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In this study, carbon fiber paper (CFP) was prepared by adding carboxyl nitrile latex (XNBRL) and phenolic resin (PF) into the carbon fibers suspension instead of the immersion method. It was found that XNBRL and PF adsorbed and flocculated on the surface of the carbon fibers as cationic agent was used. And with the increase of XNBRL addition, the retention rate of the pulp and the size of the flocs gradually increased. Due to the low residual carbon rate of XNBRL, most of it was decomposed into small molecular gases during carbonization, with the increase of XNBRL addition, the CFP became fluffy gradually, and its thickness, resistivity and air permeability increased, while the density and tensile strength decreased, and the basis weight was basically unchanged. Owing to the high residual carbon rate of PF, the basis weight, density and tensile strength of the CFP gradually increased with the increase of PF addition, while the thickness, resistivity and air permeability gradually decreased. Therefore, XNBRL could promote the retention of PF during paper forming, when the XNBRL dosage was 60 wt% and PF was 300 wt%, the basis weight of CFP was 74.55 g/m2, the thickness was 0.22 mm, the tensile strength was 10.85 MPa, the resistivity was 0.0284 Ω·cm, and the air permeability was 2005.34 mL·mm/ (cm2·h·mmHg). • Carbon fiber paper was prepared using carboxyl nitrile latex and phenolic resin in-pulp addition method. • The retention rate of the pulp and the flocs size gradually increased with the increase of carboxyl nitrile latex content. • Carbon fiber paper exhibited excellent comprehensive performance. [ABSTRACT FROM AUTHOR]

[Display omitted] • Chemical profiling of different paper grades was performed along the recycling chain. • Untargeted analysis of semi-volatiles and non-volatiles using GC- and LC-MS. • Chemometrics application to identify specific features by paper grade and site. • Exploration of the possible sources of detected compounds in the paper recycling chain. • Numerous chemical compounds associated with plastics have been detected. Paper packaging made with recycled paperboard is used to pack various consumer goods that can include amongst others, electronics, toys, food, cosmetics, and stationery. Chemical profiling of the various paper recycling grades used in the manufacture of recycled paperboard was undertaken to investigate possible sources of contaminants and their propagation in the paper recycling chain. Pre-consumer, retail and post-consumer paper-based materials were collected at papermills, corrugators, grocery stores, household waste, solid waste disposal sites and recycling facilities. In the GC-MS analysis, phthalates, long-chain aliphatic compounds, and fatty acids were the most commonly detected compounds whilst phthalates and bisphenols featured most prevalently in the LC-MS analysis. The factors that were identified as likely contributors to the detection of the different chemical compounds included the presence of wood derivatives, the use of certain chemical additives during manufacturing, and exposure of paper to contaminants from consumers, other goods and the environment. Waste mingling, recovery, sorting and reprocessing into recycled paper were also shown to influence the chemical profile of paper materials. Sparse partial least squares-discriminate analysis indicated that newspaper and office paper had unique chemical constituents, whilst cartons were shown to have higher variability. By looking at key stages of paper recycling, this study showed that the possible persistence and transformation of chemical compounds in additives must be evaluated when considering the recyclability of paper-based materials. Further, it highlighted that different separation approaches may be required to reduce contaminant exposure opportunities in post-consumer paper materials. [ABSTRACT FROM AUTHOR]

