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Developing cost-effective and stable materials for the electrocatalysis of hydrogen evolution reaction (HER) remains challenging. In this study, efficient catalysts for HER were synthesized by integrating the cobalt and molybdenum oxides via electrodeposition, followed by subsequent sulfurization of the as-prepared oxides using chemical vapor deposition (CVD). This methodology allowed the incorporation of both cobalt and molybdenum components into the catalyst in a single step. The as-synthesized CoSx@MoSx/MoOx-based catalysts exhibited excellent hydrogen production performance in acidic media owing to the presence of Co-S and Mo-S bonds in the hybrid structure. Particularly, CoSx@MoSx/MoOx(90@360) and MoSx@CoOx(180@180) displayed the best HER performances with low overpotentials of 80 mV and 150 mV, respectively. The catalysts were highly stable, with their stability preserved for over 1000 cycles with marginal reduction in overall efficiency. Therefore, these findings suggest the potential of CoSx@MoSx/MoOx and MoSx@CoOx composites as ideal candidates for developing low-cost catalysts for electrochemical hydrogen production. [ABSTRACT FROM AUTHOR]

Integrating more active components into a catalyst material could facilitate the development of multifunctional electrocatalysts for energy conversion and storage applications. In this study, we developed a multifunctional electrocatalyst, namely, Pd alloyed with Co-Fe deposited on N-doped mesoporous carbon derived from tissue paper (Pd@Co-Fe/N-TDC). The synergism in Pd@Co-Fe/N-TDC, stemming from the interatomic alloy between Pd and Co-Fe, N-doped mesoporous carbon with defective surfaces, distribution of polyhedral Pd nanoparticles, and strong metal-support interfacial interaction, resulted in significantly high electrocatalytic performance for both oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). Pd@Co-Fe/N-TDC was found to be an efficient bifunctional oxygen electrocatalyst, and this was evidenced by a high onset potential (1.01 V) and kinetic current density (2.6 mA/cm2) for the ORR and by a low overpotential (296 mV) and a low Tafel slope value (38 mV/dec) for the OER, along with a small Δ E of 736 mV. The catalyst also exhibited high durability for both ORR and OER, even after 10000 and 5000 cycles, respectively. Theoretical assessment provides an insight into the synergism of active metal sites in Pd@Co-Fe/N-TDC, which showed its potential for use as a non-Pt electrocatalyst for energy applications. [ABSTRACT FROM AUTHOR]

Summary: In the pulp and paper industry, black liquor, which is a biomass resource, is burned to produce electricity. Black liquor is concentrated to 21 wt% water through an evaporator before being burned in a boiler. For the evaporator, a multiple‐effect evaporator (MEE) is mainly used, but it requires a large amount of energy and cost. Therefore, it is crucial to reduce energy and cost of evaporation process. Hence, this study suggested a novel process model that integrated mechanical vapor recompression (MVR) with MEE to increase the energy efficiency. The suggested MVR‐assisted evaporation process was composed of preheating and evaporation processes to effectively concentrate black liquor. In addition, it reduced the steam consumption of MEE by using MVR, which uses relatively inexpensive electric energy in the pre‐evaporation process. In the simulation results, the steam, electricity consumption, and the latent heat recovered from the secondary vapor of the suggested process were quantitatively analyzed to verify the energy efficiency. The results indicate that the proposed process increases substantial energy efficiency compared to the conventional process. Then, the appropriateness of the suggested process was evaluated by the techno‐economic analysis. The total annualized cost (TAC) is determined for both current and potential future economic benefits. TAC of the MVR‐assisted MEE configuration can be reduced by up to 77.54%. [ABSTRACT FROM AUTHOR]

Summary: Microfluidic fuel cell (MFC) stacking is a prerequisite to enhance its power output for practical applications. However, most MFC stacks reported in the present literature require external pumps to maintain the co‐laminar flow and complex fluidic management networks for homogeneous flow and reactant distributions. To address these issues, a novel paper‐based self‐pumping MFC stack with potassium formate as the fuel and hydrogen peroxide as the oxidant is proposed in this study. The capillary action is employed to achieve passive liquid flow. A vertical stack structure with the unit cells piled one above another compactly is adopted to reduce the volumetric costs. The experimental results show that the maximum power outputs of the two‐cell and three‐cell stack prototypes are 4.01 and 7.26 mW cm−2, outperforming the MFC unit by 5.81 and 10.52 times, respectively. The superior performance is attributed to its distinct vertical stacking structure, which brings the enhanced capillary flows in the paper wicks and reduced ohmic losses in comparison with the unit cell. Further, effects of the filter paper and reactant concentrations on the stack performance were examined, and mass transfer of the fuel and/or oxidant to the electrode/electrolyte interface was identified as the main limiting factor. A loose microstructure of the paper wick was found beneficial in enhancing the mass transfer. The potential applications of the MFC stack in a variety of portable electronics are broad. [ABSTRACT FROM AUTHOR]

