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ABSTRACT: Thermo-electrochemical cells (TECs) are a new kind of energy conversion device that can convert thermal energy into electricity. TECs can be integrated with supercapacitors (SCs) to store the generated electricity. TECs consist of two major components namely electrodes and electrolyte. The selection of appropriate electrode materials with rational nanostructured design should improve the thermoelectrochemical performance of the TECs. In this study, bilayer of nickel cobalt selenide nanowires was successfully grown on activated carbon cloth (NCS/ACC) via one step hydrothermal method and its electrochemical performance was evaluated and compared with nickel selenide (NS/ACC) and cobalt selenide on activated carbon cloth (CS/ACC). NCS/ACC exhibited the best electrochemical performance compared to other electrodes, leading to its further investigation in an asymmetric supercapacitor (ASC) configuration with activated carbon (AC) as the cathode. The NCS/ACC ASC demonstrated superior rate capability with 85% capacitive retention after 10,000 cycles, along with a high specific energy (28 Wh kg-1) and specific power (646 W kg-1). Subsequently, the NCS/ACC electrode was employed in a thermo-electrochemical cell (TEC) for heat to electricity conversion, revealing a Seebeck coefficient of -2 mV/K with high reversibility. Thereby, NCS/ACC electrode can be a suitable candidate for bi-functional applications, showcasing its efficacy in both supercapacitors and heat to electricity conversion technologies. KEYWORDS: Heat to electricity conversion; Supercapacitors; Electrodes; Metal selenide; Thermo-Electrochemical Cell. TRANSLATE is a €3.4 million EU-funded research project that aims to develop a new nanofluidic platform technology to effectively convert waste heat to electricity. This technology has the potential to improve the energy efficiency of many devices and systems, and provide a radically new zero-emission power source. The TRANSLATE project has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement number 964251, for the action of 'The Recycling of waste heat through the Application of Nanofluidic ChannelS: Advances in the Conversion of Thermal to Electrical energy'. More information can be be found on the TRANSLATE project website: https://translate-energy.eu/

A thermal diluted acid pretreatment using brewers spent grain (BSG) was optimised to improve enzymatic hydrolysis while minimising energy and chemical inputs. First, the use of hydrochloric or sulfuric acid for pretreatment was compared, using hydrochloric acid for the next steps. Three different dilute acid thermal pretreatment combinations were optimised in terms of acid concentration, temperature and time using a response surface methodology. Optimization was based on i) highest remaining protein content in the solid fraction (C1: 0.49% HCl; 87.7°C; 92 min), ii) highest liquid recovery (C2: 0.80% HCl; 121.0°C; 142 min), iii) lowest acid concentration applied to achieve largest protein and lowest remaining solid levels (C3: 0.10% HCl; 104.0°C; 70 min); and iv) a final condition based on the lowest water retention capacity when using HCl (C4: 0.20% HCl; 121.0°C; 20 min). The efficiency of enzymatic hydrolysis was evaluated, in the absence and presence of a large concentration of reducing carbohydrates, by centrifuging the slurry after acid pretreatment, recovering the solid fraction and resuspending it in fresh water. In C2, the enzyme (Depol 40L) was added directly to the entire slurry after pretreatment. For C1, C3, and C4 direct addition of enzyme to the whole slurry resulted in a higher release of carbohydrates during hydrolysis. Only in the case of C2 did the use of the resuspended solid result in a higher carbohydrate release. The overall carbohydrate recovery efficiency in the liquid fractions for C1, C2, C3 and C4 corresponded to 399.1 (±26.1), 535.8 (±28.7), 257.0 (±11.5), and 446.3 (±81.1) mg carbohydrate per Gram of BSG (dry weight), respectively. C1 and C4 were considered the optimal pretreatments as these combined a low acid concentration and energy input prior to enzymatic hydrolysis.

A central concern for large-scale sensor networks and the Internet of Things (IoT) has been battery capacity and how to recharge it. Recent advances have pointed to a technique capable of collecting energy from radio frequency (RF) waves called radio frequency-based energy harvesting (RF-EH) as a solution for low-power networks where cables or even changing the battery is unfeasible. The technical literature addresses energy harvesting techniques as an isolated block by dealing with energy harvesting apart from the other aspects inherent to the transmitter and receiver. Thus, the energy spent on data transmission cannot be used together to charge the battery and decode information. As an extension to them, we propose here a method that enables the information to be recovered from the battery charge by designing a sensor network operating with a semanticfunctional communication framework. Moreover, we propose an event-driven sensor network in which batteries are recharged by applying the technique RF-EH. In order to evaluate system performance, we investigated event signaling, event detection, empty battery, and signaling success rates, as well as the Age of Information (AoI). We discuss how the main parameters are related to the system behavior based on a representative case study, also discussing the battery charge behavior. Numerical results corroborate the effectiveness of the proposed system.

