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Carbon paper is one of the most widely used gas diffusion layer substrate materials due to its stable performance, relatively low cost, and easy for subsequent processing. Water-soluble phenolic resin, which is more ecologically friendly than alcohol-soluble phenolic resin, was used to prepare carbon paper as the precursor of the carbon matrix. And the effect of different resin solution concentrations on the properties of carbon paper was explored. The results showed that the graphitization, electrical conductivity and mechanical properties of carbon paper increased with the increase of resin solution concentration. When the concentration of resin solution was 20 wt%, the performance of carbon paper was relatively optimal. The graphitization of the carbon paper reached 65.45%, the porosity reached 80.74%, the resistance value at 1 MPa pressure was only 7.61 mΩ cm2, the tensile strength was 1.57 MPa, and the elastic modulus was 1210.98 MPa. [ABSTRACT FROM AUTHOR]

Enzymes derived from microbial sources have gained increasing popularity in industrial applications over the past decades. Despite the high production cost, alkaline proteases have wide applications in industries such as tanneries, food production, and detergents. In recent years, there has been a shift towards utilizing natural carbon sources for cultivating microorganisms and extracting proteases in order to reduce production costs. This study aimed to investigate the biochemical and kinetic properties of protease enzymes obtained from Aspergillus niger cultivated in a paper waste medium and compare with the enzyme produced in a basal medium. Glucose is a more favorable carbon source compared to cellulose, so paper waste was pretreated with cellulose-degrading bacteria to convert cellulose into smaller carbohydrates. After the growth of A. niger in basal and combinational media, the enzymatic properties were compared between the extracted enzymes by using casein as substrate. The results demonstrated that A. niger could produce protease enzymes in the paper waste medium similar to the basal medium with more than 5-fold cost saving. The specific activity of the enzymes isolated from the basal and paper waste media was calculated to be 184.95 ± 10.56 U ml−1 and 169.88 ± 11.05 U ml−1, respectively. Carbon sources did not affect the optimum pH and temperature of the protease enzyme, which were found to be 8 and 37 °C, respectively. This study provides valuable insights into the production of alkaline protease from A. niger using a combinational medium (paper waste pretreated by cellulose-degrading bacteria), offering a cost-effective approach for industrial applications. [ABSTRACT FROM AUTHOR]

This paper describes the fabrication and characterization of porous SiC ceramics derived from highly-filled preceramic papers. The SiC ceramics were obtained by spark plasma sintering of stacked preceramic papers at temperatures of 2100 and 2200 °C under pressures of 5–60 MPa for 10 min. The microstructure and phase composition were analyzed by scanning electron microscopy and X-ray diffraction, respectively. Gas permeation tests were performed using hydrogen permeation cell at room temperature. It is revealed that the porosity of sintered SiC can be varied from 9 to 45 % depending on the sintering parameters. The shrinkage of the materials during spark plasma sintering occurs in four stages. The linear shrinkage value of the material increases from 7 to 47 % at 2100 °C and from 20 to 50 % for the samples sintered at 2100 and 2200 °C, respectively. Correlation dependencies between porosity and mechanical properties of the fabricated SiC were established. The obtained porous SiC ceramics exhibit high bending strength of 165 MPa and gas permeation flux of 78 molH 2 /m2/s at the porosity of 36 % that make it suitable for ceramic-based membranes. [ABSTRACT FROM AUTHOR]

Aerogel composites reinforced by fibers have found extensive applications in the field of thermal insulation and energy conservation. However, the composites are hindered by their high infrared radiation transmittance and weak interface adhesion in practical applications. Herein, we designed and prepared a novel thin composite called 'fiber/whisker/aerogel paper' (SWAP) with a thickness of less than 1 mm. The SWAP integrated SiC nanowhiskers (SiC nw) as opacifiers and ultrafine SiO 2 fibers as reinforcement, fabricated through wet manufacturing and sol-gel process. The 'fiber/aerogel paper' (SAP) and SWAP exhibited low thermal conductivity at room temperature, measuring 0.025 W/(m·K) and 0.033 W/(m·K), respectively. Additionally, they exhibited low densities of 0.195 g/cm3 and 0.225 g/cm3, respectively. Notably, SWAP exhibited excellent high-temperature insulation performance, primarily due to its low infrared transmittance (50% at 3 μm). The incorporation of SiC nw and ultrafine SiO 2 fibers collectively enhanced the interfacial adhesion with the aerogel matrix even amidst rigorous testing (weight loss less than 3%). SWAP also demonstrated flexibility, high thermal stability, hydrophobicity, and flame resistance. Furthermore, a comprehensive investigation into the performance variations and influencing g factors of the material was conducted under different heat treatment conditions. This research provides guidance for the application of such materials under high temperatures. [ABSTRACT FROM AUTHOR]

The ZrO 2 fiber paper exhibits excellent thermal insulation properties, however, its limited mechanical strength and insufficient thermal stability hinder its widespread applications. The composite fiber papers, using mullite fibers possessing a high aspect ratio and exceptional thermal stability combined with ZrO 2 fibers, were fabricated via a vacuum-assisted filtration method. This method involved the successive stacking of composite fibers with alumina sol, using vacuum-induced directed water flow to create a layered structure reminiscent of nacre. The layered structure of the nacre, which demonstrates remarkable strength and hardness, has also served as a source of inspiration for the architectural design of the fiber paper. The tensile strength of pure ZrO 2 fiber paper was significantly enhanced by the addition of 7 wt% mullite fibers, resulting in a remarkable increase to 0.1805 kN/m. The paper exhibited exceptional resistance to bending, maintaining 96 % of its bending strength even after undergoing 100 cycles. The thermal shrinkage of the composite paper, containing 15 wt% mullite fibers, was reduced from 17.75 % observed in pure ZrO 2 fiber paper to a mere 1.32 % after undergoing heat treatment at a temperature of 1300 °C for 2 h. The composite paper, measuring 5 mm in thickness and consisting of 7 wt% compositions, displayed exceptional thermal insulation properties when exposed to a hot side temperature of 1370 °C. It effectively insulated temperatures up to approximately 1000 °C. [ABSTRACT FROM AUTHOR]

Ni-doped WC/Mo 2 C composites for hydrogen evolution reaction (HER) were synthesized in situ grown on carbon fiber paper (CFP) by molten salt method in argon at 1000 °C for 6 h, named as Ni-xWC-y/2Mo 2 C@CFP. The effects of different W/Mo molar ratios (3:1, 2:1, 1:1, 1:2, 1:3) on the phase composition, microstructures, and HER performances were investigated. The results showed that the W/Mo molar ratio had a synergistic effect in HER of Ni-doped WC/Mo 2 C composites, and as W/Mo molar ratio at 1:1, the composite presented the best electrocatalytic activity. Meanwhile, its surface appeared to have a wrinkle-like structure, and the biphasic heterostructure emerged at the intersection of the dual-phase WC and Mo 2 C lattices. The introduction of a biphasic heterostructure could promote charge transfer and improve HER efficiency. Predictably, the electrocatalysts with the optimal W/Mo molar ratio 1:1 exhibited the best hydrogen evolution performance, needed only 43.7 mV overpotential to reach 10 mA cm−2 current density with a Tafel slope at 21.3 mV dec−1. In this work, the high-efficiency electrocatalysts of Ni-doped 1WC-1/2Mo 2 C@CFP have been prepared, which provides an insight into theoretical research of composite carbon-based electrocatalysts. [ABSTRACT FROM AUTHOR]

To solve the durability problem caused by carbon corrosion in the porous carbon paper gas diffusion layer (GDL) of proton exchange membrane fuel cell (PEMFC), a Cr 7 C 3 ceramic coating on porous carbon paper by molten salt method was prepared. The obtained Cr 7 C 3 coating is dense and shows good adherent with the carbon paper. Based on the corrosion resistance testes, it is concluded that the Cr 7 C 3 coated carbon paper can keep high chemical stability in the long-time acid immersion accelerated corrosion tests and simulated cathodic proton exchange membrane fuel cells environment. The carbon paper with Cr 7 C 3 coating shows a small current density with a value of about 1.1 × 10−5 A cm−2 in the potentiostatic polarization test under 1 M H 2 SO 4 + 2 ppm HF at 70 °C and1.4 V SCE for 72 h. Meanwhile, the resistivity of carbon paper with Cr 7 C 3 coating prepared is 30% lower than that of pure carbon paper, and the conductivity is 1.5 times that of pure carbon paper. [ABSTRACT FROM AUTHOR]