Summary: A novel bioprocess design to convert paper mill sludge (PMS) to biofuels is proposed in this work. The design utilizes cellulosic fiber recovered from the PMS via optimized de‐ashing (HCl washing) step. This work specifically provided a technical and economic analysis of paper mill sludge conversion into biofuel production using a novel protocol. The protocol is based on scanning electron microscopy (SEM) analysis to assess the quality of the contained cellulose prior to further processing. The results are crucially important to determine the suitability of the PMS feedstock to produce biofuels. SEM analysis was employed as a preliminary screening tool to evaluate sludge digestibility and conversion. The SEM characterization technique established a direct relationship between the fiber morphology, presence of crystals salts and sugar yield after enzymatic hydrolysis. Substantial structural changes were observed before and after de‐ashing the sludge samples, leading to a correlation between the surface morphology and the washing step. The results suggested that de‐ashing changes the surface morphology and upon analysis, increased the sugar yield up to about 86% as opposed to 2.2% in sludge sample A as an example. The PMS conversion into biofuel was simulated using Aspen PLUS and compared to a similar process using corn stover as feedstock. The simulation results showed it is 20% cheaper to produce bioethanol from PMS compared to corn stover. The simulation revealed less energy demand by around 13 320 MJ/h compared to that when corn stover was used. [ABSTRACT FROM AUTHOR]

Summary: This work describes a two‐step method of in situ electrodeposition and following oxidation to prepare carbon paper (CP) modified with tin dioxide (SnO2) particle as bifunctional electrode for vanadium redox flow battery. Electrodeposition technique was employed to load metal tin particle on CP, which was subsequently oxidized to tin dioxide at high temperature. CPs modified by SnO2 with different content (CP/SnO2‐1, CP/SnO2‐2, and CP/SnO2‐3) were obtained by controlling electrodeposition time. CP/SnO2 presents an increase in electrochemical performance including faster charge and mass transfer compared with pristine CP. Among all samples, CP/SnO2‐2 with proper decorated SnO2 exhibits superior electrocatalytic performances for V3+/V2+ and VO2+/VO2+ reactions. Raised performances can be attributed to that SnO2 nanoparticles provide more active sites leading to rapid electrochemical kinetic of vanadium redox reactions. In addition, mass transfer can be accelerated due to the excellent hydrophilicity of SnO2. The cell using CP/SnO2‐2 as bifunctional electrode exhibits better stability and higher capacity retention during 50‐cycle charge‐discharge test. The cell for CP/SnO2‐2 shows higher energy and voltage efficiency, suggesting that introduction of SnO2 can decrease electrochemical polarization. At 150 mA cm−2, energy efficiency of the cell increases by 7.8% through using CP/SnO2‐2. [ABSTRACT FROM AUTHOR]

Summary The development of an efficient water electrolyser is essential for sustainable hydrogen production; however, its application remains limited by the insufficient performance of the electrode. Herein, we report a rapid, simple, and cost‐effective fabrication of an Ni‐Co‐S cathode for the hydrogen evolution reaction (HER), which is directly usable for an anion exchange membrane water electrolyser (AEMWE). The Ni‐Co‐S electrocatalysts are prepared on a carbon paper (CP) substrate by a one‐step electrodeposition method by controlling deposition parameters such as the deposition potential, time, and electrolyte composition. The optimized Ni‐Co‐S/CP electrode demonstrates a high HER activity with an overpotential of 91 mV at −10 mA/cm2 in 1.0 M KOH. An AEMWE single cell employing the Ni‐Co‐S/CP cathode coupled with a commercial IrO2/CP anode exhibits a current density of 1.7 A/cm2 at 2.4 Vcell, which is higher than that of an AEMWE single cell with a commercial Pt/C/CP cathode; this is attributable to the enhancement of the electron and reactant/product transfer via appropriate cathode design. [ABSTRACT FROM AUTHOR]

