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Mitigation of global warming, energy security and industrial competitiveness urge the energy-intensive pulp and paper industry (PPI) to transform energy use practices. This study investigates how the PPI has responded to the need for the energy transition in the 2000s. Finland and Sweden as forerunners of energy-efficient operation and decarbonization of the PPI are used as target countries. Understanding of changes in energy consumption is complemented using decomposition analysis (Logarithmic Mean Divisia Index Method) and the energy efficiency index approach. Analysis of companies’ investments in energy technologies is used for explaining changes in energy production. Evidence of significant development towards the more sustainable operation of the PPI was found. Energy consumption per produced unit has decreased, i.e., energy efficiency has improved. Fossil fuels have been partially replaced with bio-based alternatives. Thus, the CO2 intensity has decreased substantially. The generation of renewable electricity has increased in both countries. Examples of Finland and Sweden indicate that the PPI has great potential to contribute to CO2 emission reduction worldwide in the future as energy efficiency can be further improved, and the share of fossil fuels can be decreased increasing the use of biofuels and self-generated green electricity at least in kraft pulp mills.

Made available in DSpace on 2022-04-29T08:31:12Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-10-01 Organization and planning of reverse logistics networks make sustainable processes more efficient. Thus, an important sector for connecting the collection and waste paper recycling echelons is the intermediate center. In this study, a Mixed Integer Linear Programming model, which is multi-objective, multi-product, multi-level and multi-period, was developed to optimize the waste paper logistics processes of intermediate centers. The formulation includes the following echelons: collection, considering vehicle routing with different capacities; inventory of non-baling materials; baling sorted waste and inventory of bales; selling bales; disposal of non-recyclable waste. The aims of the model include: maximizing the collected waste; minimizing distances; maximizing both the production and sale of bales, and minimizing costs. According to research carried out in the literature, the developed model is a new proposal and to implement it, the Weighted Goal Programming and Revised Multi-Choice Goal Programming approaches were used to deal with multiple objectives and incorporate uncertainty into the quantity of waste available for collection. To analyze the proposed model, computational tests were executed with instances based on real data from a Brazilian company in the sector. For all performed tests, General Algebraic Modeling System 23.6.5 modeling language and CPLEX 12.2.0.2 solver were used for modeling and optimization. The results show that this study presents formulation and technological approaches that represent real situations and provide competitive solutions to the problem. Sáo Paulo State University “Júlio de Mesquita Filho” [Universidade Estadual Paulista Júlio de Mesquita Filho] School of Engineering of Guaratinguetá [Faculdade de Engenharia de Guaratinguetá] Production Department, Av. Ariberto Pereira da Cunha, 333, Portal das Colinas Agulhas Negras Military Academy [Academia Militar das Agulhas Negras] Rodovia Presidente Dutra, km 306, s/n Escola Preparatória de Cadetes do Exército Avenida Papa Pio XII 350 Jardim Chapadão Campinas - SP Brazil, Avenida Papa Pio XII, 350, Jardim Chapadão, Campinas - SP Sáo Paulo State University “Júlio de Mesquita Filho” [Universidade Estadual Paulista Júlio de Mesquita Filho] School of Engineering of Guaratinguetá [Faculdade de Engenharia de Guaratinguetá] Production Department, Av. Ariberto Pereira da Cunha, 333, Portal das Colinas

We employed a microwave-assisted two-pot in-situ deposition technique to incorporate zinc oxide particulates in the structure of filter paper to produce antimicrobial paper. The process involved successive immersion of filter paper samples in ZnSO4 (precursor solution) and NaOH (precipitating agent) to form Zn(OH)2, which transformed into ZnO during microwave treatment. Successful deposition of ZnO particles on the filter paper was confirmed via X-ray diffraction and the corresponding morphologies were observed using field emission scanning electron microscopy. The ZnO-deposited papers were tested for antimicrobial activity and were found to be more effective against Staphylococcus aureus (gram-positive) than Escherichia coli (gram-negative). Bacterial populations were reduced by up to 92 ± 2% and 57 ± 4% for S. aureus and E. coli, respectively. Also, it was found that the samples prepared using higher concentrations of ZnSO4 and NaOH exhibited better antimicrobial properties.

With the increased awareness of reusing solid wastes for higher sustainability and the concern of water pollution associated with phosphorus over-emission, there are strong interests in developing solid waste based adsorbents for purifying phosphorus-containing wastewater. As a rich calcium resource, paper mill sludge (i.e., a major solid waste from pulping industry) can be used as phosphorus removal adsorbent after calcination. Thus, in this work, a simple and clean thermally treating route has been proposed for preparing calcium-containing biochar from paper mill sludge. The effect of the physicochemical properties of paper mill sludge and its carbonization condition on phosphorus adsorption has been analyzed. Moreover, the influence of some key adsorption parameters, e.g., biochar dosage, initial pH of solution, co-existing anions, initial phosphorus concentration and contact time has also been investigated. The results showed that the phosphorus adsorption data could be fitted well with pseudo-second-order kinetic and Langmuir isothermal models. The calculated maximum adsorption capacity of the as-prepared optimal calcium-containing biochar could reach to 68.49 mg·g−1 at 25 °C. Combined with the characterization results, it can be reasonably inferred that the adsorption process was chemisorption-dominated. Lastly, the application of this spent adsorbent in agriculture field has also been discussed. In brief, this work provided a feasible strategy for converting paper mill solid waste to an environmental functional material (i.e., calcium-rich biochar) for remediation of eutrophic water.

