Este trabalho apresenta um estudo da literatura pertinente sobre qualidade da energia elétrica. O estudo apresentado está baseado na evolução do tema em nível nacional e internacional, buscando explicar o conceito dos principais fenômenos e selecionar as recentes resoluções e normas que regem os princípios de medição e os limites dos distúrbios eletromagnéticos que os caracterizam. As normas da IEC foram selecionadas para a aplicação na construção de um protótipo de um medidor de qualidade da energia elétrica, onde o princípio construtivo é o de instrumento virtual por sua flexibilidade de arquitetura. A implementação do protótipo dá-se em um microcomputador padrão de mercado pelo software LabVIEW, através de vários módulos independentes para cada distúrbio a ser medido. Os resultados numéricos das simulações executadas frente a cada distúrbio, gerando comparações entre valores aplicados e valores medidos são apresentados em forma de tabelas com seus respectivos erros percentuais para cada grandeza de cada módulo. / This dissertation presents a study of existing literature about power quality. The study presented is based on a theme evolution in national and international environment, trying to explain the main phenomenon conceptions and select the most recent standards that rule the measurement conceptions and the electromagnetic disturbances limits that characterize it. The IEC standard were selected to build a prototype of a power quality measure device where the construction conception is a virtual instrument because it has a flexible architecture. The prototype implementation was made from a common computer by the LabVIEW software through some independent modules for each disturbance to be measured. The numerical results of executed simulations of each disturbance generating comparisons between applied values and measured values are presented as tables within their percentage error for each phenomenon of each module.

abstract: The problem of practice addressed in this mixed methods action research study is the underachievement of fifth-grade students in mathematics. This study explores the effects of an innovation designed to help students develop a growth mindset by utilizing self-regulation strategies to improve academic growth in mathematics. Students’ underachievement in mathematics has been illustrated by both state and international assessments. Throughout the decades, mathematics instruction and reforms have varied, but overall students’ psychological needs have been neglected. This innovation was designed to develop students’ psychological characteristics regarding facing challenges in mathematics. For this purpose, two guiding theories were utilized to frame this research study, Dweck’s mindset theory and self-regulation theory. To address the research questions of this study, pre- and post-questionnaire data, observational data and student work was analyzed. Results of the qualitative data indicated that the innovation positively impacted students’ mindsets and use of self-regulation strategies. However, quantitative data indicated the innovation had no effect on students’ use of self-regulation strategies or academic growth, and a negative impact on students’ mindsets. / Dissertation/Thesis / Doctoral Dissertation Educational Leadership and Policy Studies 2020

Modern space geodetic techniques are required to provide measurements of millimetre-level accuracy. A new fundamental space geodetic observatory for South Africa has been proposed. It will house state-of-the-art equipment in a location that guarantees optimal scientific output. Lunar Laser Ranging (LLR) is one of the space geodetic techniques to be hosted on-site. This technique requires optical (or so-called astronomical) seeing conditions, which allow for the propagation of a laser beam through the atmosphere without excessive beam degradation. The seeing must be at ~ 1 arc second resolution level for LLR to deliver usable ranging data. To establish the LLR system at the most suitable site and most suitable on-site location, site characterisation should include a description of the optical seeing conditions. Atmospheric turbulence in the planetary boundary layer (PBL) contributes significantly to the degradation of optical seeing quality. To evaluate astronomical seeing conditions at a site, a two-sided approach is considered – on the one hand, the use of a turbulence-resolving numerical model, the Large Eddy Simulation NERSC (Nansen Environmental and Remote Sensing Centre) Improved Code (LESNIC) to simulate seeing results, while, on the other hand, obtaining quantitative seeing measurements with a seeing monitor that has been developed in-house. / Dissertation (MSc)--University of Pretoria, 2012. / Geography, Geoinformatics and Meteorology / MSc / Unrestricted

