16 research outputs found

    Conceptual Framework for Designing Virtual Field Trip Games

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    This thesis aimed to provide designing models to explore an alternative solution for a field trip when it becomes impossible for several reasons such as the limitation of cost and time. Virtual field trip games are relatively new means to create virtual field trips in game environments through adding game aspects to learning aspects to enhance the learning experience. The simple combining of game and learning aspects will not guarantee the desired effect of virtual field trips. Theoretical and logical connections should be established to form interweave between both aspects. This thesis proposes a designing framework by establishing three links between game design aspects and learning aspects. The three links are constructed by modelling: the experiential learning theory (ELT), the gameplay, and the game world. ELT modelling quantifies the theory into the internal economy mechanic and balances the levels of game task difficulty with the player’s ability through game machinations, game modelling links the learning process to gameplay, and world modelling connects field environment to game environment. The internal economy mechanic and its components (resources, internal mechanic, feedback loop), formulating equations to define generic player’s interactions and identify indicators to capture evidence of achievements via a mathematical (evaluation) model. The game modelling includes skill models to design two important high-order skills (decision-making and teamwork) and connects them to the evaluation model. The game world is modelled through defining its variables and relationships’ rules to connect both environments (game and field) expanding the evaluation model. The framework is supported by essential learning theories (ELT, task-based learning, some aspects of social learning) and pedagogical aspects (assessment, feedback, field-based structure, high-order skills) and connected to the key game elements (interaction, multimodal presentation, control of choice…etc) of field-based learning along with suitable game mechanics. The two research studies that were conducted as part of this thesis found that the designing framework is useful, usable, and provides connections between learning and game aspects and the designed VFTG based on the framework improved learning performance along with providing motivation and presence. This suggests the effectiveness of the framework

    Synthesis and characterization of new flavin systems with biomimetic and photovoltaic applications

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    This thesis describes the incorporation of a flavin unit into a range of systems spanning photovoltaics and biomimetic self-assembly. The flavin unit is better known as a cofactor in a range of enzymes. However, the unique physical and self-assembly properties were exploited in this research programme to develop new systems with photovoltaic and biomimetic self-assembly applications. In Chapter 1 a general introduction relating to flavins and photovoltaics is provided. In Chapter 2, the aim was to explore the effect of the addition of fullerene to a range of acceptors in the expectation of forming new acceptor materials with a wide range of LUMO energies. In Chapter 3, the aim was to investigate the effect of coupling a flavin unit to a naphthalenediimides (NDI) unit in the expectation of forming hybrid materials for solar energy conversion. Chapter 4 describes the formation of conjugated polymers featuring a flavin moiety, in the expectation that these materials will have photovoltaic properties. Chapter 5 describes the synthesis of push-pull flavin systems with pH dependent visisble light absorption characteristics. Finally Chapter 6 describes the synthesis of water soluble ammonium salts to furnish new micelle based systems with hydrogen bonding recognition properties

    Synthesis and Characterization of Naphthalenediimide-Functionalized Flavin Derivatives

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    Two acceptor–acceptor dyads have been synthesized featuring a flavin moiety and a naphthalenediimide (NDI) unit. The NDI unit is linked to the flavin through a short spacer group via either the N(3) or N(10) positions of the flavin. We have investigated the UV-Vis and redox properties of these multi-electron accepting systems which indicate that these materials display the collective properties of their component systems. Fluorescence spectroscopy measurements have revealed that their emission properties are dominated by the flavin unit

    Correction: Zainalabdeen, N., et al., Synthesis and Characterization of Naphthalenediimide-Functionalized Flavin Derivatives. Int. J. Mol. Sci. 2013, 14, 7468–7479.

