. The material of the interface was found to influence significantly the contact friction and its behavior. Cyclic loading-unloading experiments showed the friction coefficient dramatically changed after only a few loading cycles, indicating the contact history is important in controlling the friction behaviors of SiNLs at nanoscales. This thesis is concluded with a summary of the results and proposed future studies. / text

<p>This licentiate thesis uses descriptive, mainly official,Swedish statistics to analyse industrial structure, productionand foreign trade in an industry that is traditionallydifficult to describe in numbers, that of medical devices. Forthe purposes of the thesis, the Swedish Medical Device industryis defined as companies classified in the SE-SIC manufacturingcodes 33101 (medical equipment and instruments, etc), 33102(dental products) and 35430 (invalid vehicles). Also otherbranches contribute, notably parts of SIC 51460 (wholesale inmedical equipment and pharmaceutical goods) and 73103 (medicalresearch and development) although their medical device volumecannot be specified. Additional items have been identified interms of specific product groups rather than as "belonging" toa specific SIC industrial code.</p><p>Taken together, this is considered to correspond reasonablywell to the scope of the field as defined by the Global MedicalDevice Nomenclature (GMDN), a new European standard forclassifying medical devices in a more generic way than do theEuropean Medical Device Directives (or other pieces oflegislation). No quantification according to GMDN can be madeas yet, however, as that requires changing reporting habits inindustry as well as in official statistical classification andnomenclature regimes.</p><p>With the manufacturing code SE-SIC 33101 as main object, thestudy for the first time presents data on the regionaldistribution, size classes of employment, company starting timeand company dynamics, in the form of entries to and exits fromthe code, over a six-year period. The latter analysis includesa follow-up of the "exits", some firms reappearing in otherparts of industry and others disappearing–surprisinglyfew among them being limited companies. Although this industryis comparatively mature, considerable mobility among themid-sized companies is indicated for reasons of real changes or(to some degree) factors inherent in the industrialclassification system. Some structural changes in companies inthe ≥50 employees bracket are identified. It is notedthat American actors, directly or indirectly, are increasinglyinvolved with the medical device industry in Sweden, and that anumber of technology-based companies that were started mostlyin the early eighties have recently reached the 50+ employeelevel.</p><p>The analysis of identifiable production and internationaltrade in medical devices spans a period of 17 years based onofficial statistics following the HS/CN nomenclatures. Adatabase has been built, bottom-up, from the 8-digit CN levelwith production, exports and imports values for close to 100items collected in 12 product groups, for presentation purposesgrouped under three main headings. Compound annual growth ratesfor the latter are presented for three five-year periods1985-2000, showing that Swedish production and exports have hadan overall growth of 10 per cent p.a. This has kept Swedenahead of the international overall growth of 6- 7 per cent p.a.in recent years, products in the main group "Aids&Implants" growing more than 20 per cent p.a. Growth rates inthe most recent five-year period are lower, however. Healthynet exports figures are presented, the figure for 2002nominally representing 40 per cent of the production value incurrent as well as constant prices.</p><p>Production figures are given at industry (local unit) levelas well as at product group level. The product-based figuresidentified for Production 2001 are estimated to SEK 13,3billion, Exports to SEK 13,7 billion and Imports to SEK 9,7billion. Figures for the Apparent Domestic Market arecalculated for the corresponding entities. It is obvious,however, that the statistics do not capture the real productionvalue as exports exceed production both at overall level and inmajor product groups, particularly those on a high systemstechnology level. The situation is not uncommon for a number ofreasons; further, cases in the statistics methodologyliterature confirm that medical instrument-related codes areliable to this phenomenon. Corrections, including adjustmentsof both production and exports values, are possible butdemanding already at one individual 4-digit HS/CN level. This,therefore, must be considered outside the scope of an academicstudy.</p><p>The basic tablework developed for this thesis will be madefreely available to external parties for their own use providedthe author, with contact details, is named as the source.(Processing for commercial purposes is not expected, however.)Any suggestions for improvements are welcomed.</p>