Nitrogen-fixing bacteria (NFB) can reduce nitrogen at ambient pressure and temperature. In this study, we treated effluent from a paper mill in sequencing batch reactors (SBRs) and monitored the abundance and activity of NFB with a view to producing a sludge that could work as a biofertilizer. Four reactors were inoculated with activated sludge enriched with NFB and fed with a high C/N waste (100:0.5) from a paper mill. Though the reactors were able to reduce the organic load of the wastewater by up to 89%, they did not have any nitrogen-fixing activity and showed a decrease in the putative number of NFB (quantified with qPCR). The most abundant species in the reactors treating high C/N paper mill wastewater was identified by Illumina MiSeq 16S rRNA gene amplicon sequencing as Methyloversatilis sp. (relative abundance of 4.4%). Nitrogen fixation was observed when the C/N ratio was increased by adding sucrose. We suspect that real-world biological nitrogen fixation (BNF) will only occur where there is a C/N ratio ≤100:0.07. Consequently, operators should actively avoid adding or allowing nitrogen in the waste streams if they wish to valorize their sludge and reduce running costs. PRACTITIONER POINTS: Efficient biological wastewater treatment of low nitrogen paper mill effluent was achieved without nutrient supplementation. The sludge was still capable of fixing nitrogen although this process was not observed in the wastewater treatment system. This high C/N wastewater treatment technology could be used with effluents from cassava flour, olive oil, wine and dairy industries.

Cellulose based nanomaterials have the great potential to be applied to paper as bulk additive or coating material to improve overall final properties, especially in secondary fiber. In the present work, the effect of applying different kinds of cellulose nanofibrils (CNF) to papers obtained from recycled fibers using size press on physical, mechanical and barrier properties was investigated and compared with the sole use of starch as coating material. The coating process of CNF was carried out by the addition of size press grade starch to coating suspension. As a cellulose source, wheat straw was evaluated and CNF was obtained through oxidative and enzymatic pretreatments. Results indicate that starch/CNF suspension improves the overall paper properties. As a result of the deposition of coating suspension contains of 4 % wt. periodate-oxidized CNF onto paper surface, tensile and burst indices of papersheets increased as 52.2 % and 194.4 %. Significant decreases were observed in air permeability as 69.8 %. Compression tests also have been conducted to evaluate papersheets end-use properties. In comparison to the other pretreated CNF, due to is lower viscosity, applying periodate-oxidized CNF as size press significantly increased the mechanical properties of the papers fabricated from the recycled pulps. TUBITAK-TEYDEBTurkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [1505]; Scientific and Technological Research Council of Turkey, Technology and Innovation Funding Programs Directorate [1505, 5180044] This work was supported by TUBITAK-TEYDEB 1505 (The Scientific and Technological Research Council of Turkey, Technology and Innovation Funding Programs Directorate 1505), Project No. 5180044. WOS:000703585400013 2-s2.0-85108063350

Funding Information: The financial support of the Austrian Federal Ministry of Digital and Economic Affairs and the National Foundation for Research, Technology and Development , Austria, is gratefully acknowledged. We also thank the industrial partners Mondi, Canon Production Printing, Kelheim Fibres, and SIG Combibloc for their support. Publisher Copyright: © 2021 Copyright: Copyright 2021 Elsevier B.V., All rights reserved. Hydrophobization of cellulosic materials and particularly paper products is a commonly used procedure to render papers more resistant to water and moisture. Here, we explore the hydrophobization of unsized paper sheets via the gas phase. We employed three different compounds, namely palmitoyl chloride (PCl), trifluoroacetic anhydride/acetic anhydride (TFAA/Ac2O)) and hexamethyldisilazane (HMDS) which were vaporized and allowed to react with the paper sheets via the gas phase. All routes yielded hydrophobic papers with static water contact angles far above 90° and indicated the formation of covalent bonds. The PCl and TFAA approach negatively impacted the mechanical and optical properties of the paper leading to a decrease in tensile strength and yellowing of the sheets. The HMDS modified papers did not exhibit any differences regarding relevant paper technological parameters (mechanical properties, optical properties, porosity) compared to the non-modified sheets. XPS studies revealed that the HMDS modified samples have a rather low silicon content, pointing at the formation of submonolayers of trimethylsilyl groups on the fiber surfaces in the paper network. This was further investigated by penetration dynamic analysis using ultrasonication, which revealed that the whole fiber network has been homogeneously modified with the silyl groups and not only the very outer surface as for the PCl and the TFAA modified papers. This procedure yields a possibility to study the influence of hydrophobicity on paper sheets and their network properties without changing structural and mechanical paper parameters.

