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Thermal paper contains potentially toxic compounds such as bisphenol A (BPA), which is used as a color developer. BPA has been reported in thermal paper in concentrations up to 42,600 μg g −1 . The exposure to BPA via dermal transfer has been recently discussed as a significant contribution to the overall human exposure and the estimated daily intake (EDI) has been reported up to 218 μg d −1 . BPA has been also detected in recycled paper with concentrations up to 46 μg g −1 . Due to the fact that BPA is a known endocrine disruptor and migrates from materials, regulatory restrictions have been established to prevent risks for the human health. As a consequence, structural analogues, such as bisphenol S (BPS) have been introduced into the market. Little is known about the presence and toxicity of these emerging replacements, and concern has risen about them. The present review gives an overview of the occurrence and levels of BPA and replacements in thermal paper. BPA is still the most common color developer found in thermal paper, followed by BPS. The analytical methods used for quantification of BPA and BPA replacements in paper products are also reviewed. BPA is transferred from thermal paper products to the finger pads upon handling it. Paper-skin transfer followed by penetration of BPA depends on conditions (e.g. greasiness of fingers and use of hand cream). It is, however, still debated whether thermal paper as a source for human exposure contributes significantly to the overall internal BPA exposure. [ABSTRACT FROM AUTHOR]

This work developed a simple, easy-to-prepare, and inexpensive indicator (R-Paper) based on rub-coating of red cabbage on readily available paper substrates to detect the freshness of fish in out-of-lab settings. A single-step rub-coating method was used to incorporate anthocyanins on paper substrates, without the extraction of the compound from red cabbage. The preparation of the indicator and its usage is quick and does not require additional chemicals, personnel expertise, or laboratory facilities. The functional colorimetric interface created by directly rubbing red cabbage on paper was used for fish quality monitoring, which displayed a naked-eye detectable color change from purple (for fresh fish) to blue (for spoiling fish) and then to blue-green (for spoiled fish), corresponding to total volatile basic nitrogen (TVB-N) and pH changes. To provide a user-friendly quantitative analysis of this color change, we used the free Android software Color Grab to quantify the color using L* , a* , b* , and RGB indices. To the best of our knowledge, this work is the first report on an indicator prepared by rub-coating red cabbage onto paper-based substrates for fish spoilage monitoring through smartphone-based analysis. To verify that the R-Paper indicator performs on a par with the indicators using extracted anthocyanins, its performance was compared with indicators prepared using anthocyanins extracted from red cabbage (AR-Paper). Naked-eye analysis, simple preparation, ease of use, low cost, and free smartphone-based analysis make the R-Paper indicator an appropriate food quality indicator in resource-limited areas. [Display omitted] • A colorimetric indicator prepared by rub-coating red cabbage on paper is developed to assess the freshness of fish. • A cost-free smartphone application was employed for measuring the colorimetric response of the indicator. • The indicator displayed quantifiable colors of purple for fresh fish, blue for spoiling, and blue-green for spoiled fish. • The preparation and usage of the indicator is simple and does not require specialized laboratory equipment or expert users. [ABSTRACT FROM AUTHOR]

As a unique class of dynamic nanostructures, biomimetic DNA walking machines that exhibit geometrical complexity and nanometre precision have gained great success in photoelectrochemical (PEC) bioanalysis. Despite certain achievements, the slow reaction kinetics and low processivity severely restrict the amplification efficiency of the DNA walker-mediated biosensors. Herein, by taking advantage of efficient DNA rolling machines, a three-dimensional (3D) DNA nanomachine-mediated paper-based PEC device for speedy ultrasensitive detection of miR-486–5p was successfully constructed. To achieve it, a novel In 2 S 3 /SnS 2 sensitized heterojunction was firstly in-situ grown on the Au-modified paper fibers and implemented as the photoanode with effective separation of photogenerated carriers to achieve an enhanced initial photocurrent. Subsequently, the copper hexacyanoferrate(II)-modified CuO nanosphere was introduced as a multifunctional signal regulator via the competitive capture of electron donors and photon energy with the photoelectric layer for efficiently quenching the PEC signal. With the introduction of targets, the DNAzyme-driven DNA nanomachine with editable motion modes was gradually activated and it could continuously cleave the tracks DNA labeled quenching probes, finally achieving the recovery of PEC signal. As a proof of concept, the elaborated paper-based PEC device presented a wide linear range from 0.1 fM to 100 pM and a detection limit of 35 aM for miR-486–5p bioassay. This work provides an innovative insight to the exploitation of DNA nanobiotechnology and nucleic acid signal amplification strategy. [ABSTRACT FROM AUTHOR]

The paper recommender system has provided great convenience for people to obtain knowledge of what they are interested in. Existing recommendation works mainly rely on learning entities' feature representations (network embedding) from the Heterogeneous Information Networks (HINs) through meta-paths. Most of them suffer from the difficulty of designing and selecting meta-paths in HIN. Moreover, changes in papers' captive audiences and users' reading favor in the recent trends are always covered up by long-term trends. To this end, we introduce a multi-attention aware recommendation method, named MARec. Specifically, to efficiently design and select meta-paths, we propose an auxiliary node-driven HIN construction method and combine it with the graph attention network (GAT) to learn the entities' feature representations. To endow the recommendation results with timeliness, we design an attention-aware Bi-directional LSTM (Bi-LSTM) and a compensation mechanism to incorporate the recent trend changes. Furthermore, to take advantage of the importance of different papers/users, we utilize an attention mechanism to capture their importance by adaptively fusing the interactive historical data of those paper/user entities. We use extensive experiments on three real-world datasets to show that our proposed MARec outperforms current representative baselines by 11.49%, 11.40%, and 13.37% on average on three main metrics. • A general heterogeneous information network towards simplifying meta-path design. • Embedding with attention mechanism avoids painstakingly selecting meta-paths. • Feature extraction under multi-time scale greatly improves the recommended results. • MARec demonstrates superior performance on different real-world domain datasets. [ABSTRACT FROM AUTHOR]

Over 100 million tons of cotton waste are produced annually, representing 35–40% of global textile waste. However, less than 30% of cotton waste is recycled annually. In particular, the fibers less than 7 mm in length dropped during the opening and carding process of cotton waste fabrics have not found a mature utilization method. This work demonstrates and reveals a strategy to transform short cotton fibers into a renewable cellulose fiber self-reinforcing composite paper (CCP). Recycled cotton staple fibers less than 3 mm were prepared into CNFs by TEMPO oxidation. The use of recycled cotton fiber (3–7 mm) as reinforcement and CNFs as a matrix results in a composite material bonded through hydrogen bonding. The recovered cotton fibers and CNFs soliquoid combine together to form a paper pulp, which is then transformed into CCP using wet-laid webs and hot-pressing techniques. When the CNF content reached 5%, the tensile strength of CCP was 86.68 MPa, which is 1.8 times that of the commercial A4 paper. The tensile strength of the CCP only decreases by 25% from the dry state to the wet state, while that of A4 paper after soaking water is almost zero. This makes CCP a special paper with broad application prospects. Since CNF extracted from cotton waste textiles is used as a strengthening agent and without any chemical adhesives added in the paper-making process, which makes the production process of CCP cleaner and can be recycled in a closed loop. Overall, the promising strategy achieves at least four objectives related to cleaner production: maximum recycling of cotton waste, CNF instead of traditional chemical adhesives used in paper-making, water recovery (internal recycling), and realising closed-loop recycling. This technology can potentially be applied to a wide range of colored papers and intelligent packaging papers in the future. [Display omitted] • Cellulose nanofibers extracted from cotton waste were used as an adhesive in papermaking. • A cellulose fiber self-reinforcing composite paper was prepared from cotton waste. • The cellulose composite paper has excellent mechanical strength and water stability. • The cellulose composite paper can be easily recycled with a prolonged life cycle. [ABSTRACT FROM AUTHOR]

