491 research outputs found
Investigation of a Solar Assisted Heating System
Low emissivity transpired solar collectors (low-Δ TSCs) consist of metal solar absorber, collector plates, with a spectrally sensitive surface, perforated with holes. Ambient air is drawn through the holes and heated by convection from the solar collector plate, increasing the air temperature by up to 25 K. The heated air can be used for e.g. space heating or pre-heating hot water, in buildings. The performance of low-Δ TSCs combined with heat pumps in various configurations, to deliver heat to buildings, has been investigated using computational models and compared with conventional heating systems to determine the potential energy, carbon and cost savings available. The results showed that using low-Δ TSCs incorporated into a heat pump based ventilation air system produced annual savings in energy, CO2e and costs of up to 14%, compared to similar systems where the TSC was not used. The greatest savings were achieved when using an exhaust air heat pump. Recommendations for further development of this novel technology are also presented
Study of novel solar assisted heating system
The potential for energy, carbon dioxide equivalent (CO2e) and cost savings when using low emissivity (low-Δ) transpired solar collectors (TSCs), combined with heat pumps in a range of configurations, has been investigated using computer modelling. Low-Δ TSCs consist of metal solar collector plates with a spectrally sensitive surface, perforated with holes. Ambient air is drawn through the holes and heated by convection from the solar collector plate, increasing the air temperature by up to 25 K. The heated air can be used for e.g. space heating, or pre-heating water in buildings. The models developed have been used to compare the performance of low-Δ TSC/heat pump heating systems in small and large buildings, at a range of locations. The model results showed savings in energy, CO2e and costs of up to 16.4% when using low-Δ TSCs combined with an exhaust air heat pump compared with using the exhaust air heat pump alone. Practical application: If the UK is to meet its target of reaching net zero greenhouse gas emissions by 2050, it will be necessary to adopt low or zero carbon heating technologies. The novel low emissivity transpired solar collector device investigated can contribute to this. Its advantages include: (i) utilising solar radiation; (ii) readily integrated with existing heating systems e.g. heat pumps; (iii) significant energy, CO2e emissions and cost savings; (iv) low cost device; (v) minimal energy input i.e. one small fan; (vi) can be retrofitted to existing buildings; (vii) its benefits were applicable at all of the (wide range of) locations tested
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Sensitivity analysis of time-step in modeling river and aquifer interaction
Center for Water and the Environmen
The contribution of social work field education to work-integrated learning.
The International Journal of Work-Integrated Learning is an Open Access journal which means that all content is freely available without charge to the user or his/her institution. Users are allowed to read, download, copy, distribute, print, search, or link to the full texts of the articles, or use them for any other lawful purpose, without asking prior permission from the publisher or the author.fals
The postcranial anatomy and osteohistology of Terrestrisuchus gracilis (Archosauria, Crocodylomorpha) from the Late Triassic of Wales
The earliest crocodylomorphs, known as nonâcrocodyliform crocodylomorphs, first appeared during the Late Triassic. In contrast to extant crocodylians, which are all semiâaquatic, early crocodylomorphs represent terrestrial taxa with a fully erect posture and in most cases a small body size. Their gracile skeletons suggest an active mode of life, possibly similar to contemporaneous, bipedal theropod dinosaurs. Despite this remarkable body plan, the postcranial morphology of early crocodylomorphs has rarely been documented in detail, restricting our ability to infer aspects of their functional morphology and evolution. Here, we provide a detailed description of the postcranium of Terrestrisuchus gracilis, a smallâbodied crocodylomorph from the Late Triassic of PantâyâFfynnon Quarry (southern Wales, UK), including a description of long bone tissues based on histological thin sections. Almost all elements of the postcranial skeleton have been preserved. The skeleton of Terrestrisuchus gracilis is highly gracile, even for a nonâcrocodyliform crocodylomorph. Osteological correlates of the appendicular skeleton suggest that Terrestrisuchus gracilis had a digitigrade, quadrupedal posture. A quantitative analysis of limb robustness corroborates that Terrestrisuchus gracilis was a quadruped. Histological analysis suggests that all sampled specimens were skeletally immature and had fast growth at the time of death, as indicated by the lack of an external fundamental system and the predominance of fibrolamellar bone. The bone tissue is similar to that recently described for Saltoposuchus connectens and certain nonâcrocodylomorph pseudosuchians, but differs from Hesperosuchus agilis and crocodyliforms, in which parallelâfibred bone is more prevalent
The possible impact of precooling and community cooling hubs on reducing post-harvest losses in hibiscus farming: A case study from Uganda