Accurate estimation of battery state of charge (SOC) is of great significance to improve battery management and service life. An unscented Kalman filter (UKF) method is used to increase the accuracy of SOC estimation in this paper. Firstly, a battery model that the parameters are identified by using the least squares algorithm is established, which is foundation of the two-order RC equivalent circuit model. Secondly, SOC is estimated by UKF. In order to validate the method, experiments have been carried out under different operating conditions for LiFePO4 batteries. The obtained results are compared with that of the extended Kalman filter. Finally, the comparison shows that the UKF method provides better accuracy in the battery SOC estimation. Its estimation error is less than 2%, which is better than EKF algorithm. An effective method is provided for state estimation for battery management system.

AbstractOver the last decade the progress in amorphous and nanocrystalline silicon (nc‐Si) for photovoltaic applications received significant interest in science and technology. Advances in the understanding of these novel materials and their properties are growing rapidly. In order to realise nc‐Si in the solar cell, a thicker intrinsic layer is required. Due to the indirect band gap in the crystallites, the absorption coefficients of nc‐Si are much lower. In this work we have used electrochemical etching techniques to produce silicon nanocrystals of the sizes 3–5 nm. Viable drop cast deposition of Si nanocrystals to increase the thickness without compromising the material properties was investigated by atomic force microscopy, optical microscopy, photoemission spectroscopy and optical absorption methods.

Abstract An electrical power generator for use with biomass cooking stoves has been developed. The design is intended for users in developing countries who lack regular access to electricity. Electricity is generated based on the thermoelectric effect. A bespoke heat collector captures heat from the combustion chamber of the cooking stove and transfers it to a single thermoelectric generator (TEG) module. To maintain a sufficiently high temperature difference across the TEG, heat is dissipated using a passive single phase liquid thermosiphon system. This cooling system eliminates the requirement for mechanical components such as fans or pumps, which are unreliable and draw significant electrical power. In a controlled laboratory setting, a maximum power of 5.8 W has been produced from a single TEG installed into a low cost ceramic cooking stove currently disseminated in large numbers in Malawi, Africa. The TEG power is controlled using a maximum power point tracking (MPPT) conditioning circuit with an estimated efficiency of ~70%. The circuit provides a stable 5 V output via a USB connector for charging mobile phones, lights, power banks and other devices. Experiments have shown that the device is capable of performing for extended periods without significant reduction in performance. The magnitude of the power generated by this passive cooling system is observed to be comparable to that delivered by similar TEG-stove systems driven by active cooling. An average power generation of over 4 W was achieved which, including circuit efficiency, provided ~10 W·h of useful electrical energy over a 4 h burning interval, which is sufficient for charging low powered electrical appliances. Five prototypes fitted with data measurement and acquisition were deployed to families in rural Malawi in order to evaluate real-life performance of the technology. Initial field-trial results have advocated the viability of the TEG-stove technology for charging low powered electronic devices typically used in developing countries such as Malawi.

The development of appropriate Electric Vehicle (EV) charging strategies has been identified as an effective way to accommodate an increasing number of EVs on Low Voltage (LV) distribution networks. Most research studies to date assume that future charging facilities will be capable of regulating charge rates continuously, while very few papers consider the more realistic situation of EV chargers that support only on-off charging functionality. In this work, a distributed charging algorithm applicable to on-off based charging systems is presented. Then, a modified version of the algorithm is proposed to incorporate real power system constraints. Both algorithms are compared with uncontrolled and centralized charging strategies from the perspective of both utilities and customers.

Rapid advancement in nanotechnology has led to the development of a myriad of useful nanomaterials that have novel characteristics resulting from their small size and engineered properties. In particular, two-dimensional (2D) materials have become a major focus in material science and chemistry research worldwide with substantial efforts centered on their synthesis, property characterization, and technological, and environmental applications. Environmental applications of these nanomaterials include but are not limited to adsorbents for wastewater and drinking water treatment, membranes for desalination, and coating materials for filtration. However, it is also important to address the environmental interactions and implications of these nanomaterials in order to develop strategies that minimize their environmental and public health risks. Towards this end, this review covers the most recent literature on the environmental implementations of emerging 2D nanomaterials, thereby providing insights into the future of this fast-evolving field including strategies for ensuring sustainable development of 2D nanomaterials.