[Display omitted] • Evaluated paper mill sludge waste conversion into value added packaging materials. • Enzymatic pretreatment enhanced micro- and nanofibrillated cellulose (MNFC) production. • Enzymatic hydrolysis and mechanical centrifugation showed a synergistic effect. • The presence of inorganics improves MNFC preparation and composite formation. • Sludge MNFC-derived packaging films showed high mechanical strength. The production of micro- and nano-fibrillated cellulose (MNFC) from paper mill sludge (PS) using simple enzymatic and mechanical treatments has been evaluated for their performance as value-added materials in packaging and other applications. Sludge from a US paper mill was analyzed for the viability of this conversion process. The enzymatic treatment was conducted at variable concentrations using an enzyme cocktail of exoglucanase and endoglucanase, followed by mechanical dual asymmetric centrifugation (DAC) treatment. The presence of inorganics and lignin facilitated the mechanical defibrillation of the fibers, making the MNFC production more energy-efficient. The prepared MNFC was characterized for fibrillation, charge, crystallinity, and surface morphology. Scanning electron microscopic (SEM) images show the highly fibrillated MNFC and the distribution of inorganic nanoparticles on the fiber surface. The X-ray diffractometric (XRD) analysis shows 44–65 % crystallinity. Furthermore, MNFC-based films derived from PS demonstrated excellent strength and flexibility, making them suitable for packaging and other applications. Overall, this conversion approach can save the paper industry millions of dollars in disposal costs while upcycling waste and reducing greenhouse gas (GHG) emissions associated with waste streams. [ABSTRACT FROM AUTHOR]

A new materials composed of TiFe particles stabilized onto a carbon support is described. The carbon support is derived from a waste from the paper industry called Kraft Black liquor. The particles are generated through an impregnation/reduction process of a mixture of titanium ethoxide and iron nitrate followed by a thermal treatment. The generated particles have been investigated through XPS, XRD and SEM analysis as well as tested for hydrogen storage. The hydrogen storage at 25 °C leads to a capacity of up to 0.5 wt% while at 150 °C, free of the carbon absorption, leads to a capacity of 0.2 wt% without any prior activation process. Novel TiF@carbo(HIPE) materials have been synthesized while employing Kraft black liquor as carbonaceous source. A specific carbo-reduction thermal treatment allows a synergetic TiFe particles external shell reduction concomitant with the surrounding carbonaceous backbone oxidation enhancing thereby the materials specific surface area and associated microporosity. Pre-activation free, TiFe@Carbo(HIPE) can achieve a capacity up to 0.5 wt% at 25 °C where TiFe particles and the carbonaceous host support are acting cooperatively. [Display omitted] • Generation and characterization of carbon from a waste from the paper industry. • Generation of TiFe nanoparticles on the carbon. • Characterization of the TiFe nanoparticles. • Use of the hybrid composite TiFe@Carbon for hydrogen storage. [ABSTRACT FROM AUTHOR]

In this study, the microstructure of carbon fiber paper is modified through H 3 PO 4 etching to enhance the electrolyzer performance. The effects of different H 3 PO 4 concentrations and different soaking times on the hydrogen evolution reaction are firstly investigated. The electrochemical test results show that the best performance of etched electrodes is achieved at a H 3 PO 4 concentration of 1 M and a soaking time of 12 h, with a significant reduction in charge transfer resistance and overpotential. Subsequently, to explore the change mechanism in electrochemical properties, the microstructure of the carbon paper is investigated using Scanning Electron Microscope (SEM) and Mercury Intrusion Porosimetry (MIP) tests, which show uniformly distributed micropores appear on the surface of the carbon fibers after etching, and the porosity increases from 0.74 to 0.8. Brunauer-Emmett-Teller (BET) tests show that the specific surface area of the carbon paper increases from 0.72 m2/g to 4.06 m2/g, which effectively increases the interfacial contact area between the catalyst layer and the liquid gas diffusion layer. Furthermore, a 3D multi-physics model is established to further elucidate the impact mechanism of changes in porosity, conductivity, and active specific surface area on the performance of anion exchange membrane electrolyzer, with changes in active specific surface area having the greatest effect. • Microporous structure of the carbon paper LGDL is modified by etching. • The etching method effectively improves the performance of AEMEL. • The increase in specific surface area and porosity greatly reduces the resistance. • Numerical modeling to analyze the impact of microscopic parameters on AEMEL. • LGDL with high specific surface area has a positive effect on AEMEL's development. [ABSTRACT FROM AUTHOR]