Agriculture workers can be exposed to hazardous concentrations of airborne contaminants such as, particulate matter (PM), carbon dioxide (CO2), and volatile organic compounds (VOCs). Exposure to these contaminants has been associated with a high prevalence of acute and chronic respiratory symptoms: coughing, wheezing, shortness of breath, and phlegm, as well as a reduction in lung function. Commercial low-cost indoor air quality (IAQ) monitors have the ability to detect many of the contaminants commonly found in agriculture. Limited research has been conducted on the performance of low-cost monitors in different occupational settings. Therefore, the purpose of this study was to evaluate whether the Foobot (Airboxlab, San Francisco, CA, USA), a low-cost (IAQ) monitor, is sufficiently robust to operate in agricultural environments and provide useful and accurate information to farmers. Foobots were deployed at two sites, a tractor repair shop (“Shop”) for 43 days and a finishing room in a swine production building (“Barn”) for 40 days, where they monitored PM2.5, CO2, and VOCs. Reference direct-reading monitors to compare Foobot readings were collocated with the Foobots. Paired sample results were compared over 19 days at the shop and 21 days at the barn. At neither of the two sites did the Foobots meet the National Institute for Occupational Safety and Health (NIOSH) acceptable bias criterion of ± 10% when compared to the reference monitors. Linear regression results indicate that a strong linear relationship does not exist (R2< 0.66) between the Foobots and reference monitors. A significant difference (P< 0.031) was found between contaminant concentrations reported by each Foobot but the difference was not found to be substantial. The Foobot CO2 and VOC concentrations were highly correlated (R2=0.99). However, a strong linear relationship between the Foobot CO2 concentrations and the reference CO2 concentrations was not found at the shop (R2 = 0.02) or barn (R2 = 0.61). After 40 days in the barn, the Foobots were reporting that damage had occurred to the sensors and were no longer functioning. In addition, the PM sensors in the three Foobots in the barn were contaminated after the study. Therefore, it was concluded that the Foobots were unable to supply farmers with accurate information and were not durable enough for agricultural environments. Future research will investigate the use of other low-cost monitors in agriculture.

Aim: The aim of the study was to analyse the injuries and illnesses in Swedish Para athletes during four Paralympic Games (PG), 2012-2018. The research questions (RQ) were: 1) what was the injury incident rate (IR), and which anatomical areas were affected by injuries? 2) what was the illness IR and which physiological systems were affected by illnesses? 3) did the injury and illness IR differ between the Swedish delegation and the reference group (RG), where most athletes participating in the four PGs were included? 4) were there any associations between injury and illness IR and subgroups of athletes? Method: A retrospective analysis of data from a large ongoing prospective study of injuries and illnesses initiated by the International Paralympic Committee in 2012. Data from 157 Swedish Paralympic athletes were analysed and compared to previous results from the RG.  For RQ1, 2 and 3, injuries and illnesses were reported as IR, calculated per 1000 athlete days, in the Swedish delegations (RQ1-3) and compared to the RG (RQ3). For RQ4, a univariate logistic regression analysis was conducted to find possible associations between risk of injury and illness, and subgroups. Results: The injury IR in Swedish athletes varied between the four PGs, from 2.5 to 59.5 per 1000 athlete days. Most injuries occurred in the upper limb. There was a particularly high occurrence of injuries in Para ice hockey players. The illness IR varied from 3.6 per 1000 athlete days in London (2012), to 39.5 in Sochi (2014). The respiratory tract was most affected by illness, in both Swedish athletes and the RG. Most injuries and illnesses in the Swedish delegation were acute onset, but only a minority led to days lost from training and competition. The Swedish delegation had a lower injury IR per 1000 athlete days compared to the RG in all PGs, except for Pyeongchang (2018), where they had an almost three times higher IR. The illness IR for the Swedish delegation was, compared to the RG, lower in London (2012), the same in Rio (2016) and higher in both Sochi (2014) and Pyeongchang (2018). Participation in the Winter Games was associated with a higher risk for both injury and illness compared to the Summer Games. There was also an increased risk of injury for athletes in a contact sport compared to a non-contact sport. Conclusions: This thesis indicates that there is a need to continue monitoring Para athletes, both during and between competitions, to get more knowledge about injury and illness incidence patterns, as well as preventable risk factors. The latter would be especially important for Para ice hockey. It is yet to see if the awareness of the importance of hygiene measures and physical distancing to reduce spreading of infections, brought on by the Covid-19 pandemic, will affect the occurrence of respiratory tract infections during large sporting events.

The thesis deals with design of the device for monitoring four signals from the probes for scanning ECG, PPG and heart pressure. The thesis is mainly focused on hardware design of the device and the most important part is the selection of the storage media to which will be the data recorded and the selection of the microprocessor which has to be able to meet the requirements of the device. For the data recording is used SD card and the ARM based MCU was selected from the AT91SAM7S series. This thesis also deals with the software design for MCU which is needed to launch the device and with design of PC applications used for setting the device and for downloading the measured data. At the end there are presented results of the constructed device.

The first two chapters are devoted to theoretical analysis of issues relating to portable EKG monitor. This chapters are aimed to further acquaint the reader with the issue for subsequent easier of understanding on further steps in the implementation of the device which will be contain in the following chapters. The first chapter is mainly a medical nature. We describe the anatomy and functional properties of the heart. In the next chapter we are deal with detail of electrocardiograph and the conditions for its proper function. Other chapters are devoted to the actual implementation of the facility. We are dealing with the issue of build functional portable EKG monitor. This practical part begins by fourth chapter, which consists block diagram of the device and discusses the required parameters. Next most extensive chapter is devoted to a detailed breakdown of the electrical circuit, including the calculation of the individual components. The last chapter describes the implementation and outcome measurements on test persons.

