Photoconductivity of CdS-CdSe granular films: influence of microstructure

We study experimentally the photoconductivity of CdS-CdSe sintered granular films obtained by the screen printing method. We mostly focus on the dependences of photoconductivity on film's microstructure, which varies with changing heat-treatment conditions. The maximum photoconductivity is found for samples with compact packing of individual grains, which nevertheless are separated by gaps. Such a microstructure is typical for films heat-treated during an intermediate (optimal) time. In order to understand whether the dominant mechanism of charge transfer is identical with the one in monocrystals, we perform temperature measurements of photoresistance. Corresponding curves have the same peculiar nonmonotonic shape as in CdSe monocrystals, from which we conclude that the basic mechanism is also the same. It is suggested that the optimal heat-treatment time appears as a result of a competition between two mechanisms: improvement of film's connectivity and its oxidation. Photoresistance is also measured in vacuum and in helium atmosphere, which suppress oxygen and water absorption/chemisorption at intergrain boundaries. We demonstrate that this suppression increases photoconductivity, especially at high temperatures.Comment: 12 pages, 8 figures, final versio

Dovetails: personhood, citizenship, and craft between children and older adults

This paper presents Dovetails, an intergenerational co-creative participatory design project, and explored ways of working with recipients of care through Craft methods leveraging reciprocity to support wellbeing and Citizenship. Working alongside older adults from Beamish Museum’s wellbeing community and a children’s charity, researchers supported the two participating groups to design and make ambitious, novel artefacts for one another using woodwork. Each group learned new skills and sought to improve the lives of the other group’s members through making. We came to understand the artefacts created as material embodiments of care and we present transferable insight for future study design to encourage reciprocity through Craft. We contribute new nuanced understandings of Personhood and Citizenship in this context. Participants reported pride in their achievements, confounding expectations, raising ambitions, and reframing their understanding of their own wellbeing, for example in the context of dementia diagnosis. Dovetails bore meaningful benefits for individual participants and the groups themselves, beyond the timescale of our engagement, as they formed ongoing allegiances. We discuss framing design research through a ‘Craft Lens’, as a multi-faceted way to explore creative engagements, which enriched our understanding of making, and gift-giving to support Personhood through Social Citizenship

Small particle size lipid emulsions, satiety and energy intake in lean men

Lipid emulsions have been proposed to suppress hunger and food intake. Whilst there is no consensus on optimal structural properties or mechanism of action, small particle size (small-PS) stable emulsions may have greatest efficacy. Fabuless®, a commercial lipid emulsion reported in some studies to decrease energy intake (EI), is a small-PS, ‘hard’ fat emulsion comprising highly saturated palm oil base (PS, 82 nm). To determine whether small-PS dairy lipid emulsions can enhance satiety, firstly, we investigated 2 ‘soft’ fat dairy emulsions generated using dairy and soy emulsifying agents (PS, 114 nm and 121 nm) and a non-emulsified dairy control. Secondly, we investigated a small-PS palmolein based ‘hard’ fat emulsion (fractionated palm oil, PS, 104 nm) and non-emulsified control. This was a 6 arm, randomized, cross-over study in 18 lean men, with test lipids delivered in a breakfast meal: (i) Fabuless® emulsion (FEM); (ii) dairy emulsion with dairy emulsifier (DEDE); (iii) dairy emulsion with soy lecithin emulsifier (DESE); (iv) dairy control (DCON); (v) palmolein emulsion with dairy emulsifier (PEDE); (vi) palmolein control (PCON). Participants rated postprandial appetite sensations using visual analogue scales (VAS), and ad libitum energy intake (EI) was measured at a lunch meal 3.5 h later. Dairy lipid emulsions did not significantly alter satiety ratings or change EI relative to dairy control (DEDE, 4035 kJ; DESE, 3904 kJ; DCON, 3985 kJ; P > 0.05) nor did palm oil based emulsion relative to non-emulsified control (PEDE, 3902 kJ; PCON, 3973 kJ; P > 0.05). There was no evidence that small-PS dairy lipid emulsions or commercial Fabuless altered short-term appetite or food intake in lean adults