[Display omitted] • Paper-based cascade sensitized structure of CuInSe 2 /Cu 3 (BTC) 2 /Y:ZnO was assembled. • The entropy-driven SDA propelled DNAzyme roller amplification strategy was designed. • Surface plasmon resonance-enhanced cascaded sensitization effect was proposed. Herein, the surface plasmon resonance (SPR)-enhanced cascaded sensitization effect of CuInSe 2 /Cu 3 (BTC) 2 /yttrium doped ZnO (Y:ZnO) photosensitive structures were integrated on lab-on-paper photoelectrochemical (PEC) biosensing platform for the ultrasensitive detection of microRNA-21 (miRNA-21) based on entropy-driven strand displacement amplification (SDA) propelled DNAzyme roller amplification strategy. The Y element doping equipped the paper-based Y:ZnO nanorods with enhanced PEC performance, which was further cosensitized with Cu 3 (BTC) 2 metal-organic framework (MOF) and CuInSe 2 quantum dots (QDs), giving a cascaded sensitization effect for generating a robust and stable photocurrent signal. The SPR effect between CuInSe 2 QDs and Au nanoparticles (NPs) was activated with the aid of entropy-driven SDA propelled DNAzyme roller amplification-induced conversion of target miRNA-21 to Au NPs-labelled track DNA (track DNA-Au), which could effectively promote the photogenerated carrier separation and transfer of CuInSe 2 /Cu 3 (BTC) 2 /Y:ZnO cascade sensitized structures via hot-electron transfer mechanism, further enhancing the photocurrent signal. Based on this designed "signal-on" mode, the quantitative detection of miRNA-21 was achieved with high sensitivity, good specificity, and excellent practicability, which provided a promising model for developing lab-on-paper diagnostic tool for biomedicine. [ABSTRACT FROM AUTHOR]

[Display omitted] • Sonication improves the absorption of metallic salt in the paper. • Ultrasound catalyzes the synthesis of metallic nanoparticles. • A longer sonication time during salt absorption increases the number of nanoparticles obtained. • Nanoparticles obtained by sonochemistry are an easy and reproducible method to modify paper. This work focuses on a systematic method to produce Ag, Cu, and Ag/Cu metallic nanoparticles (MNPs) in situ assisted with ultrasound on cellulose paper. By tuning the concentration of AgNO 3 and CuSO 4 salt precursors and ultrasound time, combined with a fixed concentration of ascorbic acid (AA) as a reducing agent, it was possible to control the size, morphology, and polydispersity of the resulting MNPs on cellulose papers. Notably, high yield and low polydispersity of MNPs and bimetallic nanoparticles are achieved by increasing the sonication time on paper samples pre-treated with salt precursors before reduction with AA. Moreover, mechanical analysis on paper samples presenting well-dispersed and distributed MNPs showed slightly decreasing values of Young's modulus compared to neat papers. The strain at break is substantially improved in papers containing solely Ag or Cu MNPs. The latter suggests that the elastic/plastic transition and deformation of papers are tuned by cellulose and MNPs interfacial interaction, as indicated by mechanical analysis. The proposed method provides insights into each factor affecting the sonochemistry in situ synthesis of MNPs on cellulose papers. In addition, it offers a straightforward alternative to scale up the production of MNPs on paper, ensuring an eco-friendly method. [ABSTRACT FROM AUTHOR]

• The diffusion of water molecules enhanced by increasing temperature, with anisotropic diffusion coefficients. • Viscous force hindrance trapped almost all water molecules at the oil-paper insulation interface. • Under the combined influence of temperature and electric field, the number of water clusters at the interface increased. • The water diffuses differs significantly when electric field is normal to the interface compared to tangential interface. • Water molecules polarized in the direction normal to the insulation interface require a higher electric field strength. Oil-paper insulation is commonly used in transformers and is subject to dynamic changes in moisture content and distribution due to the influence of multiple physical fields such as temperature and electric fields. Moisture at the interface of oil-paper insulation can distort the interfacial electric field and cause insulation failure, but it is difficult to measure and characterize. In this study, molecular dynamics was used to simulate the diffusion behavior of water molecules at the interface of natural ester oil-paper insulation at temperatures ranging from 298 to 373 K, and the effect of electric fields on water diffusion was also analyzed. The results showed that without an electric field, water molecules in natural ester insulating oil tend to cluster at 298 K. Water molecules gradually diffuse towards the interface of the natural ester oil-paper insulation, but most remain at the interface and are difficult to penetrate into the cellulose insulating paper. In addition, normal diffusion is gradually enhanced at 298–328 K, reaching a minimum at 343 K. The interaction energy between water molecules and natural ester insulating oil decreases with increasing temperature, while the interaction energy with cellulose insulating paper decreases and then increases, reaching a minimum at 343 K. The combined influence of temperature and electric fields leads to an increase in the number of water clusters at the oil-paper interface. The interaction energy between water molecules and both natural ester insulating oil and cellulose insulating paper is enhanced, inhibiting the diffusion of water into the insulating paper. It was also found that the ability of water to diffuse differs significantly when the electric field direction is normal to the interface compared to when it is tangential to the interface. This is due to the fact that the water molecules when subjected to electric field action turn to polarize, and their electric field direction diffusion coefficient decreases, but still much higher than the non-electric field action direction. Further, the study found that the natural ester oil-paper insulation interface polarization is directional, and water molecules polarized in the direction normal to the insulation interface require a higher electric field strength. [ABSTRACT FROM AUTHOR]

• A numerical model of bubble growth in oil-paper system is established based on bubble dynamics. • Criterion for bubble escaping from insulating paper is determined by force balance. • Decrease of tank pressure results in bubble formation at lower temperature. • Bubble would be grown larger to overcome increased surface tension caused by larger surface cavities. • Established model provides a mathematical simulation model for bubble formation and subsequent bubble-induced discharge. The initiation of bubbles at the surface of insulating paper under high temperature may result in partial discharge and ultimately lead to the insulation failure of oil-immersed transformers. To study the formation mechanism of bubbles, the process of bubble growth at the oil-paper interface is established by using Rayleigh-Plesset equation. The Ideal Gas Law as well as the Hertz-Knudsen relation is used to quantify the flux of water vapor entering the bubble. The growth curve of bubbles in the oil-paper during temperature rise is calculated. And the Initial Temperature of Bubble Escape (ITBE) is then obtained based on the force analysis of the bubble growth. The results show that the bubble detaches from the surface of paper when its radius reach 198 μm, which is consistent with experimental observations. And the minimum average relative error between the predicted ITBE and experimental results is 1.11%. The effect of influence factors on the ITBE of oil/paper are then studied in detail. It is shown that the increased moisture content in paper accelerates the growth rate of bubbles, then reduces the ITBE. And the higher pressure inside oil tank restrains the bubble growth through the overall process. Additionally, as the cavity size of paper increase, the surface tension of bubble increases. Consequently, the bubbles require a larger size to achieve sufficient buoyancy for their escape from the aged paper. [ABSTRACT FROM AUTHOR]

Paper used in the printing industry generally contains a relatively thin porous coating covering a thicker fibrous base layer. The three-dimensional pore structure of coatings has a major effect on fluid flow patterns inside the paper medium. Understanding and quantifying the flow properties of thin coating layers is hence crucial. Pore spaces within the coating have an average size of about 180 nm. We used scanning electron microscopy combined with focused ion beam (FIB-SEM) to visualize the nano-scale pore structure of the paper coating layer. Post-processing of the FIB-SEM images allowed us to reconstruct the three-dimensional pore space of the coating. The 3D FIB-SEM images were analyzed in detail to obtain pore size distribution and porosity value. The permeability was estimated using the GeoDict software, based on solutions of the Stokes equation. By determining the porosity and permeability of increasingly larger domain sizes, we estimated the size of a representative elementary volume (REV) for the coating layer to be 60 µm 3 , which is well within the volume analyzed using FIB-SEM. The estimated porosity and permeability of the REV domain were 0.34 and 0.09 mDarcy, respectively. Using the pore morphology method, capillary pressure-saturation ( P c - S ) and relative permeability curves of the REV domain could be constructed next. The P c -S curves showed that the coating had a high air entry suction, which is very favorable for printing in that ink will invade the coating as soon as it is applied to the coating. Our results are essential for macroscale modelling of ink penetration into a coating layer during inkjet printing. Macroscopic models can be valuable tools for optimization of the penetration depth and the spreading of ink on and within paper substrates. [ABSTRACT FROM AUTHOR]

Sunflower stalk was evaluated as a potential fiber source to make fluting paper using neutral sulfite semi-chemical pulping process, in comparison with Mazandaran wood and paper industry mill made hardwood-based neutral sulfite semi-chemical (NSSC) pulp. Sunflower stalk consists of two distinct fractions including inner bulky pith and outer woody wall. The stalk has to be de-pithed for the purpose of papermaking because of lower cellulose, and higher ash content in pith-containing stalk. The results of pulping showed that the rate of delignification in NSSC cooking of de-pithed sunflower stalk with 20% lignin was surprisingly very low, despite of being a non-wood fiber source. However, sunflower stalk NSSC pulp showed very good response to refining and produced denser sheet due to lower digester yield and higher fiber flexibility coefficient, in comparison with Mazandaran wood and paper industry pulp sample. In addition, sunflower stalk pulp has been demonstrated to be an appropriate fiber source for making fluting paper at higher or comparable tensile-loaded strength properties such as tensile and burst, and higher compression-loaded strength properties including corrugated medium test and ring crush test. [ABSTRACT FROM AUTHOR]