Summary: It is well recognized that combining nonpotable water with solar energy to desalinate water and produce water vapor is an effective route to solve the shortage of fresh water. However, the solar vapor generation suffers from either low solar energy efficiency or complex and high‐cost devices. Herein, we explore a black membrane based on polypyrrole (PPy) and filter paper to enhance solar‐to‐vapor conversion performance, thus providing a low‐cost, stable, and strong efficient solar vapor generator. This device displays high solar‐to‐vapor conversion efficiencies of up to approximately 92.2% and 95.6% under irradiation of 1 and 4 kW m−2, respectively. Therefore, this paper‐based high solar‐to‐vapor conversion and scalable evaporator provides a promising solution to the problem of freshwater scarcity and nonrenewable recourses. [ABSTRACT FROM AUTHOR]

Summary: This article proposes a methodology based on artificial intelligence to enhance methane production from waste paper. The proposed methodology combines fuzzy logic‐based modelling and modern optimization. Firstly, a robust Adaptive Network‐based Fuzzy Inference System model of methane production process through fuzzy logic modelling is created using experimental datasets. Second, a particle swarm optimizer was used to obtain the optimal process conditions. During the optimization procedure, the beating time and feedstock/inoculum ratio are employed as decision variables in order to maximize methane production. The obtained resulted from the proposed methodology are compared with those obtained by response surface methodology. The results of the comparison confirmed the superiority of the proposed methodology. The fuzzy model shows a better fitting to the experimental data compared to ANOVA. The fuzzy model showed a higher coefficient of determination and a lower value of root mean squared errors compared to ANOVA. Moreover, the proposed strategy, that is, modelling and optimization, is an effective method for increasing the biomethane yield at extended range conditions. [ABSTRACT FROM AUTHOR]

Summary: Tremendous research has focused on the wearable electronic device, leading to the basic requirement of suitable power sources. Herein, we report one bendable paper‐based zinc‐air battery with a novel hollow channel structure. It achieves a maximum power density of 138 mW/cm2, outperforming the state‐of‐art paper‐based batteries reported previously. The boosted performance is assigned to the low charge transfer resistance and facilitated mass transfer from the hollow structure. It demonstrates the positive design of microchannel structure is profitable for the power‐generation enhancement, and offers a possible route to commercialize the paper‐based power generators. [ABSTRACT FROM AUTHOR]

Summary: Porous conducting carbon fiber‐based composite paper is used as an electrode backing in the fuel cell assembly. It not only acts as a channel through which the reactant and product gases pass to and from the bipolar plate and the catalyst site but also helps in the flow of electrons. In order to perform its role efficiently, it should have sufficient strength, high electrical conductivity, and ideal porous structure. Carbon paper has been fabricated, which builds up the required composite properties. Studies have been conducted to optimize the fiber/matrix ratio in the carbon paper, while ensuring the perfect combination of porosity, mechanical strength, and electrical conductivity for an electrode in a proton electrolyte membrane fuel cells. Detail physico‐mechanical and electrochemical characterizations further ascertain that the fiber/matrix ratio plays an important role in tuning the composite properties. The polarization curve of the unit proton exchange membrane (PEM) fuel cell (with an effective electrode area 4 cm2) shows a peak power density of 916 mW/cm2 for the sample with fiber/matrix ratio of 65:35, which is almost the same as the commercially available sigracet gas diffusion layer (SGL) carbon paper tested under similar conditions. Further, proportionally enlarging the electrode area to 100 cm2 shows that the carbon paper not only shows almost repeatable results in a given set up but also scales up. [ABSTRACT FROM AUTHOR]

Summary: Direct liquid fuel cell (DLFC) and membraneless fuel cell using the anode consisting of buckypaper (BP) and vitamin B12 (Vit B12) (BP/Vit B12) is introduced in physiological condition, while vitamin C (Vit C) is used as anodic fuel. Due to the high sensitivity of Vit B12 and the inherent feature of BP, the onset potential for the oxidation reaction of Vit C catalyzed by BP/Vit B12 is −0.1 V (vs Ag/AgCl), and its anodic current density measured at 0.3 V (vs Ag/AgCl) is 1.82 mA cm−2 even in a low Vit C concentration (10 mM). Regarding performance in fuel cells, maximum power density (MPD) of Vit C fuel cell containing membrane and Pt‐based air cathode is 0.62 ± 0.067 mW cm−2 in 0.01 M Vit C, and this is 3.1 times higher than that of fuel cell containing pristine BP. In addition, in a paper‐based flexible membraneless fuel cell using BP/bilirubin oxidase as cathode and the concentration of cerebrospinal fluid within the human body (0.35 mM Vit C), its MPD is 57.7 ± 4.02 μW cm−2. This means this suggested Vit C fuel cell system can replace the conventional primary batteries considered as the power source of implantable sensors and stimulation devices to treat neurological disorders. [ABSTRACT FROM AUTHOR]

