37 research outputs found
Fortissat Science Alliance podcast: Calum McAndrew
No full textCalum McAndrew is a public engagement professional at the University of St Andrews. He took part in the Fortissat Science Alliance podcast recordings in March 2021.What is the Fortissat Science Alliance?The Fortissat Science Alliance is a Wellcome Trust & Children In Need "Curiosity" project. This scheme provided informal STEM learning opportunities for young people who attended the community centre Getting Better Together Shotts (GBT Shotts) between 2019 and 2023. Due to the COVID-19 pandemic, deliveries had to pivot online so the podcast was founded. These recordings were made via Zoom with warm-up STEM activities sent to every young person in advance, along with a profile page for each researcher, so that they were relaxed and able to ask excellent questions.Link to episode on Spotify.Depending on the broadcast date, podcast deliveries were co-sponsored by Glasgow Science Festival, EXPLORATHON 2021, or EXPLORATHON 2022/23.For the duration of the project, it was supported jointly by Children in Need and the Wellcome Trust. In 2021, EXPLORATHON episodes were supported by the European Commission [grant agreement ID 101036101]. In 2022-23, EXPLORATHON episodes were supported by the Engineering & Physical Sciences Research Council [grant number EP/X020894/1].Author contributions to contentCalum McAndrew was the guest featured on this episode. Rebecca Hay was the youth worker coordinating the young people who conducted the interviews as well as co-editing and broadcasting the recordings. Iain Hamilton co-edited the episodes. Kirsty Ross was the STEM consultant for the project and uploaded completed episodes to Figshare. </p
An optimised sorghum brewing process
Get PDFWhilst there is a tradition of indigenous opaque sorghum beer production in Africa, the manufacture of Western-style clarified lager beers from sorghum is a relatively recent development, originating in late 1980’s Nigeria. There remains substantial scope to optimise the process by tailoring the equipment and conditions utilised more specifically to the raw material. This was the context to the main objectives of this PhD project: towards an improved sorghum brewing process. Two principal approaches were employed: 1. The reduction of primary energy usage by developing novel modifications to the mashing and wort boiling unit operations and 2. Characterisation of the material properties of a substantial co-product of sorghum brewing, sorghum spent grains (SSG) as a pre-requisite to assessing its suitability for the production of value-added products and/or biofuel.
The gross chemical composition of five SSG samples sourced from commercial breweries in Africa were determined, with the sum of individual components accounting for 97.8 % material on a dry weight basis (d.b.; average value). The SSG samples contained relatively high amounts of protein (>38.0 %) as compared to values quoted for brewers’ spent grains. SSG samples were found to contain considerable amounts of residual starch (>4.55 %; d.b.), which suggested that the practice for milling and mashing with unmalted sorghum, in the breweries from which samples were sourced, could be further optimised.
By boiling at reduced temperature, required energy input is reduced as the latent heat of evaporation is not provided. In Chapter 3, the impact of reduced temperature boiling on the formation and stripping of key wort volatile compounds was evaluated at both industrial scale and pilot scales (10 hL). As compared to control boiling (3.5 % evaporation), the stripping efficiency of simmer boiling (0 % evaporation) was reduced for some volatiles, including: hexanal, linalool, and β-myrcene. One key lager flavour volatile, dimethyl sulphide (DMS), displayed similar patterns of stripping when comparing simmer and control boils.
In Chapter 4, we report the evaluation of a novel wort boiling technology in production-scale trials at a brewery in Ghana. The ‘PDX’ wort boiler utilises direct steam injection into wort and claims improved efficiency of heat transfer and volatile stripping. The present work demonstrated that steam injection technology could provide an approximate 50 % reduction in energy input during the boil, without significant deleterious effects on final product quality. Finished beverages produced using steam injection technology were determined to be within brand specifications by a trained sensory panel.
Chapters 5 and 6 report investigations aimed at reducing the energy input when mashing with unmalted sorghum and developing knowledge of how the structure and composition of different sorghum cultivars interacts with the mashing conditions employed. Designed experimentation was used to investigate the impact of mash conditions on a novel low-temperature mashing system and a high-temperature enzyme mashing system. The reduced energy, low-temperature system was comparable to the high-temperature system in terms of extract and FAN yield, when mashing with unmalted Sorghum bicolor cv. Fara Fara. Furthermore, both enzyme systems were able to produce acceptable wort using agricultural sorghum varieties, providing that the starch properties were similar to brewing cultivars in terms of their pasting characteristics and grain hardness. Poor mashing properties were associated with cultivars displaying increased physical interaction of endosperm protein with starch, resulting in reduced starch swelling during mashing
An optimised sorghum brewing process
Get PDFWhilst there is a tradition of indigenous opaque sorghum beer production in Africa, the manufacture of Western-style clarified lager beers from sorghum is a relatively recent development, originating in late 1980’s Nigeria. There remains substantial scope to optimise the process by tailoring the equipment and conditions utilised more specifically to the raw material. This was the context to the main objectives of this PhD project: towards an improved sorghum brewing process. Two principal approaches were employed: 1. The reduction of primary energy usage by developing novel modifications to the mashing and wort boiling unit operations and 2. Characterisation of the material properties of a substantial co-product of sorghum brewing, sorghum spent grains (SSG) as a pre-requisite to assessing its suitability for the production of value-added products and/or biofuel.
