6,611 research outputs found
Irresistible Revolution: Black, Trans, and Disabled World-Making through Activist Portraiture
This practice-based dissertation project engages large-scale portraiture to confront and resist the fungibility of Blackness. The project comprises a selection of twenty drawings and an exegesis in which I analyze my aesthetic process in order to shed light on theoretical problems and gaps in Trans, Disability, Black studies and activisms. This collection of writing also discusses and presents activist struggle, white supremacy in the arts, abolitionist organizing and speculative futures. These theoretical explorations are supported by reflections on the collaborative creation process and the ways in which the portraits have been received. To this end, I have included interviews I conducted with the portrait subjects and through textual analysis of ways in which the portraits have been taken up in art and activist contexts. I argue that studying and supporting Black disabled activist practice can inform ways forward for disability arts in the Canadian milieu
Flexographic printed nanogranular LBZA derived ZnO gas sensors: Synthesis, printing and processing
Within this document, investigations of the processes towards the production of a flexographic printed ZnO gas sensor for breath H2 analysis are presented. Initially, a hexamethylenetetramine (HMTA) based, microwave assisted, synthesis method of layered basic zinc acetate (LBZA) nanomaterials was investigated. Using the synthesised LBZA, a dropcast nanogranular ZnO gas sensor was produced. The testing of the sensor showed high sensitivity towards hydrogen with response (Resistanceair/ Resistancegas) to 200 ppm H2 at 328 °C of 7.27. The sensor is highly competitive with non-catalyst surface decorated sensors and sensitive enough to measure current H2 guideline thresholds for carbohydrate malabsorption (Positive test threshold: 20 ppm H2, Predicted response: 1.34). Secondly, a novel LBZA synthesis method was developed, replacing the HMTA by NaOH. This resulted in a large yield improvement, from a [OH-] conversion of 4.08 at% to 71.2 at%. The effects of [OH-]/[Zn2+] ratio, microwave exposure and transport to nucleation rate ratio on purity, length, aspect ratio and polydispersity were investigated in detail. Using classical nucleation theory, analysis of the basal layer charge symmetries, and oriented attachment theory, a dipole-oriented attachment reaction mechanism is presented. The mechanism is the first theory in literature capable of describing all observed morphological features along length scales. The importance of transport to nucleation rate ratio as the defining property that controls purity and polydispersity is then shown. Using the NaOH derived LBZA, a flexographic printing ink was developed, and proof-of-concept sensors printed. Gas sensing results showed a high response to 200 ppm H2 at 300 °C of 60.2. Through IV measurements and SEM analysis this was shown to be a result of transfer of silver between the electrode and the sensing layer during the printing process. Finally, Investigations into the intense pulsed light treatment of LBZA were conducted. The results show that dehydration at 150 °C prior to exposure is a requirement for successful calcination, producing ZnO quantum dots (QDs) in the process. SEM measurements show mean radii of 1.77-2.02 nm. The QDs show size confinement effects with the exciton blue shifting by 0.105 eV, and exceptionally low defect emission in photoluminescence spectra, indicative of high crystalline quality, and high conductivity. Due to the high crystalline quality and amenity to printing, the IPL ZnO QDs have numerous potential uses ranging from sensing to opto-electronic devices
In search of 'The people of La Manche': A comparative study of funerary practices in the Transmanche region during the late Neolithic and Early Bronze Age (250BC-1500BC)
This research project sets out to discover whether archaeological evidence dating between 2500 BC - 1500 BC from supposed funerary contexts in Kent, flanders and north-eastern Transmanche France is sufficient to make valid comparisons between social and cultural structures on either side of the short-sea Channel region. Evidence from the beginning of the period primarily comes in the form of the widespread Beaker phenomenon. Chapter 5 shows that this class of data is abundant in Kent but quite sparse in the Continental zones - most probably because it has not survived well. This problem also affects the human depositional evidence catalogued in Chapter 6, particularly in Fanders but also in north-eastern Transmanche France. This constricts comparative analysis, however, the abundant data from Kent means that general trends are still discernible. The quality and volume of data relating to the distribution, location, morphology and use of circular monuments in all three zones is far better - as demonstrated in Chapter 7 -mostly due to extensive aerial surveying over several decades. When the datasets are taken as a whole, it becomes possible to successfully apply various forms of comparative analyses. Most remarkably, this has revealed that some monuments apparently have encoded within them a sophisticated and potentially symbolically charged geometric shape. This, along with other less contentious evidence, demonstrates a level of conformity that strongly suggests a stratum of cultural homogeneity existed throughout the Transmanche region during the period 2500 BC - 1500 BC. The fact that such changes as are apparent seem to have developed simultaneously in each of the zones adds additional weight to the theory that contact throughout the Transmanche region was endemic. Even so, it may not have been continuous; there may actually have been times of relative isolation - the data is simply too course to eliminate such a possibility
RAPID report for research expedition DY146. 4 February – 9 March 2022, RRS Discovery. Research Expedition Report No. 76