Graphical abstract Enzyme-linked immunosorbent assay (ELISA) is widely used for the detection of disease biomarkers. However, it utilizes time-consuming procedures and expensive instruments, making it infeasible for point-of-care (POC) analysis especially in resource-limited settings. In this work, a multicolorimetric ELISA biosensor integrated on a paper/polymer hybrid microfluidic device was developed for rapid visual detection of disease biomarkers at point of care, without using costly equipment. This multicolormetric ELISA platform was built on multiple distinct color variants resulted from the catalytic oxidation of 3,3′,5,5′-tetramethylbenzidine (TMB) and the etching of gold nanorods (AuNRs). The vivid color changes could be easily distinguished by the naked eye, and their red mean values allowed quantitative biomarker detection, without using any sophisticated instruments. When this multicolorimetric ELISA was integrated on a paper/polymer hybrid analytical device, it not only provided integrated processing and high portability but also enabled fast assays in about 50 min due to the unique advantages of paper/polymer hybrid devices. The limit of detection of 9.1 ng/μL of the hepatitis C virus core antigen, a biomarker for hepatitis C, was achieved using this multicolorimetric ELISA platform. This multicolor ELISA analytical device provides a new versatile, user-friendly, affordable, and portable immunosensing platform with high potential for on-site detections of various viruses, proteins, and biomarkers for low-resource settings such as at home, public venues, rural areas, and developing nations. Supplementary Information The online version contains supplementary material available at 10.1007/s00216-021-03359-8.

In this study, Taguchi experimental design was used to the optimize operating parameters for the degradation of paper mill effluent using electrochemical (EC) process with two-dimensional concentric aluminum tube electrodes (CATE). For this purpose, four significant experimental factors were used in four levels pH (6–9), electrolysis time (10–40 min), voltage (6–12 V) and surface area (357–624 cm(2)). The process parameters were optimized, through performing L16 orthogonal array of Taguchi technique, for the removal of chemical oxygen demand (COD) and turbidity. The percent COD and turbidity reductions were transferred into an accurate S/N ratio for a larger value is the better (LBT) response. The study presents a unique method of finding optimum combination of process parameters to illustrate their effect on the turbidity and COD reduction. The treatment conditions for the maximum elimination of the pollutants were second level of pH (7), third level of ET (30 min), fourth level of voltage (12 V) and second level of surface area (446 cm(2)). The confirmation experiment results were within the confidence intervals (CI) indicating an acceptable agreement between predicted and observed values. Based on the p-values, the electrolysis time and voltages were found to be the most significant factors for both COD and turbidity reduction. The findings of research indicated, that the Taguchi method can be used successfully for the treatment of paper industry effluent by electrochemical technique.

Currently, most of the collected waste medium-density fiberboards (MDF) is incinerated or landfilled, as economically viable recycling methods are yet to be developed. By steam refining waste medium-density fiberboards (MDF), it is possible to hydrolyze the incorporated resins and isolate a high yield fiber fraction. Further refining of the steam treated fibers might enable the fibers to be utilized in applications such as paper packaging, facilitating a cascading use of the waste material stream. To this end, intimate knowledge of the material is needed. In this study, the steam refined fibers of two waste MDF samples containing differing amounts of softwood and hardwood underwent refining and beating. The resulting fibers were characterized regarding their morphology and paper test sheets were produced to evaluate their strength (compression-, tensile- and tear-strength). Distinct differences in response to refining between the MDF samples were apparent. For the sample with the higher hardwood share an increase in strength properties with increasing steam treatment severities could be observed and it was possible to produce test sheets with comparable compression strength to recycled pulp for industrial corrugated paperboard. For the sample with a higher share of softwood, the steam treatment severity did not show any influence on fiber morphology or paper properties, and the resulting paper strength was low in comparison to the other steam refined waste MDF sample. Graphic Abstract

The development of industry and of the Internet of Things (IoTs) have brought energy issues and huge challenges to the environment. The emergence of triboelectric nanogenerators (TENGs) has attracted wide attention due to their advantages, such as self-powering, lightweight, and facile fabrication. Similarly to paper and other fiber-based materials, which are biocompatible, biodegradable, environmentally friendly, and are everywhere in daily life, paper-based TENGs (P-TENGs) have shown great potential for various energy harvesting and interactive applications. Here, a detailed summary of P-TENGs with two-dimensional patterns and three-dimensional structures is reported. P-TENGs have the potential to be used in many practical applications, including self-powered sensing devices, human–machine interaction, electrochemistry, and highly efficient energy harvesting devices. This leads to a simple yet effective way for the next generation of energy devices and paper electronics.

In the tourism industry, the sales of local specialties is an important part, and the package design and integrity of the specialties are very important. This paper first introduced the support vector machine (SVM) algorithm that was used for detecting defects on the surface of paper packages. Then, the design of red wind packages was briefly described, and the simulation experiment was carried out on SVM algorithm using red wine packages with different degrees of surface defects. Proper parameters were tested using the k-fold cross-validation method. The results demonstrated that the properties of paper improved the value of packages and the SVM algorithm had better accuracy than artificial recognition in recognizing different degrees of defects on the surface of packages. In conclusion, this paper describes the application of paper in packages and provides an effective method for the defection of defects on the surface of packages. This study provides an effective references to the improvement of package values and the enhancement of package integrity.