• Evaluation of a new dengue NS1 test, with febrile illness case samples. • Comparable sensitivity and specificity of DEN-NS1-PAD to commercial diagnostic tests. • Nested-PCR was used as gold standard method for comparison. This study aimed to evaluate a microfluidic paper-based analytical device (DEN-NS1-PAD) based on a rapid NS1 antigen test for diagnosing dengue at the point of care. 219 serum samples from suspected dengue cases were tested with the developed DEN-NS1-PAD and commercial RDT by SD BIOLINE. The results were compared with the nested-PCR results. The limit of detection of DEN-NS1-PAD was 0.78 ng mL−1. It showed 88.89% sensitivity, 86.67% specificity, and a substantial agreement correlation (κ = 0.7522) compared with nested-PCR. In contrast, SD BIOLINE for NS1 (SD-NS1) detection showed 87.88% sensitivity, 90.00% specificity, and had a substantial agreement correlation with nested-PCR (κ = 0.7788). DEN-NS1-PAD is a valuable tool for diagnosing DENV infections, especially for diagnosed patients with early acute phase samples with high viral load. DEN-NS1-PAD has better sensitivity than SD-NS1 but less specificity. [ABSTRACT FROM AUTHOR]

Drawing on a corpus of clickbait headlines (Chakraborty et al., 2016) and using ideas from the relevance-theoretic pragmatic framework (Sperber and Wilson, 1986/95), this paper examines some of the ways in which writers of clickbait headlines arouse the curiosity of their readers by creating an "information gap" (Loewenstein, 1994). Comparative corpus analysis is combined with close analysis of illustrative examples to explore the contribution that particular parts-of-speech make to the creation of successful clickbait. I focus on two main categories that are overrepresented in clickbait headlines to a statistically significant degree: (i) definite referring expressions and (ii) superlatives and intensifiers. The results and analysis reveal that these parts-of-speech contribute to an information gap by encouraging readers to construct new conceptual files based on the terms used in the headline, while providing little or no content for those files. This then drives the reader to click on the associated link with the expectation that the article will contain relevant information with which he can enhance his conceptual files, and that this, in turn, will reward him with cognitive effects. • Uses corpus analysis to confirm and explore overused categories in clickbait headlines. • Uses relevance-theoretic notions to analyse empirical findings from corpus analysis. • Reinterprets the information gap approach to curiosity in relevance-theoretic terms. • Analyses the role of superlatives and definite determiners in information gap creation. [ABSTRACT FROM AUTHOR]

For decades, the northern fulmar (Fulmarus glacialis) has been found to ingest and accumulate high loads of plastic due to its feeding ecology and digestive tract morphology. Plastic ingestion can lead to both physical and toxicological effects as ingested plastics can be a pathway for hazardous chemicals into seabirds' tissues. Many of these contaminants are ubiquitous in the environment and the contribution of plastic ingestion to the uptake of those contaminants in seabirds' tissues is poorly known. In this study we aimed at quantifying several plastic-related chemicals (PRCs) -PBDE209, several dechloranes and several phthalate metabolites- and assessing their relationship with plastic burdens (both mass and number) to further investigate their potential use as proxies for plastic ingestion. Blood samples from fulmar fledglings and liver samples from both fledgling and non-fledgling fulmars were collected for PRC quantification. PBDE209 and dechloranes were quantified in 39 and 33 livers, respectively while phthalates were quantified in plasma. Plastic ingestion in these birds has been investigated previously and showed a higher prevalence in fledglings. PBDE209 was detected in 28.2 % of the liver samples. Dechlorane 602 was detected in all samples while Dechloranes 601 and 604 were not detected in any sample. Dechlorane 603 was detected in 11 individuals (33%). Phthalates were detected in one third of the analysed blood samples. Overall, no significant positive correlation was found between plastic burdens and PRC concentrations. However, a significant positive relationship between PBDE209 and plastic number was found in fledglings, although likely driven by one outlier. Our study shows the complexity of PRC exposure, the timeline of plastic ingestion and subsequent uptake of PRCs into the tissues in birds, the additional exposure of these chemicals via their prey, even in a species ingesting high loads of plastic. [Display omitted] • Plastic-related chemicals were measured in the fulmar Fulmarus glacialis. • PBDE209 was detected in 28% of fulmars' liver with an average of 1.36 ng/g. • Dechloranes were detected in all livers with an average of 0.36 ng/g. • Detectable phthalate concentrations were found in 33% of plasma samples. • No significant positive correlation between any contaminants and plastic burdens. [ABSTRACT FROM AUTHOR]

Waste paper, a major fraction of municipal solid waste, has a potential to serve as renewable feedstock for the biorefineries of fuels, chemicals and materials due to rich in cellulose and abundant at low cost. This study evaluates the possibility of waste office paper (WOP) to serve as a potential feedstock for the biorefinery production of poly (3-hydroxybutyrate). In this study, the WOP was pretreated, enzymatically saccharified and the hydrolysate was used for PHB production. The hydrolysate mainly consists of glucose (22.70 g/L) and xylose (1.78 g/L) and the corresponding sugar yield was about 816 mg/g. Ammonium sulphate and C/N ratio 20 were identified as most favorable for high yield of PHB. The batch fermentation of Cupriavidus necator using the pretreated WOP hydrolysate resulted in cell biomass, PHB production and PHB content of 7.74 g/L, 4.45 g/L and 57.52%, respectively. The volumetric productivity and yield achieved were 0.061 g/L/h and 0.210 g/g sugar, respectively. The results suggested that WOP could be a potential alternative feedstock for the biorefinery production of bioplastics. [ABSTRACT FROM AUTHOR]

Levoglucosan is used as a tracer of biomass burning; however, its determination often requires expensive analytical techniques. Therefore, this study describes the development of an inexpensive and useful method using paper-based analytical devices (PADs) to determine levoglucosan based on colorimetric measurements. The color intensities were correlated with the analytical concentrations and presented linear behavior in the range from 0 to 64.8 μg mL−1. The achieved limits of detection and quantification were 2 and 6 μg mL−1, respectively. The conversion rate of levoglucosan into glucose was 81 ± 8% and the average recovery was 105 ± 9%. Moreover, the method presented selectivity for levoglucosan, showing variation in colorimetric signal intensity lower than 8% in the presence of other saccharides (xylose, glucose, galactose, maltose, mannose, arabinose, and fructose). The accuracy of the method was confirmed by comparison with gas chromatography-mass spectrometry. The proposed method was explored to determine levoglucosan in samples of atmospheric particulate matter collected in Goiania city (Brazil) and the values ranged from 0.08 to 1.10 μg m−3, showing the high impact of the biomass burning to the particulate matter in the region's atmosphere. The method was also used to detect levoglucosan in rainwater samples. Therefore, the use of PADs can simplify fieldwork involving the determination of levoglucosan in atmospheric particulate matter. Image 1 • Paper-based analytical devices were used to determine levoglucosan. • The method is inexpensive, useful and presented selectivity for levoglucosan. • The highest levoglucosan concentration was determined in the dry season. • The particulate matter chemical composition was highly affected by biomass burning. [ABSTRACT FROM AUTHOR]

The high-yield separation of polymeric parts from wood-derived lignocellulosic material is indispensable in biorefinery concepts. For the separation of cellulose and xylan from hardwood paper pulps to obtain pulps of high cellulose contents, simple alkaline extractions were found to be the most suitable technology, although having certain limitations. These are embodied by residual alkali resistant xylan incorporated in the pulp matrix. Further purification in order to produce pure cellulose with a low uniformity could be achieved selectively degrading residual xylan and depolymerizing the cellulose macromolecules by xylanase and cellulase. The latter help to adjust cellulose chain lengths for certain dissolving pulp grades while reducing the demand for ozone in subsequent TCF bleaching. Experiments applying different commercially available enzyme preparations revealed the dependency of xylanase performance on the residual xylan content in pulps being stimulated by additional cellulase usage. The action of the latter strongly depends on the cellulose allomorphy confirming the impact of the pulp morphology. Hence, the combined application of both types of enzymes offers a high potential for upgrading pulps in order to produce a pure and high-value cellulose product. [ABSTRACT FROM AUTHOR]