Summary: Paper microfluidic devices are innovative platforms for building miniaturized devices for energy harvesting, energy storage, and sensing applications. Such devices are reported to be used as membraneless microfluidic fuel cells to power portable electronic in a pump‐less manner by leveraging the embedded capillaries and co‐laminar flow. This paper demonstrates fabrication and characterization of the high‐performance metal‐free aluminum‐air microfluidic paper fuel cell (AAMPFC). Herein, aluminum foil acts as an anode, buckypaper with built‐in multiwalled carbon nanotubes (MWCNTs) acts as a cathode and sodium hydroxide (NaOH) works as an electrolyte. The novel AAMPFC is analyzed with various electrolyte concentrations, and maximum output voltage, current density, and power density are recorded. This easy‐to‐fabricate AAMPFC platform, costing less than US$ 0.5, is further optimized to achieve peak energies by stacking four AAMPFCs (in series and parallel) with various concentrations of electrolyte (NaOH). With parallel configuration, maximum open‐circuit potential (OCP), peak current (mA/cm2), and power density (mW/cm2) of 1.32 V, 50.67 mA/cm2 and 22.80 mW/cm2, respectively, are observed with optimized electrolyte, while with series stacked configuration, a stable OCP of 4.10 V is measured. In a series configuration, AAMPFC generated sufficient power to powering a scientific calculator with LCD display for 3 days and 11 LEDs for 10 hours continuously. This research work provides a significant method to enhance the output power with inexpensive parameters (buckypaper, single paper microchannel) to power portable electronic devices. Further, the performance can be enhanced by investigating AAMPFC with various grades of aluminum foil in combination with different grades of porous cellulose papers. [ABSTRACT FROM AUTHOR]

Summary: Miniaturization of devices, combined with other features such as portability, proneness to automation, rapid performance, amenability to integration, multiplexing, and cost‐effectiveness, is rapidly increasing for various sensing and energy harvesting applications. One such emerging area is the development of microfluidic fuel cell on cellulose papers, which has enormous scope to optimize its performance. This is primarily because such devices eliminate the need for membranes as well as external pumps since they have built‐in colaminar flow embedded capillaries. Such peripherals are usually used in conventional microfluidic fuel cells, which are fabricated using methods like photolithography, PDMS lithography, and 3D printing. This paper presents investigations on microfluidic paper–based fuel cells (MPFCs) with different cellulose absorbent pads for their performance optimization. Herein, the MPFC utilizes formic acid as fuel, oxygen from quiescent air as oxidant, and sulfuric acid as electrolyte for conducting ionic exchange under colaminar flow. The electrodes are realized through simple pencil strokes depositing a thin layer of graphite. The porous graphite electrodes act as diffusion agents breathing oxygen directly from the atmospheric air. Such an MPFC configuration, costing less than US $1, was optimized to achieve maximum energy density by examining various combinations of absorbent pads with different grades of cellulose papers. It is seen that the maximum open circuit potential is 0.46 V, while the maximum current and power densities are 1505.66 μAcm−2 and 173.97 μWcm−2, respectively, with a grade 6 absorbent pad. Such performance can be further enhanced by investigating MPFCs with various graphite pencils with a diverse number of strokes at different concentration levels. [ABSTRACT FROM AUTHOR]