The present study reports the characterization of reverse osmosis (RO) technology at water treatment plant Cogen-2 in paper and Board mills, Pakistan. RO is a commonly used process to obtain de-mineralized water for high-pressure boiler operation in thermal power plants. Scaling and fouling in three-stage RO plants is a major challenge in chemical industry due to the use of raw brackish water in the power plant of paper and board mills. In our study, the feed water quality of RO was changed from soft water to raw water to make it economical. The cleaning frequency was increased three times than normal, which was unsafe for operation and it was required to control scaling and fouling to achieve the desired result. Differential pressures behavior of all stages for 2-month data was observed without acid treatment, and the results of Langelier Saturation Index (LSI) control parameters (temperature, pH, total dissolved solids, calcium hardness, and alkalinity) clearly showed the abnormality. To optimize scaling and fouling of RO, the LSI factor was controlled in total reject water for the next 2 months by acid treatment in feed water. Duration of chemical cleaning and membranes’ life has been extended by fouling and scaling control. Understanding the effect of operational parameters in RO membranes is essential in water process engineering due to its broad applications in drinking water, sanitation, seawater, desalination process, wastewater treatment, and boiler feed water operation. The product flow increased from 18.3 to 19.9 m3/h, and this was due to a decrease in the rejection flow from 8.2 to 6.7 m3/h. The total reject stream pressure also increased from 8.1 to 9 bar. A lower value of LSI of 1.6 is obtained in the reject water stream after the acid treatment.

This study evaluates the use of fermentation to increase nutrient availability in pulp and paper bio-sludge (PPBS) as feed for black soldier fly larvae (BSFL). Rearing of BSFL on fermented PPBS was carried out in a climate chamber in order to assess nutrient availability and larvae survival and growth. The PPBS used came from a chemo-thermomechanical pulp/groundwood pulp mill. The PPBS was fermented at 35 °C and 55 °C, respectively, at initial pH of 10. The effects of sediment and liquid from fermented PPBS on larvae dry weight, survival rate until the prepupae stage, bioconversion, and reduction rate of PPBS were measured. The bioconversion of the liquids (4.1–6.6%) was substantially higher than for both the sediments and untreated PPBS (≤ 0.4%). The survival rate, on the other hand, was substantially lower (26.3–30.9 %) than for the sediments and untreated PPBS (49.5–52.6%). Neither the sediments nor the liquids had significant effects on the larvae weight or on the PPBS reduction rate. The sediments had no significant effect on the survival rate or the bioconversion. This study demonstrates that fermentation dissolves a part of the PPBS and that dissolved substances in the fermentation liquid readily convert to larvae biomass. However, the bulk of the lignocellulose is not dissolved, and most of PPBS nutrients remain unavailable for growth of the larvae. Further research should focus on improved pretreatment of PPBS to increase availability of nutrients and thereby improve the feasibility of BSFL as a recycling method for PPBS.

Microfluidic paper-based analytical devices (μPADs) have developed rapidly in recent years, because of their advantages, such as small sample volume, rapid detection rates, low cost, and portability. Due to these characteristics, they can be used for in vitro diagnostics in the laboratory, or in the field, for a variety of applications, including food evaluation, disease screening, environmental monitoring, and drug testing. This review will present various detection methods employed by μPADs and their respective applications for the detection of target analytes. These include colorimetry, electrochemistry, chemiluminescence (CL), electrochemiluminescence (ECL), and fluorescence-based methodologies. At the same time, the choice of labeling material and the design of microfluidic channels are also important for detection results. The construction of novel nanocomponents and different smart structures of paper-based devices have improved the performance of μPADs and we will also highlight some of these in this manuscript. Additionally, some key challenges and future prospects for the use of μPADs are briefly discussed.

This paper aimed to modify the ignitability of the bagasse paper by using talc powder, 1,3-di-aniline-2,2,2,4,4,4-hexachlorocyclodiphosph(V)azane, and nanocellulose crystal. The formation of cellulose nanocrystals (CNCs) was detected using transmission electron microscopy (TEM), X-ray diffraction (XRD). Thermal analysis as thermal gravimetric analysis (TGA) of the specimens recorded the improvement of the highest % of ash residue at 750 °C compared to the untreated one. The shape of the flame spread was studied. The ignition properties were studied for the untreated and treated specimens by limiting oxygen index (LOI) and flame chamber (UL/94), which recorded enhancing compared to the untreated specimen. This improvement was recorded either by measuring the mechanical properties (tensile strength, burst strength, elongation, and elasticity) of the specimens. The current article showed that the treated specimen was recorded the highest values compared to the untreated one in all physical, mechanical, and ignition properties, so these treatment paper sheets may be used as fire-retardant packaging materials.