Die Reichweiteverifikation von Protonen ist ein wichtiger Schritt zur Erhöhung der Präzision der Protonentherapie. Eine neue Methode ist das Prompt -Ray Timing, bei dem Reichweiteinformation aus der Zeitverteilung detektierter Gammaquanten gewonnen wird. Für eine genaue Reichweitebestimmung wird jedoch eine präzise und konstante Zeitreferenz benötigt. Um entdeckte Phasenverschiebungen zwischen Protonbunch und der als Zeitreferenz genutzten Hochfrequenz des Zyklotrons korrigieren zu können, werden Proton- Bunch-Monitore eingesetzt. Diese Arbeit soll abschätzen, ob und wo Proton-Bunch-Monitore im Protonenstrahl eingesetzt werden können. Nach ersten Abschätzungen mit dem Lynx von IBA Dosimetry wurden zwei Monitore auf Basis einer szintillierenden Faser und dem U100-Spektrometer von Target in die äußeren lateralen Bereiche von Protonenstrahlen verschiedener Energien bei niedrigen Strahlströmen (0,01 nA bis 0,1 nA) gebracht. Es zeigt sich eine systematische Abhängigkeit der Relativzeit und der horizontalen Position im Strahl, welche auf die Strahlumlenkung zurückzuführen ist. Diese resultiert in einer systematischen Abhängigkeit der mittleren Reichweite und der horizontalen Position. Durch Abschätzung der Protonenrate für einen klinischen Strom von 2 nA konnten potentielle Einsatzorte im Strahl-Halo identifiziert werden. Weitere Untersuchungen sind jedoch notwendig, um die Einsetzbarkeit zur Korrektur von Phasenverschiebungen unter klinischen Bedingungen zu erproben. / The range verification of protons is an important step towards increasing the precision of proton therapy. A new method is the prompt -ray timing, where range information is obtained from the time distribution of detected gamma quanta. However, the method requires a precise and constant time reference for accurate range determination. proton bunch monitors can be used to correct detected phase shifts between proton bunch and the cyclotron radio frequency used as a time reference. This work should estimate if and where proton bunch monitors can be used in the proton beam. According to initial estimates with the Lynx from IBA Dosimetry, two monitors based on scintillating fiber and Target’s U100 spectrometer were used in the outer lateral regions of proton beams of different energies at low beam currents (0.01 nA to 0.1 nA). It shows a systematic dependence of the relative time and the horizontal position in the beam, which is due to the beam deflection. This results in a systematic dependence of the mean range and the horizontal position. By estimating the proton rate for a clinical current of 2 nA, potential positions of application in the beam halo were identified. However, further investigations are needed to test the applicability for the correction of phase shifts under clinical conditions.

Introduction Measuring the beam profile on a medical cyclo-tron in real time can aid in improved tuning of the cyclotron and give important information for a smooth operation. Typically the beam profile is measured by an autoradiography technique or even by a scintillator that can be viewed in real time [1, 2]. Another method is to use collimators in front of the target to assess the beam center-ing [3]. All these methods have potential draw-backs including; an inability to monitor the beam in real time for the radiograph, exhibiting a non-linear correlation in signal response to the power deposited for a scintillator, and not providing a 2-dimensional profile of the complete beam for collimators. Our goal was to design a realtime, linear, 2-dimensional beam-profile monitor that is able to withstand the high power of a PET cyclotron. Material and Methods The beam-profile monitor (PM) is designed for the TR13, a 13MeV negative hydrogen-ion cyclotron at TRIUMF. The design follows the concept of a ‘harp’ monitor, widely used at TRIUMF for tuning proton and radioactive ion beams, and is installed on the extraction port without separation from the tank vacuum. The TR13 monitor is designed to withstand a 13 MeV proton beam with a beam current of up to 25 µA, has an active area of 10 by 10 mm and does not affect the 10-7 torr tank vacuum. The device consists of a water-cooled Faraday cup made out of aluminium for low activation and two orthogonal rows of eight tungsten electrodes each mounted on a water-cooled support frame. Electrodes are spaced 1 mm apart from each other, see FIG. 1. The electrodes are electrically isolated from each other and each has a current pickup soldered to it. The material and the shape of the electrodes are optimized to withstand the deposited power of the proton beam. A voltage of -90 V is applied to the electrodes to repel secondary electrons and prevent crosstalk between neighbouring electrodes. The electrode current is amplified using a custom current amplifier, and read by an ADC. From there, the current data is displayed on a PC. This allows one to observe changes of the beam profile in real time. The electronics are designed to read out all sixteen channels in parallel, or, if only a limited number of ADC channels are available, to cycle through the different channels. In our current setup all sixteen channels are read out simultaneously. Results and Conclusion The beam-profile monitor provides a real-time representation of the proton beam, see FIG. 2. The data can also be recorded and analyzed at a later time. The linearity of the monitor has been measured up to 30 µA of proton beam current [4]. With the use of the monitor, it was possible to increase the output of the ion source into the target by 50% in comparison to the standard tune.