Utilization of the quality-upgraded waste paper in the manufacture of paper and board will reduce the wood consumption and pulping energy. While the optical property of the fibers from recycled old newspaper is very poor, in-situ calcium carbonate formation on those fibers by injecting carbon dioxide to the mixed slurry of those pulp and calcium oxide improved their brightness. Upgrading recycled old newspaper to substitute more expensive wood furnish, such as recycled old magazine, was successfully demonstrated in the present study. This study showed that the in-situ calcium carbonate formation process improved the optical quality of the recycled old newspaper by covering colored impurities with newly formed calcium carbonate, and improved calcium carbonate retention in papermaking process by attaching them to fibers. The strength reduction by the presence of newly formed calcium carbonate in the paper was recovered by adding strength agent. High ash retention at high ash content under the strong turbulence in the modern paper mill was achieved by the application of the in-situ calcium carbonate formation method. The quality-upgrade of recycled fibers and cost saving in the manufacture of duplex paperboard were demonstrated in the mill trial. [ABSTRACT FROM AUTHOR]

[Display omitted] • This special section includes papers on computer graphics education. • These papers are the best papers from the Eurographics 2022 Education Papers Program. • Specific topics include ray-tracing, the Vulkan API, and virtual reality. [ABSTRACT FROM AUTHOR]

Highlights • scanner path utilized as a manipulatable variable in paper machine cross-directional control. • faster response to load disturbances. • estimation of process noise and basis weight estimate uncertainty based on web-wide transmittance measurement. • adaptive model between transmittance and basis weight. ABSTRACT The cross-directional (CD) basis weight control on paper machines is improved by optimizing the path of the scanning measurement. The optimal path results from an LQG problem and depends on how the uncertainty of the present estimate of the basis weight and the intensity of process noise vary in CD. These factors are assessed by how accurately the CD basis weight estimate predicts the measured optical transmittance with a linear adaptive model on synchronized basis weight and transmittance data. Simulations on optimized scanner path in disturbance scenarios are presented, and the practical implementation of scanner control is discussed. [ABSTRACT FROM AUTHOR]

This work focuses on the effect of graphite powder grain size on the properties of carbon paper and proton exchange membrane fuel cell. In this paper, graphite powders of different grain sizes (0.5–30 μm) are added to carbon paper for proton exchange membrane fuel cell. Furthermore, the carbon paper is subjected to hydrophobic treatment at polytetrafluoroethylene (PTFE). The research results show that with the increase in graphite grain size, the cell performance increases at dry condition, the carbon paper containing 10 wt% PTFE and graphite powder grain size of 30 μm has the best performance, which power density of 892 mW cm−2 and limit current density of 2.40 A cm−2. With the increase in graphite grain size, the cell performance decrease at wet condition, the carbon paper containg 20 wt% PTFE and graphite powder grain size of 0.5 μm has the best performance, which power density of 524 mW cm−2 and limit current density of 1.84 A cm−2. The paper illustrates that reducing the grain size of graphite powder is beneficial to enhancing the water management ability of gas diffuse layer and reduces the performance loss at wet condition, while, increasing the gas transmission resistance and the performance loss at dry condition. • The innovative carbon paper structure regulation method. • The effect of grain size of carbon powder on carbon paper. • The effect of grain size on cell performance in different condition. [ABSTRACT FROM AUTHOR]

The deinking in the paper industry is in great demand, and microbial enzymes are key players. In the present study, the endoglucanase production from newly isolated fungi Aspergillus niger MPS25 is reported. The optimization of endoglucanase production was carried out using one factor at a time approach resulting in endoglucanase activity (2.37 IU/ml) at 45 °C and pH 8 in submerged fermentation (SmF), which shows optimum enzyme activity at 60 °C. Interestingly, the metal ions viz. Co2+ stimulated the endoglucanase activity, whereas Mn2+ reduced the enzyme activity, which shows that this enzyme can be used for effluent treatment released through deinking. The enzymatic hydrolysis of wheat straw produced 26.96 ± 0.108 mg/g of reducing sugars, indicating its potential in saccharification and the biofuel industry. Furthermore, the validation of the deinking efficiency of this enzyme resulted in improved deinking of mixed office waste and old newspapers by 31.5% and 20.4%, respectively. The strength properties, viz. burst factor and tear index, breaking length, and tensile index of the handmade paper sheets, were also improved which were analyzed by the scanning electron micrographs. The FTIR and XRD analysis of pulp provided insights into the changes in functional groups and cellulose crystallinity, respectively. These results indicate that multi-efficient endoglucanase from Aspergillus niger MPS25 is suitable for enzyme-based eco-friendly deinking for waste paper recycling and lignocellulosic biomass saccharification. [Display omitted] • The endoglucanase from newly isolated fungi Aspergillus niger MPS25 is reported. • The endoglucanase showed stability at 60 °C with wide pH range. • The endoglucanase significantly improved the deinking efficiency for mixed office waste (31.5%) and old newspapers (20.4%). • The SEM, FTIR and XRD analysis provided technological insights for process scale up. • This multi-efficient endoglucanase proved to be suitable enzyme in eco-friendly recycling of MOW and ONP. [ABSTRACT FROM AUTHOR]

Per- and polyfluoroalkyl substances (PFASs), a new class of contaminants of emerging concern in different water sources and industrial discharges, have been highlighted, mainly ascribed to the high mobility, persistent, and bioaccumulative behaviors. In this work, the analytical detection of PFASs in the paper mill processing discharge (PMPD), physicochemical parameters, tannin and lignin, and phenolic content were carried out. The phytotoxicity evaluation and bioaccumulative profiles of PMPD-assisted irrigation have been conducted using a soilless cultivation system. The cytotoxicity, genotoxicity and human exposure risk were ascertained via in vitro assay on the human hepatocellular carcinoma (HepG2) cell and the estimation of daily intake, respectively. PFASs were quantitatively detected at the mean concentration of 2712.72 ng/L, consisted of mainly perfluoroalkyl carboxylic acids (PFCAs), perfluoroalkane sulfonic acids (PFSAs), perfluoroalkane sulfonamidoacetic acids (FASAAs), perfluoroalkane sulfonamides (FASAs), and fluorotelomer sulfonic acids (FTSAs). Significant reductions of the physical elongation, dry weight, and chlorophylls up to 33.49%, 31.71%, and 52.17% were recorded. Profound increase in the proline (101.81%), hydrogen peroxide (55.56%), superoxide anion (67.86%), lipid peroxidation (43.91%), and protein oxidation (32.31%), and up-regulation of antioxidant enzymes activities have been quantified. Bioaccumulation and translocation of PFASs revealed a concentration-, chain length- and functional group-dependent trend within different plant compartments. PFASs-contaminated PMPD treatments induced dose-dependent cell viability reduction and DNA damage in the HepG2 cell. The findings have highlighted that PMPD could be an underestimated source of PFASs, which represents a sharp threat to plants and public health via the water-food crop-human continuum. Future studies gearing towards the genomic profiling of PFASs in different plant species are suggested. [Display omitted] • Detection of per- and polyfluoroalkyl substances (PFASs) in the industrial effluent. • Phytotoxicity evaluation using a hydroponic system. • Distortions of physical traits and chlorophylls in the plant model. • PFASs triggered oxidative stress damages and up-regulation of antioxidant enzymes. • PFASs induced profound dose-dependent cytotoxicity and genotoxicity in human cell. [ABSTRACT FROM AUTHOR]

Sheet-like transition metal sulfides have promising applications in photocatalysis and energy conversion. This study provides a petal-like Cu 2 WS x nanosheet structure supported on carbon paper (CP) synthesized by a simple one-step solvothermal method. Cu 2 WS x microstructures with different morphologies were synthesized by solvothermal vulcanization of thioacetamide (TAA) at different concentrations. The Cu 2 WS x /CP was used as the counter electrode of DSSCs and compared with the Pt FTO electrode. It was proved that Cu 2 WS x -7 M/CP had the best electrocatalytic performance and obtained 9.01% photoelectric conversion efficiency. The different sulfide concentration changes the morphology of Cu 2 WS x and continuously affects the specific surface area and catalytic activity of the material. The better electrochemical performance shows that Cu 2 WS x /CP is expected to become a substitute for expensive Pt CE materials in dye-sensitized solar cells (DSSCs). [Display omitted] • One-step solvothermal method for the growth of petal-like Cu 2 WS x on carbon paper. • The effect of sulfide concentration on Cu2WSx was explored for the first time by TAA. • For the first time, Cu 2 WS x /CP was used as a counter electrode for DSSCs. • At a sulfide concentration of 7 M, Cu 2 WS x /CP exhibited a value of 9.01% PCE (Pt 7.67%). [ABSTRACT FROM AUTHOR]

Different heating processes were applied to pretreat the pulp and paper mill sludge to enhance the hydrolysis stage. Hot air oven, autoclave, microwave and water bath were used for comparison. Chemical analyses exposed that all the pretreatment methods have shown improvement in solubilisation of organic matter. Among the pretreatments studied, heat transfer through hot air (80 °C for 90 min) mode had the highest impact on sludge solubilisation. There was an increase in cellulose (P = 0.0096), acid soluble (P = 0.0053) and insoluble lignin (P = 0.0012), but decrease in hemicellulose (P = 0.0009) content after pretreatment. The XRD and FT-IR spectroscopic characterisation shows the development of aliphatic, unsaturated and carbonyl carbon functionalities in the pretreated samples at higher severities. FESEM picture also confirms the change in structure after pretreatment. Thus, pretreatments contribute to disruption of the lignocellulosic structure making the cellulose easily accessible to acidogenic microorganisms. [ABSTRACT FROM AUTHOR]

