En raison de leur capacité à intervenir dans les processus rédox, les ligands non-innocents ont depuis longtemps suscité un intérêt chez les spectroscopistes, mais leur potentiel en catalyse n'a été que récemment considéré. Le comportement non-innocent des ligands iminosemiquinonate et de leurs dérivés est bien établi et maîtrisé, et, associés à différents métaux, ces ligands ont démontré leur efficacité dans diverses applications synthétiques, telles que les oxydations et les réactions de couplage. Ce travail de thèse a pour objectif de développer des réactivités induites par des complexes de cuivre et nickel coordinés par des ligands de type iminosemiquinonate. Tout d'abord, la capacité de ces complexes à générer des radicaux CF3 par réduction d'une source électrophile de trifluorométhylation a été démontrée, et les espèces organométalliques résultant de l'oxydation monoélectronique centrée sur le ligand ont été identifiées par spectroscopie UV-visible. Un système catalytique a également été mis au point pour la trifluorométhylation radicalaire d'éthers d'énol silylés, d'hétéroarènes et l'hydrotrifluorométhylation d'alcynes. Les propriétés rédox des ligands iminosemiquinonates ont permis l'accès au premier complexe CuII–CF3 coordiné par des ligands oxydés iminobenzoquinones. L'étude de sa réactivité a mis en évidence le rôle essentiel des ligands oxydés, qui stabilisent le degré d'oxydation +II du cuivre, sans empêcher un comportement de CuIII haute valence. Ces observations ont été attestées par un ensemble de données spectroscopiques et théoriques. Enfin, l'étude de l'influence des ligands iminosemiquinonate sur la structure et la réactivité d'espèces cuivre–nitrène, impliquées dans les réactions de transfert de nitrène catalytique, est au centre d'un projet en cours. / Because of their ability to get involved in redox events, non-innocents ligands have long sparked the interest of spectroscopists, and their potential in catalysis has only later been considered. Iminosemiquinonate radical ligands and their derivatives are well-established non-innocent ligands and have been previously used with several metals, showing their efficiency in specific synthetic applications, such as oxidations and cross-couplings. This thesis work deals with the development of reactivities using iminosemiquinonate copper and nickel complexes. First, the ability of these complexes to induce the controlled generation of CF3 radicals by reduction of a CF3+ source was demonstrated, and key organometallic species resulting from a ligand-centered single electron transfer were identified using UV-vis spectroscopy. Catalytic conditions were developed and applied to the trifluoromethylation of silyl enol ethers, heteroarenes and hydrotrifluoromethylation of alkynes. Then, the synthesis of the first well-defined CuII–CF3 complex bearing fully oxidized iminobenzoquinone ligands was achieved. The study of its reactivity revealed the prominent role of the redox ligands, which stabilize a (+II) oxidation state without preventing its ability to behave as a high-valent CuIII complex. These observations were substantiated by a combination of advanced EPR spectroscopy techniques with DFT calculations. Finally, the influence of iminosemiquinonate ligands on the structure and the reactivity of copper–nitrene species, in catalytic nitrene transfer reactions, is the focus of a last project, which is still in progress.