The purpose of RRS Discovery research expedition DY146 was to refurbish the eastern boundary portion of the RAPID 26°N array of moorings that span the Atlantic from the Bahamas to the Canary Islands. The expedition started in Southampton on 4 February 2022 and ended on 9 March 2022 in Southampton, UK. The moorings are part of a purposeful Atlantic wide array that observes the Atlantic Meridional Overturning Circulation and the associated heat and freshwater transports. The RAPIDMOCHA-WBTS array is a joint UK- US programme. During DY146 moorings were removed at sites: EB1, EBHi and EBH4. Moorings were serviced at sites: EBH1, EBH2 and EBH3. Moorings were equipped with instruments to measure temperature, conductivity and pressure, and a number of moorings were also equipped with current meters and/or
biogeochemical sensors, including oxygen, carbon and nutrient sensors. CTD stations were conducted throughout the cruise for purposes of providing pre- and post-deployment calibrations for mooring instrumentation (including oxygen and carbonate chemistry sampling). Shipboard underway measurements were systematically logged, processed and
calibrated, including: surface meteorology, 5m depth sea temperatures and salinities, water depth, and navigation. Water velocity profiles from 15 m to approximately 800 m
depth were obtained using two vessel mounted Acoustic Doppler Current Profilers (one 75 kHz and one 150 kHz)
The Role of Cybersecurity in the Public Sphere - The European Dimension
he aim of this paper is to present the areas in EU and domestic legal systems which cover currently applicable laws on cybersecurity and the related cyber-liability. Legal regulations related to cybersecurity that are currently in force embrace only a very narrow understanding of the notions of cyberspace and cybercrime. This paper aims to present those areas of the existing regulations in which the notions of cyber-liability have been preliminarily defined. Issues that are currently viewed as only marginally relevant to the functioning of states in the domain of cyberspace operations or artificial intelligence are also related to cyber-liability. The paper covers issues related to online platforms as well as the role of the state and public administration, network technologies and financial
institutions in cybersecurity system especially from European perspective. It also investigates the issues related to strategic and political responsibility, cooperation mechanisms, obligations of telecommunication entrepreneurs, personal data and drone operations in public space. Part of the paper is also
related to the movement of cultural assents, digital platforms, blocking injunctions and blocking access, threats of the cyberterrorism, cybersecurity, cybercrime in Hungary, including COVID-19 environment, as well as authorities competent for cybersecurity in Germany. This broad perspective is used to better understand regulatory purposes in European contexts to secure digital society development
Active vibration control of a flexible robot link using piezoelectric actuators
Nuisance vibrations are a concern throughout the engineering realm, and many re-searchers are dedicated to finding a solution to attenuate them. This research primarily focusses upon the suppression of vibrations in a robot system, with the control system being designed so that it is both affordable and lightweight. Such constraints aim to provide a solution that may be utilised in a variety of applications. The utilisation of piezoelectric elements as both actuators and sensors provides several advantages in that they are lightweight, easily integrated into an existing system and have a good force to weight ratio when used as actuators. To read and control these elements a single board computer was employed, in acknowledgement of the constraining parameters of the design. The amalgamation of vibration control and robotics has lent to the re-search being conducted with separate objectives set, isolating certain elements of the overall system design for validation. Ultimately, these separate investigations progress to the integration of the robot and control systems prior to further research concerning nonlinear vibrations, dynamic control and the discrete-time domain modelling of the system.This research first investigates the viability of the chosen components as a vibration attenuation solution. In addition, analytical models of the system have been created, for two types of sensors to determine the most effective; an inertial measurement unit and a collocated pair of piezoelectric sensors. These models are based on Euler-Bernoulli beam theory and aim to validate the control theory through a comparison of the experimental data. These experiments isolate the vibration problem from a robot system through the investigation of the control of a long slender beam envisioned as a robot manipulator link, but excited using a shaker platform in a sinusoidal manner. An observation of the theory related to the voltage produced by the piezoelectric elements, suggests that even with the application of only proportional control by the system, the controlled output would have components indicative of both proportional and derivative control. This observation and the underlying theory are further analysed within this research.The next objectives are to compare the performance of the control system developed in this research which utilises a Raspberry Pi 3B+ [1] with one that employs a dSPACE MicroLabBox [2], and to determine the suitability of the former for use with robot sys-tems. With the former ensuring that the constraints placed on the design, those which influenced the selection of the components, does not conclude to the dSPACE Micro-LabBox system being overtly preferable. The latter investigates both the impact of the system’s inclusion on the functionality of the system and the system’s perform-ance with respect to the intended application. The KUKA LBR iiwa 7 R800 [3] robot manipulator is utilised to satisfy this objective, wherein the link is mounted on the end effector of the manipulator acting as an eighth link. The final investigation in this research pertains to the attenuation of nonlinear vibrations experienced by a robot manipulator link. Additional components were added to the link to induce a geometric nonlinearity in the system. An analytical model of the amended system was created to validate the theory through comparison with experimental results. The control system was employed for multiple cases to ascertain the level of its performance with regards to the suppression of nonlinear vibrations
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