Point-of-care testing (POCT) technology is urgently required owing to the prevalence of the Internet of Things and portable electronics. In light of the attractive properties of low background and high sensitivity caused by the complete separation of excitation source and detection signal, the paper-based photoelectrochemical (PEC) sensors, featured with fast in analysis, disposable and environmental-friendly have become one of the most promising strategies in POCT. Therefore, in this review, the latest advances and principal issues in the design and fabrication of portable paper-based PEC sensors for POCT are systematically discussed. Primarily, the flexible electronic devices that can be constructed by paper and the reasons why they can be used in PEC sensors are expounded. Afterwards, the photosensitive materials involved in paper-based PEC sensor and the signal amplification strategies are emphatically introduced. Subsequently, the application of paper-based PEC sensors in medical diagnosis, environmental monitoring and food safety are further discussed. Finally, the main opportunities and challenges of paper-based PEC sensing platforms for POCT are briefly summarized. It provides a distinct perspective for researchers to construct paper-based PEC sensors with portable and cost-effective, hoping to enlighten the fast development of POCT soon after, as well as benefit human society. • The merits of functionalized paper for PEC sensor are introduced. • Photosensitive material and signal amplification strategy of paper-based PEC sensor are discussed. • The application of paper-based PEC sensor in the field of POCT is highlighted. • The limitations and challenges of paper-based PEC sensor are summarized. [ABSTRACT FROM AUTHOR]

Heavy metals released by anthropogenic activities are extremely toxic to animals and plants due to their bioaccumulative and persistent environmental presence. In the current study, silver nanoparticles (AgNPs) were synthesized utilizing eco-friendly processes, and their potential in colorimetric Hg2+ ion sensing in environmental samples was examined. An aqueous extract of Hemidesmus indicus root (Sarsaparilla Root, ISR) rapidly converts silver ions into AgNPs within 5 min of exposure to sunlight. Transmission electron microscopy confirms that ISR-AgNPs are spherical, ranging from 15 to 35 nm. Fourier-transform infrared spectroscopy revealed phytomolecules stabilized the NPs with hydroxyl and carbonyl substituents. The ISR-AgNPs detect Hg2+ ions by a colour change that can be seen with the naked eye within 1 min. The probe is interference-free and detects the presence of Hg2+ ions in sewage water. A method for fabricating ISR-AgNPs onto paper was disclosed, and this portable ISR-AgNPs embedded paper device was found to be good at sensing mercury present in the water. The findings show that environmentally friendly synthesized AgNPs can contribute to developing onsite colorimetric sensors. [Display omitted] • Rapid silver nanoparticles synthesis using sunlight and Hemidesmus indicus root extract. • Phytochemicals stabilize the AgNPs. • Paper fabricated with AgNPs sense mercury with good selectivity. • AgNPs disrupt bacterial membranes and kill them. [ABSTRACT FROM AUTHOR]

• The oil-paper insulation model of mixed unmodified and amino-modified SiO 2 was established. • The MSD of microwater in two models was studied and the diffusion coefficient was derived. • The relative concentration of miceowater in the two oil-paper models was analyzed. • The frontier molecular orbital of the two nanopartilces was studied by First-Principle. Nanoparticles can significantly improve the insulation property of oil-paper insulation systems. In this paper, amino-modified SiO 2 nanoparticles were used as nano-additives to establish a soybean oil-cellulose paper oil-paper insulation model, and the effect of amino-modified SiO 2 nanoparticles on micro-water diffusion in oil-paper insulation systems was systematically studied. Simulation experiments show that amino-modified SiO 2 nanoparticles can effectively delay the diffusion of water molecules in oil-paper insulation. As the temperature rises, compared with unmodified SiO 2 nanoparticles, the diffusion motion of water molecules in amino-modified SiO 2 nanoparticles oil–water model is slower. When the temperature is 383 K, the water molecule diffusion coefficient of the unmodified model is 1.22 times that of the modified model, and amino-modified SiO 2 nanoparticles can form special hydrogen bonds with water molecules, preventing water molecules from further diffusing into cellulose paper, breaking the cellulose chain leads to a decrease in mechanical property, and further generating small molecules such as water and acid, which accelerate the aging of oil-paper insulation systems. Indirectly improve the electrical performance and aging performance of oil-paper insulation. [ABSTRACT FROM AUTHOR]

• A selective paper-based antibody-free COVID-19 assay. • The enzymatic activity of the virus-related 3CL protease is applied for detection. • All our tests were validated against PCR tests displaying similar selectivity and sensitivity. • Our sensor displays an ultrafast detection turnover of ca. 1 min. • No instruments are required to perform the simple colorimetric diagnosis. COVID-19 is caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). SARS-CoV-2 has led to high mortality worldwide, with social and financial effects expected to persist for years to come. Since asymptomatic individuals cause a large portion of transmission, actions taken to curb the COVID-19 pandemic mostly rely on procedures aimed at detecting viral-related molecules in infected carriers. Currently, leading available detection methods fall short in reliability or point-of-care mass screening applicability. Here, we present an unprecedented antibody-free smart pH paper-based seconds-long detection platform against the virus-related enzyme 3CLpro as a saliva biomarker of SARS-CoV-2 infection. The selective proteolytic activity of 3CLpro is directly detected from native saliva using a peptide substrate-embedded pH-paper platform. 3CLpro presence in infected individuals leads to an ultrafast pH-drop in the paper matrix, thus leading to a sharp color change as direct means of detection. Ultrafast detection, simplicity, no requirement of surface chemistry by sensitive biomolecules, long-term stability, and point-of-care compatibility for COVID-19 mass screening were demonstrated. Forty-two subjects were tested, exhibiting highly sensitive and specific detection of SARS-CoV-2 infection. Finally, we foresee that this universal approach could be implemented for the multiplexed detection of other viral infections by detecting specific viral proteases. Importantly, since our approach does not require immune-specific antibodies for specific detection, the overall platform is extremely cost-efficient, less than 2 USD cents per assay, and suitable for the worldwide mass screening of viral infections, particularly in remote and developing world locations. Moreover, we propose an extremely easy-to-use and produce practical test strip design. [ABSTRACT FROM AUTHOR]

[Display omitted] • Robust pH/moisture sensitive smart packaging paper (CS/CMC-Anth) was fabricated. • The anthocyanin release amount in distilled water was reduced about 58.72%. • The tensile strength of colorimetric paper was reinforced from 9.51 MPa to 55.68 MPa. • Freshness of fruits and pork can be real-time detected by discernible color change. • Shelf life of fruits can be extended at least one week under ambient conditions. Intelligent packaging system for real-time visual monitoring the freshness of foods plays a key role in the field of food safety. Employing biopolymer as matrix and natural anthocyanin as pH sensing indicator has arouse growing interest for freshness detecting in recent years. However, the anthocyanin migration phenomenon and relatively poor mechanical strength of film restricted the practicability of biopolymer-based smart packaging system. In this work, we constructed a sort of pH/moisture sensitive chitosan (CS)/carboxymethyl cellulose (CMC) coacervates containing anthocyanin (cyanidin cation type, extracted from blueberry) on cellulosic paper by facile layer-by-layer assembly, in which anthocyanin was firmly anchored. The accumulated release amount of anthocyanin in distilled water was reduced from 78.14% to 19.42% compared to pristine CMC-Anth paper. The maximum tensile strength was significantly improved from 9.51 MPa for initial filter paper to 55.68 MPa for (CS/CMC-Anth) 4 colorimetric paper and the compact CS/CMC-Anth bilayer endowed colorimetric paper with excellent structural stability upon folding at least 1000 times. The assembled (CS/CMC-Anth) 4 colorimetric paper delivered response to pH/moisture and can be employed to real-time monitor the freshness of pork and fruits. The integration of intelligent sensor technology and food science will make the food industry present a green, efficient, intelligent, accurate and diversified business model in the future. [ABSTRACT FROM AUTHOR]