The gross chemical composition of five SSG samples sourced from commercial breweries in Africa were determined, with the sum of individual components accounting for 97.8 % material on a dry weight basis (d.b.; average value). The SSG samples contained relatively high amounts of protein (>38.0 %) as compared to values quoted for brewers’ spent grains. SSG samples were found to contain considerable amounts of residual starch (>4.55 %; d.b.), which suggested that the practice for milling and mashing with unmalted sorghum, in the breweries from which samples were sourced, could be further optimised.
By boiling at reduced temperature, required energy input is reduced as the latent heat of evaporation is not provided. In Chapter 3, the impact of reduced temperature boiling on the formation and stripping of key wort volatile compounds was evaluated at both industrial scale and pilot scales (10 hL). As compared to control boiling (3.5 % evaporation), the stripping efficiency of simmer boiling (0 % evaporation) was reduced for some volatiles, including: hexanal, linalool, and β-myrcene. One key lager flavour volatile, dimethyl sulphide (DMS), displayed similar patterns of stripping when comparing simmer and control boils.
In Chapter 4, we report the evaluation of a novel wort boiling technology in production-scale trials at a brewery in Ghana. The ‘PDX’ wort boiler utilises direct steam injection into wort and claims improved efficiency of heat transfer and volatile stripping. The present work demonstrated that steam injection technology could provide an approximate 50 % reduction in energy input during the boil, without significant deleterious effects on final product quality. Finished beverages produced using steam injection technology were determined to be within brand specifications by a trained sensory panel.
Chapters 5 and 6 report investigations aimed at reducing the energy input when mashing with unmalted sorghum and developing knowledge of how the structure and composition of different sorghum cultivars interacts with the mashing conditions employed. Designed experimentation was used to investigate the impact of mash conditions on a novel low-temperature mashing system and a high-temperature enzyme mashing system. The reduced energy, low-temperature system was comparable to the high-temperature system in terms of extract and FAN yield, when mashing with unmalted Sorghum bicolor cv. Fara Fara. Furthermore, both enzyme systems were able to produce acceptable wort using agricultural sorghum varieties, providing that the starch properties were similar to brewing cultivars in terms of their pasting characteristics and grain hardness. Poor mashing properties were associated with cultivars displaying increased physical interaction of endosperm protein with starch, resulting in reduced starch swelling during mashing
Multiple sets of solutions for harmonic elimination PWM bipolar waveforms: Analysis and experimental verification
Get PDFMultiple sets of solutions for the selective harmonic elimination pulse-width modulation method for inverter control exist. These sets present an independent solution to the same problem but further investigation reveals that certain sets may offer an improved overall harmonic performance. In this paper, a minimization method is discussed as a way to obtain these multiple sets of switching angles. A simple distortion harmonic factor that takes into account the first two most significant harmonics present in the generated waveform is considered in order to evaluate the performance of each set. The bipolar waveform is thoroughly analyzed and two cases are considered; single-phase patterns which eliminate all odd harmonics and three-phase counterparts which eliminate only the nontriplen odd harmonics from the line-to-neutral pattern but such harmonics are naturally eliminated from the line-to-line waveform. Experimental results support the theoretical considerations reported in the paper
The composition and ultrastructure of sorghum spent grains
No full textThe present study aimed to investigate the composition and structure of sorghum spent grains (SSG) as a pre‐requisite for evaluating potential applications of this brewery co‐product. SSG samples sourced from African breweries employing a grist with a proportion of a hammer milled‐unmalted sorghum (Sorghum vulgare cv. Fara Fara) were found to be heterogeneous materials containing remnants of intact grains, and with particles ranging in size from <0.1 to >2 mm. Samples contained a considerable amount of residual starch (4.6–10.0% d.b.), much higher than typically reported for barley‐derived spent grains. This probably arises from the use of grists high in unmalted sorghum, but indicates that improvements in brewing process efficiency could be achieved with improvements, for example, in milling and mashing protocols. The crude protein content of the SSG samples was unexpectedly high (38.0–41.2% d.b.), indicating that this material would have potential value as an animal feed or source of refined protein. Potential reasons for this higher than expected residual protein content are discussed. The remainder of SSG gross composition (mean of five samples) was cellulose (11.4% d.b.), hemicellulose (17.3% d.b.), lipid (8.5% d.b.), lignin (9.4% d.b.) and ash (4.46% d.b.), with a total mass recovery of close to 98% represented by all analysed components
Nixon's “full-speech”: imaginary and symbolic registers of communication
