Quantitative and Qualitative Studies for Real Monitoring of Interfacial Molecular Water

2022 ◽  
Author(s):  
Moataz Mekawy ◽  
Hidenori Noguchi ◽  
Jin Kawakita
Keyword(s):  
Qualitative Studies ◽  
Molecular Water

Structure, Stability and Water Adsorption on Ultra-Thin TiO2 Supported on TiN

2019 ◽  
Author(s):  
Jose Julio Gutierrez Moreno ◽  
Marco Fronzi ◽  
Pierre Lovera ◽  
alan O'Riordan ◽  
Mike J Ford ◽  
...  
Keyword(s):  
Density Functional ◽  
Water Adsorption ◽  
Chemical Potential ◽  
Energy Gap ◽  
Molecular Water ◽  
Structure Stability ◽  
Ambient Conditions ◽  
Rutile Structure ◽  
The Stability ◽  
The One

<p></p><p>Interfacial metal-oxide systems with ultrathin oxide layers are of high interest for their use in catalysis. In this study, we present a density functional theory (DFT) investigation of the structure of ultrathin rutile layers (one and two TiO<sub>2</sub> layers) supported on TiN and the stability of water on these interfacial structures. The rutile layers are stabilized on the TiN surface through the formation of interfacial Ti–O bonds. Charge transfer from the TiN substrate leads to the formation of reduced Ti<sup>3+</sup> cations in TiO<sub>2.</sub> The structure of the one-layer oxide slab is strongly distorted at the interface, while the thicker TiO<sub>2</sub> layer preserves the rutile structure. The energy cost for the formation of a single O vacancy in the one-layer oxide slab is only 0.5 eV with respect to the ideal interface. For the two-layer oxide slab, the introduction of several vacancies in an already non-stoichiometric system becomes progressively more favourable, which indicates the stability of the highly non-stoichiometric interfaces. Isolated water molecules dissociate when adsorbed at the TiO<sub>2</sub> layers. At higher coverages the preference is for molecular water adsorption. Our ab initio thermodynamics calculations show the fully water covered stoichiometric models as the most stable structure at typical ambient conditions. Interfacial models with multiple vacancies are most stable at low (reducing) oxygen chemical potential values. A water monolayer adsorbs dissociatively on the highly distorted 2-layer TiO<sub>1.75</sub>-TiN interface, where the Ti<sup>3+</sup> states lying above the top of the valence band contribute to a significant reduction of the energy gap compared to the stoichiometric TiO<sub>2</sub>-TiN model. Our results provide a guide for the design of novel interfacial systems containing ultrathin TiO<sub>2</sub> with potential application as photocatalytic water splitting devices.</p><p></p>

scholarly journals A meta-ethnographic study of fathers’ experiences of caring for a child with a life-limiting illness

2020 ◽  
pp. 026921632097915
Author(s):  
Gianina-Ioana Postavaru ◽  
Helen Swaby ◽  
Rabbi Swaby
Keyword(s):  
English Language ◽  
Psychosocial Interventions ◽  
Healthcare Services ◽  
Ethnographic Study ◽  
Qualitative Studies ◽  
Future Research ◽  
Care Experience ◽  
Care Giving ◽  
Critical Appraisal Skills ◽  
Limiting Condition

Background: There is a growing body of qualitative studies examining parents’ experiences of caring for a child with a life-limiting condition, coinciding with recent evidence that indicates an increasing incidence of paediatric life-limiting conditions. However, research focusing on fathers’ needs remains sparse and is often diluted among a predominant ‘mother’s voice’, raising questions about whether practices in clinical settings meet fathers’ needs. Aim: To provide an in-depth assembly of the current state of knowledge around fathers’ experiences of caring for their children diagnosed with life-limiting conditions and understand the implications for healthcare services and policies. Design: A meta-ethnography was conducted to synthesise findings from existing qualitative studies exploring fathers’ experiences of caring. Data sources: Four electronic databases (PubMed, PsycINFO, CINAHL and Science Direct) were searched up until April 2020. Qualitative studies exploring fathers’ care experience and published in English language were included. The Critical Appraisal Skills Programme (CASP) checklist was employed for study quality appraisal. No temporal limits were used. Results: Sixty-three studies met the inclusion criteria. Thirty life-limiting conditions were included. Based on responses from 496 fathers, a conceptual model was developed which translates key experiences within the fathers’ caregiving journeys. The overarching concepts identified were: the paradox of support, challenges in the caring process, ‘nobody thinks of men’, impact on family life and the fall of the curtain: an irrevocably altered world. These and associated sub-concepts are discussed, with recommendations for future research and practice provided. Conclusion: The findings indicate the value of a family-oriented approach to develop psychosocial interventions and support channels for fathers, thus empowering them whilst reducing the care-giving burden on the family unit.

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