Rewritable paper is of great significance for environmental and sustainable development. Specially, the water rewritable paper based on hydrochromism has aroused extensive research interesting for being clean, convenient and compatible with the current ink jet printer. Nevertheless, previously reported water rewritable paper requires complex and time-consuming fabricating process. Here, we report a facile strategy to fabricate structural colored water rewritable paper simply via two step infiltration on commercially available paper. After infiltration of graphene laminates and SiO 2 colloidal spheres in sequence, the obtained paper is integrated with assembled graphene laminates (AGLs)/amorphous colloidal arrays (ACAs) hierarchical composite structure. Owing to the advantageous micro-topography, selective separation capacity and high visible light absorption property of the underlying AGLs, SiO 2 ACAs with vivid structure color can be realized. Moreover, the hydrochomism of the hierarchical composite structure is resulted from the synergistic contribution of the hydrophilic structural color and the visible light absorption property of AGLs. Our strategy is based on the environmental-friendly structural color and convenient to realized, which offers a promising alternative to rapidly fabricate colored water rewritable paper. [Display omitted] [ABSTRACT FROM AUTHOR]

This study presents a novel method for synthesizing hierarchical porous zinc oxide (ZnO) nanostructures by thermally decomposing green-synthesized hydrozincite. The hydrozincite was prepared at room temperature using zinc acetate dihydrate and calcium carbonate (CaCO 3) in cellulose printing papers as the precipitating agent. The resulting ZnO particles exhibit a distinctive flower-like morphology, consisting of porous nanosheets composed of interconnected nanoparticles. The average crystallite size of the hierarchically structured zinc oxide nanoparticles, as determined via X-ray diffraction Rietveld refinement method, was found to be 18.8 nm when calcined at 500 °C. However, with increasing calcination temperature to 600, 700, and 800 °C, the average crystallite size also increased to 24.3, 30.4, and 47.2 nm, respectively. The ZnO synthesized at temperatures of 500 °C, 600 °C, and 700 °C exhibits higher electrocatalytic activity toward the hydrogen evolution reaction (HER) compared to both the ZnO synthesized at 800 °C and commercial ZnO. This enhanced performance can be primarily attributed to the nanosized ZnO particles, which provide a substantial surface area, high accessibility of active sites, and fast charge transfer kinetics. In terms of photocatalytic activity, all the samples show HER improvement under the UV light irradiation, attributed to the generation of photoexcited charge carriers. The ZnO synthesized at 800 °C and the commercial ZnO exhibit greater enhancements in photocatalytic activity compared to the other samples. This implies that larger solid particles with fewer nanopores result in a greater exposed surface area for UV-light absorption. The hierarchically structured ZnO nanoparticles demonstrate promising electrocatalytic and photocatalytic activities, as well as stability, opening up potential applications in various fields, including energy conversion and environmental remediation. [ABSTRACT FROM AUTHOR]

[Display omitted] • Designing materials using rice-leaf-mimetic paper as a substrate. • Engineering rice-leaf-mimetic paper with hydrochromic dyes or biolubricants. • Processes based on mass-producible papermaking unit operations. Biomimetics has revolutionized materials innovation by drawing inspiration from biological systems. Cellulosic paper, a sustainable biomaterial, offers immense potential for biomimetic research. Paper-based biomimetic materials, which replicate the structures and functionalities of natural materials by utilizing the cellulosic fiber network as a substrate or skeleton, provide customizable functional properties, thereby enabling advanced applications. Here, we introduce rice-leaf-mimetic paper, inspired by the leaf's microstructure and biowax-based cuticle. This paper exhibits self-cleaning superhydrophobicity and showcases possibilities for additional functionalities, including antibacterial properties and food preservation, as evidenced in our prior research. We propose its utilization as a substrate for rewritable and biolubricant-infused surfaces. These somehow distinct surfaces draw inspiration from the chemistry and microstructure of the rice leaf. Although incorporating hydrochromic dyes enables rewritability, controlling the retention time of colors remains challenging. The biowaxy structure of the paper prolongs color maintenance by inhibiting water evaporation. Moreover, the hierarchically rough microstructure of rice-leaf-mimetic paper effectively stores biolubricant molecules, reducing friction and enhancing slipperiness. Surface microcavity ratio analysis provides insights into the paper's biolubricant-storability. The surface engineering of rice-leaf-mimetic paper using hydrochromic dyes or biolubricants holds potential for designing novel materials. Unveiling the vast potential of easily scalable papermaking processes alongside biomimetics and surface engineering opens new avenues for materials innovation. [ABSTRACT FROM AUTHOR]

• Liquid water saturation in carbon paper is measured • Quantifies the capillary trapping effect of isolated water drops in carbon papers • Proposes a model describing liquid water drops transport In previous macroscopic average models of proton exchange membrane fuel cells (PEMFCs), liquid water was assumed to be continuous throughout the carbon paper. The transport of disconnected water drops in carbon paper has long been neglected in these models, which tend to underestimate water saturation in carbon paper. This study proposes a two-phase flow model that considers the transport of disconnected water drops to simulate the air-water transport in carbon paper. The proposed model was established based on the relationship between capillary force and liquid water saturation, and this relationship was obtained by conducting centrifuge experiments. In the centrifuge experiment, initially, the water saturation inside the carbon paper sample was one, and the centrifugal acceleration was zero. As the centrifugal acceleration increased, the water saturation decreased owing to the centrifugal force. After twenty seconds, the water saturation no longer decreases because the centrifugal force on the liquid water is balanced by the capillary force. Centrifugal acceleration was used to evaluate the capillary force. When the centrifugal acceleration was 185 m s − 2 , the saturation of the water drops in the balanced state was 32.0%. As the centrifugal acceleration increases to 739 m s − 2 , the saturation decreases to 6.5%. According to the experimental results, a function correlating the saturation and centrifugal acceleration, that is, the capillary force, was established. Finally, the results show that the centrifugal acceleration is more than 18.5 times that of the gravitational acceleration, indicating that the effect of gravity on the motion of water drops is negligible. [Display omitted] [ABSTRACT FROM AUTHOR]

Paper with simultaneous fire-resistance and hydrophobicity have greatly potential applications in the fields of packing, storage and delivering information, which attracts increasing attention recently. Different from the traditional cellulose-based paper which is extremely easily damaged by water and fire, a new type of highly flexible, fire-resistant and hydrophobic paper based on Si 3 N 4 nanowires and polydimethylsiloxane (PDMS) is reported. Specially, the Si 3 N 4 @PDMS core-shell nanowires with 3D interlocking structure are designed, in which the Si 3 N 4 nanowires act as the inorganic fire-resistant frameworks and the PDMS shell with low surface energy provides the hydrophobic surface. The Si 3 N 4 @PDMS core-shell nanowires are intertwined and interlaced to form a highly flexible Si 3 N 4 @PDMS paper. The tensile strength of Si 3 N 4 @PDMS paper is 6.19 MPa, indicating the good mechanical property. The obtained Si 3 N 4 @PDMS paper has the characteristics of writability, fire-resistance and hydrophobicity. The high thermal stability of Si 3 N 4 nanowires makes Si 3 N 4 @PDMS paper exhibit excellent fire resistance. No obvious change is observed for the commercial paper with Si 3 N 4 @PDMS paper as the fire-shielding layer after heating for 30 min. In addition, the contact angles of water droplets are all greater than 110° over the surfaces of Si 3 N 4 @PDMS paper after mechanical damages, chemical corrosions and thermal treatments. Si 3 N 4 @PDMS paper can be used in oil/water separation and oil collection. More importantly, Si 3 N 4 @PDMS paper can be used for writing without being damaged by fire or water. The present work may inspire the development and application of functional paper and is expected to become a breakthrough in the traditional paper industry. [ABSTRACT FROM AUTHOR]

The catalytic ozonation processes with continuous-flow reactors were used for pulp and paper mill wastewater treatment. [Display omitted] • The pulp and paper wastewater is treated effectively by catalytic ozonation with continuous-flow reactor. • The porous ceramsite catalytic ozonation can be used for continuous-flow process. • The porous ceramsite catalyst is continuously and stably operated for 30 days. • The lowest E EO value is reached at the O 3 dosage of 15 g/L. • The degraded or transformed organic pollutants present in PPMW by O 3 alone system and catalytic ozonation system were identified. The pollutants in wastewater can be degraded effectively by heterogeneous catalytic ozonation due to the production of hydroxyl radical (•OH) with strong oxidation power. For the natures of low weight, large specific surface area, excellent physical strength and stable chemical characteristics, the porous ceramsite was chosen for catalytic ozonation of wastewater in the present study, and the practical application parameters of the system were investigated for the actual pulp and paper mill wastewater (PPMW) in the continuous-flow reactor including temperatures, feeding flow rate, O 3 flow rate and O 3 dosage. The optimum experimental conditions were obtained (T = 25 ℃, feeding flow rate = 0.25 L/min, O 3 flow rate = 0.5 L/min, O 3 dosage = 15 g/L) for the process of catalytic ozonation. The results show that the effluent concentration of COD decreases from about 200 mg/L to 10 mg/L, namely the removal efficiency is about 95 %. The stability of the catalyst over time was tested in the continuous-flow reactor for 48 days, confirming that the porous ceramsite exhibits good performance in 30 days. The reusability of the catalyst was studied after the used catalyst was washed with Milli-Q water and ethanol, exhibiting good catalytic activity of the regenerated catalyst in three cycles. The fluorescent excitation-emission matrix (EEM), UV–vis analysis and GC–MS analysis were used for analyzing the organic pollutants in raw PPMW and after treatment. These results indicate that the process of catalytic ozonation with porous ceramsite has a high treatment efficiency on PPMW, and the continuous-flow reactor can be more practically used for a full-scale community PPMW application at a mill level. [ABSTRACT FROM AUTHOR]