Coronavirus disease (COVID-19) has spread all across the world. Low- and medium-income countries are more affected economically and socially compared to developed countries due to the lack of a rapid, robust, and affordable testing infrastructure. Furthermore, the high cost of real-time polymerase chain reaction (PCR) system, sophisticated user-handling procedure, and high expense of the conventional clinical tests are the root causes of the less accessibility of the testing systems to the users. In this study, a COVID-19 Point-of-Care (POC) ecosystem model is proposed for the low- and medium-income countries (or energy deprived countries) that will facilitate the technological development with locally available fabrication components. In addition, the nontechnological development phases have also been discussed, which encompasses the collaboration among academia, local as well as government bodies, and entrepreneurial ventures. In addition, a hypothetical design of a microfluidic paper-based analytical (μPADs) POC platform is proposed to detect COVID-19 analyte using unprocessed patient-derived saliva, which is a miniaturized form-factor of conventional real-time polymerase chain reaction (PCR) technique. The device contains four major reaction zones, which are sample zone, buffer zone, loop-mediated isothermal amplification (LAMP) Master Mix zone, Ethylenediamine tetraacetic acid (EDTA) zone, and sensor zone. To obtain quicker test results and easier operation, a handheld image acquisition technique is introduced in this study. It is hypothesized that in a remote setting, the proposed design could be used as an initial guideline to develop a POC COVID-19 testing system, which may be simple, easy-to-use, and cost-effective., (© 2021 John Wiley & Sons Ltd.)

This paper analyses the economics of cogeneration potential in the pulp and paper industry of Vietnam. The analysis focuses on six large existing paper mills, their planned capacity expansion and nine planned new mills up to 2010. The analysis considered five alternative fuels (coal, diesel, fuel oil, natural gas and rice husk), three different technologies (steam turbines, gas turbines and reciprocating engines) and two modes of operation (thermal match and power match) of cogeneration. It also considered the case of sale of excess power to the grid. The analysis indicates that cogeneration is a viable option in the paper and pulp industry in Vietnam and the potential is about 200 MW. IRR in most of the cases ranges between 15 and 30% and the general payback period is between 3 and 5 years. Cogeneration remains a viable option even without sale of power to the grid and under different unfavourable conditions of fuel price, investment and other factors. Copyright © 2005 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Different energy and exergy concepts and methods are presented and applied to a Swedish pulp and paper mill. Flow diagrams show that the exergy content is mostly much less than the energy content of the flows. The largest exergy losses appear in the boilers. Heating processes are highly exergy inefficient. A limited Life Cycle Exergy Analysis (LCEA) shows that the exergy output amounts to over 3 times the spent exergy as non-sustainable resources. By replacing the present use of non-sustainable resources, mostly fuel oil, the mill could move towards a truly sustainable process. Copyright 2005 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Summary: Perovskite solar cells are one of the most promising photovoltaic technology, presenting the fastest power conversion efficiency (PCE) growth from 3.8 % to 24.2 % in just 10 years. However, there are still challenges hindering its commercialization such as the expensive back‐contact made of gold. Carbon‐based materials, mainly carbon pastes made of carbon black and graphite, have already proven to be good candidates as back‐contacts because of their features such as low cost, high conductivity, and high stability. In this work, the replacement of gold back‐contact by a carbon paper with a microporous layer coated with a PEDOT:PSS dispersion is reported. To the best of the author's knowledge, this material has never been reported for perovskite solar cells. A PCE of 9.22 % was obtained, representing 62 % of the PCE obtained for the same cell but with a gold back‐contact. [ABSTRACT FROM AUTHOR]

The through-plane permeability of the gas diffusion media (GDM) is investigated experimentally with regard to the microporous layer (MPL) composition and the gas diffusion layer (GDL) composition and structure. The MPL composition is held constant at 80% carbon powder and 20% polytetrafluorethylene (PTFE) (by weight) for various carbon loadings. The decrease or increase in GDM permeability was found to be dependent on the structure of the GDL used in conjunction with the type of carbon powder. It was found that low-surface- area carbon powder (Vulcan XC-72R) forms thin, dense MPLs with small cracks when compared to high-surface-area powder (Ketjenblack EC-300J), which creates thick, rough MPLs with large cracks with increased carbon loadings. For most cases, the permeability decreases with increasing carbon loading; however, the non-woven, straight fibre carbon papers using Ketjenblack EC-300J show the lowest permeability at the lowest carbon loading. Furthermore, the percentage reduction from the GDL substrate permeability appears to be predictable for similar structures with increasing carbon loading. The increase in PTFE loading from 10% to 30% in the GDL was shown to have a significant impact on the percentage reduction from the original GDL permeability of ~9% to 15% for the GDM composed of Vulcan XC-72R as carbon powder; however, such effects are insignificant when using Ketjenblack EC- 300J carbon powder. [ABSTRACT FROM AUTHOR]