Abstract In visible light communication (VLC), light emitting diodes (LEDs) are used as transmitters; the air is the transmission medium and the photodiodes are used for receivers. This is often referred to as light fidelity (Li-Fi). In this thesis, we provide the methodology to evaluate the performance of VLC hotspot networks in the context of data downloading on the move scenarios by using throughput-distance relationship models. In this context, first we study the different properties of optical transceiver elements, noise sources, characterization and modelling of artificial light interference, different link topologies and then we introduce the throughput-distance relationship model. Secondly, the analytically based throughput-distance relationship has been developed for evaluating the performance of VLC hotspot networks in indoor environment in both day and night conditions. Simulation results reveal that background noise has a significant impact on the performance of VLC hotspots. As expected, in both indoor and outdoor environments the VLC hotspot performs better at night than during day. The performance of VLC hotspot networks is also quantified in terms of received file size at different bit error rate requirements and velocities of the mobile user. Thirdly, we study the performance of hybrid (Radio-Optical) WLAN-VLC hotspot and compare its performance with stand-alone VLC-only or WLAN-only hotspot cases. In this case, we also consider the data download on the move scenarios in an indoor environment for a single-user as well as for multi-user cases. In this hybrid WLAN-VLC hotspot, both the WLAN and the VLC are characterized by their throughput and communication range. Simulations have been performed to evaluate the performance of such network for data downloading on the move scenario by taking into account performance metrics such as filesize, average connectivity and system throughput. Simulation results reveal that the considered hybrid WLAN-VLC performs always better than stand-alone VLC-only or WLAN-only hotspot both for a single and multi-user cases. Finally, this thesis analyses the feasibility and potential benefits of using hybrid radio-optical wireless systems. In this respect, cooperative communication using optical relays are also introduced in order to increase the coverage and energy efficiency of the battery operated device. Potential benefits are identified as service connectivity and energy efficiency of battery operated device in an indoor environment. Simulation results reveal that user connectivity and energy efficiency depend on user density, coverage range ratio between single-hop and multi-hop, relay probabilities and mobility of the user. / Tiivistelmä Näkyvään valoon pohjautuvassa tiedonsiirrossa (VLC) valodiodeja (LED) käytetään lähettiminä, ilma on siirtokanava ja valoilmaisimia käytetään vastaanottimina. Tätä kutsutaan usein nimellä light fidelity (Li-Fi). Tässä työssä tarjoamme menetelmiä VLC ”hotspot” verkkojen suorituskyvyn arviointiin tiedonsiirtonopeus-etäisyysmalleilla skenaarioissa, jossa tietoa ladataan liikkeessä. Tässä kontekstissa tutkimme ensin optisen lähettimen komponenttien eri ominaisuuksia, kohinan lähteitä, keinovalon häiriömalleja ja tiedonsiirtolinkkien topologioita, jonka jälkeen esittelemme tiedonsiirtonopeuden ja etäisyyden välisen mallin. Toiseksi kehitetyn analyyttisen tiedonsiirto-etäisyys mallia käytetään arvioitaessa VLC hotspot verkkojen suorituskykyä sisäympäristössä sekä päivä että yö olosuhteissa. Simulointien tulokset osoittavat, että taustakohinalla on suuri vaikutus VLC verkkojen suorituskykyyn. Kuten odotettua, sisä- ja ulkotiloissa VLC hotspot toimii paremmin yöllä kuin päivällä. VLC hotspot verkkojen suorituskyky arvioidaan myös vastaanotetun tiedoston koon, eri bittivirhesuhteen vaatimuksilla ja liikkuvan käyttäjän nopeuden suhteen. Kolmanneksi tutkimme hybridi WLAN-VLC hotspot verkon suorituskykyä ja vertaamme sen suorituskykyä pelkän VLC- tai WLAN hotspot tapauksessa. Käsittelemme myös skenaarioita jossa tiedoston lataus tapahtuu liikkeessä sisätilassa yhden käyttäjän sekä monen käyttäjän tapauksissa. Tässä hybridi WLAN-VLC hotspot, sekä erilliset WLAN- ja VLC verkot ovat määritelty niiden tiedonsiirtonopeuden ja kantaman perusteella. Näiden verkkojen suorituskykyä arvioitaessa on tehty joukko tietokonesimulointeja verkossa tapahtuvasta tietojen lataamisesta liikkeessä ottamalla huomioon suorituskyvyn mittarit kuten tiedoston koko, keskimääräinen yhteyden kesto ja saavutettu läpäisy. Simuloinnin tulokset paljastavat, että hybridi WLAN-VLC toimii aina paremmin kuin pelkkä VLC tai WLAN hotspot sekä yhden että monen käyttäjän tapauksessa. Lopuksi työssä analysoidaan ehdotetun järjestelmän toteutettavuus ja mahdolliset edut käytettäessä hybridejä radio-optisia langattomia järjestelmiä. Tältä osin esitellään myös kooperatiiviseen viestintään perustuvat optiset releet parantamaan verkon kattavuutta ja energiatehokkuutta akkukäyttöisissä laitteissa. Mahdolliset hyödyt tunnistetaan palvelun konnektiivisuudessa ja energiatehokkuudessa akkukäyttöisissä laitteissa sisätiloissa. Simulointien tulokset osoittavat, että käyttäjien konnektiivisuus ja energiatehokkuus riippuvat käyttäjätiheydestä, kantaman ja etäisyyden välisestä suhteesta yhden hypyn ja monen hypyn välillä, releointi todennäköisyydestä ja käyttäjien mobiliteetista.