The development of self-powered UV photodiode on green substrate is still a challenge. In this study, highly conductive Al doped ZnO (AZO) film was sputter-deposited on paper substrate at room temperature; subsequently, paper-based Schottky photodiodes were successfully fabricated by following Au-ZnO-Al and Au-ZnO-AZO-Al structure designs, respectively. These UV light-based devices operate successfully without external power. Au-ZnO-AZO-Al photodiode shows improved response and faster speed compared to Au-ZnO-Al photodiode. The one-dimensional Poisson simulation results demonstrate that the improvement is attributed to the strong electric field in the ZnO-AZO n-n+ high-low junction, thus, enhancing the collection rate and drifting speed of the photogenerated carriers. In addition, AZO can form favorable ohmic contact with the Al electrodes, further improving the device performance. The photo-response of the paper-based photodiode device shows high reproducibility and stability. Based on these outstanding results, we conclude that these paper-based electronic devices have great potential to replace conventional petroleum-based flexible electronic devices, thus, contributing to the green/sustainable development. [ABSTRACT FROM AUTHOR]

[Display omitted] • Facile and scalable self-assembly of perylene diimide polymer with carbon paper. • Effective facilitation of carrier separation by π-π built-in electric field. • Narrowed band gap and low VB due to the VB tail states induced by π-π interactions. • Enhanced photocatalytic water oxidation activity of the PDIP/CP photocatalyst sheet. • Suitability of the PDIP/CP photocatalyst sheet for large-scale applications. Photocatalytic water splitting is a highly promising future energy technology. In contrast to the extensive work on particulate photocatalysts, there is still a lack of sufficient investigation for regularized photocatalysts. Here, from perylene diimide polymer (PDIP) and commercial carbon paper (CP), we develop a self-assembled PDIP/CP photocatalyst sheet that is easily scalable and can be used for photocatalytic water oxidation. Driven by strong interfacial π-π interactions, the PDIP spontaneously adsorbs onto the CP, which leads to a narrowed band gap, down-shifted VB edge, and enhanced separation of the photogenerated charge carriers of the PDIP. Under visible light, the PDIP/CP photocatalyst sheet shows significantly enhanced photocatalytic water oxidation activity (4 h cumulative oxygen evolution is 1.7 times higher than that of the powder-suspended system) and considerable cycling stability. The PDIP/CP photocatalyst sheet has the potential for large-scale device applications. [ABSTRACT FROM AUTHOR]

Given its superior structure, the abundance of surface functional groups, and low cost, cotton fiber filtration paper can be used as the support for hydrogen evolution reaction (HER) and oxygen evolution reaction catalysts (OER) instead of copper foam (CF), nickel foam (NF), or carbon cloth (CC). Herein, the chemical plating method was used to create thin self-supporting electrodes based on cotton fiber filtration paper (FP). The Co-Ni-P amorphous nanospheres can be uniformly dispersed on the self-supporting FP due to its porous structure and oxygen functional groups. The Co-Ni-P/FP electrode has an overpotential as low as 125 mV for HER and 320 mV for OER at the current density of 10 mA cm−2. Additionally, according to density functional theory (DFT) calculations, the Co atom added to the Ni-P nanosphere can lead to considerably more charge accumulation around the Co and Ni active sites, which greatly encourages the HER and OER processes. The novel porous support, FP, provides a fresh way the preparation of self-supporting electrodes. [Display omitted] • Filter paper is used to prepare the self-supporting electrode as the substrate. • The preparation method is simple and the properties are stable. • Rich oxygen-containing functional groups of FP promote deposition and dispersion. • Explore the excellent electrochemical performance of amorphous Co-Ni-P/FP by DFT. [ABSTRACT FROM AUTHOR]

In this paper, a facial strategy is employed to directly growing ZnO nanorods (ZnONR) on carbon fiber paper (CFP) and functionalizing with silver nanoparticles (AgNP), constructing a structural stable paper-based electrode (AgNP/ZnONR@CFP). This unique AgNP/ZnONR hierarchical nanoarchitecture provides large surface area and an easy substrate penetrable structure facilitating enhanced electrochemical features towards flavonoids oxidation. When the electrode is evaluated as a binder-free sensor for flavonoids detection, three distinct and separate differential pulse voltammetric peaks for luteolin, daidzein, and baicalein are observed, demonstrating the simultaneous and selective detection of these flavonoids possible. The AgNP/ZnONR@CFP sensor demonstrates a remarkable wide linear relationship with low detection limits for luteolin, daidzein, and baicalein detection in a mixed solution. When the sensor is employed to analyze luteolin, daidzein, or baicalein in real extracts from Japanese Honeysuckle, Soybean, and Chrysanthemum morifolium, satisfactory recovery rates (ranging from 96.3 % to 102.5 %) and low relative standard deviation (RSD) values (less than 5.0 %) are obtained. In addition, an assembled sensor device (two-electrode) based on this trimmable AgNP/ZnONR@CFP electrode exhibits remarkable quick response and excellent sensitivity for luteolin, daidzein, or baicalein detection, facilitating real-time and portable detection, highlighting its great potential in batch production of the sensor devices. [Display omitted] • A binder-free electrode is prepared for simultaneous luteolin, daidzein and baicalein detection. • The sensor exhibits high activity with wide linear range and low detection limit. • A two-electrode sensor device is assembled using the AgNP/ZnONR@CFP electrode. • The novel sensor device allows real-time, portable detection and paves the way for mass production. [ABSTRACT FROM AUTHOR]

• A Goal Programming model to optimize a waste paper recycling network was elaborated. • The model considers objectives related to sustainability, multiple products and periods. • Vehicle routing, different-capacity vehicles and multiple trips are highlights. • The possibility of storing material at the collection points is considered. • The formulation provides relevant solutions to assist decision-makers. Organization and planning of reverse logistics networks make sustainable processes more efficient. Thus, an important sector for connecting the collection and waste paper recycling echelons is the intermediate center. In this study, a Mixed Integer Linear Programming model, which is multi-objective, multi-product, multi-level and multi-period, was developed to optimize the waste paper logistics processes of intermediate centers. The formulation includes the following echelons: collection, considering vehicle routing with different capacities; inventory of non-baling materials; baling sorted waste and inventory of bales; selling bales; disposal of non-recyclable waste. The aims of the model include: maximizing the collected waste; minimizing distances; maximizing both the production and sale of bales, and minimizing costs. According to research carried out in the literature, the developed model is a new proposal and to implement it, the Weighted Goal Programming and Revised Multi-Choice Goal Programming approaches were used to deal with multiple objectives and incorporate uncertainty into the quantity of waste available for collection. To analyze the proposed model, computational tests were executed with instances based on real data from a Brazilian company in the sector. For all performed tests, General Algebraic Modeling System 23.6.5 modeling language and CPLEX 12.2.0.2 solver were used for modeling and optimization. The results show that this study presents formulation and technological approaches that represent real situations and provide competitive solutions to the problem. [ABSTRACT FROM AUTHOR]

[Display omitted] • Optimization study of Photo-Fenton and PDS/UV processes for BOD and COD removal. • Photo-Fenton process was able to enhance biodegradability. • PDS/UV process on the best condition only could maintain the biodegradability. • The operational cost of Photo-Fenton processes is much cheaper than PDS/UV process. The aim of this study is to provide an Advanced Oxidation Process (AOP) based solution to enhance biological treatment efficiency by improving biodegradability of wastewater. Photo-Fenton and Peroxydisulfate (PDS)/UV processes were selected in this study as a representative of hydroxyl and sulfate radical based AOPs. A central composition design (CCD) employed to optimize operational cost and BOD/COD ratio to determine optimal conditions for enhancing wastewater treatment efficiency. The study achieved a maximum COD removal of 71.5 % and increased wastewater biodegradability. Optimal conditions for Photo-Fenton process were DOD (H 2 O 2) 0.28, [Fe2+] 106.26 mg/L, and pH 2.32, costing 2.27 USD per 1 kg COD removed. For PDS/UV process, 75.5 % COD removal was achieved at a cost of 10.6 USD/1 kg removed COD. The PDS/UV process had higher COD removal than Photo-Fenton but did not improve wastewater biodegradability. Optimal conditions were DOD (PDS) 0.19, pH 6.68, costing 10.6 USD/1 kg COD removed. [ABSTRACT FROM AUTHOR]