SUMMARY Previous studies by the authors have shown that energy savings in pulp and paper mills offer opportunities for increased electricity production on-site or wood fuel export. The energy export implies reductions in CO2 emissions off-site, where fossil fuel or fossil-fuel-based electricity is replaced. To assess this potential and the related profitability for a future situation, four energy market scenarios were used. For a typical Scandinavian mill, the potential for CO2-emission reductions was 15-140 kton year−1 depending on the scenario and the form of energy export. Extrapolated to all relevant mills in Sweden, the potential was 0.4-3.1 Mton year−1, which is in the order of percent of the Swedish CO2 emissions. Wood fuel export implies larger reduction in CO2 emissions in most scenarios. In contrast, electricity export showed better economy in most of the cases studied; with annual earnings of 5-6 M€, this is an economically robust option. In the market pulp mill investigated, the wood fuel export was in the form of lignin. Lignin could possibly be valued as oil, regarding both price and potential for CO2-emission reduction, making lignin separation an option with good profitability and large reductions of CO2 emissions. Copyright © 2011 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

The increasing environmental consideration and the growth of instability of the energy market call for methods that can process the organic fraction of municipal solid waste (OFMSW) into fuel instead of disposal. Due to the pyrolysis and gasification that are efficient procedures to achieve valuable products, gasification of OFMSW with different particle sizes and compositions was carried out in the presence of Ni and Ni-Ce-loaded Y-zeolite in a multizone tubular kiln reactor. During the experiments, 500°C was applied in the first reactor zone, while the 2nd zone was at an elevated temperature of 600°C or 900°C in the presence of steam. The combined pyrolysis and gasification experiments were also carried out without a catalyst with the same operating conditions. The feedstock was collected from the organic fraction of a Hungarian mechanical-biological treatment (MBT) plant and was separated into four different fractions based on particle size: <1 cm dry biomass and fine particles, 1-2 cm paper-rich, 2-6 cm paper and plastic-rich feedstocks, and <6 cm mixture of these fractions. During the experimental work, product yields; gaseous product composition; the ratio of H2/CO, CO2/CO, and CH4/CO; and lower heating value were determined in the function of feedstock composition, the applied temperature, and catalysts. It was found that the hydrogen content and H2/CO ratio of gaseous products were increased due to catalyst application and temperature elevation in the 2nd reactor zone. The addition of Ce to the Ni/Y-zeolite catalyst was advantageous in the case of hydrogen formation at a lower temperature (600°C). The hydrogen and methane content of products obtained from the catalytic pyrolysis-gasification of paper and plastic-rich OFMSWs on elevated temperatures were higher, which increased the lower heating value of those products. Based on the elemental analysis of the obtained solid residues, it was found that paper/plastic-rich feedstock released hydrogen and carbon with a higher extent. 1-2 cm feedstock-related solid residues had the highest H/C ratio which caused a 12.5-12.8 MJ/kg gross heating value. As a result, combined pyrolysis and gasification appear to be an efficient method to attain valuable outputs from OFMSW not only in gas but also in solid products. [ABSTRACT FROM AUTHOR]

Summary: Co‐laminar flow microbial fuel cells (MFCs) with flow‐through electrodes are proposed to improve the power density. Carbon paper was used for the porous electrodes and the membrane‐less MFCs containing a microscale (5.4 μL) anode chamber were microfabricated in a planar monolithic cell for integration with microfluidic devices. The diffusion region between the electrolytes was numerically analyzed and fuel cell performance experiments were conducted with a wastewater inoculum‐based mixed culture biofilm. The effects of the electrolyte flow rate (1‐30 μL min−1) and electrode width (0.5‐2.0 mm) on the fuel cell performance were investigated. The power density was maximized at 692 ± 34 W m−3 under optimal conditions including a 10 μL min−1 flow rate and 1.5 mm electrode width, resulting in suitable biofilm formation and low internal resistance. This study provides valuable information for the commercialization of microfluidic MFCs as a power source for portable medical and electronic instruments. [ABSTRACT FROM AUTHOR]