Paper and pulp mills generate substantial quantities of cellulose-rich sludge materials that are disposed in landfills at a large scale. For sustainability purposes, sludge materials can be bioprocessed to produce renewable fuels and useful chemicals. The enzymatic hydrolysis of cellulose is the process bottleneck that affects the conversion economics directly by using zero-cost raw materials. In order to study and optimize the process, the characteristics of the sludge raw materials should be first evaluated. In this work, sludge samples were obtained from paper mills located at different locations in Wisconsin and Minnesota. Part of the sludge samples was washed (de-ashed) with hydrochloric acid while the other part remained unwashed. The samples were subjected to multiple spectroscopic analyses techniques to evaluate the morphological properties of cellulose fibers and to estimate the total structural carbohydrate content. The results showed that the de-ashing process changed some fiber characteristics and cellulose crystallinity structure in all sludge samples. Sludge sample A (obtained from Kraft pulp and recycled paper mill region) showed a high percentage of fiber, with crystalline cellulose, compared to the other two sludge samples suggesting that sludge A is a valuable source to make value-added products. Aspen Plus mass and energy calculations performed in view of the ‘zero’ cost and the reliable supply of sludge raw materials producing 2 mol H2/mol glucose. Moreover, the results showed that extracting crystalline cellulose from these sludge samples is more profitable than crystalline cellulose made from the other lignocellulosic feedstocks. The results reported here showed that the utilization of these sludge materials would be an economically attractive and promising alternative for the production of hydrogen.

In China, Xuan paper has been the paper of choice as artwork support and for conservation, for several centuries. However, little is known about its material properties, especially given the many grades of sized and unsized Xuan paper. In addition, there is a lack of information on its degradation. In this research, a selection of contemporary unsized Xuan papers was investigated, representing diverse raw materials. Seven out of twelve contemporary unsized Xuan papers were determined to be approximately neutral and contain > 2% alkaline reserve, indicating good durability. Viscometry was used to determine the degree of polymerisation (DP) as none of the samples gave significant reactions to the phloroglucinol spot test. The average DP of ten contemporary unsized Xuan papers is ~ 1700, excluding two papers that have presumably been sun-bleached, and that exhibit significantly lower DP. Using X-ray fluorescence, it can be demonstrated that Ca and Si are the dominant elements and interestingly, Ca content is directly correlated with ash content and with alkaline reserve. Accelerated degradation was performed at two sets of environmental conditions, i.e. 90 °C, 30% RH and 60 °C, 70% RH, and the established degradation rates agreed with the Collections Demography model of paper degradation meaning that degradation of Xuan papers proceeds in the same way as other types of paper. This research gives fundamental insights into contemporary unsized Xuan papers, which exhibit good stability during accelerated degradation despite the low starting DP in the context of the samples used in this study. Our findings may inform methods of Xuan paper production, selection of Xuan paper for conservation purposes, as well as preventive conservation of Xuan paper-based artefacts.

Starch and derivatives thereof have proven their usefulness in paper coating processes. Among these derivatives, cationic starch has been widely used in the paper industry as a flocculation, dispersion and ink fixing agent. In another context, nanoscale cellulosic materials have been shown to improve the strength, retention of fillers, the barrier properties of packaging paper products, and printing qualities. This review summarizes the recent studies on the general components used in paper coating, describes the conventional and alternative synthetic processes of cationic starches and nanocellulose, and deals with their current and potential applications in papermaking, focusing primarily on surface treatments. Moreover, environmental applications have been considered to expand the understanding and usefulness of these materials. Further research on modified polysaccharides is encouraged to replace, in a feasible way, petro-based components of coating formulations, and to provide paper surfaces with new properties.

Loop-mediated isothermal amplification (LAMP) has been widely used to detect many infectious diseases. However, minor inconveniences during the steps of adding reaction ingredients and lack of simple color results hinder point-of-care detection. We therefore invented a fluorometric paper-based LAMP by incorporating LAMP reagents, including a biotinylated primer, onto a cellulose membrane paper, with a simple DNA fluorescent dye incubation that demonstrated rapid and accurate results parallel to quantitative polymerase chain reaction (qPCR) methods. This technology allows for instant paper strip detection of methicillin-resistant Staphylococcus aureus (MRSA) in the laboratory and clinical samples. MRSA represents a major public health problem as it can cause infections in different parts of the human body and yet is resistant to commonly used antibiotics. In this study, we optimized LAMP reaction ingredients and incubation conditions following a central composite design (CCD) that yielded the shortest reaction time with high sensitivity. These CCD components and conditions were used to construct the paper-based LAMP reaction by immobilizing the biotinylated primer and the rest of the LAMP reagents to produce the ready-to-use MRSA diagnostic device. Our paper-based LAMP device could detect as low as 10 ag (equivalent to 1 copy) of the MRSA gene mecA within 36-43 min, was evaluated using both laboratory (individual cultures of MRSA and non-MRSA bacteria) and clinical blood samples to be 100% specific and sensitive compared to qPCR results, and had 35 day stability under 25 °C storage. Furthermore, the color readout allows for quantitation of MRSA copies. Hence, this device is applicable for point-of-care MRSA detection.

There is a relative lack of research on the development of creepage discharge in aged oil-paper insulation subjected to AC-DC combined voltage in converter transformers. In this study, based on the physical and chemical properties of oil-paper, we propose a sphere-plate electrode model to study the creepage discharge parameters and characteristic spectra of aged oil-paper subjected to AC-DC combined voltage. The results show that the creepage discharge inception voltage of aged oil-paper is related to the AC voltage component of the AC-DC combined voltage. However, when the DC voltage component is 60 kV, the flashover phenomenon was found to occur in one of the severely aged samples before the AC voltage was applied. Despite being subjected to the same DC voltage, the flashover phenomenon did not occur in three other samples aged to different degrees. Large-amplitude discharges were found to appear earlier in the severely aged samples. At the same creepage discharge stage, as the aging time of the oil-paper increased, the number of large-amplitude discharges was found to rapidly increase, and the time interval between adjacent discharges was found to gradually decrease. At each stage of the creepage discharge, the small-amplitude discharge has a “hump” shaped distribution. The larger the DC voltage component, the shorter the endurance time of aged oil-paper, and the more severe the damage to the oil-paper. The DC voltage component was found to have an accelerating effect on the development of creepage discharge in aged oil-paper insulation.