The reuse of waste papers by conversion into valuable carbon materials has received considerable attention for diverse applications such as energy storage and water purification. However, traditional methods for converting waste papers into materials with suitable properties for specific applications are often complex and ineffective, involving consecutive carbonization and activation steps. Herein, we propose a simple one-step microwave (MW)-assisted synthesis for preparing waste paper-derived porous carbons (WPCs) for energy storage and water purification. Through a 30-min synthesis, WPCs with graphitic structure and high specific surface area were successfully produced. The fabricated WPCs exhibited outstanding charge storage capability with a maximum specific capacitance of 237.7 F g−1. Additionally, the WPC demonstrates a high removal efficiency for various dyes, achieving a maximum removal efficiency of 95.0% for methylene blue. The developed one-step MW synthesis not only enables the production of porous carbon from waste paper, but also offers a viable approach to address solid waste management challenges while simultaneously yielding valuable materials. [Display omitted] • Waste paper-derived porous carbons were synthesized by one-step microwave synthesis. • Within 30-min MW synthesis, graphitic and high-surface area WPCs were produced. • WPC exhibits outstanding electrochemical capacitance of 237.7 F g−1. • WPC exhibits high removal of various dyes, with maximum of 95.0% for methylene blue. [ABSTRACT FROM AUTHOR]

[Display omitted] • Paper mill sludge ash (pm SA) was used as catalysts to activate PMS. • Aerobic calcination was conducive to the exposure/formation of octahedral FeIII. • The O O bond fracture was the root pathway for FeIV O production. • The release of solid calcium in pm SA could inhibit the active decay of FeIV O. • The pm SA could effectively degrade similar pollutants in near-neutral water. The excellent performance of high-valent iron-oxo species (FeIV O) in the degradation of pollutants by activating peroxymonosulfate (PMS) had attracted much attention. However, the generation and reaction mechanisms were still unclear. In this study, iron-rich paper mill sludge was used as a raw material for the first time to prepare iron-based catalysts with abundant octahedral FeIII sites (Fe oct III). The results showed that the highest content of Fe oct III was found in the paper mill sludge ash obtained by aerobic calcination at 800 °C (pm SA800), and the pm SA800 could exhibit excellent catalytic activity (0.4785 min−1) and stability during the oxytetracycline (OTC) degradation process. The characterization and density functional theory (DFT) calculations further indicated that the Fe oct III was the dominant active site for FeIV O production. PMS tended to be adsorbed on two adjacent Fe oct III sites to form a [Fe oct III-OSO 2 OO(H)-Fe oct III] complex with a two-site adsorption configuration. Subsequently, the O O and O H bonds in [Fe oct III-OSO 2 OO(H)-Fe oct III] broken by absorbing energy, generating FeIV O. It's worth noting that the Ca species of pm SA800 effectively stabilized the pH of the reaction solution, which ensured the stable and continuous production of FeIV O. This work provides a new idea and insight for preparing catalysts that could produce FeIV O active species. [ABSTRACT FROM AUTHOR]

Waste paper and tyre are typical solid wastes with distinct composition. Their pyrolysis could generate varied volatiles that may interact with each other or with resulting char. In this study, the co-pyrolysis of waste paper and tyre was investigated at 400 and 600 ºC, with the focus on understanding the interaction of the volatiles on evolution of the products. The results show that the interaction of the volatiles at 400 ºC forms more gaseous products like CO and CO 2 , while the interactions of the heavier organics at 600 ºC forms more oil (49.3% vs 42.6%). The interaction of the volatiles also affects the generation of sulfur-containing organics and diminishes the paper-derived aldehydes and ketones or the heavy organics with the π-conjugated structures in the oil. In addition, the volatile-char interactions exist and form the char of higher carbon content through promoting carbonization and deoxygenation reactions, generating char of higher thermal stability and higher hydrophilicity via tailoring functional group, pore structures and morphologies of the char. [Display omitted] • Interaction of volatiles in co-pyrolysis of waste paper and tyre exists. • Co-pyrolysis promotes formation of gases at 400 ℃ while oil at 600 ℃ via condensation. • Paper-derived intermediates capture CH x * /H* radicals, minimizing CH 4 /H 2 formation. • Volatiles interactions interfere formation of S-containing organics and aldehydes/ketones. • Co-pyrolysis affects composition, stability, functionality and morphologies of char. [ABSTRACT FROM AUTHOR]

The development of greatly stable and cost-effective electrocatalysts for urea electro-oxidation reactions (UERs) is urgent and challenging for promoting urea removal in the wastewater and advanced energy conversion devices. We demonstrated that nickel-iron borate (NiFe-B) electrocatalysts supported on carbon paper (CP) for UERs through a one-pot solvothermal method. NiFe-B electrocatalysts were obtained with numerous Ni/Fe molar ratios in the precursors, and the physicochemical features of the NiFe-B were examined by X-ray diffraction, scanning and transmission electron microscope, and X-ray photoelectron spectroscopy. The optimized NiFe-B/CP exhibited a low onset potential (E onset = 0.287 V vs. SCE) with a Tafel slope of 27.9 mV/dec on CP, demonstrating much greater performance UERs. Furthermore, the NiFe-B/CP catalysts have shown a superior activity for the UERs in alkaline solution and exhibit more than two-fold enhancement in activity than Ni-B. Facile, cost-effective fabrication and highly efficient urea oxidation create the NiFe-B electrodes as attractive materials for UERs. [Display omitted] • Amorphous Ni-Feborate/CP fabricated via facile hydrothermal process. • NiFe-B-2/CP electrode materials exhibited a lower onset potential with an overpotential of 327 mV at 10 mA cm−2. • Mass activities of NiFe-B-2/CP electrode materials reach up to 51.7 A/g. • NiFe-borate materials are a promising candidate for efficient electrocatalytic reactions. [ABSTRACT FROM AUTHOR]

Paper-based digital microfluidic biochips (PB-DMFBs) have emerged as the most promising solution to biochemical applications in resource-limited regions. However, like silicon chips, the reliability of PB-DMFBs is affected by physical defects. Even worse, since electrodes, conductive wires, and droplet routings are entangled on the same layer, multiple faults may occur simultaneously. Such faults not only cause waste of samples and human resource but also affect the correctness of the diagnostics. In this paper, we propose a reliability scheme with emphasis on design-for-reliability (DfR) and probability-based fault tolerance to ensure the correct functionality of PB-DMFBs with multiple faults. • Multiple fault assumption is considered for electrode open fault and wire open fault models. • Design-for-Reliability design flow is proposed for alternative droplet paths to bypass the faulty electrodes. • On-the-fly fault tolerance procedure is proposed to tolerate the faulty electrodes. • The proposed procedure has the least dependence on sensors for fault tolerance automation. [ABSTRACT FROM AUTHOR]

The thin-walled tubular deployable composite boom (DCB) can realize folding and deploying functions, and it has a good application prospect in space field. This paper investigates the folding behaviour of the tubular DCB by analytical modeling. Based on the Archimedes' helix, the geometrical model of the DCB was established. By combining equilibrium equation and energy principle, an analytical model to predicted the folding moment versus rotational displacement of the DCB was presented. The failure indices in the equal-sense and opposite-sense folding processes were calculated utilizing Tsai‐Hill and maximum stress criteria. Analytical results agreed well with experimental and numerical results. At last, the influence of geometric parameters (i.e., radius, central angle and thickness of cross-section) on the folding behaviour of the DCB was further studied using the analytical model. [Display omitted] • An analytical model is presented to predict the folding behaviour of the deployable composite boom (DCB). • Failure indices are calculated using two criteria in equal-sense and opposite-sense folding processes. • The analytical model is validated against experimental and numerical results, showing good prediction accuracy. • Geometric parameters (radius, central angle, and thickness) significantly affect the folding behavior of the DCB. [ABSTRACT FROM AUTHOR]

Developing flexible gas sensors based on reduced graphene oxide (rGO) are highly promising for practical application, however, it is still challenging due to the sacrificed solution-processibility and mechanical properties after reduction. To address this issue, we here introduce solution-processed rGO and designed a flexible hydrogen (H 2) film sensor by coupling with Pd nanoclusters as the activators via direct colloids mixing and subsequent vacuum filtration. The rGO/Pd nanocluster film features with structural compactness, surface homogeneity, excellent mechanical flexibility, high-efficiency output, and simplification of compositing method. In addition, the film sensor exhibited high response value, fast behavior and stable sensing behavior towards high-concentration H 2 compared with bare rGO film owing to the significant activation role of Pd nanoclusters with ultrasmall sizes (average size: 3.3 nm). Conclusively, this work provides an ingenious and effective way for the design of rGO-based flexible sensor, and shows promise for efficient portable and cost-effective monitoring of environmentally H 2 gases leaks. [ABSTRACT FROM AUTHOR]

