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Abstract Economically harvesting energy from a microbial fuel cell (MFC), increasing its electrical power production, and developing its role as a practical energy supply, needs a low-cost and high-performance design of the MFC compartments. According to this strategy, a novel monolithic membrane electrode assembly (MEA) was fabricated and evaluated as an air–cathode in a single-chamber MFC (SCMFC). The MEA was made of bacterial cellulose (BC), conductive multi-walled carbon nanotubes (CNT), and nano-zycosil (NZ). BC, as a nano-celluloses with oxygen barrier property, can maintain anaerobic conditions for the anode compartment. Binder-less CNT coating on BC avoids costly binders such as poly-tetra fluoro ethylene (PTFE) and Nafion and decreases the MEA charge transfer resistance. NZ, as a very cheap modifier, not only prevents the anolyte leakage but also provides more MEA’s active sites for the oxygen reduction reaction (ORR). The electrochemical performance of the MEA was compared to a PTFE- based gas diffusion electrode (GDE) in the SCMFC. The MEA cell provided a pulse power density of 1790 mW/m2, roughly twice as high as the pulse power density of GDE (920 mW/m2). SCMFC’s internal resistance decreased from 1.84 KΩ (with GDE) to 0.8 KΩ (with MEA). Also, the cell’s columbic efficiency increased from 4.2% (with GDE) to11.7% (with MEA). Additionally, the capacitance of the MEA (65 mF) was much higher than the value for GDE (0.73 mF). Thus, the MEA compared to the GDE showed higher performance in the SCMFC for electricity generation and wastewater treatment at a lower cost.

Abstractπ‐Conjugated polyelectrolytes (CPEs) have been studied as interlayers on top of a separate hole transport layer (HTL) to improve the wetting, interfacial defect passivation, and crystal growth of perovskites. However, very few CPE‐based HTLs have been reported without rational molecular design as ideal HTLs for perovskite solar cells (PeSCs). In this study, the authors synthesize a triphenylamine‐based anionic CPE (TPAFS‐TMA) as an HTL for p‐i‐n‐type PeSCs. TPAFS‐TMA has appropriate frontier molecular orbital (FMO) levels similar to those of the commonly used poly(bis(4‐phenyl)‐2,4,6‐trimethylphenylamine) (PTAA) HTL. The ionic and semiconducting TPAFS‐TMA shows high compatibility, high transmittance, appropriate FMO energy levels for hole extraction and electron blocking, as well as defect passivating properties, which are confirmed using various optical and electrical analyses. Thus, the PeSC with the TPAFS‐TMA HTL exhibits the best power conversion efficiency (PCE) of 20.86%, which is better than that of the PTAA‐based device (PCE of 19.97%). In addition, it exhibits negligible device‐to‐device variations in its photovoltaic performance, contrary to the device with PTAA. Finally, a large‐area PeSC (1 cm2) and mini‐module (3 cm2), showing PCEs of 19.46% and 18.41%, respectively, are successfully fabricated. The newly synthesized TPAFS‐TMA may suggest its great potential as an HTL for large‐area PeSCs.

Abstract Background Parabolic Trough Solar Collector (PTSC) is one of the most popular and an effective device that converts solar radiation into a heat or useful energy. However, it suffers from high temperature gradient and low thermal efficiency. The solution for this problem is to use new advanced coolants (hybrid nanofluids) in order to enhance PTSC's thermal efficiency. Methods A numerical analysis on the thermo-hydraulic performance of a PTSC receiver's tube equipped with conical turbulators is presented. The Navier-Stokes equations are solved using Finite Volume Method (FVM) coupled with Monte Carlo Ray Tracing (MCRT) method. The flow and thermal characteristics as well as entropy generation of the PTSC's receiver tube are investigated for three hybrid nanofluids (Ag-SWCNT, Ag-MWCNT, and Ag-MgO) having a mixing ratio of (50:50) dispersed in Syltherm oil 800, Reynolds number (5000 to 100,000) and fluid inlet temperatures (400 to 650 K). Significant findings The conical turbulators effectively augmented the thermal performance by 233.4% utilising Ag-SWCNT/Syltherm oil instead of pure Syltherm oil. The performance evaluation criterion is found to be in the range of 0.9–1.82. The thermal and exergetic efficiencies increased by 11.5% and 18.2%, respectively. The maximum decrement in the entropy generation rate and entropy generation ratio are 42.7% and 33.7%.

The fast decay in PEM fuel cells of a highly active, high performance, but unstable Fe/N/C catalyst like our NC_Ar + NH3 follows a chemical, not an electrochemical, demetallation mechanism for its ORR active FeN4 sites in the catalyst micropores.