Carbon fiber paper (CFP) is one of the most widely used gas diffusion layer materials for proton exchange membrane fuel cells (PEMFC) due to its excellent properties such as high conductivity, high strength, high air permeability and corrosion resistance. In this study, CFP was prepared using the phenolic resin (PF) in-pulp addition method. The effect of PF content on the properties of hot-pressed paper (HPP) and CFP was investigated. The results showed that when the dosage of polyethylene oxide (PEO) was 1.5 wt%, the flocculation effect of PEO on PF was basically complete, and the water filterability and retention of carbon fiber pulp were relatively optimal. After HPP was carbonized into CFP, the hydrophobicity, average pore size, porosity, and air permeability increased, while the resistivity and tensile strength decreased. With the increase of PF content, the tensile strength of CFP gradually increased, while the average pore size, porosity, air permeability and resistivity decreased. When the PF content was 250 wt%, the average pore size of CFP was 36.5 μm, the water contact angle was 127°, the porosity was 69.7%, the air permeability was 7.81 × 103 mL mm/(cm2·h·mmHg), the resistivity was 21.1 mΩ cm, and the tensile strength was 15.7 MPa. In addition, the CFP prepared using PF in-pulp addition method had a relativity uniform pore size distribution and high air permeability. Therefore, this work shows that the CFP prepared using this technique exhibits excellent comprehensive performance, and enables the manufacturing of CFP to be more efficient, low-cost, and environmentally friendly. [Display omitted] • Carbon fiber paper was prepared efficiently using the phenolic resin in-pulp addition method. • Polyethylene oxide exhibits strong adsorption ability on phenolic resin in carbon fiber pulp. • The melting temperature of phenolic resin is a critical point in the preparation process of carbon fiber paper. • Carbon fiber paper possesses a relatively uniform pore size distribution and high air permeability. [ABSTRACT FROM AUTHOR]

Smart actuators have shown great potential for a range of industries, including artificial muscles, sensors, and smart devices. However, traditional actuators often suffer from small deformation and complex materials and manufacturing processes. Graphene oxide (GO) has emerged as an ideal candidate for moisture-responsive actuators due to its excellent moisture sensitivity. In this study, we present the development of a moisture-responsive actuator using a simple and straightforward approach based on a monolayer graphene oxide (GO) paper. By utilizing the different affinity of its two sides for water, the graphene oxide actuator demonstrates excellent performance in response to humidity gradients, achieving a large bending amplitude with a curvature of 3 cm−1. Furthermore, the graphene oxide actuator was used as a humidity-sensitive switch to perform on and off switch movements, demonstrating its capability for autonomous detection for real-time humidity monitoring. This work provides a new avenue for the development of moisture-responsive materials and their potential applications in the design of intelligent control systems, actuators, soft robots, artificial muscles, and switches. [Display omitted] • The paper introduces a novel moisture-responsive actuator made of a single layer of graphene oxide paper. • The actuator exploits the different water affinity of its two sides to bend in response to humidity changes. • The actuator can also function as a humidity-sensitive switch, enabling autonomous and real-time humidity detection. • The paper demonstrates the potential of graphene oxide as a material for smart actuators, sensors, and devices. [ABSTRACT FROM AUTHOR]

To identify the trends of the top 100 cited articles on economic evaluation in preventive oral health programs. Top 100 papers involving economic evaluation or cost analysis of preventive oral health programs were selected by querying Scopus and Web of Science databases. Bibliometric analysis was performed using the Bibliometrix tool in R Studio. Performance analysis and science mapping were performed for these 100 articles. Performance analysis included publication-related metrics, citation-related metrics, and citation-publication-related metrics. Science mapping provided information on citation analysis, co-citation analysis, bibliographic coupling, co-word analysis, and co-authorship details. The total citation number of the top 100 most cited articles ranged from 4 to 98, with publication dates spanning from 1978 to 2023. The majority of articles (33.70 %) originated from the USA, while Community Dentistry and Oral Epidemiology stood out as the journal with the highest number of articles published in the top 100 (16 out of 100). Griffin PM emerged as the most cited author, based on the frequency measurement of the number of papers. Program data economic evaluation was the most commonly reported study design, and fluoridation programs were the most frequent topic. The most reported type of economic analysis performed in the articles was cost-effectiveness analysis. The bibliometric analysis of the top 100 most-cited articles on economic evaluation of preventive oral health programs revealed the lacunae in the research literature on this topic. Therefore, preventive oral health programs should be economically evaluated to eliminate the disparity in resource allocation particularly in upper middle income and low-income countries. [Display omitted] [ABSTRACT FROM AUTHOR]