Kraft paper (KP) has the advantages of being biodegradable, recyclable, and environmentally friendly. It has a wide range of applications in paper packaging, food packaging, and other fields. However, the non-waterproof characteristic of KP limits its application in harsh environments or special paper packaging, etc. To solve the problem of poor water resistance of KP, a simple and efficient method is proposed to prepare superhydrophobic coatings on kraft paper (SKP) by spraying method using hydrophobic Nano-calcium carbonate (Nano-CaCO 3) particles and rosin (RA) as raw materials. Here, the micro-nano structures are mainly constructed by hydrophobic Nano-CaCO 3 particles, and RA is utilized as a binder to improve the adhesion between the nanoparticles and the paper. The results indicated that the water contact angle (WCA) of SKP reached 154.5° and the water sliding angle (WSA) was 3.2°. And after 34 h of immersion in water, the WCA of SKP surface can remain above 150°. It can also withstand 30 times of sandpaper abrasion and 30 times of tape peeling. Overall, SKP shows excellent stability, water resistance, stain resistance and self-cleaning. It is expected to protect important documents in harsh environments. [Display omitted] [ABSTRACT FROM AUTHOR]

In this study, continuous carbon reinforced C f /(Ti 0.2 Zr 0.2 Hf 0.2 Nb 0.2 Ta 0.2)C–SiC high entropy ceramic matrix composites were additively manufactured through paper laminating (PL), direct slurry writing (DSW), and precursor infiltration and pyrolysis (PIP). (Ti 0.2 Zr 0.2 Hf 0.2 Nb 0.2 Ta 0.2)C high entropy ceramic (HEC) powders were synthesized by pressureless sintering and ball milling. A certain proportion of HEC powder, SiC powder, water, binder, and dispersant were mixed to prepare the HEC-SiC slurry. Meanwhile, BN coating was prepared on the 2D fiber cloth surface by the boric acid-urea method and then the cloth was cut into required shape. Additive manufacturing were conducted subsequently. Firstly, one piece of the as-treated carbon fiber cloth was auto-placed on the workbench by paper laminating (PL). Then, the HEC-SiC slurry was extruded onto the surface of the cloth by direct slurry writing (DSW). PL and DSW process were repeated, and a C f /HEC-SiC preform was obtained after 3 cycles. At last, the preform was densified by precursor infiltration and pyrolysis (PIP) and the final C f /HEC-SiC composite was prepared. The open porosity of the C f /HEC-SiC composites, with the HEC volume fractions of 15, 30 and 45%, were 7.7, 10.6, and 11.3%, respectively. And the density of the C f /HEC-SiC composites, with the HEC volume fractions of 15, 30 and 45%, were 2.9, 2.7 and 2.3 g/cm3, respectively. The mechanical properties of the C f /HEC-SiC composites increased firstly and then decreased with the HEC content increase, reaching the maximum value when the HEC volume fraction was 30%. The mechanical properties of the C f /HEC-SiC composites containing 45, 30 and 15% HEC were as follows: flexural strength (180.4 ± 14 MPa, 183.7 ± 4 MPa, and 173.9 ± 4 MPa), fracture toughness (11.9 ± 0.17 MPa m1/2, 14.6 ± 2.89 MPa m1/2, and 11.3 ± 1.88 MPa m1/2), and tensile strength (71.5 ± 4.9 MPa, 98.4 ± 12.2 MPa, and 73.4 ± 8.5 MPa). From this study, the additive manufacturing of continuous carbon fiber reinforced high entropy ceramic matrix composites was achieved, opening a new insight into the manufacturing of ceramic matrix composites. [ABSTRACT FROM AUTHOR]

In this study, we developed a novel, simple, rapid, and low-cost colloidal gold-based immunochromatography method, with filter paper replacing nitrocellulose membrane as the substrate. To obtain adequately immobilized protein, chitosan was used to functionalize the filter paper. After conditions and parameters were optimized, the novel immunochromatography method was applied for detection of sulfonamide residues in milk. Quantitative detection was accomplished using a smartphone and Photoshop software (Adobe Inc., San Jose, CA), allowing us to screen 13 sulfonamides with a limit of detection ranging from 0.42 to 8.64 μg/L and recovery ranging from 88.2 to 116.9% in milk. The proposed novel method performed similarly to the conventional method that uses a nitrocellulose membrane as the transport medium, and it had lower cost and better usability because of the inexpensive and easily available filter paper. [ABSTRACT FROM AUTHOR]

Peer-reviewed conferences, the main publication venues in CS, rely critically on matching highly qualified reviewers for each paper. Because of the growing scale of these conferences, the tight timelines on which they operate, and a recent surge in explicitly dishonest behavior, there is now no alternative to performing this matching in an automated way. This paper introduces Large Conference Matching (LCM) , a novel reviewer–paper matching approach that was recently deployed in the 35th AAAI Conference on Artificial Intelligence (AAAI 2021), and has since been adopted (wholly or partially) by other conferences including ICML 2022, AAAI 2022-2024, and IJCAI 2022-2024. LCM has three main elements: (1) collecting and processing input data to identify problematic matches and generate reviewer–paper scores; (2) formulating and solving an optimization problem to find good reviewer–paper matchings; and (3) a two-phase reviewing process that shifts reviewing resources away from papers likely to be rejected and towards papers closer to the decision boundary. This paper also describes an evaluation of these innovations based on an extensive post-hoc analysis on real data—including a comparison with the matching algorithm used in AAAI's previous (2020) iteration—and supplements this with additional numerical experimentation.2 [ABSTRACT FROM AUTHOR]

Nonalcoholic fatty liver disease (NAFLD) is a major cause of chronic liver disease globally and in India. The already high burden of NAFLD in India is expected to further increase in the future in parallel with the ongoing epidemics of obesity and type 2 diabetes mellitus. Given the high prevalence of NAFLD in the community, it is crucial to identify those at risk of progressive liver disease to streamline referral and guide proper management. Existing guidelines on NAFLD by various international societies fail to capture the entire landscape of NAFLD in India and are often difficult to incorporate in clinical practice due to fundamental differences in sociocultural aspects and health infrastructure available in India. A lot of progress has been made in the field of NAFLD in the 7 years since the initial position paper by the Indian National Association for the Study of Liver on NAFLD in 2015. Further, the ongoing debate on the nomenclature of NAFLD is creating undue confusion among clinical practitioners. The ensuing comprehensive review provides consensus-based, guidance statements on the nomenclature, diagnosis, and treatment of NAFLD that are practically implementable in the Indian setting. [ABSTRACT FROM AUTHOR]

There is a growing realization on the part of lawmakers, policy experts and practitioners that cyber risks and threat vectors constitute a critical and strategic challenge for all outer space operations. Stakeholders' professional attention and resources are beginning to focus on measures for mitigating these risks and threats. Space-based activities depend on the reliable functionality of computer systems and the wireless communications connecting them through use of the electromagnetic spectrum resource – all of which constitute parts of the infrastructure of cyberspace both on Earth and in space. Thus, cyber risks and vulnerabilities arise in all aspects of outer space operations: satellite launches and their orbital telemetry, tracking, and control (TTC); operational communications (space-to-space, earth-to-space and space-to-earth); and other spectrum-dependent space transmissions. Additional cyber vulnerabilities are present in the terrestrial systems supporting space operations, including launch systems and supply chains for dedicated equipment and services. The mitigation of such cyber threats and vulnerabilities in the more traditional terrestrial context is a rapidly developing area of law and policy aiming to counter the activities of malicious cyber actors whether they are criminals, States or hostile ideological groups. On the one hand, the threat mitigation aspects of cybersecurity have by no means been resolved, as hostile actors use increasingly sophisticated means to achieve their ends. On the other, progress has been made with respect to measures and best practices recognized as critical to boosting cybersecurity for space activities. This article focuses on one of these: information sharing (IS) among trusted participants in a secure platform designed for sharing actionable cybersecurity data. The primary goal of such sharing is to reduce the informational asymmetry between the attacker and the target, whether the latter is a State, private company, or other entity. Cyber attackers leverage their knowledge of the target's vulnerabilities, and only need to be right on one occasion to cause operational, financial, and/or reputational damage that may impair the long-term functionality of the targeted entity. Yet when a group of potential targets can reliably share data on cyber risks and measures to counter them, the informational asymmetry is reduced, and cybersecurity improved. Several conditions exist for optimizing IS which provides actionable information, and for ensuring that trust is developed and maintained among IS participants. Finally, in the context of outer space-related cybersecurity threats, the paper argues that IS proves critical because of two elements: the aggravated asymmetry of cyber threat vectors in outer space, and their distinctive space-related characteristics. • There is a growing realization that cyber risks and threat vectors constitute a critical and strategic challenge for all outer space operations. • Stakeholders' professional attention and resources are focusing on measures for mitigating these risks and threats. • Space-based activities depend on the reliability of computer systems and their wireless connection, – which constitute the infrastructure of cyberspaceon Earth and in space. • Cyber risks and vulnerabilities arise in all aspects of outer space operations, andadditional. • Cyber vulnerabilities are present in the terrestrial systems supporting them. • Several conditions exist for optimizing IS which is actionable, and for ensuring that trust is maintained among IS participants. • Several conditions exist for optimizing IS which is actionable, and for ensuring that trust is maintained among IS participants. • Information sharing for outer space cybersecurity is critical because of the aggravated asymmetry of cyber threat vectors in space and their distinctive space-related characteristics. [ABSTRACT FROM AUTHOR]

