Microplastic (MP) pollution has recently been recognized as a threat to the biosphere including humans due to its widespread distribution, persistent nature and infinitesimal size. This study focused on the solid phase degradation of microplastic residues (particularly low density polyethylene, LDPE) in water through heterogeneous photocatalysis process by designed photocatalysts of zinc oxide nanorods (ZnO NRs) and platinum nanoparticles deposited on zincoxide nanorods (Pt NPs-ZnO NRs) under visible light irradiation. These photocatalysts were assessed following standard protocol (ISP 10678: 2010), and characterized using SEM, EDX andoptical spectroscopies (UV-VIS and PL). Deposition of Pt-NPs on ZnO NRs for certain minutes has been found optimum that enhanced the photodegradation process about 38% under UV irradiation and 16.5% under visible light irradiation by improving of both electrons-holes pair separation process and visible light absorption. Photocatalytic degradation of LDPE films was confirmed by FTIR spectroscopy, dynamic mechanical analyzer (DMA), optical and electron microscopes. When LDPE film irradiated in presence of Pt-ZnO, degradation was found quicker than ZnO alone of similar concentration which exhibited formation of a large number of wrinkles, cracks and cavities on the film surface. Dynamic mechanical analyzer (DMA) test indicated stiffness and embrittlement of exposed LDPE films in presence of photocatalysts. Thus, the present work provides a new insight about modified catalysts for the degradation of microplastics in water using visible light.

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People with visible facial difference often experience other people reacting negatively to their appearance. For many, this is part of everyday life. Research has identified social support as critical in adaptation processes. This is the case both for those whose facial difference was apparent at birth, and those who experienced injury or illness. There is a lack of a comprehensive theoretical construct for exploring how personal communities provide resources needed by adults to live well with visible facial difference. The combination of semi-structured interviews and creation of personal community maps provided opportunities to explore the interplay between respondent accounts and patterns of relationships people are embedded within. Seventeen adults with visible facial difference and two unaffected ‘significant others’ were interviewed. The findings provide evidence that personal communities are important social spaces for negotiation of resources that enable adults to feel connected, valued and safer within wider communities. Social support was not described as a property of the individual, but as experienced with combinations of people that change according to situation, place, or time. A diversity of personal community patterns were found, largely consistent with findings from Spencer and Pahl (2006), with one variation which increased intimate support. Some personal communities were less supportive and consequently people were at risk of isolation. Processes within personal communities were helpful both in dealing with negative social environments and in helping establish different versions of ‘normal’ life. The importance of focussing on social contexts, when seeking to understand how people live with visible facial differences, is highlighted. / University of Bradford Studentship

Connected Vehicle (CV) is a motorized vehicle that can communicate with its interior and exterior surroundings. Connected Vehicle focuses on localized vehicle-to-vehicle (V2V) and vehicle-to-infrastructure (V2I) to support safety, mobility and environmental applications. In this work, a simulation framework is presented. The framework quantifies Connected Vehicle performance in a forward collision warning situation. The simulation framework evaluates the performance using a vehicular traffic simulator with data from an intersection in Toronto, ON Canada. Various communication methodologies are evaluated at different Connected Vehicle market penetration rates. While DSRC is an interference limited communication methodology and visible light communications is a line-of-sight communication, the combination of both is evaluated to quantify the vehicular network safety performance in terms of time to collision. The performance of DSRC in a vehicular network is quantified in an interference dominant environment and the VLC performance in the vehicular network is evaluated at different weather conditions. In a specific vehicular traffic situation namely for- ward collision warning, this research quantified the VLC performance improvement in vehicular network safety to be 11% in addition to DSRC.This work concludes with the simulation and prototyping of camera communications for vehicular applications. Specifically this thesis presents multiple input / multiple output camera communications link utilizing a luminary array as a transmitter and two orthogonal low cost rolling shutter cameras as a receiver with the purpose of increasing the achievable data rate with one camera. This work has demonstrated that there is at most a doubling in the data rate using two cameras over a single one. This data rate increase is achievable using a specific camera setup namely orthogonal cameras. / Thesis / Master of Applied Science (MASc)