No full textCommunicative interchanges play a foundational role in establishing the social. This being said, communicative behaviour can also lead to stalemates and conflict in which demands of recognition outweigh the prospect of hearing or saying anything beyond what is thought to be known. This paper foregrounds a dimension of communication often neglected by approaches prioritizing mass communications and new media technologies, namely the psychical and inter-subjective aspects of communicative exchange. More directly, this paper introduces and develops a Lacanian psychoanalytic theory of two interlinked registers of communicative behaviour. The first of these is the imaginary: the domain of one-to-one inter-subjectivity and behaviour that serves the ego and functions to consolidate the images subjects use to substantiate themselves. The second - far more disturbing and unpredictable - is the symbolic. It links the subject to a trans-subjective order of truth, it provides them with a set of socio-symbolic co-ordinates, and it ties them into a variety of roles and social contracts. In an elaboration of these two registers, illustrated by brief reference to Nixon’s admission of guilt in his interviews with David Frost, I pay particular attention to both the potentially transformative symbolic aspect of communicative behaviours and the ever-present prospect that such relations will ossify into imaginary impasses of mis-knowing (méconnaissance) and aggressive rivalry
Mashing with unmalted sorghum using a novel low temperature enzyme system: impacts of sorghum grain composition and microstructure
Get PDFBrewing lager beers from unmalted sorghum traditionally requires the use of high temperature mashing and exogenous enzymes to ensure adequate starch conversion. Here, a novel low-temperature mashing system is compared to a more traditional mash in terms of the wort quality produced (laboratory scale) from five unmalted sorghums (2 brewing and 3 non-brewing varieties). The low temperature mash generated worts of comparable quality to those resulting from a traditional energy intensive mash protocol. Furthermore, its performance was less dependent on sorghum raw material quality, such that it may facilitate the use of what were previously considered non-brewing varieties. Whilst brewing sorghums were of lower protein content, protein per se did not correlate with mashing performance. Rather, it was the way in which protein was structured (particularly the strength of protein starch interactions) which most influenced brewing performance. RVA profile was the easiest way of identifying this characteristic as potentially problematic
Fault-tolerant operation of single-phase SR generators
Get PDFThis paper studies fault-tolerant operation of multipole single-phase switched reluctance generators (SRGs), in particular, an 8/8-pole switched reluctance machine. The multipole single-phase SRG system is advantageous for reduced cost and higher efficiency compared to polyphase equivalents. However, using the classical phase-leg topology, a phase fault may prevent generating operation completely, since redundancy in the number of phases does not exist like polyphase systems. A new power converter topology which connects two coil banks in parallel is proposed for higher fault tolerance with minimum additional cost. Faulty coils can be disconnected with the proposed converter and the SRG can continue generating operation after coil faults with reduced output power. Output power per coil current under faults is studied. Open- and short-circuit coils are studied through linear analysis, finite-element analysis and static torque measurement. Generated currents under faults with the proposed converter are measured. The capability of the system to disconnect faulty coils dynamically is also shown
The association between life course socioeconomic position and life satisfaction in different welfare states:European comparative study of individuals in early old age
Get PDFBACKGROUND: whether socioeconomic position over the life course influences the wellbeing of older people similarly in different societies is not known.OBJECTIVE: to investigate the magnitude of socioeconomic inequalities in life satisfaction among individuals in early old age and the influence of the welfare state regime on the associations. Design: comparative study using data from Wave 2 and SHARELIFE, the retrospective Wave of the Survey of Health, Ageing, and Retirement in Europe (SHARE), collected during 2006-07 and 2008-09, respectively.SETTING: thirteen European countries representing four welfare regimes (Southern, Scandinavian, Post-communist and Bismarckian).SUBJECTS: a total of 17,697 individuals aged 50-75 years.METHODS: slope indices of inequality (SIIs) were calculated for the association between life course socioeconomic position (measured by the number of books in childhood, education level and current wealth) and life satisfaction. Single level linear regression models stratified by welfare regime and multilevel regression models, containing interaction terms between socioeconomic position and welfare regime type, were calculated.RESULTS: socioeconomic inequalities in life satisfaction were present in all welfare regimes. Educational inequalities in life satisfaction were narrowest in Scandinavian and Bismarckian regimes among both genders. Post-communist and Southern countries experienced both lower life satisfaction and larger socioeconomic inequalities in life satisfaction, using most measures of socioeconomic position. Current wealth was associated with large inequalities in life satisfaction across all regimes.CONCLUSIONS: Scandinavian and Bismarckian countries exhibited narrower socioeconomic inequalities in life satisfaction. This suggests that more generous welfare states help to produce a more equitable distribution of wellbeing among older people.</p
Author Correction: Considerations in the search for epistasis
No full textBalvert M, Cooper-Knock J, Stamp J, et al. Author Correction: Considerations in the search for epistasis. Genome Biology . 2025;26(1): 12