Electron/phonon heat co-transfer, dielectric/magnetic dual loss, and 2D interlinked frameworks codetermine the ultrawide absorption bands, high thermal conductivity, and excellent electrical insulation of CF/M/C (M = Co, Ni, or Fe/Fe 3 O 4) 2D interlinked frameworks. [Display omitted] • A facile soaking-annealing strategy for CF/M/C (M = Co, Ni, Fe/Fe 3 O 4) 2DIFs. • Precisely modulating the interfaces, porosity, and defects. • Optimizing the thermal, electrical, and EMW absorbing properties. • Revealing the synergistic enhancement mechanism. Reasonable design of protective multifunctional materials is highly required for the safety protection of devices/personnel from electromagnetic radiation and heat damage in the 5G/6G era. Herein, a simple soaking-annealing route was adopted to carbonize filter paper into 2D interlinked carbon fiber frameworks inlaid with magnetic nanoparticles, and the products were referred to as CF/M/C 2DIFs (M = Co, Ni, or Fe/Fe 3 O 4). The concentration and type of metal ions as well as the annealing temperature of the CF/M/C 2DIFs were controlled to precisely modulate their composition, porosity, and defects. Results show that the CF/Co/C 2DIFs produced under T a = 600 °C and [Co2+] = 0.45 mol/L exhibit high thermal conductivity (2.931 ∼ 3.167 W/m·K) at small loads (10 ∼ 30 wt%) owing to not merely the presence of 2D interlinked path for electron/phonon heat co-transfer but the reasonable control of interface/defects for weakening phonon/electron defect/interface scattering. Also, the CF/Co/C 2DIFs can attenuate microwaves over a broad frequency range via dielectric/magnetic dual loss and 2DIFs, which boosts their loss ability and matching performance. The excellent performance in both heat dissipation and EM wave absorption proves that the CF/M/C 2DIFs can be a promising candidate for next-generation electronic packaging materials in heat management, military, and aerospace fields. [ABSTRACT FROM AUTHOR]

[Display omitted] • Multi-layer forming technology can integrate triboelectric material with electrode. • The all CPTENGs can exhibit excellent humidity, acid and alkali resistance. • The CPTENGs can yield a V OC , I SC and power density of 227.1 V, 6.9 μA and 520 mW/m2. • Matching CPTENGs with P-ZISC can obtain a self-charging power system (PSCPS). • The PSCPS can drive some miniaturized electronics for a long time. Triboelectric nanogenerators (TENGs) are regarded as a promising technology to drive the development of flexible/wearable electronics and self-powering sensor. Application of cellulose paper as the triboelectric positive materials makes TENGs more environmentally friendly. However, the limited output performance and stability in harsh environments and oxidation and corrosion of the metal electrodes have limited the practical application of cellulose paper based triboelectric nanogenerators (CPTENGs). Here, we have integrated cellulose paper-based triboelectric material and electrode in one sheet by using multi-layer forming technology in paper industry; the upper triboelectric layer shows excellent triboelectric positive performance, hydrophobicity and acid and alkali resistance, while the bottom electrode exhibits promise conductivity. The all CPTENGs can yield a maximum open-circuit voltage (V OC) of 227.1 V, a short-circuit current (I SC) of 6.9 μA. Furthermore, the V OC values of the all CPTENGs increase from 0.02 V to 225.1 V at the load resistance of 100 Ω∼10 GΩ; and a power density of 520 mW·m−2 is also obtained at a load resistance of 30 MΩ. Moreover, the V OC of CPTENGs not only retains up to 78 % of its initial value at a high relative humidity of 90 %, but also almost maintains unchanged in a wide range of the pH environment (pH = 1∼13). More importantly, the CPTENGs can be readily matched with paper-based zinc supercapacitor (P-ZISC) to act as an all paper based self-charging power system (PSCPS). The PSCPS is capable of driving various miniaturized electronics, such as electronic watch, temperature/humidity indicator, demonstrating its potential application in a sustainable power source for portable and green electronics. [ABSTRACT FROM AUTHOR]

Paper-based nucleic acid detection and diagnosis are currently gaining much interest in point-of-care (POC) applications. The major steps involved in any nucleic acid amplification testing (NAAT) based diagnostics are nucleic acid isolation, reverse transcription (RT) (in the case of RNA), amplification and detection. RT is an important step in quantifying the viral load in case of disease diagnosis as well as quantifying gene expression levels in other molecular studies. cDNA synthesis is routinely carried out using a thermal cycler, with the process requiring temperatures between 40ºC to 65ºC. Here we report for the first time an instrument-free RT, performed at room temperature on cellulose-based paper devices. cDNA synthesis on paper was confirmed by RT-PCR and Sanger sequencing of the PCR products. Purified RNA from varied sources such as cell lysate, tissue and blood were used to test the methodology. Synthetic hepatitis C virus (HCV) RNA and human blood RNA were used as proof-of-concept to demonstrate the use of these devices in diagnostic applications. Further, ready-to-use paper-based reverse transcription (PRT) devices have been developed, wherein only the RNA sample is added on the device and the cDNA can be eluted after 30 min of incubation at room temperature. The devices were found to be stable for 30 days at − 20ºC storage. The cellulose-based PRT devices are simple, time saving and user-friendly for a complete instrument-free cDNA synthesis at room temperature. [Display omitted] • A complete instrument-free reverse transcription at room temperature is demonstrated. • Reverse transcription can be performed on cellulose paper-based microfluidic device. • Ready-to-use PRT devices need only the addition of RNA and water to obtain cDNA. • The reaction is completed in 30 mins, thus time saving. [ABSTRACT FROM AUTHOR]

[Display omitted] • 28 out of 57 target PFAS were detected in paper products from China. • 9 groups of PFAS with 1–3 confidence levels were identified by non-target analysis. • Ethanol in food simulants can increase the migration of PFAS. • Long-chain PFAS in popcorn bags can be degraded by microwave heating. • PFAS in some paper products exceeded the recommended daily intake values. The contamination characteristics, migration patterns and health risks of per- and polyfluoroalkyl substances (PFAS) were investigated in 66 Chinese paper products by using target and non-target screening methods. Among 57 target PFASs, 5 and 6 PFASs were found in the hygiene paper products (

In the current study, the exergoeconomic analysis of a cogeneration pulp and paper plant under bi-operating modes at different environment temperatures of 290, 295, 305, 310, and 320 K was investigated. Two operating modes of the cogeneration system, i.e., a hybrid operating mode using a power boiler and a recovery boiler and a singular operating mode using a power boiler only, were considered. Natural gas was utilized as the main fuel in the power boiler, while black liquor with heavy fuel oil was employed in the recovery boiler. The total capital investment, total operating, exergy, unit exergy, and exergy destruction costs for each operating mode were evaluated. The results indicated that the total capital investment cost was 3420.27 $/h, and the total capital investment and the operation and maintenance costs in the hybrid and singular modes were 5853.27 and 6226.67 $/h, respectively. As well, the unit exergy cost and the exergy cost of steam introduced by the power boiler were 39.31 $/MWh and 2503.69 $/h, respectively. Where these values for the recovery boiler were 34.69 $/MWh and 554.30 $/h, respectively. Furthermore, the exergy destruction costs at an environment temperature of 320 K for the power and recovery boilers were 1436.6 and 213.63 $/h, respectively. In the hybrid mode, the soda at a 10% concentration was recovered, with a rate of 32 t per hour desired for the cooking process in the pulp mill. In addition, the use of black liquor as a bio-fuel in the recovery boiler saved 14% of the consumption of natural gas. • Exergoeconomic analysis was performed for the pulp and paper industry. • Hybrid and singular operating modes for different ambient temperatures were studied. • Unit exergy cost, exergy cost, and exergy destruction cost were evaluated. • Using black liquor as a bio-fuel in RB saved about 14% of natural gas consumption. [ABSTRACT FROM AUTHOR]

The commented paper claimed the preparation of a new compound, Bi 1/2 Li 1/2 Fe 1/2 W 1/2 O 3. By this commentary, we show that erroneous experimental evidence was provided for such claims. We demonstrate that the main phase in the commented paper is Bi 2 WO 6. [ABSTRACT FROM AUTHOR]