This doctoral thesis focuses on applying different organocatalysts in several enantioselective reactions and aerobic photooxidations using visible light. Chapter 1 describes using a chiral primary amine-salicylamide derived from (1R,2R)-cyclohexane-1,2-diamine as chiral organocatalyst in the asymmetric conjugate Michael addition of aldehydes and ketones to maleimides, giving the corresponding enantioenriched succinimides. The same organocatalyst is used in the enantioselective Michael addition of aldehydes to nitroalkenes, yielding enantiopure γ-nitroaldehydes. Furthermore, these Michael additions of aldehydes to maleimides and nitroalkenes are carried out employing sustainable and environmentally friendly deep eutectic solvents (DES), being able to reuse the catalytic system for several cycles. Chapter 2 describes using a chiral primary-amine monocarbamate derived from (1R,2R)-cyclohexane-1,2-diamine as chiral organocatalyst in the enantioselective α-amination of aldehydes with azodicarboxylates, obtaining the corresponding α,α-disubstituted aldehydes with the absence of solvent under mild conditions. This simple orgacatalytic system’s applicability is demonstrated by preparing a chiral oxazolidinone precursor of amino acids. The reaction is also successfully scaled-up. In addition, theoretical calculations were performed to demonstrate how the absolute configuration of the final adducts is produced. Chapter 3 shows how riboflavin tetraacetate, a cheap vitamin B2 derivative, is an appropriate metal-free photocatalyst in the aerobic photooxidation of xanthenes, thioxanthenes and dihydroacridines under visible light irradiation. / This research work has been possible thanks to funding from the Spanish Ministerio de Economía y Competitividad (PGC2018-096616-B-100, CTQ201788171-P), the Generalitat Valenciana (AICO 2021/013) and the University of Alicante (VIGROB-173). The author wishes to express his gratitude to the Institute of Organic Synthesis for a research contract (I-PI/21-20) and to the University of Alicante-Banco Santander consortium for a grant to spend a three-months research period in the Chemistry Interdisciplinary Project research center (ChIP) of the University of Camerino (Italy) under the supervision of Dr. Matteo Tiecco.

Visible-light communication (VLC) has several advantages over the commonly used radio frequency (RF) spectrum, including high bandwidth and low crosstalk. These features have become of more significance, especially as the proliferation of wireless devices increases and causes spectrum crowding. The white light in VLC systems is typically obtained from blue/violet light-emitting diodes (LEDs) and phosphors partially converting blue light into longer wavelength colors spanning the visible-light band. One phosphor that is frequently used is cerium-doped yttrium aluminum garnet (YAG). However, YAG suffers from a low color-rendering index (CRI) and high correlated color temperature (CCT). Lead halide perovskites provide an alternative to YAG and have been extensively utilized for optoelectronic devices owing to their tunable bandgap and high photoluminescence quantum yield (PLQY). However, their drawbacks, e.g., lead toxicity and instability, hinder their widespread application. Herein, in order to take advantage of a high-performance lead-free tin-based halide perovskite phosphor that has a high absolute PLQY of near unity and a wide spectral emission ranging from 500 to 700 nm, we fabricated ultraviolet (UV) micro light-emitting diodes (micro-LEDs) with a peak wavelength at 365 nm to match the peak of the photoluminescence excitation (PLE) spectra of the material to obtain strong yellow-spectrum emission. Together with a blue LED, white light was obtained with a CRI of 84.9 and 4115-K CCT. Despite the long PL lifetime of the perovskite material, which is in the order of μs, a net data rate of 1.5 Mb/s was achieved using orthogonal frequency-division multiplexing (OFDM) with adaptive bit and power loading to take advantage of the exceptionally high PLQY of the phosphor to improve the data throughput of the VLC system using higher modulation orders. Furthermore, through improvements to the nanostructure of lead-free tin-based halide perovskite phosphor and the use of excitation sources with a higher power, the data rate is expected to be even higher. The lead-free nature of this material, along with its wide spectrum and high conversion efficiency, makes it a promising alternative to conventional toxic perovskite-based phosphors. As the first demonstration of VLC links using lead-free perovskite, this study paves the way for safer, more sustainable VLC systems.

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