Introduction We developed low-cost, portable paper-based diagnostic devices for detection of human immunoglobulin M (IgM) and immunoglobulin G (IgG) in serum without any sample preparation. These devices can be used to help identify presence of diseases, used to provide rapid results ( Materials and Methods We successfully accomplished colorimetric detection of human IgG and human IgM using a sandwich-style assay within the microfluidic paper device via vertical flow immunoassay configuration. The reaction zone in the wax printed paper layer is a small circular pattern. Gold nanoparticles conjugated with anti-human IgG and IgM antibodies have been used for colorimetric detection of IgG or IgM by naked eye. Colorimetric signal can be precisely quantified through implementation of image analysis software which can be developed as an app for a smartphone. The size of the device is 2 cm × 2 cm × 1 mm. Results Colorimetric detection of human IgG was accomplished at 100 fg/mL concentration using a gold nanoparticle–conjugated anti-human IgG antibody. The developed platform has a dynamic range of IgM and IgG concentrations between 0.1 pg/mL and 100 μg/mL. These devices provided a color readout in Conclusions Because of the inherent simplicity of the device operation and their ease of use, there is no variation between samples and users of the device. This low-cost approach enables multiplexing with >1 measurement performed in parallel at the same time. We anticipate that because of the sensitivity, specificity, ease of use, and overall reliability, this approach will become a standard for diagnosis of diseases and health conditions.

The present work describes a sensitive, simple, cost-effective and fast analytical procedure to detect the parabens in industrial waste effluent water samples using novel activated carbon nanofiber (CNF) modified filter paper based solid phase extraction technique coupled with liquid chromatography with photodiode array detector (UPLC-PDA). The carbon nanofiber coated filter paper was used as an adsorbent and also characterized by field emission scanning electron microscope (FESEM) showed superior porous structure. Various factors effecting the adsorption and desorption process were studied. The optimum parameters which improve the efficiency are paper length 1 cm × 2 cm, adsorption time 15 min, eluent methanol, eluent volume 5 mL, sample pH 7, desorption time 2 min, 2% salt addition and 300 rpm stirring rate respectively. The parabens exhibited superior linearity ranging from 0.1-50 ng mL-1. The regression coefficient (R2) value ranging from 0.9981-0.9989. This method exhibited good sensitivity with the quantification limit (LOQ) between 0.5-0.75 ng mL-1 and detection limit (LOD) over the range of 0.1-0.25 ng mL-1. The precision was expressed from the RSDs values from 0.74-0.97 %. The spiked analytes revealed excellent recoveries in the range of 95.30-116.72 % with RSD less than 5.72 % for all the water samples also applied for real samples.

The paper corrugation tube is an innovative kind of energy absorbing structure and shock absorber which can play an important role on the cushioning energy absorption for airdrop equipments and transportation packaging. The deformation characteristics and failure modes of the regular triangle, quadrangle, pentagon and hexagon paper corrugation tubes were comparatively studied by a series of axial static compression experiments, the cushioning energy absorption was evaluated by the seven characteristic parameters (e.g. initial peak force, mean crush force, total energy absorption, specific energy absorption, crush force efficiency, unit area energy absorption and stroke efficiency), and the influences of tube direction, cross-sectional shape, tube length and compression rate on failure modes and cushioning energy absorption were analyzed and compared. These researches showed that the tubes along X direction only have the accordion deformation mode, yet the tubes along Y direction have four deformation modes including steady state progressive buckling, Euler buckling, angular tear and transverse shear. For the paper corrugation tubes along Y direction, the cross-sectional shape has obvious influence on the cushioning energy absorption of structures, and the specific energy absorption and unit area energy absorption of regular triangle and pentagon tubes are better than those of the tubes with regular quadrilateral and hexagonal cross-section at compression rates of 12 and 48mm/min. The tube length of 150 mm or compression rate of 72 mm/min would cause the increase of contribution proportion of non-ideal deformation mode and the decrease of cushioning properties. The paper corrugation tubes along X direction have more stable and controllable deformation mode, yet the paper corrugation tubes along Y direction have better cushioning energy absorption.