Two-dimensional (2D) materials are widely used in various applications due to their extraordinary properties. In particular, their electrochemical stability, low electrical resistance, and huge specific surface area make them very interesting active materials for supercapacitors. Herein, flexible, biodegradable, and low-cost supercapacitors are introduced in a very simple way based on hand-drawing pencil traces or -rubbing molybdenum disulfide (MoS 2), titanium trisulfide (TiS 3) and franckeite traces on the paper. Results demonstrate that pencil-drawn paper has higher capacitance performance (∼6.39 F/g) among the suggested electrodes. Interestingly, the introduced MoS 2 /pencil, TiS 3 /pencil, and franckeite/pencil drawn paper electrodes reveal dramatic improvements with long cyclic life thanks to the occurrence of synergetic effects and higher available active cites within the heterostructures. Moreover, the assembled symmetric solid-state supercapacitors retain their performance even under applied bending, indicating their excellent potential for wearable/flexible applications. [Display omitted] • Paper-based pencils, MoS 2 , TiS 3 , and franckeite supercapacitors are introduced as low-cost, and flexible supercapacitors. • Through the incorporation of these layered materials, the performance of the supercapacitors is greatly enhanced. • In addition to their acceptable performance under bending, the electrodes have a very promising cyclic life. [ABSTRACT FROM AUTHOR]

This paper presents a novel design and operation of microbial fuel cells (ΜFCs), which contain monolayer paper-based substrate/electrodes and microchannels with co-laminar flow. The electrodes with multi-wall carbon nanotubes are fabricated by the screen-printing method and the microchannels are patterned using photo-lithography. A double-inlet and diverging channel design is incorporated in the fuel cell configuration and demonstrated significantly improved performance. The fluid flows of electrolytes through the porous paper media are simulated using steady-state and transient computational fluid dynamics The best performance is achieved under the following conditions: an electroactive microbial (S. oneidensis) concentration of OD 600 1.5, 50 mM electron donor (lactate), and direct immobilized of the inoculum on the anode surface. The developed MFCs achieves a peak power density of 19.4 ± 0.23 μW cm−2 and maximum current density of 190.4 ± 1.39 μA cm−2, surpassing the performance of all previously reported paper-based single MFCs that utilize paper-based electrodes. In addition, hybrid-type MFCs that containing enzymatic air-breathing cathodes are investigated to enhance their performance. The novel paper based self-pumping MFC has the potential to make lab-on-a-chip type portable medical diagnosis devices with integrated power sources practical and feasible. [Display omitted] • A paper-based membraneless co-laminar flow microbial fuel cell was developed. • Microfluidic fuel cell was micromachined as a monolayer structure in paper substrate. • Co-laminar flow of the electrolyte through paper was simulated using CFD analysis. • Inoculation method, anolyte type, and cell configuration were tested and optimized. • A hybrid microbial-enzymatic fuel cell was also examined for performance improvement. [ABSTRACT FROM AUTHOR]

[Display omitted] • A new thiophene based fluorescent receptor has been synthesized for the specific detection of Ag+ ions. • The synthesized receptor (ADC) was characterized by NMR and mass spectroscopic techniques. • The detection limit (LOD) was calculated to be 4.98 µm and the limit of quantification (LOQ) as 6.36 µm for the sensing of Ag+ ions by receptor ADC. • The complexation was confirmed through 1H NMR titration, IR spectra and DFT analysis. • Strip paper, cotton swab, ointment, water sample experiments and bio-imaging were carried out for the detection of Ag+ ions utilizing ADC. A simple thiophene based chalcone as fluorescent receptor (ADC) was synthesized by Claisen Schmidt condensation method upon linking 2-acetyl thiophene (1) and N,N -dimethylamino benzaldehyde (2). The synthesized receptor is well characterized by NMR, IR, and mass spectroscopic techniques. The ADC receptor was examined for the detection of metal ions, in which it had a noticeable blue shifted fluorescence enhancement for Ag+ ions. Upon binding towards Ag+ ions, the photoinduced electron transfer (PET) process is inhibited via intramolecular charge transfer (ICT) process taking place. The binding stoichiometry of ADC + Ag+ complexation ratio is noted to be 2:1, which was further confirmed by jobs plot method, 1H NMR titration, IR spectral analysis, and DFT studies. The limit of detection (LOD) and limit of quantification (LOQ) was found to be 4.98 µm and 6.36 µm respectively. Additionally, ADC showed color changes upon binding with Ag+ ions in strip paper, cotton swab test through UV-365 nm illumination. Moreover, ADC was successfully utilized for the practical applications of Ag+ ion detection in water samples, ointment and bacterial cell lines. [ABSTRACT FROM AUTHOR]

Various organic and inorganic hazardous substances are commonly originated during the processing of virgin or recovered fibers (RCFs), when the pulp and paper (P&P) are produced. Hence, pulp and paper industry (PPI) strongly need to employ advanced waste treatment processes as a powerful tool to comply with the stringent environmental regulations in one hand, and to increase their profitability in the current declining P&P markets, on the other hand. Among the treatment alternatives, anaerobic digestion (AD), is an interesting cost-effective alternative with a small environmental footprint and has been increasingly adopted by the PPI to reach this goal. However, the application of AD to deal with wastes generated in P&P mills has been restricted due to a number of limitations, regarding the anaerobic reactor design and the operating conditions. Hence, the optimization of the AD performance would be a crucial step in order to increase the economic benefits, and also to satisfy the strict environmental protection standards. To this end, this paper presents an overview on the current state of the developments associated with AD treatment of P&P mill wastes to assess the applicability of this treatment process for the management of this type of complex wastes. In this context, suggestions are provided to maximize both biogas production and removal efficiency, focusing on the relationship between waste composition and reactor design and operational conditions, which will enhance methane capture and contribute to prevent global warming. [ABSTRACT FROM AUTHOR]

Due to accelerated modernization, urban environmental waste is being generated at an exponential rate, and paper is one of the largest solid wastes. Among them, digital printing waste paper has remarkable fiber quality and purity, making it a superior renewable fiber resource. However, the printing method and ink/toner used in the digital printing process are different from traditional printing methods, and the waste paper is relatively difficult to deink, resulting in the traditional waste paper utilization industry (recycled paper) is not given much attention and becomes low-value waste paper. How to realize the resourcefulness and high-value and efficient utilization of digital printing waste paper fiber (DPWF) is a real problem that needs attention in the field of renewable resources. In this paper, DPWF was used in the field of melt blending filled thermoplastic resin composites to avoid the waste paper deinking process while improving various properties of the material. It is shown that the best mechanical properties of the composites are achieved at 35% DPWF content. At the same time, coupling agent was used to further improve the properties of the composites in response to the interfacial incompatibility between fiber and resin. The best modification effect was achieved when the coupling agent was added at 3%, at which time the interfacial, water absorption, crystallization and thermal properties of the composites were improved, among which vinyltrimethoxysilane (A171) and γ-methacryloxypropyltrimethoxysilane (KH570) had significant effects. • DPWF is an excellent quality recyclable fiber resource, with 35% being its optimal content when used as a reinforcement. • Three structurally similar modifiers were used for the improvement of interfacial boundaries and 3% was the optimum content. • The kinetics of water absorption and thermal decomposition of the composites were investigated. [ABSTRACT FROM AUTHOR]

Abstract In recent years, paper has been used as an alternative to traditional substrate materials in the development of strain sensors and accelerometers due to its flexibility, disposability due to environment low footprint and low cost. A lack of knowledge about the sources of nonlinearity in the mechanical behavior of paper makes difficult to consistently predict its performance. The characterization procedures available in the literature are based on both static and dynamic loading as a first attempt to describe the elastic behavior of paper in sensing applications. However, these procedures do not reveal the necessary information to describe the elastic behavior of paper under dynamic excitation. In this work, the nonlinear dynamic response of a harmonically excited paper-based cantilever beam is studied. A lumped model with a quadratic nonlinearity is adopted to describe the nonlinear response of paper-based cantilever beams. The obtained results show that the nonlinear resonance frequency response is dependent on the intrinsic properties of paper when discarding hygrothermal variations of paper as the main source of nonlinear behavior. It was found that the estimation of two nonlinear elastic parameters, α p (hysteresis nonlinear parameter) and E 0 (linear elastic modulus) could yield an improved description of the elastic behavior of paper subjected to vibrations. It was concluded that the existing paper characterization standards should be adapted to better predict the dynamic behavior of paper-based mechanical systems. Different types of paper materials were analyzed to study the influence of the intrinsic characteristics of paper on the nonlinear parameters. Highlights • The inherent characteristics of paper are the source of nonlinear vibration. • Paper can be modeled as a lumped parameter stiffness model with quadratic nonlinearity. • The standard T535-om96 is not suitable to characterize paper based systems. • Porosity has no apparent influence on the nonlinear parameters obtained. • Nonlinear dynamic behavior can be influenced by the filler and fiber types. [ABSTRACT FROM AUTHOR]