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    Note: In lieu of an abstract, this is an excerpt from the first page. In the original version of the manuscript [1] some of the analytical data for compounds 1 and 2 were incorrect. The correct NMR data are presented below. The authors apologize for any inconvenience this may have caused to the readers of this journal. Compound 1: 1H NMR (500 MHz, DMSO-d6) δ 11.64 (s, 1H), 8.73 (s, 4H), 8.57 (d, J = 1.4 Hz, 1H), 8.16 (dd, J = 8.9, 1.4 Hz, 1H), 7.81 (d, J = 8.5 Hz, 2H), 7.64 (d, J = 8.5 Hz, 2H), 6.99 (d, J = 8.9 Hz, 1H), 4.08 (t, J = 7.0 Hz, 2H), 3.28 (m, 2H), 1.69 (quin, J = 7.0 Hz, 2H), 1.33 (m, 8H), 0.86 (t, J = 6.8 Hz, 3H). 13C NMR (125 MHz, DMSO-d6) δ 162.6 (2xC = 0), 162.3 (2xC = 0), 158.9, 155.1, 151.9, 140.8, 136.6, 136.1, 135.2, 133.7, 131.1 (2xC), 130.5 (4xC), 130.3 (q, J = 4 Hz), 128.6 (q, J = 4 Hz), 128.4 (2xC), 126.6, 126.5 (2xC), 126.4 (q, J = 31 Hz), 126.3 (2xC), 126.2, 123.2 (q, J = 271 Hz), 117.8, 39.9, 30.9, 28.5, 28.3, 27.1, 26.3, 21.9, 13.7. Compound 2: 1H NMR (500 MHz, CDCl3) δ 8.77 (s, 4H), 8.58 (d, J = 1.4 Hz, 1H), 8.03 (dd, J = 9.1, 1.4 Hz, 1H), 7.87 (d, J = 8.4 Hz, 2H), 7.76 (d, J = 9.1 Hz, 1H), 7.27 (d, J = 8.4 Hz, 2H), 5.37 (s, 2H), 4.61 (br s, 2H), 4.19 (t, 2H), 2.47 (sept, J = 6.7 Hz, 1H), 1.74 (m, 2H), 1.47–1.23 (m, 10H), 1.07 (d, J = 6.7 Hz, 6H), 0.87 (t, J = 6.9 Hz, 3H). 13C NMR (125 MHz, CDCl3) δ 163.1 (2xC = O), 162.9 (2xC = O), 159.0, 155.0, 149.9, 138.9, 137.5, 135.2, 134.9, 134.3, 131.7 (2xC), 131.5 (2xC), 131.2 (q, J = 4 Hz), 131.1 (4xC), 130.9 (q, J = 4 Hz), 128.6 (2xC), 127.1 (2xC), 127.0 (q, J = 28 Hz), 126.8 (2xC), 123.1 (q, J = 270 Hz), 116.9, 51.5, 44.9, 41.2, 31.9, 29.4, 29.3, 28.2, 27.6, 27.2, 22.8, 20.2 (2xC), 14.2

    Acceptability and feasibility of strategies to shield the vulnerable during the COVID-19 outbreak: a qualitative study in six Sudanese communities.

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    BACKGROUND: Shielding of high-risk groups from coronavirus disease (COVID-19) has been suggested as a realistic alternative to severe movement restrictions during the COVID-19 epidemic in low-income countries. The intervention entails the establishment of 'green zones' for high-risk persons to live in, either within their homes or in communal structures, in a safe and dignified manner, for extended periods of time during the epidemic. To our knowledge, this concept has not been tested or evaluated in resource-poor settings. This study aimed to explore the acceptability and feasibility of strategies to shield persons at higher risk of severe COVID-19 outcomes, during the COVID-19 epidemic in six communities in Sudan. METHODS: We purposively sampled participants from six communities, illustrative of urban, rural and forcibly-displaced settings. In-depth telephone interviews were held with 59 members of households with one or more members at higher risk of severe COVID-19 outcomes. Follow-up interviews were held with 30 community members after movement restrictions were eased across the country. All interviews were audio-recorded, transcribed verbatim, and analysed using a two-stage deductive and inductive thematic analysis. RESULTS: Most participants were aware that some people are at higher risk of severe COVID-19 outcomes but were unaware of the concept of shielding. Most participants found shielding acceptable and consistent with cultural inclinations to respect elders and protect the vulnerable. However, extra-household shielding arrangements were mostly seen as socially unacceptable. Participants reported feasibility concerns related to the reduced socialisation of shielded persons and loss of income for shielding families. The acceptability and feasibility of shielding strategies were reduced after movement restrictions were eased, as participants reported lower perception of risk in their communities and increased pressure to comply with social commitments outside the house. CONCLUSION: Shielding is generally acceptable in the study communities. Acceptability is influenced by feasibility, and by contextual changes in the epidemic and associated policy response. The promotion of shielding should capitalise on the cultural and moral sense of duty towards elders and vulnerable groups. Communities and households should be provided with practical guidance to implement feasible shielding options. Households must be socially, psychologically and financially supported to adopt and sustain shielding effectively