In this research, Fe 2 O 3 nanorod arrays grown on carbon fiber paper were studied, and carbon-coated Fe 2 O 3 (Fe 2 O 3 @C) and sulfurized Fe 2 O 3 @C (Fe 2 O 3 @C-S) were fabricated by carbon coating and sulfurization processes. To promote the application of these materials in supercapacitors, their electrochemical properties were systematically investigated. Based on the results, the materials obtained utilized a pseudocapacitive mechanism for energy storage. Specifically, Fe 2 O 3 exhibited a moderate specific capacitance and extraordinary cycling stability, and no degradation was observed after 10,000 cycles. Impressively, sulfurization greatly enhanced the rate capability and specific capacitance of the sample. As a result, Fe 2 O 3 @C-S attained a specific capacitance of 976.4 mF cm–2 at 4 mA cm–2 and a robust rate capability of 97.30% at 20 mA cm–2, outperforming Fe 2 O 3 @C (84.39%) and Fe 2 O 3 (70.55%) and demonstrating good cycling stability (92.9%). Notably, Fe 2 O 3 @C-S was active as a positive electrode material; thus, a symmetric supercapacitor was assembled, which yielded a volumetric energy density of 1.46 mWh cm–3 at 16.71 mW cm–3 and maintained an energy density of 0.91 mWh cm–3 even at 145.63 mW cm–3. Moreover, the device exhibited good cycling stability with a capacity retention of 88.3% after 10,000 cycles at 10 mA cm–2. The integration of Fe 2 O 3 nanorod arrays on conductive substrates, coupled with the above modifications, strongly promoted the material's energy storage performance. Our study emphasized the significant potential of Fe 2 O 3 @C-S as an efficient electrode material for supercapacitors. • Fe 2 O 3 /CFP exhibited outstanding cycling stability with no capacity degradation. • Fe 2 O 3 @C-S showed greatly enhanced specific capacitance and rate capability. • Pore structure demonstrated a crucial factor in determining the performance. [ABSTRACT FROM AUTHOR]

Glutathione (GSH) acts a crucial role in the normal operation of manifold life activities and is closely bound up with many human diseases. Here, a SERS-colorimetric bimodal paper-based biosensor based on Mn-doped CDs/silver nanoparticles (Mn-CDs/AgNPs) has been fabricated for high-efficiency quantification of intracellular GSH. The Mn-CDs/AgNPs with fine oxidase-like characteristic and SERS enhancement ability has been assembled onto the Whatman filter paper (WFP) to cleverly fabricate paper chip (Mn-CDs/AgNPs@WFP) which can trigger the oxidation of colorless 3,3′,5,5′-tetramethylbenzidine (TMB) into blue TMBox and simultaneously enhance the SERS signal of TMBox. However, the introduction of GSH inhibits the oxidation of TMB, leading to color fading of paper chip and diminishment of SERS signal. Considering this, the bimodal paper-based sensing platform can be exploited for SERS-colorimetric detection of GSH, manifesting excellent selectivity, reliable stability, and satisfactory precision. The detection limits of SERS and colorimetric detection modes are as low as 0.41 μM and 0.53 μM, respectively. Furthermore, this proposed bimodal biosensor has been successfully utilized for the determination of intracellular GSH and validated by commercial GSH assay kit, which provides a mighty and convenient tool for intracellular GSH detection and can boost future effort about exploitation of other multimode paper-based biosensors as well as promote their appliances in disease diagnosis. [ABSTRACT FROM AUTHOR]

• Pulp and paper industry sludges are potential conditioners of coarse-textured soil. • Sludge amendment increased total soil porosity and plant available water. • 30–40% of the amount of C added in sludge materials was respired in two months. • Decomposition of the sludges led to short-term net N immobilisation. • The extent of impacts depends on application rate and sludge characteristics. Building up the organic matter content of coarse-textured soils with organic amendments seeks to ameliorate the productivity of these soils, which is limited by plant available water and nutrient supply. Wood fibre-based sludges from the pulp and paper industry have potential for soil conditioning. In this study, the effects of three different pulp and paper mill sludges at application rates of 10 and 20 vol-% on water retention, respiration, and nitrogen (N) dynamics were examined in a series of laboratory studies using coarse field soils. Water retention curves comprising 13 matric potentials revealed that the amendments increased total soil porosity and volumetric water content at matric potentials corresponding to macro- and mesopores size range with pore diameters of >30 μm and 30–0.2 μm, respectively. Volumetric water content at field capacity increased by c. 10–30%, depending on the type (fresh, lime-stabilised and fibre sludge) and application rate of the amendment, with no marked change in the water content at the permanent wilting point. This was reflected as a mean increase of 1.9–3.3 mm in the plant available water content relative to the non-amended soils (17 mm), which corresponds to 19–33 m3 per hectare. At most, an increase of 5.5 mm (55 m3 ha−1) in plant available water was achieved by the fibre sludge amendment at an application rate of 20 vol-%. During a 60-day laboratory incubation, c. 30–40% of the carbon (C) added to soil in the sludge materials was respired as carbon dioxide. Additional N accelerated decomposition without increasing total respired C. Decomposition of the amendments in the soil led to a net N immobilisation of roughly 5–10 mg min-N g−1 added C, which occurred mainly during the first two weeks after soil incorporation. Overall, pulp and paper mill sludge amendments may serve to alleviate water shortages during drought in coarse-textured soils, but may generate a transient plant-microbe competition in N uptake. [ABSTRACT FROM AUTHOR]

• The influence of nanoparticles on the dielectric properties of neem oil was investigated. • Dielectric properties of the base liquid increases with nanoparticles loading. • Effect of temperature on the dielectric loss of the nanofluids was investigated. • The compatibility test of the nanofluid with kraft paper was investigated. • Nanofluid has no pronounce effects on the dielectric properties of kraft paper. Methyl ester from vegetable oil has been considered a potential replacement for mineral oil used for power transformer cooling and insulating applications. However, some pertinent properties in making this liquid a better transformer oil based on the laydown standards need to be enhanced to maximize the use of this insulating liquid. Technology involving nano-modification can enhance the properties of these ester liquids placing them in a better position as a good alternative. In this study, we aim to investigate the performance of methyl ester liquid from neem seed oil, a non-food grade oil, when modified with SiO 2 insulating nanoparticles at several concentrations. Furthermore, Kraft paper compatibility has also been analyzed to observe their compatibility after impregnation. The breakdown strength, temperature-dependent dissipation loss factor, dielectric constant, and viscosity of both pure and nanofluid samples of neem ester liquid have been measured per standard methods. The nanofluid's dielectric performance has been significantly enhanced by the presence of SiO 2 nanoparticles according to results obtained from the experiment. For instance, the dielectric dissipation factor at an operating frequency of 60 Hz has been improved by 96%, 89%, and 79% at 30 °C, 50 °C, and 70 °C respectively relative to the base neem liquid. This remarkable improvement has been attributed to the SiO 2 nanoparticle's ability to polarize, trap, and de-trap mobile electrons develop in nanofluid when an electric field is applied. [ABSTRACT FROM AUTHOR]

• The influence of nanoparticles on the dielectric properties of neem oil was investigated. • Dielectric properties of the base liquid increases with nanoparticles loading. • Effect of temperature on the dielectric loss of the nanofluids was investigated. • The compatibility test of the nanofluid with kraft paper was investigated. • Nanofluid has no pronounce effects on the dielectric properties of kraft paper. Methyl ester from vegetable oil has been considered a potential replacement for mineral oil used for power transformer cooling and insulating applications. However, some pertinent properties in making this liquid a better transformer oil based on the laydown standards need to be enhanced to maximize the use of this insulating liquid. Technology involving nano-modification can enhance the properties of these ester liquids placing them in a better position as a good alternative. In this study, we aim to investigate the performance of methyl ester liquid from neem seed oil, a non-food grade oil, when modified with SiO 2 insulating nanoparticles at several concentrations. Furthermore, Kraft paper compatibility has also been analyzed to observe their compatibility after impregnation. The breakdown strength, temperature-dependent dissipation loss factor, dielectric constant, and viscosity of both pure and nanofluid samples of neem ester liquid have been measured per standard methods. The nanofluid's dielectric performance has been significantly enhanced by the presence of SiO 2 nanoparticles according to results obtained from the experiment. For instance, the dielectric dissipation factor at an operating frequency of 60 Hz has been improved by 96%, 89%, and 79% at 30 °C, 50 °C, and 70 °C respectively relative to the base neem liquid. This remarkable improvement has been attributed to the SiO 2 nanoparticle's ability to polarize, trap, and de-trap mobile electrons develop in nanofluid when an electric field is applied. [ABSTRACT FROM AUTHOR]

Proper equipment maintenance can significantly reduce overall operating costs by boosting productivity. Management personnel often consider maintenance an expense; however, a more positive approach is to view maintenance as a profit center. Considering this new perspective, the requirements for maintenance management have changed drastically from the traditional concept of fix-it-when-broken to a more complex approach that entails adopting a maintenance strategy for a more integrated approach and alignment. This paper presents a Goal Programming (GP) approach to define the most cost-effective method for maintaining some critical pumps in the paper industry. The failure mode and effects analysis (FMEA) criteria consider each machine failure's occurrence, severity, and detection. After determining the weights, the optimal strategy for each failure is calculated by solving the goal programming. Thus, FMEA can be used to design a network structure for each pump failure mode. For this purpose, the limitations and goals affecting the model are obtained from research literature and interviews with experts. Regarding resource utilization and failure reduction, the results demonstrate that predictive and preventive maintenance strategies are superior to corrective strategies. Therefore, these strategies can predict failures, provide helpful information to maintenance managers, and limit the negative aspects of a failure regarding safety and cost. [ABSTRACT FROM AUTHOR]