For the first time the feasibility of using an alkaline wastewater coming from the pulp and paper industry as an activator, partially (50 vol%) replacing commercial sodium hydroxide, in the production of cork-based activated carbons was evaluated. The activated carbons showed the highest value of specific surface area ever reported for cork-based activated carbons (1670 m 2 /g), surpassing several other commercial and waste-based ones. These eco-friendly cork and paper waste-based activated carbons were then evaluated as methylene blue adsorbent materials. The influence of contact time, methylene blue initial concentration and adsorbent amount on the methylene blue removal efficiency by the activated carbons was studied. Extremely fast (>99.9% removal in 5 min) and efficient methylene blue adsorption (uptake of 350 mg/g) by the cork and paper waste-based adsorbents was achieved, which demonstrates the huge potential of these innovative adsorbents. These activated carbons were produced using two unexplored industrial by-products (alkaline wastewater and cork) and, therefore, may be an inexpensive source of activated carbons, which can be used for the effective removal of dyes from wastewaters. Furthermore, despite the very large surface area and high removal efficiency this is not a nano material (being around 30–50 μm in size), its capabilities being due to its unique cork-derived microstructure, and hence it can be handled and removed/filtered much more easily than nanocarbons, and without any associated health or environmental risks. [ABSTRACT FROM AUTHOR]

Designing efficient non-precious metal catalysts with superior activity and stability for water splitting has been the pursuit of researchers. The purpose of this work is to investigate the influence of 2-amino terephthalic acid on the surface engineering of flower-like Co-N-C for improved water splitting in an alkaline solution. The flower-like Co-N-C grown on carbon paper (Co-N-C/CP) were fabricated by a facile hydrothermal and subsequent annealing process. When the ratio of Co2+ and 2-amino terephthalic acid reaches 1:2 in the precursors, the resultant Co-N-C/CP exhibits the overpotential of 181 mV and 290 mV at 10 mV cm−2 for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), respectively. Furthermore, the Co-N-C/CP (1:2)||Co-N-C/CP(1:2) water splitting systems deliver a current density of 10 mA cm−2 at 1.56 V. After 1500 cycles, the required voltage for water splitting still maintains at 1.57 V. The outstanding electrocatalytic properties are attributed to the tuning electron structure on the surface of Co-N-C, which promotes the charge transfer and chemical mass transport during water splitting in an alkaline solution. This study provides a new opportunity to develop highly efficient cobalt-based catalysts for enhanced water splitting. [Display omitted] • 2-amino terephthalic acid (2-NH 2 -BDC) was used to assist in the synthesis of flower-like Co-N-C for overall water splitting. • The surface electronic structure and morphology of flower-like Co-N-C can be modulated by adjusting the Co/N ratio. • The Co-N-C/CP (1:2) exhibits excellent activity and stability for HER and OER in an alkaline solution. • Co-N-C/CP(1:2)║Co-N-C/CP(1:2) shows the superior catalytic ability for overall water splitting. [ABSTRACT FROM AUTHOR]

Designing efficient non-precious metal catalysts with superior activity and stability for water splitting has been the pursuit of researchers. The purpose of this work is to investigate the influence of 2-amino terephthalic acid on the surface engineering of flower-like Co-N-C for improved water splitting in an alkaline solution. The flower-like Co-N-C grown on carbon paper (Co-N-C/CP) were fabricated by a facile hydrothermal and subsequent annealing process. When the ratio of Co2+ and 2-amino terephthalic acid reaches 1:2 in the precursors, the resultant Co-N-C/CP exhibits the overpotential of 181 mV and 290 mV at 10 mV cm−2 for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), respectively. Furthermore, the Co-N-C/CP (1:2)||Co-N-C/CP(1:2) water splitting systems deliver a current density of 10 mA cm−2 at 1.56 V. After 1500 cycles, the required voltage for water splitting still maintains at 1.57 V. The outstanding electrocatalytic properties are attributed to the tuning electron structure on the surface of Co-N-C, which promotes the charge transfer and chemical mass transport during water splitting in an alkaline solution. This study provides a new opportunity to develop highly efficient cobalt-based catalysts for enhanced water splitting. [Display omitted] • 2-amino terephthalic acid (2-NH 2 -BDC) was used to assist in the synthesis of flower-like Co-N-C for overall water splitting. • The surface electronic structure and morphology of flower-like Co-N-C can be modulated by adjusting the Co/N ratio. • The Co-N-C/CP (1:2) exhibits excellent activity and stability for HER and OER in an alkaline solution. • Co-N-C/CP(1:2)║Co-N-C/CP(1:2) shows the superior catalytic ability for overall water splitting. [ABSTRACT FROM AUTHOR]

The horizontal flame spread over paper samples was investigated using a subatmospheric cabin with varied O 2 concentration. The 25 kPa is found to be a clear turning point for the flame illumination and structure, radiative heat flux and flame spread rate (FSR), which leads to the transition boundary between the extinction limits and power law regions. In the extinction limits (non-linear) region below 25 kPa, the oxygen partial pressure is low with a small Da number. Consequently, the flame spread is gas phase kinetics controlled, resulting in low burning rate, low radiative heat loss and weak buoyancy, and thus the FSR is more sensitive to the oxygen concentration while less sensitive to the ambient pressure. In the power law (linear) region above 25 kPa, in contrast, the oxygen partial pressure is high and the Da number is large, and the flame spread is heat transfer controlled, which weakens the dependence of FSR on oxygen concentration and enhances the dependence on air pressure. [ABSTRACT FROM AUTHOR]

The development of efficient and sensitive point-of-care testing is crucial for preparedness in the post-pandemic era. Although paper-based lateral flow assays have attracted attention and have various advantages for rapid, on-site diagnosis, they have low sensitivity. To overcome the limitations of the existing assays, in this study, we aimed to develop a new, one-step, nanozyme-amplified SlipChip for the sensitive detection of C-reactive protein (CRP). The SlipChip was constructed by combining wax-printed paper with different channel designs. The three-dimensional (3D) fluidic configuration of the SlipChip allowed for the sequential delivery of reagents, enabling mixing and signal amplification with a one-step sliding operation. As a signal-amplifying reagent, peroxidase-mimicking porous platinum nanozyme (pPtNZ) was synthesized using a simple wet chemical method. The pPtNZ conjugated on the test line catalyzes the oxidation of diaminobenzidine (DAB) in the presence of hydrogen peroxide, increasing the color intensity. The immunoassay results of the SlipChip were easily interpreted within 20 min, and the color intensity was visually enhanced by DAB precipitation over time, resulting in up to 6-fold signal amplification. The proposed pPtNZ-SlipChip exhibited high analytical performances for the one-step detection of serum and salivary CRP from 0.1 to 1000 ng/mL, with a limit of detection of 0.03 ng/mL. These results revealed the potential and applicability of the pPtNZ-SlipChip, with the advantages of simplicity, sensitivity, low cost, and portability for on-site detection and point-of-care testing. [ABSTRACT FROM AUTHOR]

Characterization of neutral sulphite semi-chemical black liquor (NSSCBL), sampled from paper manufacturing process that uses recycled fibers as primary feedstock, was carried out for potential bioenergy and biomaterial applications. Physico-chemical characteristics including inorganic elements content, thermogravimetric analysis, GC/MS, and FT-IR are presented. The black liquor of the recycled fibers in the manufacturing process revealed unique characteristics in terms of chemical composition profile compared to the black liquor originating from regular pulp and paper industries. The major findings include the presence of chemical compounds, from a non-plant origin, such as derivatives of hexanedioic acid in significant quantities. The favorable biofuel characteristics of this black liquor are: neutral pH, a higher volatile content, and HHV. The recycled paper NSSCBL can be a good candidate for biomaterial and biofuel applications. [ABSTRACT FROM AUTHOR]

In recent years, the pulp and paper industry has changed a lot and products have been constructed in quite different methods using new technologies. It can be due to the emergence of challenges and constraints such as shortage of raw materials, energy consumption (fossil fuels, electric, etc.), management of the resulting pollutants, environmental issues, ongoing legal requirements and cleaner production strategies. In Iran, the pulp and paper industry's technological development is not keeping pace with global growth. Iran's pulp and paper mills supply a small fraction of domestic market. The reasons can be due to old technologies being used in factories, aging machinery, low productivity of production systems and lack of coordination with modern technologies. It leads to low-quality of paper products and willingness to buy local products. The aim of this study is to select the most appropriate technologies in the pulp section, due to high impact of pulp quality on the quality of final paper. Using a 2-filterd fuzzy decision-making, hierarchical structure of research is designed to assess technological alternatives according to the selected criteria. Findings show that after passing through two filters, Kraft method was chosen as the most appropriate method. The Kraft process has still many advantages like the high quality of the produced pulp and self-sufficiency in energy supply. This framework offers an appropriate procedure for identifying and selecting technologies that has not been used in past researches. Using this framework facilitates using a clear procedure for evaluating and selecting technology and prevents future losses for organizations. [ABSTRACT FROM AUTHOR]