Le présent travail concerne principalement l'élaboration d'un nouveau ligand en l'occurrence le cyclen-hydrazone, luminescent et efficace pour une détection relativement sélective de l'ion d'intérêt biologique, Zn2+. La synthèse du groupement azaxanthone à greffer sur le cyclen a été décrite. A partir de ces ligands, la complexation de zinc, a été traitée dans le but de développer une sonde optique sélective pour les ions métalliques de la première série de transition. Une étude photophysique associée à un travail de modélisation théorique en solution a plus particulièrement montré la formation de deux nouveaux complexes de zinc. Finalement, le contrôle des conditions de déprotection par hydrazinolyse du cyclen-glyoxal-azaxanthone, a montré que le motif azaxanthone puisse être maintenu dans la conception de nouveaux complexant de métaux de la première série de transition. / This study deals with the development of a new ligand: the cyclen-hydrazone, luminescent and effective for a relatively selective detection of biological ion, Zn2+. The synthesis of graft azaxanthone group to the cyclen was described. From these ligands zinc complexation was treated in order to develop an optical probe selective for the first row transition metals. A photophysic study associated with theoretical modeling work in solution, specifically showed the formation of two new zinc complexes. Finally, the monitoring of deprotection by hydrazinolysis of cyclen-glyoxal-azaxanthone, showed that the azaxanthone deprotection could be maintained in the design of new metals complexes of the first serie of transition metals.

Thesis (M. A. (Criminology)) -- University of Limpopo, 2016 / The study focused on Community Policing Forums (CPFs), sector policing and visible policing which are the policing strategies that are currently used to bring police officers closer to the community in order to identify and address the root causes of crime. These strategies are also meant to improve police service delivery which will satisfy and meet the community’s expectations about police services. The study also focused on factors which affect the lack of police service delivery to the community. Quantitative research design was used to evaluate Mamotintane community’s level of satisfaction with police service delivery. Non-probability sampling was used in which purposive or judgmental sampling methodology was used to select the 120 community members from Mamotintane Village. A fixed-response questionnaire that was written in English then translated in Sepedi which is the language commonly used by the target population was used in the study. A Statistical Package for Social Science (IBM SPSS Statistics Version 22) software was then used to analyse the data which was presented in a form of graphs and tables. Summary of the empirical findings are that a large number of 33% community members disagree that CPFs are successfully established in the community where police officers have regular meetings with community members in order to discuss about crimes which are affecting the community. A large number of 43% respondents strongly agree that police corruption has a negative impact to the community.

Cílem této práce je prezentovat metody pro akceleraci výpočtů stínů a osvětlení.  Práce se zabývá akcelerací na vzorek přesných stínů pomocí stínových těles na různých platformách. Obsahem práce je také zvýšení přesnosti stínových map a zvýšení přesnosti osvětlování scény s mnoha světly.

Det är som lärare i grundsärskolan och som blivande speciallärare en utmaning att få alla elever att känna sig delaktiga i sitt lärande och sin lärprocess samt att ge eleverna inflytande över sin utbildning. Att synliggöra kunskapsmålen i undervisningen så det blir betydelsefullt och begripligt är en aktuell fråga i arbetet med grundsärskoleelever.  Syftet med studien är att bidra med kunskap om undervisning i grundsärskolan genom att studera några speciallärares upplevelser av elevernas lärprocess och måluppfyllelse. Studien utgår då från en fenomenologisk ansats. Våra frågeställningar är vilka faktorer som påverkar elevers måluppfyllelse? Hur synliggör lärare elevers kunskapsmål för eleven? Hur gör lärare för att elever ska bli delaktiga i sin lärprocess?  För insamling av empirin användes kvalitativa metoder genom observationer och intervjuer. Studien är analyserad utifrån ett salutogent perspektiv och som teori har KASAM, Känsla Av SAMmanhang använts (Antonovsky, 2005). KASAM handlar i undervisningssammanhang om att eleven ska känna begriplighet, hanterbarhet och meningsfullhet i sin lärprocess och sitt lärande. Studiens resultat visar att när elevernas mål ska synliggöras och de ska bli delaktiga i sina lärprocesser är tydlighet en framgångsfaktor. Även att som lärare vara bekräftande, uppmuntrande och att få eleverna aktiva är faktorer som påverkar positivt. Lärarna visualiserar målen på olika sätt men det har inte framkommit att de genomgående använder någon specifik modell eller metod samt om de visualiserade målen är begripliga och hanterbara. I intervjuerna påtalar flera av lärarna att de vill ha ett system eller en modell för att kunna få eleverna mer delaktiga i sina lärprocesser och i sina kunskapsmål samt som stöd för bedömning. / As a teacher in Compulsory school for children with intellectual disabilities and as a future special teacher, it is a challenge to make all students involved in their learning and their learning process and to give the students influence over their education. Making the knowledge goals visible so it becomes meaningful and understandable is a current issue in the work with special school students. The purpose of the study is to contribute with knowledge about teaching in Compulsory school for children with intellectual disabilities by studying some special teachers' experiences of the students' learning process and goal fulfillment. Our question statements are what factors affect students' goal fulfillment? How do teachers make knowledge goals visible to students? How do teachers get students involved in their learning process? The study has a phenomenological approach, qualitative methods were used through observations and interviews. The study is analyzed from a salutogenic perspective and as a theory, SOC, Sense of Coherence has been used (Antonovsky, 2005). In a teaching context, SOC is about the student feeling comprehensibility, manageability and meaningfulness in their learning process and learning. The results of the study show that clarity when it comes to making goals visible and making students involved in their learning processes is a success factor. As a teacher, being affirmative, encouraging and getting students active are also factors that have a positive effect. The teachers visualize the goals in different ways, but it has not emerged that they consistently use any specific model or method and whether the visualized goals are comprehensible and manageable. Several of the teachers says in the interviews that they want a system or a model to use to get the students more involved in their learning process and in their knowledge goals.