Summary: Microporous layers (MPLs) have a crucial effect on the performance of direct methanol fuel cells (DMFCs). High polytetrafluoroethylene (PTFE) loading is normally adopted to remove water in a conventional cathode MPL based on carbon black, which hinders oxygen transport and increases ohmic resistance. In this study, we report a novel cathode MPL based on polypyrrole nanowires, which were grown on hydrophobic carbon paper via in situ electropolymerization. Compared with carbon black, the unique structure of polypyrrole nanowires allows for less PTFE content to obtain similar hydrophobicity. The maximum power density of a DMFC based on the novel MPL (20 wt% PTFE) is 101.1 mW cm−2, which is about 1.3 times that based on a traditional MPL (40 wt% PTFE, 79.4 mW cm−2). This improvement can be ascribed to increased oxygen transfer and decreased ohmic resistance, which were evidenced by oxygen gain and electrochemical impedance spectroscopy. [ABSTRACT FROM AUTHOR]

The fabrication of heterostructures via solution process is one of the essential technologies for realizing efficient advanced-generation optoelectronics. Hybrid structures comprising colloidal quantum dots (CQD) and organic semiconducting molecules are garnering considerable research interest because of their complementing optical and electrical properties. However, blending both the materials and forming a stable electronic ink are a challenge owing to the solubility mismatch. Herein, a CQD:organic ternary-blended hybrid solar ink is devised, and efficient hybrid solar cells are demonstrated via single-step spin coating under ambient conditions. Specifically, the passivation of the benzoic acid ligand on the CQD surface enables the dissolution in low-polar solvent such as chlorobenzene, which yields a stable CQD:organic hybrid ink. The hybrid ink facilitates the formation of favorable thin-film morphologies and, consequently, improves the charge extraction efficiency of the solar cells. The resulting hybrid solar cells exhibit a power conversion efficiency of 15.24% that is the highest performance among all existing air-processed CQD:organic hybrid solar cells. [ABSTRACT FROM AUTHOR]

Presents a study to evaluate the possibilities of investing in a new chemical recovery cycle, including a new recovery boiler and evaporation plant, at a Swedish board mill. Consideration of energy costs in the pulp and paper industry; Use of a sensitivity analysis; Examination of changes in the price of electricity and oil.

Summary: Numerical simulation is widely used in research and design of the battery thermal management system (BTMS). Battery cells are commonly homogenized to a block for module or pack level modeling. However, how the homogenization method affects results is not proven. This paper works on a hard‐cased Li‐ion battery to find a proper simplification method. First, a detailed three‐dimensional thermal model (model A) is set up and validated by experimental data. Then, the other three models with different simplification strategies are proposed. They are model B (the cell is homogenized to a block), model C (the cell preserves only core region and housing case), and model D (based on model C, the thin insulation films are also considered). Take the results of model A as a reference, the calculation accuracy and efficiency are summarized. It is found that model B shows the best efficiency and is a proper choice for evaluation of temperature dynamics, while model D is more recommended when the internal temperature distribution of the battery is more concerned. [ABSTRACT FROM AUTHOR]

Summary: The purpose of this paper is to investigate the perspective of using wood waste, especially the one that resulted from the construction and demolition activities, to produce sustainable bioenergy. The context of this research is characterized by a more accelerated need for development, a growing need for energy to fuel all human activities, and a greater awareness of the pressure on the environment and the negative effects produced. One of the major challenges for environmental protection is the issue of mitigating CO2 emissions, and among the biggest contributors to the CO2 emissions is the construction industry. Given the current rhythm of society development, a decrease in construction activities is not possible so a solution can be better management of the waste produced in various stages. If the need for better waste management is joined with the need for more sustainable energy, then using waste to produce bioenergy seems like a good solution. This study focuses mainly on wood waste and to respond to the research purpose it uses bibliometric literature search, scientometric analysis, and in‐depth discussions. The data were obtained by interrogating the ISI Web of Science database using the keywords "bioenergy", "wood waste" and "construction and demolition" as search criteria. The extraction of data was done using the PRISMA method and processed with VOSviewer and Bibliometrix software. The processing of the data was done so to obtain information related to the importance of the research topic given by the number of publications, the most studied topics revealed by a keywords co‐occurrence analysis and a trend topic plot, as well as the world scientific productions on the studied topics. The main results indicate a significant increase, in the last years, of the interest in the studied topics, all over the world. Wood waste is considered as a direct combustion fuel or as a raw material for components of fuels used to produce energy, as well as components for new building materials. Given the limitations of other renewable energy sources, wood biomass is a subject that must be considered more in the future. The use of wood waste as biomass for the production of bioenergy can be a very good solution that will bring the advantage of both ensuring a renewable source of energy and at the same time decreasing the impact of the building industry on the environment. [ABSTRACT FROM AUTHOR]