We report a simple and cost-effective paper-based and colorimetric dual-mode detection of As(iii) and Pb(ii) based on glucose-functionalized gold nanoparticles under optimized conditions. The paper-based detection of As(iii) and Pb(ii) is based on the change in the signal intensity of AuNPs/Glu fabricated on a paper substrate after the deposition of the analyte using a smartphone, followed by processing with the ImageJ software. The colorimetric method is based on the change in the color and the red shift of the localized surface plasmon resonance (LSPR) absorption band of AuNPs/Glu in the region of 200-800 nm. The red shift (Δ

Lightweight yet strong paper with high toughness is desirable especially for impact protection. Herein we demonstrated electrically conductive and mechanically robust paper (AP/PB-GP) made of reduced graphene oxide via interfacial crosslinking with 1-aminopyrene (AP) and 1-pyrenebutyrat (PB) small molecules. The AP/PB-GP with thickness of over ten micrometer delivers a record-high toughness (∼69.67 ± 15.3 MJ m−3 in average), simultaneously with superior strength (close to 1 GPa), allowing an impressive specific penetration energy absorption (∼0.17 MJ kg−1) at high impact velocities when used for ballistic impact protection. Detailed interfacial and structural analysis reveals that the reinforcement is synergistically determined by π-π interaction and H-bonding linkage between adjacent graphene lamellae. Especially, the defective pores within the graphene platelets benefit the favorable adsorption of the pyrene-containing molecules, which imperatively maximizes the interfacial binding, facilitating deflecting crack and plastic deformation under loading. Density functional theory simulation suggests that the coupling between the polar functional groups, e.g., −COOH, at the edges of graphene platelets and −NH2 and −COOH of AP/PB are critical to the formation of hydrogen bonding network.

Neotame is an artificial sweetener with increasing consumption in recent years, excessive intake of it may bring potential health risk. In this work, a rapid method was developed to detect neotame in instant grain beverages, which was based on surface-enhanced Raman scattering (SERS) technique and filter paper-based silver nanoparticles (AgNPs@FP) substrates. The designed substrate exhibits good SERS activity with an enhancement factor of 105 because of the synergistic effect of the concentrated silver nanoparticles and filter paper. Meanwhile, the stability and repeatability of this fabricated substrate have been investigated with the relative standard deviation of 6.1%. In addition, it shows an excellent linear relationship (R 2 = 0.997) between the SERS signal and the logarithm concentration of neotame with a wide concentration range (0.05–5 g/kg) in the quantitative analysis. The limit of detection of neotame can be as low as 0.01 g/kg in instant grain beverages, which is below the maximum allowable addition level for neotame in instant grain beverages set in China (GB2760-2014, 0.16 g/kg). The proposed method has great potential for the identification and quantification of neotame in food safety applications with high sensitivity.

There is growing demand for simple to operate, sensitive, on-site quantitative assays to investigate concentrations of drug molecules in pharmaceutical preparations for quality assurance. Here, we report on the development of two colorimetric analysis methods for the study the antibiotic doxycycline hyclate (DOX) and the nasal decongestant oxymetazoline hydrochloride (OXY), in solution as well as in their respective formulations. We compare a UV/vis spectrophotometry method with a color change recorded on a microfluidic paper-based analytical device (μPAD). Detection is based on the pharmaceutical compounds coupling with diazotized 4-aminoacetophenone (DAAP) under alkaline conditions to produce colored azo-dye products. These azo-compounds were monitored by absorbance at 425 nm for DOX and 521 nm for OXY, with linear calibration graphs in the concentration range of 0.5–35 mg L−1 (DOX) and 1.0–40 mg L−1 (OXY) and limits of detection of 0.24 mg L−1 (DOX) and 0.32 mg L−1 (OXY). For the μPAD method, color intensity was measured from photographs and a linear increase was observed at concentrations from above approximately 15 mg L−1 for both compounds and up to 35 mg L−1 for DOX and 40 mg L−1 for OXY. The developed methods were also applied to the formulated pharmaceuticals and no interference was found from the excipient. Thus, the paper-based device provides an inexpensive, simple alternative approach for use outside centralized laboratories with semi-quantitative capability.

Paper sludge is the water treatment waste, which produced during paper production. Paper sludge (PS) waste utilization is the common problem in the EU and internationally. According to the waste management directive No. 2008/98/EC, paper sludge waste should not be utilized in landfills. In the European Union, alone 93 million tons of PS generated yearly. Nowadays most of the paper sludge waste used as fuel for incineration power plants (up to 55 %). According to waste management legislation such waste management should be avoided as well. Very small portion (10 %) of PS is used in construction sector. In construction, paper sludge used as additive in concrete composite materials. Such legislation of waste management generates the motivation of this study. In this study authors propose to produce composite panels in which PS is the main material of composite. As the binding material, clay proposed due to its good binding properties and therefore its natural material. Such produced panels proposed to use it for sound absorption applications. To determine composites sound absorption coefficient standard ISO 10534-2 method was used. The sound absorption coefficient in different octave bands reached up to 0.59.

Process-monitoring laboratories in the pulp and paper industry generally use a combination of wet chemical analyses and physical measurements to certify the fitness of a production pulp for a specific end-use. These laboratory tests require time and the effort of trained personnel, limiting their utility for real-time process control. Here we show that Raman probes of unrefined cellulosic pulps, well-suited to the online measurement of in-process materials, can predict the quality attributes of manufactured papers. The accuracy of prediction improves when the covariance is modelled in a reduced measurement space selected by a data-driven, feature-selection technique referred to as a Template Oriented Genetic Algorithm (TOGA). TOGA, combined with discrete wavelet transform (DWT), isolates functional-group features that correlate best with mechanical properties paper derived from refined pulp. Paper makers refine market pulps to build sheet strength using a beating process that decreases freeness as it increases fibre-fibre bonding. Methods demonstrated here predict manufactured sheet properties obtainable after any specified degree of refining from the Raman spectrum of an unrefined pulp. This analysis capacity will enable both vendors of market pulp and makers of sheet paper to specify in advance the amount of beating required to produce a desired product, thereby saving cost and conserving resources.