The key focus of this research was to investigate the bearing options most suited to operation in a novel direct drive linear generator. This was done through bearing comparisons, modelling and testing. It is fundamental that the linear generator is designed to suit the marine environment. Key design constraints include reliability, survivability, maintenance intervals and cost. Resilient mechanical structural components, such as bearings, will prolong the time a device can operate without maintenance hence prolonging the operating period. Effective lifespan predictions for bearings will feed into the structural design of the generator which forms part of an overall objective to combine each generator design stage into one integrated design process. This promises to provide a cost effective, light weight generator design. This thesis covers the initial investigations into effective, long life and low-wear bearings to meet the operating demands of WEC. It includes an assessment of conventional bearing technology, designs of water-fed hydrostatic bearings and testing of novel polymer bearings. The development of an experimental test rig from a prototype linear generator is described. The rig was built in order to validate and fully explore the potential of self-lubricating, submersible polymer bearings with the ultimate aim of identifying wear constants and frictional properties of the bearings in the low-speed, mid to high-load, oscillating operation of a WEC in order to more accurately predict a bearing lifespan. The outcome of this research served to underpin the need for the design of application specific bearing systems to be based on empirically determined data and observations from test data taken from application specific tests. For inclusion in the design of these linear generators, sizing a bearing requires knowledge of the electrical loading in addition to the expected operating conditions of a WEC. Choosing bearing materials and hence lubricant regimes is dependant on the thermal operating characteristics. Then bearing knowledge in terms of size, load capacity and lifespan can be put directly into the structural model. This iterative process of design can then be merged into a fully integrated generator design tool hence this research was part of the development of an integrated design tool for direct drive generators.

4 pp. / Recently, a number of global positioning system (GPS) devices have been introduced commercially which exploit GPS, transforming frequent measurements of time and location, into an estimate of energy expenditure. This fact sheet reviews how GPS watches (GPS fitness units) measure energy expenditure of individual during physical activity. We list popular GPS watches that are on the market and showed pros and cons of these watches. After our field testing, we decided that Garmin Forenunner 305 is our best pick for the GPS watch. We included information on Geocashing, which is one of popular outdoor activities using GPS receiver or other navigational techniques.

The thesis numerically explores the use and behavior of Active Hydraulic Devices (AHDs), creating a new capability to simulate and control a pipe system’s transient performance. Automatic control valves are the first type of AHDs studied in this research. Due to the challenges inherent in the design of a pressure relief valve (PRV), the general principles of PRV use and selection are studied along with the system’s response to the PRV parameters. A new application of PID (proportional, integral and derivative) control valve is envisioned that combines a remote sensor at the upstream end of a pipeline to create a non- or semi- reflective boundary at the downstream end. Case studies show that, with such a boundary, the reflection and resonance of pressure waves within the pipeline are sometimes eliminated and invariably limited. The second type of AHDs studied in this research is the governed hydro turbine, the most complicated hydraulic component in terms of transient analysis and waterhammer control. A complete numerical model is developed for the turbine installations in either urban water networks or conventional hydropower generation systems. Using the model, transient simulations for several realistic hydro projects are presented along with various transient control measures.

With more than 5 billion users globally, mobile devices have become ubiquitous in our daily life. The modern mobile handheld device is capable of providing many multimedia services through a wide range of applications over multiple networks as well as on the handheld device itself. These services are predominantly driven by data, which is increasingly associated with sensitive information. Such a trend raises the security requirement for reliable and robust verification techniques of users.This thesis explores the end-user verification requirements of mobile devices and proposes a novel Behaviour Profiling security framework for mobile devices. The research starts with a critical review of existing mobile technologies, security threats and mechanisms, and highlights a broad range of weaknesses. Therefore, attention is given to biometric verification techniques which have the ability to offer better security. Despite a large number of biometric works carried out in the area of transparent authentication systems (TAS) and Intrusion Detection Systems (IDS), each have a set of weaknesses that fail to provide a comprehensive solution. They are either reliant upon a specific behaviour to enable the system to function or only capable of providing security for network based services. To this end, the behaviour profiling technique is identified as a potential candidate to provide high level security from both authentication and IDS aspects, operating in a continuous and transparent manner within the mobile host environment.This research examines the feasibility of a behaviour profiling technique through mobile users general applications usage, telephone, text message and multi-instance application usage with the best experimental results Equal Error Rates (EER) of 13.5%, 5.4%, 2.2% and 10% respectively. Based upon this information, a novel architecture of Behaviour Profiling on mobile devices is proposed. The framework is able to provide a robust, continuous and non-intrusive verification mechanism in standalone, TAS or IDS modes, regardless of device hardware configuration. The framework is able to utilise user behaviour to continuously evaluate the system security status of the device. With a high system security level, users are granted with instant access to sensitive services and data, while with lower system security levels, users are required to reassure their identity before accessing sensitive services.The core functions of the novel framework are validated through the implementation of a simulation system. A series of security scenarios are designed to demonstrate the effectiveness of the novel framework to verify legitimate and imposter activities. By employing the smoothing function of three applications, verification time of 3 minutes and a time period of 60 minutes of the degradation function, the Behaviour Profiling framework achieved the best performance with False Rejection Rate (FRR) rates of 7.57%, 77% and 11.24% for the normal, protected and overall applications respectively and with False Acceptance Rate (FAR) rates of 3.42%, 15.29% and 4.09% for their counterparts.