This study addresses the significant post-harvest losses in hibiscus farming in Uganda's Central and Eastern regions, impacting the local economy and culture. Research involving 200 farmers shows losses of 10% to 50%, particularly during the wet season due to poor storage and drying facilities. To combat this, the study proposed a three-pronged approach: ensuring gentle handling during harvest, implementing precooling techniques at the farmgate, and establishing community cooling hubs. Precooling is crucial for maintaining post-harvest quality by rapidly reducing temperatures, while community cooling hubs would offer centralized cooling and storage, mitigating losses and opening new market opportunities. This comprehensive strategy also aims to enhance agricultural practices through training, capacity building, and community collaboration, promoting a resilient and thriving farming community
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Investigation of discrepancies in satellite rainfall estimates over Ethiopia
Tropical Applications of Meteorology Using Satellite and Ground-Based Observations (TAMSAT) rainfall estimates are used extensively across Africa for operational rainfall monitoring and food security applications; thus, regional evaluations of TAMSAT are essential to ensure its reliability. This study assesses the performance of TAMSAT rainfall estimates, along with the African Rainfall Climatology (ARC), version 2; the Tropical Rainfall Measuring Mission (TRMM) 3B42 product; and the Climate Prediction Center morphing technique (CMORPH), against a dense rain gauge network over a mountainous region of Ethiopia. Overall, TAMSAT exhibits good skill in detecting rainy events but underestimates rainfall amount, while ARC underestimates both rainfall amount and rainy event frequency. Meanwhile, TRMM consistently performs best in detecting rainy events and capturing the mean rainfall and seasonal variability, while CMORPH tends to overdetect rainy events. Moreover, the mean difference in daily rainfall between the products and rain gauges shows increasing underestimation with increasing elevation. However, the distribution in satelliteâgauge differences demon- strates that although 75% of retrievals underestimate rainfall, up to 25% overestimate rainfall over all eleva- tions. Case studies using high-resolution simulations suggest underestimation in the satellite algorithms is likely due to shallow convection with warm cloud-top temperatures in addition to beam-filling effects in microwave- based retrievals from localized convective cells. The overestimation by IR-based algorithms is attributed to nonraining cirrus with cold cloud-top temperatures. These results stress the importance of understanding re- gional precipitation systems causing uncertainties in satellite rainfall estimates with a view toward using this knowledge to improve rainfall algorithms
The impact of emotions on practicum learning
Nine mature aged, experienced practitioners enrolled to gain a BSW qualification in social work were interviewed regarding a course requirement to complete the first placement. At the time of interview no recognition of prior learning for previous experience in the field was made possible for these students. As educators we had experienced considerable hostility from students who believed they should be exempt from completing this course requirement. This paper reports on interviews with the nine students, where we consider how student sentiment about completing the practice learning component might impact upon their learning experience. As anticipated, some students expressed strong negative views about being on placement. However, others were much more positive about the experience. These mixed views prompted us to explore further the relationship between emotion and practice learning. The article begins with a review of the literature concerning mature student engagement with tertiary education, followed by an overview of theory and research related to the ways feelings and emotion influence learning. Using passages from the interviews, expressions of participant anxiety, anger and excitement about the practicum are discussed with the view to extending discourse about practicum learning to include consideration of emotional intelligence and investment.<br /
Responding to COVID-19 in social work field education in Australia, New Zealand and the United States
Author(s), Kathryn Hay, "Responding to COVID-19 in social work field education in Australia, New Zealand and the United States". International Social Work pp. 1-14. [2021] Copyright © The author/s. DOI: [10.1177/00208728211048934].
Published source must be acknowledged with citation.
Reuse is restricted to non-commercial and no derivative usesPublishe
Waste heat recovery from urban electrical cable tunnels
Electrical power distribution within cities is most often distributed through underground cables located just below the road surface. Due to steadily increasing electricity demands, many power suppliers are making large investments in housing these cables in underground tunnels. These urban cable tunnels often extend to many kilometres in length. Through the electrical loading of the cables a significant amount of heat is generated. Often this heat has to be removed through
ventilation in order to avoid overheating the cables and to provide safe conditions for access. As opposed to rejecting the heat to the atmosphere, this low grade energy could potentially be recovered, upgraded if necessary, and distributed to nearby heat users above ground. This paper
discusses possible heat recovery methods applicable for urban electricity distribution networks, i.e. transformers and cable tunnels. It also presents results from a modelling-based preliminary feasibility study which used cable tunnels in London as a case study
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