This study investigates a novel isometric method utilizing an external focus instruction technique with a soft paper balloon. By emphasizing control to avoid crushing the balloon, this method promotes co-contraction of muscles without exerting pressure on the object. We aim to evaluate differences in muscle activation patterns during isometric hip abduction exercises between the paper balloon task and tasks using external resistance (hard plastic, non-elastic, and elastic bands), and further determine their influence on the contralateral side. Thirteen healthy adult males aged 20–28 years were recruited. Six trunk muscles (transversus abdominis [TrA], internal oblique [IO], external oblique, rectus abdominis, multifidus [MF], and lumbar erector spinae) and five lower-extremity muscles (gluteus maximus [GMax], gluteus medius [GMed], adductor longus, rectus femoris [RF], and biceps femoris [BF]) were measured using surface and fine-wire electrodes to compare the different isometric hip abduction exercises. The muscle activity did not differ between the abduction sides except for GMax and GMed with the elastic band and RF and BF with the hard plastic (p > 0.05). The trunk muscles (TrA, IO, and MF) were similarly activated with the paper balloon and external loading tasks; however, the paper balloon task activated trunk muscles without bearing weight, potentially avoiding pressure on the spine, knee, or hip joints. Moreover, all tasks showed muscle activation on the opposite side of the body. [ABSTRACT FROM AUTHOR]

• Pulp and paper mill sludge (PPMS) landfill sites have GHG assessment challenges. • GHG fluxes measured by chambers with (F +) and without (F-) a frame were compared. • Flux relationships up to 80 % were shown between F- and F + chambers (the standard) • Correction factors for F- chambers were built to estimate fluxes from F + chambers. • The approach can refine GHG inventories on PPMS landfill sites. Assessments of greenhouse gas (GHG) emissions in managed areas are facing various challenges. A non-flow-through, non-steady-state (NFT-NSS) chamber coupled to a frame permanently inserted into the landfilled substrates is a standard method for quantifying GHG emissions in managed areas, such as pulp and paper mill sludge (PPMS) landfill sites. Frequent measurements are needed to minimize uncertainties on GHG emission factors at the landfill site scale. However, maintaining a frame inserted into the substrates for a long time period is often impossible due to landfilling management operations. Therefore, GHG measurements using NFT-NSS chambers placed directly on substrates' surface could be an interesting option. Our objectives were to determine the relationships between CO 2 , CH 4 , and N 2 O fluxes measured with (F +) and without (F-) a frame inserted in the substrates' surface and to develop correction factors for fluxes measured without a frame. Measurements were made at different PPMS landfill sites in the province of Québec, Canada. Stronger GHG flux relationships were observed at the provincial (across sites) than the specific site scale: the variance in GHG fluxes from F- chambers explained up to 80 % of variance in fluxes from F + chambers. The measured CO 2 , CH 4 , and N 2 O fluxes in F- chambers were on average 53, 78, and 63 % lower, respectively, than those estimated by the models at provincial scale. The correction factors developed with this approach could greatly extend the number of sites where in situ GHG measurements can be done and would help refining GHG inventories at the provincial and national levels. [ABSTRACT FROM AUTHOR]