    Synthesis and Characterization of Naphthalenediimide-Functionalized Flavin Derivatives

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    Two acceptor–acceptor dyads have been synthesized featuring a flavin moiety and a naphthalenediimide (NDI) unit. The NDI unit is linked to the flavin through a short spacer group via either the N(3) or N(10) positions of the flavin. We have investigated the UV-Vis and redox properties of these multi-electron accepting systems which indicate that these materials display the collective properties of their component systems. Fluorescence spectroscopy measurements have revealed that their emission properties are dominated by the flavin unit

    Simultaneous hydrogen bonding and π-stacking interactions between flavin/porphyrin host–guest syst

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    In this Letter, we describe the formation of complexes between flavin and diamidopyridine functionalized porphyrin systems via hydrogen bonding and π-stacking interaction

    Hydrothermally stable acid-modified ZSM-22 zeolite for selective propylene production via steam-assisted catalytic cracking of n-hexane

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    To enhance the textural properties and the hydrothermal stability of porous catalysts, ZSM-22 zeolite samples were treated with different concentrations of HF aqueous solutions (0.7, 1.0 and 1.5 wt%). ZSM-22 samples that were treated with 0.7 and 1.0 wt% HF aqueous solutions showed a selective removal of aluminum atoms from TON framework. On the other hand, more concentrated HF (1.5 wt %) caused the leaching of silicon atom from the zeolites framework. The HF treated ZSM-22 samples showed smaller crystals size, better hydrothermal stability as reflected by intact textural properties as well as their mesoporosity. The modified samples also showed enhanced acidity with lower Bronsted acidity than the parent ZSM-22. ZSM-22 samples modified with low HF concentrations (0.7 and 1.0 wt%) showed better initial conversions in steam catalytic cracking (SCC) of hexane, which can be attributed to the enhancement in the acidity. However, deactivation rate was not enhanced after the HF treatment. The HF modified ZSM-22 samples showed more BTX selectivity which can be attributed to their larger external surface areas. The HF-treated samples lost more acidity, especially Bronsted acidity, after SCC reaction than the parents ZSM-22 zeolite

    Excited state charge redistribution and dynamics in the donor-Ï€-acceptor flavin derivative ABFL

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    Chromophores containing a donor-π-acceptor (D-π-A) motif have been shown to exhibit many interesting photophysical properties. The lowest electronic transition of a flavin derivative containing this motif, azobenzylflavin (ABFL), has previously been shown to be highly sensitive to solvent environment and hydrogen bonding ligands. To better understand this sensitivity, we have investigated the excited state charge redistribution and dynamics of ABFL in a low-dielectric, non-hydrogen bonding solvent by steady-state Stark and femtosecond optical transient absorption spectroscopies. The Stark measurements reveal the difference dipole moment, Δμ01, between the ground and first excited states to be 22.3 ± 0.9 D. The direction of Δμ01 in the molecular frame was assigned with the aid of TD-DFT and finite field calculations, verifying the hypothesis that electron density moves from the diethylaniline donor to the flavin acceptor in the excited state. The magnitude of the difference dipole moment was used to estimate the hyperpolarizability of ABFL, β0 = 720 × 10–30 esu. Subsequent excited state decay via charge recombination was shown to take place in a few picoseconds. The data was best fit to a kinetic model composed of a sub-picosecond internal conversion step from S2→S1, followed by a 5 ps decay to the ground state. A competing process involving formation of an additional long-lived state from S1 was also observed. Cyclic voltammetry shows one oxidation and two reduction waves and is completely reversible. This analysis lays the groundwork for developing new flavin dyads with the desired excited electronic state properties for applications such as nonlinear optical devices, molecular electronics applications, or dye-sensitized solar cells
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