The thesis is focused on the design and elaboration of the project documentation of the extension of the elementary school, which is located in Starý Plzenec. The documentation contains requirements according to valid regulations. The proposal is based on the investor's request, which was published as part of the architectural competition announcement. A new building with 1 underground and 3 floors, forming the Y-shaped ground plan, is located on a slightly sloping terrain. In the building there are cloakrooms, kitchen, dining room, 4 main and 4 professional classrooms and hygienic and technical background. The project proposes a slight modification of the existing building. This proposal solves the barrier-free accessibility of both buildings, except for the attic classroom of the existing building. The project also counts from the second construction phase, the construction of a sports hall on the schools premises, which is still not dealt with. In proposal is a new main entrance to the building from the southern side. The support system is wall-mounted. The perimeter walls are made of monolithic concrete connected to concrete monolithic horizontal bearing structures. The inner bearing walls are made of ceramic blocks. The building is covered with a single-layer flat roof with a vegetation layer. The thermal insulation of the building is solved by a thermal insulation system with a ventilated facade. Fire safety, energy saving and thermal protection are provided.

People around the globe are immensely trying to connect using light as carrier due to its low power consumption and high data transfer rates. Sound and microwaves are examples of other carriers that can be used, although they aren't nearly as efficient as light. A method of communicating is using light beneath the surface of the water. As the depth of the water increases, the temperature, pressure, and salinity of the water are changed. The refractive index of water is determined by the combination of all of these variable parameters. The goal of this thesis is to establish a relationship between changes in water temperature, salinity, and pressure resulting in changes of the refractive Index of the sea water. This thesis will demonstrate an empirical model of travelling the ultraviolet wave under sea water. We are acknowledging all of the properties that are change as the depth of the water is increasing. MATLAB was used to create a simulation of this scenario. Based on previous model of light traveling which covers the wavelengths between 400-700 nm, we have extended the model to ultraviolet range of light (200-400 nm).We design an experimental set up according to sea water parameters and then the experimental results are compared to the simulation results. The comparison shows the validity of our extension model.

This diploma thesis is focused on design and prototyping of wireless optical link for an indoor usage. In the beginning of the thesis frequency spectrums of infrared, visible and ultraviolet light are described by its typical qualities such as values of attenuation or reflection capability. On the basis of this analysis, a proper wavelength has been chosen for usage at the engineered communication system. Next part is devoted to selection of suitable communication components on basis of its declared qualities. In the following chapter this qualities are in carefully measured and after that they are compared with values provided by its manufacturer. The following section is devoted to design schemes of transceiver modules. After completion of the design the manufacturing of PCB, mounting components and the analysis of their distribution was described. The last part of this thesis deals with testing of created prototype in terms of maximum transmission distances and operating frequencies. At the very end of this project, in one small section ways to improve system characteristics was discussed.

The photocatalytic wastewater treatment facility presented in this thesis is a promising economic green technology that can degrade wastewater’s organic and ammonia pollutants, which produce environmentally sensitive products like CO2, H2O, Nitrates, etc. that can be captured and used in many biological and engineering ways. Previous advances used for this research was determining the importance of cleaning the photocatalytic nanocrystals, Fe-TiO2, as one of the revolutionary improvements that expose and maximizes the active surface of the photocatalytic nanocrystals to the pollutants enabling the strong oxidants produced by the absorption of a photon, excitation of an electron and positive hole to produce oxidants on the surface of the nanocrystals. The oxidants indiscriminately produce CO2 and H2O from living and non-living organic matter to obtain near ~100% clean water. This research focused on taking the next steps in the development of a wastewater cleaning facility tested in our laboratory. An important step involved coating Fe-TiO2 crystals onto flexible, strong, fiber-glass cloth using a sol-gel processing method. Success was found in this research by applying the coated fiberglass cloth into a photoreactor aimed to clean a large amount of water rather than the laboratory scale. / Graduate