To evaluate variation in treatment plans and pathological findings related to maxillary second and third molars based on panoramic (PAN) images and cone beam CT (CBCT) among Danish and Dutch oral and maxillofacial surgeons. This web-based "paper" clinic contained 10 cases of impacted maxillary third molars comprising clinical information, PAN, and CBCT. Treatment plan and pathological findings were established based on clinical information and PAN, thereafter, based on CBCT by 28 surgeons. Options for treatment plan for third molars were no treatment, or tooth removal. Options for treatment plan for second molars were no treatment, tooth removal, or endodontic and/or filling therapy. The surgeons assessed external root resorption, marginal bone loss, and follicular space. A change in treatment plan between PAN and CBCT was registered between 0% and 43% of the surgeons among the cases. The surgeons did not agree completely on the treatment plan in any of the cases. Variation was present among the surgeons evaluating pathological findings. In several cases, severity of root resorption was rated worse in CBCT than in PAN. Variation in treatment plan and pathological findings was observed among surgeons. No correlation between change in pathological findings and change in treatment plan was found. [ABSTRACT FROM AUTHOR]

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]

Carbon paper as a macroporous substrate of gas diffusion layer in proton exchange membrane fuel cells directly impacts the output performance of cells. In this study, we present a straightforward strategy to improve the overall performance of carbon paper by mixing short/long (6mm/10 mm) chopped carbon fibers at an optimal concentration of phenolic resin. The results show that incorporating longer carbon fibers can increase the porosity, conductivity, gas flux, and mechanical properties of carbon paper. The membrane electrode assembly achieved a peak power density of 1182.61 mW cm−2 at 60% RH using carbon paper with a long carbon fiber content of 40 wt% and an impregnation concentration of 10 wt%. This outperforms commercially available carbon paper. Based on electrochemical impedance spectroscopy results, it was confirmed that our carbon paper had a lower mass transfer resistance of only 32.17 mΩ cm−2 under conditions of 2 A cm−2 and 60% RH. This was due to its sparser three−dimensional network-like pore structure which was created by mixing different lengths (6mm/10 mm) of carbon fibers. This work provides new insights into preparing high−performance carbon papers. • The nature of carbon paper is regulated by mixing short/long (6mm/10 mm) CFs ratio. • The long carbon fiber contents of 20–40 wt% present better physical properties. • The optimal carbon papers can mitigate mass transfer resistance. • MEA composed of the optimal CP shows a higher power density than commercial CP. [ABSTRACT FROM AUTHOR]

A facile method is proposed in this work to prepare a carbon paper (CP) with outstanding properties by doping boron to catalyze graphitization at lower temperature. Boron was introduced into CP by impregnating carbon fiber preform into a boron/phenolic resin/ethanol solution, and then CP was obtained after the consecutive procedures of hot pressing, carbonization, and graphitization. Morphology, microstructure, composition, and physical properties of the doped and undoped CPs were thoroughly investigated via various techniques to exam the effects of boron concentration and graphitization temperature. Furthermore, the boron doped CP was fabricated into fuel cell gas diffusion layer (GDL) and membrane electrode assembly (MEA) to evaluate its performance through the single cell performance. The findings indicated CP doping with 2 wt% boron could lower the graphitization temperature by at least 200 °C. The B-doped GDL had a higher power density in comparison with the undoped GDLs made in our lab or from the commercial brands. • The innovative preparation method for carbon paper with high conductivity. • The effect of boron concentration and graphitization temperature on carbon paper. • The single cell performance of B-doped gas diffusion layer. [ABSTRACT FROM AUTHOR]

Food security exists when all people, at all times, have physical, social, and economic access to sufficient, safe, and nutritious food that meets their dietary needs for an active and healthy life. While there is a lengthy body of literature examining food insecurity among children, food insecurity among adolescents and young adults (AYAs) has been relatively understudied. The literature demonstrates that AYAs experiencing food insecurity have poorer physical, mental, and psychosocial health outcomes than their peers, which may persist into adulthood. As AYAs reach reproductive maturity, those experiencing food insecurity are more likely to have children who are also poorly nourished, perpetuating intergenerational poor nutrition and its associated health and socioeconomic costs. In this position paper, Society for Adolescent Health and Medicine (SAHM) recommends actions that healthcare professionals can take to achieve a goal of universal food security among AYAs. As SAHM strives to promote the optimal health of AYAs around the world, the positions in this paper affirm SAHM's commitment to promoting food security for all AYAs. [ABSTRACT FROM AUTHOR]