China's paper industry accounts for a larger proportion of the global paper industry and consumes large amounts of energy. Energy conservation and pollution reduction of the industry have become the focus of China's national development strategy. Energy efficiency is an important index which directly determines the amounts of energy consumption and pollution emissions. To understand the energy efficiency evolution of China's paper industry, this paper establishes an input-output data of the paper industry for 29 provinces in China and applies DEA method and econometric models to estimate and comprehensively discuss the energy efficiency issues based on the framework of total factor efficiency. Our results indicate that China's paper industry has a large energy saving potential even though its energy efficiency has improved during the period 1990–2013. The saving potential is about 65% under the meta-frontier and 44% under the group-frontier. Moreover, there are significant differences between different regions in production technology and energy efficiency. The performance of eastern China is better than other regions. But the technology gaps between the different regions are shrinking and converging over time. Finally, some policy recommendations are proposed to improve the energy efficiency of the industry. [ABSTRACT FROM AUTHOR]

The aim of this paper is the development of a mathematical model to compute the optimal inventory mix to face stochastic demand at minimum cost in a two-level supply chain. The paper addresses a multi-product dynamic lot-sizing problem under stochastic demand subject to capacity and service level constraints. This model is executed to compare a Make To Order (MTO) strategy to a Vendor Managed Inventory (VMI) partnership between the supplier and their customers. Both strategies provide the demand order to be produced. A schedule of production orders is determined over the planning horizon in order to minimize the inventory holding costs of the supply chain, taking into consideration that the supplier is also responsible of initiating the replenishment orders and deliveries of their customers according to the VMI partnership. The simulation model is illustrated empirically using a real case study: a paper manufacturing company that pursues to improve customer service level and supply chain inventory costs through a proper production planning of their paper machines and a suitable VMI order replenishment schedule. [ABSTRACT FROM AUTHOR]

• This research proposes a new formulation for the integrated lot-sizing and cutting-stock problem. • It is also presented analytical and numerical comparisons of the proposed model against the model from the literature. • A column generation approach and a relax-and-fix heuristic were applied to solve the proposed model. The integrated lot-sizing and cutting-stock problem has become a trend in the last decades for its applicability and advantage. Consequently, different approaches and formulations have been developed. One of them, which is widespread and related to the production and cutting process of paper, is the research subject of this paper. Fundamental considerations about the literature model are discussed and an alternative formulation is proposed, which consists of a simplified version that can provide better solutions. The upgrade modifications are proved analytically and an instance is analyzed to exemplify the discussed improvement. Moreover, computational tests are performed to compare both formulations. The novelty of the proposed formulation is the possibility of finding better solutions through the reduction of a constraint set, which guarantees the flexibility given by item and object inventories in meeting demand and it also enables a reduction in the total amount of produced paper. The proposed formulation has a significant impact on future research since the addressed model is the target of many scientific researches and practical applications. [ABSTRACT FROM AUTHOR]

Graphical abstract Grapheme oxide based ratiometric fluorescent paper sensor was developed for HClO visual determination. Highlights • Grapheme oxide based ratiometric fluorescence probe was developed for HClO detemination. • The detection limit of HOCl has been determined as 2.92 μM. • HOCl sensing by the nanoprobe is based on intramolecular charge transfer (ICT) mechanism. • Paper sensors were fabricated for the on-site and visual sensing of HOCl. Abstract In this paper, a simple and effective ratiometric fluorescent nanoprobe for visual detection of hypochlorous acid (HOCl) has been developed by loading silicon coated rhodamine B (RBDS) nanospheres on the surface of amino-modified graphene oxide (GO-NH 2) nanosheets. The fabricated nanoprobe exhibits dual-emissions peaked at 427 and 585 nm, under a single excitation wavelength of 365 nm. The blue fluorescence of GO-NH 2 can be selectively quenched by oxidation of HOCl, while the red fluorescence of RBDS remain unchanged, resulting in a distinguishable fluorescent color change from blue to pink under a UV lamp. Nanoprobes present high selective and sensitive for HOCl determination with a limit of detection (LOD) of 2.92 μM. Moreover, potable paper sensor has been prepared by coating the ratiometric fluorescent probe on filter paper, which provides a convenient and simple approach for HOCl visual detection. [ABSTRACT FROM AUTHOR]

Molybdenum oxides are widely used as electrocatalysts due to their polymetallic oxidation state, abundant reactive sites and low production cost. However, the low electrical conductivity and easy agglomeration has limited their practical application. Here, MoO 3 nanowires encapsulated with ZIF-67 polyhedra were grown in situ on expanded graphite paper (EGP) by a simple hydrothermal synthesis method, and then the precursors were pyrolyzed to obtain self-supported Co-MoO x @N-doped carbon/EGP composites. Thanks to the three-dimensional porous structure and the synergistic effect of Co and multi-valance MoO x , the as-prepared Co-MoO x @N-doped carbon/EGP exhibits the excellent performances of OER (η 10 = 256 mV) and HER (η 10 = 138 mV), and a small Tafel slope and good durability. Furthermore, the assembled water splitting device achieved a current density of 10 mA cm−2 at a low voltage of 1.62 V and the excellent stability after 24 h continuous water splitting. [Display omitted] • Self-standing Co-MoO x @NC/EGP exhibits the excellent OER performance with the overpotential of 256 mV at 10 mA cm−2. • Three-dimensional structure and heterogeneous interface can expose more active sites and promote the transfer of electrons. • The assembled water splitting device only require a voltage of 1.62 V to achieve a current density of 10 mA cm−2. [ABSTRACT FROM AUTHOR]

Low-quality materials contained in separately collected (SC) packaging waste generate environmental and economic burdens associated to both sorting operations of Material Recovery Facilities (MRFs) and landfilling of non-recyclable materials. In this study, based on quantification of both impurities and recyclable fractions, the quality of SC municipal packaging waste streams was determined by compositional analysis of the waste entering a MRF throughout a year. Foreign materials (% w/w) found in the monitored SC glass, paper plus cardboard and lightweight packaging waste, were on average 5.0, 14.7 and 23.0, respectively, while landfilled materials (% w/w) after MRF sorting operations were on average 4.3, 10.3 and 22.0, respectively. A Life Cycle Assessment study was conducted to determine the environmental impact of SC packaging waste streams quality of three different scenarios: current situation (CS), better (BS) and ideal (IS) scenario with reduced presence and absence, respectively, of improper materials in the three examined SC packaging waste streams. Emission of 32.1 kg CO 2 eq/t waste was calculated for the current situation with a reduction by 66.1% and 98.0% in CO 2 eq emission for BS and IS scenario, respectively. Similar emission reductions were calculated for ozone depletion, ionizing radiations, particle matter formation, fossil fuel depletion and primary energy demand impact categories. The environmental life cycle costing study demonstrated that total savings of € 35.2 and € 66.6 for each ton of SC packaging waste stream entering the MRF could be obtained for BS and IS scenario, respectively. [Display omitted] • Impurities in packaging waste streams generate environmental and economic burdens. • 23.0% of impurities were found in separately collected lightweight packaging waste. • Plant sorting operations generate 32.1 kg CO 2 eq for each ton of packaging waste. • € 35.2/ton of sorted packaging waste could be saved by reducing impurities content. [ABSTRACT FROM AUTHOR]

In this work, we present the development of an immunosensor for the direct, selective, and sensitive determination of symmetric dimethylarginine (SDMA) in urine, in view of the emerging role of this molecule as a biomarker for renal disease. SDMA is almost completely excreted by the kidneys, hence in renal dysfunction, the excretion is decreased, resulting in accumulation in plasma. Reference values for plasma or serum have already been established in small animal practice. Values < 15 μg/dL are considered normal, 15–19 μg/dL are values of concern, and at values > 20 μg/dL kidney disease is likely. The proposed electrochemical paper-based sensing platform uses anti-SDMA antibodies for targeted detection of SDMA. Quantification is related to a decrease in the signal of a redox indicator due to the formation of an immunocomplex that interferes with electron transfer. Square wave voltammetry measurements showed a linear correlation of the peak decline for 50 nM - 1 μM SDMA with a detection limit of 15 nM. The influence of common physiological interferences caused no significant peak reduction, indicating excellent selectivity. The proposed immunosensor was successfully applied for the quantification of SDMA in human urine of healthy individuals. Surveillance of SDMA concentration in urine could prove to be very valuable in the diagnosis or monitoring of renal disease. [ABSTRACT FROM AUTHOR]