The capacity of optical communications networks continues to grow unabated. Applications for streaming video, social networking and cloud computing, are driving exponential growth of the traffic carried over the world’s ICT networks, which has been sustained thus far through the proliferation of datacenters and efficient, effective use of existing optical fibre. To meet increasing capacity demands requires increasingly sophisticated modulation formats and spectral management to achieve effective use of the available spectrum provided by an optical fibre. Moreover, the technology developed for optical communications is finding broader application to other sectors such as data centres, 5&6 G wireless; lidar and radar. Ultimately, some essential signal processing functions must occur at speeds beyond purely electronic means even when accounting for anticipated technological development. The option is to perform signal processing in the optical domain. Optical signal processors are fundamentally analog and linear in nature. To provide high performance, an analogue processor must be well controlled in a way analogous to the numerous and sophisticated controllers employed by the process industry. Consequently, a further extension of control to deeper levels within the physical layer reaching the optical layer will be necessary. For example, current reconfigurable optical add-drop multiplexers are coloured and directional and the wavelength division multiplexing channel grid, transponders modulation format, and the routing are all fixed. Through optimization of the interface between the physical components, sensors, and processors elastic optical network technology can be achieved by employing colour-, direction-, contention-, grid-less, filter-, gap-less reconfigurable optical add-drop multiplexers, flexible channels centre frequencies and width, flexible sub-carriers in super-channels, flexible modulation formats and forward error control coding transponders, and impairment-aware wavelength routing and spectral assignment. The aim of this thesis is to advance the state-of-the-art in photonic circuits and subsystems via proposing new architecture; study of the feasibility of photonic integration and, proof of concept implementations using available resources. The goal is to introduce new architectural concepts that make effective use of physical components and/or optical processors with reduced energy consumption, reduced footprint and offer speed beyond all-electronic implementations. The thesis presents four case studies based on one or more published papers and supplementary material that advance the goal of the thesis. The first study presents a coherent electro-optic circuit architecture that generates N spatially distinct phase-correlated harmonically related carriers using a generalized Mach-Zehnder Interferometer with its N×1 combiner replaced by an N×N optical Discrete Fourier Transform. The architecture subsumes all Mach-Zehnder Interferometer-based architectures in the prior art given an appropriate selection of output port(s) and dimension N, although the principal application envisaged is phase-correlated subcarrier generation for next-generation optical transmission systems. The theoretical prediction is then verified experimentally using laboratory available photonic integrated circuit fabricated for other applications. Later on, a novel extension of the circuit architecture is introduced by replacing the optical Discrete Fourier Transform network using the combination of a properly chosen phase shifter and single MMI coupler. The second study proposes two novel architectures for an on-chip ultra-high-resolution panoramic spectrometer and presents their design, analysis, integration feasibility, and verification by simulation. The target application is to monitor the power of a wavelength division multiplexed signals in both fixed and flex grid over entire C-band with minimum scan time and better than 1 GHz frequency accuracy. The two architectures combine in synchrony a scanning comb filter stage and channelized coarse filter. The fine filtering is obtained using a ring resonator while the coarse filtering is obtained using an arrayed waveguide grating with appropriate configuration. The fully coherent first architecture is optimised for compactness but relies on a repeatable fabrication processes to match the optical path lengths between a Mach-Zehnder interferometer and a multiple input arrayed waveguide grating. The second architecture is less compact than the first but is robust to fabrication tolerances as it does not require the path length matching. The third study proposes a new circuit architecture for single sideband modulation or frequency conversion which employs a cascade Mach-Zehnder modulator architecture departing from the orthodox dual parallel solution. The theoretical analysis shows that the circuit has 3-dB optical and 3-dB electrical advantage over the orthodox solution. The 3-dB electrical advantage increases the linear operating range of Mach-Zehnder modulator before RF amplifier saturation. An experimental verification of the proposed architecture is provided using an available photonic integrated circuit. The proposed circuit can also perform complex modulation. An alternative implementation based on polarization modulators is also described. The fourth study presents the theoretical modelling of a photonic generation of broadband radio frequency phase shifter. The proposed phase shifter can generate any phase without bound: the complex transmission of the phase shifter follows a trajectory that rotates on a unit circle and may encircle the origin any number of times in either direction, which has great utility in the tuning of RF-photonic systems. The proposed concept is then verified experimentally using off the shelf low frequency electronic components.