In order to solve the problems of high cost and high brittleness of commercial carbon fiber paper, a low-cost mass production method of carbon fiber paper for flexible super capacitor was proposed. The dispersant CMC-Na is utilized to achieve uniform dispersion of chopped carbon fiber in a water system through ultrasonic dispersion. Sheath-core composite (PE/PET) fiber not only enhances the tensile strength of CFP but also consolidates the electrode network structure formed based on carbon fiber structure. The CFP-3 electrode, impregnated with 3 % AC phenolic resin, exhibits excellent mechanical and electrochemical properties. SEM images reveal that AC is deposited on each carbon fiber and that the CFP-3 electrode retains its three-dimensional structure (with a porosity of 71.2 %), providing an effective permeation path for electrons (with an electrical conductivity of 0.871 S m−1). The CFP-3 electrode can restore its original shape after folding and bending without damage. Electrochemical tests demonstrate that the CFP-3 electrode has a high areal capacitance of 507.2 mF cm−2 at a current density of 0.5 mA cm−2. At a current density of 10 mA cm−2, the capacitance retention rate of the CFP-3 electrode is 96.1 % after 5000 charge-discharge cycles, owing to the well-interconnected structure of the carbon fiber paper. Furthermore, when used as a direct electrode, CFP exhibits excellent stability. Most notably, the cost of producing the CFP-3 electrode (0.0314 m2) is only $0.195, significantly lower than that of commercial products, excluding equipment, utilities, and labor costs. This research provides valuable insights for the low-cost, large-scale production of paper-based flexible supercapacitors. [Display omitted] • Carbon fiber, PE/PET fiber, AC, CMC-Na and ultrasonic dispersion were prepared by traditional wet-mold papermaking method. • The cost of producing each CFP-3 electrode (0.0314 m2) is only $0.195, excluding equipment, utilities, and labor costs. • The areal capacitance of the CFP-3 electrode can reach 507.2 mF cm-2 at 0.5 mF cm-2 and retains 98.2% after 5000 cycles. [ABSTRACT FROM AUTHOR]

• A hydrophobic TENG based on sisal cellulose paper(SCP) was constructed to collect raindrop energy. • Both physical and chemical hydrophobic modification can effectively improve the SCP's dielectric constant. • The hydrophobic SCP-TENG modified by the chemical method is more suitable than the physical method for collecting raindrop energy. • The output electrical signal of SCP-TENG and the raindrop velocity have linear relationship. • The hydrophobic SCP-TENG can be used as raindrop-based sensors. Hydrophobic Sisal cellulose paper (SCP) was obtained by surface modification of SCP via physical adsorbing polymer and chemical grafting monomer, respectively. The influence of surface modification conditioning on the hydrophobicity, dielectric constant and dipole moment of the SCP was investigated. The results showed that the hydrophobicity and dielectric constant of the modified SCP increased with the concentration and amount of the modifiers. The output electrical performance of the TENGs assembled by the two types of hydrophobic SCP for rain energy collection was compared. The output electrical performance of the chemically modified hydrophobic SCP-TENG is higher than that of the physical modified. The maximum power density of the former reaches 8.2 mW/m2. Furthermore, based on the linear relationship between the output performance (output voltage intensity and output current intensity) of hydrophobic SCP-TENG and the droplet velocity, a raindrop-based sensor based on hydrophobic SCP-TENG was successfully constructed and estimated. [ABSTRACT FROM AUTHOR]

[Display omitted] • A convenient, panchromatic adjustable, re-writable photonic paper was prepared. • Photonic paper exhibited excellent pH, temperature, ionic strength, and ethanol responsive properties. • Photonic paper had fast wetting capability and strong reconfigurability. • A time–temperature dependent optical anti-counterfeiting system was constructed. Multi-responsive re-writable photonic paper (MRPP) with inverse opal structure was prepared by introducing [poly(hydroxyethyl methacrylate)-poly(dimethylamino ethyl methacrylate)-poly(N-isopropyl acrylamide)] (PHEMA-PDMAEMA-PNIPAM) multi-responsive gel (MRH) into silica (SiO 2) photonic crystal (PC) template. First, monomers such as HEMA, DMAEMA, and NIPAM were filled into the SiO 2 PC template. Then, MRPP with dynamic responsive color change capability was prepared by ultraviolet (UV) curing and hydrofluoric (HF) etching. MRPP has temperature, pH, ionic strength, and ethanol concertration responsiveness, fast wetting capability (∼1.4 s), strong re-writability (∼600 cycles), and the ability to use inorganic salt solution as an environmental-friendly ink to achieve panchromatic adjustment. Based on the multiple responsiveness of MRPP and its difference in solvent volatility, a time–temperature dependent optical anti-counterfeiting system with higher security level and fast identification of encryption was successfully constructed. The excellent performance of MRPP indicates its great application value in the field of re-writable photonic paper as well as information security. [ABSTRACT FROM AUTHOR]

Novel psychoactive substances (NPS) in the form of impregnated papers delivered to prisoners are of particular concern in prison settings, where they are commonly used by vaping. The purpose of this study was to create a qualitative method for identifying the various emerging NPS impregnated onto paper samples sent to prisoners. It helps to demonstrate that these findings can be used to predict drug prevalence and trends in prisons. Between 2018 and 2020, 1250 non-judicial paper samples seized from 12 English prisons were analysed to determine the NPSs being circulated. Approximately 1 cm2 paper were cut and added to 50 % (v/v) methanol in LCMS-grade water. Vortex-mixing was used to prepare extracts (30 min). Q-TOF LC/MS was used to screen the extracts. This study showed that synthetic cannabinoid receptor agonist (SCRA) was the most common drug group detected in impregnated paper seizures in English prisons between 2018 and 2020, followed by cocaine, heroin type drugs (A) and amphetamine, ketamine type drugs (B). Male prisons had a higher prevalence of SCRAs, whereas female prisons had a higher prevalence of A drugs. Furthermore, lower security prisons were found to have a higher prevalence of B drugs, pregabalin, gabapentin type drugs (C), and abused and prescription drugs than higher security prisons which unveiled a higher prevalence of nicotine. The findings of this study have revealed new information about drug use in prisons. This study will also aid in the identification of drug smuggling routes into jails, keeping prison staff up to date with the trends. • SCRA was the most prevalent drug group detected in drug-impregnated papers. • SCRAs had higher prevalence in male prisons, wheareas female prisons presented higher prevalence of Class A drugs. • Lower security level prisons had higher prevalence of Class B, Class C drugs compared to higher security level prisons. [ABSTRACT FROM AUTHOR]

[Display omitted] • FeCu@BC catalysts were synthesized using a simple one-step pyrolysis method. • FeCu@BC 600-2 exhibited good magnetic separation ability and excellent reusability. • The synergistic effect of Fe 3 O 4 , Cu0 and Biochar maintains high RhB removal. • Key ROS involves •OH at pH 3, and •OH and 1O 2 at pH 7, respectively. • sp2 C = C in biochar and Cu(I) from Cu0 facilitated the reduction of Fe(III) Treating the wastes generated from pulp and paper mills, such as black liquor and Fenton sludge is challenging. In this study, the biochar-supported Fe-Cu bimetallic catalysts were synthesized by a one-step pyrolysis method using Fenton sludge as iron source, acid-precipitated black liquor (APBL) as carbon source and copper nitrate as copper source. The catalysts were used to remove rhodamine B (RhB) dye from aqueous solution by Fenton-like reaction. The optimal catalyst (FeCu@BC 600-2) was pyrolyzed at 600 °C with an Fe/Cu mixing ratio of 2 and consisted of mesoporous biochar supported nanoscale Fe 3 O 4 and Cu0. It had a specific surface area of 104.6 m2·g−1 and a saturation magnetization of 33.3 emu·g−1. In the FeCu@BC 600-2 /H 2 O 2 system, RhB dye (10 mg·L-1) was completely removed within 60 min at acidic pH (initial pH 3, 0.2 g·L-1 catalyst, 1 mM H 2 O 2) or 6 h at neutral pH (initial pH 7, 0.25 g·L-1 catalyst, 25 mM H 2 O 2) at 30 °C. Moreover, the FeCu@BC 600-2 exhibited good magnetic separation ability, low metal leaching, excellent reusability and broad applicability to other synthetic dyes. The dye removal mechanism involved the synergistic effect of adsorption and catalytic oxidation (especially heterogeneous catalytic oxidation). At acidic pH, RhB degradation was due to •OH radical, which was generated from the activation of H 2 O 2 by ≡Cu(I) or Cu(I) oxidized from Cu0 and ≡Fe(II) in Fe 3 O 4. At neutral pH, RhB degradation was mainly due to •OH and 1O 2 with the former being produced by ≡Cu(I) and ≡Fe(II). Furthermore, Cu(I) oxidized from Cu0 and the active functional groups (such as sp2 C = C) in the biochar facilitated the reduction of Fe(III) to Fe(II), resulting in a high catalytic oxidation efficiency. [ABSTRACT FROM AUTHOR]