Abstract A new conical-cylindrical top-discharge blow tank is designed, by introducing the pulsed gas to facilitate discharging, for stable transportation for kaolin powders. A series of experimental studies on pulsed gas characteristic parameters like pulsed gas flow rate Qpulsed (5 m3/h ≤ Qpulsed ≤ 25 m3/h), pulsed interval tpulsed (1 s ≤ tpulsed ≤ 5 s) and pulsed width τpulsed (50 ms ≤ τpulsed ≤ 250 ms) are conducted with the fluidized gas flow rate of 12 m3/h. The experiments mainly test the powder mass flow rate and solid-gas ratio in the conveying process. The results indicate that the mass flow rate and solid-gas ratio range 12.6–278.04 kg/h and 0.9–19.56 kg/m3, respectively. With the increase of the pulsed gas flow rate, the mass flow rate and solid gas ratio first increase and then decrease. When the ratio of fluidized gas flow rate to pulsed gas flow rate is within 0.8–1.2, its conveying capacity reaches the maximum. Meanwhile, the increase in the pulsed interval leads to the decrease of the mass flow rate and solid-gas ratio. Moreover, the increase in the pulsed width leads to the initial increase and then the stabilization of the mass flow rate and solid gas ratio. When the pulsed width is 50 ms, the improvement of discharge would small. Conversely, increasing the pulsed width can increase the discharge, and stabilize subsequently until over 200 ms. Besides, moisture content is one of the important factors affecting kaolin powders discharge. When the moisture content is 0.83%, the pulsed gas does not improve the discharge significantly. Meanwhile, pressure distribution at different locations in the tank is also measured. The results reveal that the introduction of pulsed gas changes the pressure distribution in the tank. A pressure zone is formed on the upper part of the tank, which promotes the powder discharge.

Much of New South Wales and southern Queensland suffered from extreme drought from 2017 to 2019. This study models drought and bushfires impacts using VU‐TERM, a multi‐regional, dynamic CGE model. Prolonged drought pushed national real GDP to 0.7 per cent or more below base in 2018–2019 and 2019–2020. NSW’s real GDP fell relative to forecast by 1.1 per cent or $6.9 billion in 2018–2019 and 1.6 per cent or $10.2 billion in 2019–2020. These impacts reflect a severe diminution of farm output, given that agriculture accounts for around 1.6 per cent of NSW’s income. Bushfires exacerbated 2019–2020 losses. We assume that there is a full recovery in seasonal conditions in 2020. However, prolonged drought and bushfire destruction deplete farm capital through depressed investment and diminished herd numbers. Consequently, the income earning capacity of farms in recovery remains below that of a no drought base. The net present value of the national welfare loss is $63 billion, split between $53 billion in losses from drought and $10 billion from bushfires. The latter excludes any valuation of human lives lost, flora, fauna or forestry destruction. In the longer term, adaptation and policy responses will need to reflect the expectation of increased frequency of adverse climatic events.

AbstractCellulose and lignin nanoparticles are high‐value‐added products obtained from lignocellulosic biomasses through several steps of cellulose purification and lignin extraction. These steps drastically reduce the potential feedstock revenue when carried out as stand‐alone methodologies. To increase biomass yields, we describe here a strategy to design a biorefinery focused on producing cellulose and lignin nanoparticles as main products, but also aim to recover and benefit from other biomass components using only water‐based processes. Sequential pressurized liquid extractions and diluted acid and alkaline treatments were carried out to fractionate elephant grass biomass, yielding (for every 100 g of biomass): 30 g of cellulose pulp (converted to 9 g of cellulose nanocrystals and 9 g of cellulose nanofibers); 10 g of lignin (used to produce 8.5 g of stable colloidal lignin nanoparticles by probe‐sonication in water); 7.5 g of extractives (e.g. sterols and phenolics) and 23 g of xylose (converted to 4.1 g of furfural). Alternatively, to allow for the flexible use of the cellulose fraction in the proposed biorefinery, 22 g of glucose could be produced by enzymatic hydrolysis. The results demonstrate that water‐based processes are suitable for a holistic use of biomass, providing a comprehensive set of high‐value‐added co‐products that are renewable and cost‐effective chemical, cosmetic, food, polymer and pharmaceutical solutions.

Abstract This work presents a numerical study on the performance of a stand-alone adsorption cooling system based on the silica gel/water couple driven by hybrid photovoltaic/thermal (PVT) collectors. This system is intended for the conservation of perishable agricultural products which require air-conditioned premises to preserve them. The weather conditions are those of North Africa (Algiers). Considering the above, this paper aims at analyzing the PVT-Adsorption system with energy storage to guarantee a stabilized production and increase the solar coverage. trnsys was used to simulate the system taking into account hourly series of irradiation and ambient temperature covering one year. The performance study reveals that the DualSun PVT hybrid collectors used provide optimal annual production and that the adsorption cooling system offers more reliable production during summer. The temperature difference between the inside and outside of the cooled enclosure balances supply and demand. The loss analysis of the storage device indicates that losses depend, on the one hand, on the interior/exterior temperature difference of the storage tank with more significant values during the summer season. On the other hand, the losses also depend on the volume of the storage tank which was optimized in order to limit the heat exchange with the surroundings.