51 research outputs found

    Regional variation in digital cushion pressure in the forefeet of horses and elephants

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    In this study, we seek to understand how the digital cushion morphologies evident in horse and elephant feet influence internal and external foot pressures. Our novel use of invasive blood pressure monitoring equipment, combined with a pressure pad and force plate, enabled measurements of (ex vivo) digital cushion pressure under increasing axial loads in seven horse and six elephant forefeet. Linear mixed effects models (LMER) revealed that internal digital cushion pressures increase under load and differ depending on region; elephant feet experienced higher magnitudes of medial digital cushion pressure, whereas horse feet experienced higher magnitudes of centralised digital cushion pressure. Direct comparison of digital cushion pressure magnitudes in both species, at equivalent loads relative to body weight, revealed that medial and lateral pressures increased more rapidly with load in elephant limbs. Within the same approximate region, internal pressures exceeded external, palmar pressures (on the sole of the foot), supporting previous Finite Element (FE) predictions. High pressures and large variations in pressure may relate to the development of foot pathology, which is a major concern in horses and elephants in a captive/domestic environment

    Modelling and Experimental Characterisation of a Water-to-Air Thermoelectric Heat Pump with Thermal Energy Storage

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    Nowadays, increasing the penetration of renewable heat technologies is an important approach to minimise global primary energy use and reduce CO2 emissions for a sustainable future. Thermoelectric heat pumps, which have some unique characteristics in comparison with conventional vapour compression heat pumps, can be integrated with solar thermal energy storage to form a promising renewable heat technology. However, currently, a reliable numerical model for TeHPs suitable for building energy simulation is lacking and the benefits achievable for a TeHP thanks to the integration with heat storage are unclear. To solve these issues, in this work, an experimental apparatus consisting of a water-to-air TeHP unit with a heat storage tank is modelled and tested for the first time, under the scenarios with thermal energy storage and without thermal energy storage, respectively. The results found that the developed numerical model could well predict the output performance of the TeHP unit, with deviations within 12%. Additionally, the output performance of the TeHP unit when combined with a heat storage tank is better than that of the TeHP unit without heat storage, in terms of the maximum temperature achieved in the testing box, the temperature response speed of the testing box, and the coefficient of performance (COP) of the TeHP unit. This work not only paves the way for the following building-integrated simulations of TeHP units, but also provides guidance for the design of the integrated systems that include TeHPs and thermal energy storage

    Effect of tilt angle on the performance of a thin-film photovoltaic system

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    Solar energy is among the cleanest and most sustainable ways to enhance electrical supply's resiliency and reliability for domestic and industrial use. A Photovoltaic (PV) system is the most effective way of capturing solar energy. Long-term warranty, low-cost maintenance, and vast resource availability, solar power generation has an advantage over other approaches. Thin-film technology PV cells are a new kind of solar cell that offers an efficient technique of generating electricity from sunlight. The thin-film PV technology (FFMAT-10, Renovagen, UK) used in this study can supply 0.9 to 1.6 kW of energy to the fast-fold energy hub. The hub’s system status and configuration display battery power input, battery’s state of charge, thin-film PV power and AC power output. Two fast-fold mats (with a surface area of 25.3 m2) were connected to the energy hub. Increasing energy demand coupled with frequent power outages, and inaccessibility of electricity in rural areas necessitates the usage of PV systems at their best performance level. The study objective, therefore, sought to assess the effect of tilt angle on the performance of the thin-film PV system. The study was conducted at Kimicha in Kirinyaga County Kenya, and Juja, Kenya at tilt angles between 0o to 30o. The results indicated that the mean peak PV power for Kimicha was 347.8±231.9 W at 5o and 517.7± 131.3 W at 15ofor Juja. The maximum solar radiation during the study period was 1086.4 ±211.4 W/m2 for Juja and 973.5±219.93 W/m2 for Kimicha. From the study, it was realized that an optimal tilt angle yields optimum solar radiation that translates to maximum power production. Even though the study was conducted in two different regions, it may be applied to any other geographical location. The outcome of the study aids in acquiring self-sustaining power in the most remote locations where electricity is scarce as well as improving energy security

    Investigation of a novel composite sorbent for improved sorption characteristic

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    Novel composite sorbents are developed. Strontium chloride (SrCl2) is selected whereas expanded natural graphite and nanoparticle i.e. carbon coated nickel are integrated as the additive with different densities for the better heat transfer and sorption performance. Thermal properties such as thermal diffusivity and conductivity are investigated by the laser flash method. The sorption performance is tested by the unit which is especially designed. It is indicated that the highest thermal diffusivity could reach 2.242 mm2\ub7s-1 when the density is 1000 kg\ub7m-3 and testing temperature is 20oC. For different testing temperature and density, the thermal diffusivity range from 1.3 mm2\ub7s-1 to 2.242 mm2\ub7s-1. Also worth noting that the highest thermal conductivity could reach 2.5 mm2\ub7s-1 for the environmental temperature. One paramount factor i.e. the global conversion rate of the novel composite SrCl2 is compared and analyzed under different working conditions. It can be found that the higher desorption temperature results in the faster variation of the global conversion rate. In addition, It takes about 15 minutes and 40 minutes to finish the reaction SrCl2 8-1 and 1-0 when the desorption temperature is 180oC and 130oC, respectively. For sorption process, it is indicated that the global conversion rate varies faster with the increase of the sorption temperature. When the global conversion is 0.7, it takes about 14 to 28 minutes when sorption temperature range from -5oC to 15oC

    Research and innovation identified to decarbonise the maritime sector

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    The maritime sector requires technically, environmentally, socially, and economically informed pathways to decarbonise and eliminate all emissions harmful to the environment and health. This is extremely challenging and complex, and a wide range of technologies and solutions are currently being explored. However, it is important to assess the state-of-the-art and identify further research and innovation required to accelerate decarbonisation. The UK National Clean Maritime Research Hub have identified key priority areas to drive this process, with particular focus on marine fuels, power and propulsion, vessel efficiency, port operations and infrastructure, digitalisation, finance, regulation, and policy

    Reciprocating Joule-cycle engine for domestic CHP systems

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    The reciprocating Joule-cycle engine operates on a recuperated gas-turbine cycle and is intended to provide high thermal efficiency in small sizes (1-10 kW). It is designed to achieve a higher efficiency than a comparable gas-turbine by using a reciprocating compressor and expander to provide very high compression and expansion efficiencies. Possible power plants for small combined heat-and-power systems currently include Stirling engines, internal-combustion engines, gas-turbines and fuel cells. The reciprocating Joule-cycle engine appears to have considerable advantages compared with other prime movers in terms of efficiency, emissions and multi-fuel capability. The present study estimates the performance of such an engine and is the first stage in a larger project that will in due course produce a demonstration engine.
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