In this thesis, I investigate sense-making processes in financial markets. My focus is on the role of narratives in these routine activities in digital market places or what Cetina and Preda (2007) describe as scopic market systems. I conceptualize narratives told by market professionals in these systems as another form of market device (Callon et al., 2007) which combines different modes of knowing and explanation to cope with flows of data/information and funds, and works to generate value from assets exposed to markets. From a sociological perspective, I argue that the substitution of social network-based information search and face-to-face exchange relationships in financial markets with flow-based and anonymised representations and exchange relationships do not undermine the importance of social networks in shaping sense-making and decision-making in financial markets. However to argue so, I broaden the concept of social network with the help of Bourdieu’s (1997) notion of economic, social and cultural capital. I introduce the notions of field and meta-field of power, habitus, and position-taking by Bourdieu (1997, and Wacquant 1992) to my conceptual discussion of financial markets. In light of this, I describe financial markets as hierarchical and competitive structures inhabited by different groups of investors and intermediaries and shaped by competition and conflict among these groups. I argue that these groups’ position in the field is conditioned by their economic, social, and cultural capital which are generated and sustained within and outwith the field. Consequently, I suggest that these groups’ sense-making and investment activities and their use of market devices including storytelling acts should exhibit distinctive modes in accordance with the specific positions they have voluntarily or involuntarily taken in the field. To substantiate these claims with narrative evidence, I present the case of the Istanbul Stock Exchange (ISE) in Turkey. Opened in 1985, the ISE provides an instrumental case to study the role of sense-making narratives as another form of market device in scopic market systems with a Bourdieusian sociological framework. As gathered from publicly available information and early pilot fieldwork in the ISE headquarters, the ISE as a field has been occupied by three dominant investor types since 1991. These are domestic retail (DRIs), domestic institutional (DIIs), and foreign institutional investors (FIIs). These three groups have a dominant weight in either trading volume or share ownership in the ISE. Drawing on my (participatory) observations between 2008 and 2009 in an asset management company and four brokerage houses which served DRIs and/or DIIs and FIIs, I present evidence on how distinct combinations of economic, social and cultural capitals among these dominant investor-intermediary groups shape their sense-making activities and consequent sense-making stories in the ISE.

The aim of this doctoral dissertation project has been to investigate and describe Entrepreneurship Education in one Swedish county, E‐county. The dissertation is based on five studies, four case studies and a minor follow‐up study. Together these studies constitute a multiple case study called The Main Study. The purpose of the study has been to investigate how European policy on entrepreneurship education has been reproduced and realized in different educational settings in E‐county, and the consequences this has had for fostering students and local identity building. The two first studies, cases A and B were carried out in three schools where three high school programs were studied, the Haircare program, a technical program and a social science program. The programs were chosen so that the whole range of highschool programs were represented; a practical program, a semi‐academic program and an academic program. The third case, C, contained the specific educational program ʺSummer Entrepreneur” which was developed in a local municipality in Ecounty, and had been spread throughout Sweden. The program was developed by local people within the framework of an educational concept that had been imported from Canada, “Open For Business“. The fourth study, case D, was carried out in the educational program Youth Enterprise in local high schools, including the so called “Practice school”. The fifth study was a minor study through interviews with representatives from the different educational programs. To enable methodical triangulation, studies A to D were carried out with interviews, questionnaires, observations and document analysis. The studies were based on theories of entrepreneurship, entrepreneurship education and general education. The theoretical framework for analysis was based on Basil Bernstein’s (2000) theoretical concepts classification, framing, the pedagogic device and pedagogic identities. The major finding from the Main Study was that entrepreneurship education was already part of the educational programs studied for some time before it became part of the Swedish national curricula in 2011. Entrepreneurship had become an element in the fostering of local identities in E‐county. Since it has become a major element of the value base in the national curricula, it will probably be an important part in fostering and identity building in all Swedish schools in the future.

<p>The electrical interface to neural medical devices is researched from three perspectives, namely, the electronics within the device, the electrodes on the device, and the electromagnetic fields around the device. </p><p>A Brain-Machine Interface may allow paralyzed patients to control robotic limbs with neural signals sensed by fine wires inserted into the brain. The neural signals have an amplitude under one millivolt and must be amplified. A totally integrated amplifier is designed, manufactured, and characterized. The amplifier is fabricated in a standard half-micron CMOS process without capacitors or resistors. Two application issues not previously addressed are solved. First, the topology of the amplifier is shown to be less sensitive to long-term drift of transistor parameters than the standard topology. Second, a neural signal corrupted by 10 millivolts of powerline interference can be recovered. The amplifier has a gain of 58 dB, a bandwidth of 750 to 14k Hz, power consumption of 180 uW, and noise of 1.5 uV RMS. The design techniques proven in this amplifier are suitable for clinical Brain Machine Interfaces.</p><p>An implanted electroencephalogram (EEG) recorder may aid the diagnosis of infrequent seizure-like events that are currently diagnosed, without proof, as epilepsy. A proof-of-concept study quantifies the electrical characteristics of the electrodes planned for the recorder. The electrodes are implanted in an ovine model for eight weeks. Electrode impedance is less than 800 Ohm throughout the study. A frequency-domain determination of sedation performs similarly for surface versus implanted electrodes throughout the study. The time-domain correlation between an implanted electrode and a surface electrode is almost as high as between two surface electrodes (0.86 versus 0.92). EEG-certified clinicians judge that the implanted electrode quality is at least adequate and that the implanted electrodes provide the same clinical information as surface electrodes except for a noticeable amplitude difference. No significant issues are found that invalidate the concept of an implanted EEG recorder.</p><p>Transcranial stimulation may treat a multitude of neural and psychological illnesses. The stimulation may have higher repeatability and lower patient effort if an implanted device provides the stimulation. The shape of the device, 300 mm long by 1 mm in diameter, is unlike any present implanted device. Five techniques that deliver energy to the device are analyzed using computer simulations. The electrode for the techniques that employ an electric field to deliver the energy is a new design that exploits the anatomy of the scalp and skull. The electric field techniques deliver energy that is likely suitable for some stimulation protocols but not for all. The techniques that employ a magnetic field deliver more than the energy required, especially if the shape of the coil that creates the magnetic field is automatically optimized. However, the magnetic-field techniques heat the brain; the electric-field techniques do not heat the brain. This research validates the new delivery concepts and justifies future research.</p> / Dissertation

Metamaterials are artificially designed composite materials which can exhibit unique and unusual properties such as the negative refractive index, negative phase velocity, etc. The concept of metamaterials becomes prevalent in the electromagnetic society since the first experimental implementation in the early 2000s. Many fascinated potential applications, e.g. super lens, invisibility cloaking, and novel antennas that are electrically small, have been proposed based on metamaterials. However, most of the applications still remain in theory and are not suitable for practical applications mainly due to the intrinsic loss and narrow bandwidth (large dispersion) determined by the fundamental physics of metamaterials .In this dissertation, we incorporate active gain devices into conventional passive metamaterials to overcome loss and even provide gain. Two types of active gain negative refractive index metamaterials are proposed, designed and experimentally demonstrated, including an active composite left-/right-handed transmission line and an active volumetric metamaterial. In addition, we investigate the non-Foster circuits for broadband matching of electrically small antennas. A rigorous way of analyzing the stability of non-Foster circuits by normalized determinant function is proposed. We study the practical factors that may affect the stability of non-Foster circuits, including the device parasitics, DC biasing, layouts and load impedance. A stable floating negative capacitor is designed, fabricated and tested. Moreover, it is important to resolve the sign of refractive index for active gain media which can be quite challenging. We investigate the analytical solution of a gain slab system, and apply the Nyquist criterion to analyze the stability of a causal gain medium. We then emphasize that the result of frequency domain simulation has to be treated with care. Lastly, this dissertation discusses another interesting topic about THz spectroscopy of live cells. THz spectroscopy becomes an emerging technique for studying the dynamics and interactions of cells and biomolecules, but many practical challenges still remain in experimental studies. We present a prototype of simple and inexpensive cell-trapping microfluidic chip for THz spectroscopic study of live cells. Cells are transported, trapped and concentrated into the THz exposure region by applying an AC bias signal while the chip maintains a steady temperature at 37°C by resistive heating. We conduct some preliminary experiments on E. coli and T cell solution and compare the transmission spectra of empty channels, channels filled with aqueous media only, and channels filled with aqueous medium with un-concentrated and concentrated cells.