The paper industry wastewater even after bio-treatment at industrial scale is a major source of aquatic and soil pollution due to various unknown compounds. Hence, the study has focused on the detection of residual organic pollutants from the bleached and unbleached paper mill wastewater and both sources showed endocrine-disrupting compounds. The toxicity test with Phaseolus aureus seed germination showed inhibition of seed germination and alpha-amylase activity >25% in bleached and unbleached paper mill wastewater. The LC50 of Tubifex tubifex was noted of >50% after 48 hours incubation test. This revealed that the wastewater discharged from bleached paper mill is more toxic than unbleached paper mill waste this might be due to the use of more chemicals during bleaching and pulping process. This study has revealed that there is need to treat both paper mill wastewaters adequately prior to discharge.

Eco-friendly and cost-effective materials and processes to manufacture functional substrates are crucial to further advance the area of printed electronics. One potential key component in the printed electronics platform is an electrically functionalized paper, produced by simply mixing common cellulosic pulp fibers with high-performance electroactive materials. Herein, an electronic paper including nanographite has been prepared using a standardized and scalable papermaking technique. No retention aid was needed to achieve a conducting nanographite loading as high as 50 wt %. The spontaneous retention that provides the integrity and stability of the nanographite paper, likely originates partially from an observed water-stable adhesion of nanographite flakes onto the fiber surfaces. The resulting paper exhibits excellent electrical characteristics, such as an in-plane conductivity of 107 S/cm and an areal capacitance of 9.2 mF/cm(2), and was explored as the back-electrode in printed electrochromic displays. Funding Agencies|Digital Cellulose Centre, a competence center set up by the Swedish Innovation Agency VINNOVA; consortium of Swedish forest industries; Wallenberg Wood Science Center (Knut and Alice Wallenberg Foundation); VINNOVA "EPIC" projectVinnova [2017-05413]; Karl-Erik Onnesjo Foundation

An industry compatible chemo-refining approach was tested for preparation of micro-nanofibrillated cellulose (MNFC) from bleached softwood pulp using sodium meta-periodate and sodium chlorite as oxidizers followed by refining in Valley beater. SEM and FTIR analyses confirmed micro-nano scale fibrillation and chemical functional group modification in laboratory prepared MNFC, respectively. The water retention value, carboxyl content and viscosity of MNFC were found comparable with imported NFC as reference (R-NFC). To evaluate MNFC as strength enhancer for paper properties, 5% MNFC addition to bleached mixed hardwood pulp showed 6% reduction in bulk with 36%, 24% and 97% increment in breaking length, burst index and double fold of the handsheets, respectively without affecting tear index and optical properties than the control. Surface properties were also improved. Pulp drainability (37°SR) after MNFC addition was found suitable for papermaking. These laboratory results confirmed the potential of MNFC as a suitable strength additive for paper quality improvement.

In this study, a microfluidic paper-based analytical device (mu PAD) was integrated with a smartphone app capable of offline (without internet access) image processing and analysis for the rapid colorimetric detection of glucose. A self-inking stamp was used to form hydrophobic channels on a piece of paper-towel due to its superior water absorption efficiency. As demonstrated, the developed sensor was employed for the colorimetric detection of glucose in artificial saliva in the linear scope of 0 - 1 mM with a calculated detection limit of 29.65 mu M. The experimental results show that the quantitative analysis of glucose with the proposed smartphone platform could be completed in less than one minute. The app developed for the smartphone platform is capable of extracting the color-changing area with an embedded image processing tool which could address the problem of color uniformity in the detection zones of mu PAD. The integrated platform has great potential to be used for non-invasive measurements of glucose in body fluids, like tears, sweat and saliva.

Around 60% of the paper worldwide is made from recovered paper. Especially adhesive contaminants, so called stickies, reduce paper quality. To remove stickies but at the same time keep as many valuable fibers as possible, multi-stage screening systems with several interconnected pressure screens are used. When planning such systems, suitable screens have to be selected and their interconnection as well as operational parameters have to be defined considering multiple conflicting objectives. In this contribution, we present a Mixed-Integer Nonlinear Program to optimize system layout, component selection and operation to find a suitable trade-off between output quality and yield.

In the packaging sector of the printing industry, different coating applications are tried and investigated in order to increase the surface appearance and performance characteristics of paper and cardboard. The printability, water and ink absorption capacity, frictional resistance, light sensitivity of the visual graphical design that are going to be printed on the packaging papers are some of them. In this study, different types of cardboards that are used as a packaging material were chosen and coated with nanocrystalline cellulose (NCC)/PVA at different rates (%). In order to determine effective and economical usage conditions, the coating solutions, at three different concentrations as 3 wt.%, 5 wt. %, 7 wt.%, were prepared. The coating was applied on the test papers, which were at the same weights (350 g/m2) and had different surface properties as matte glossy, bright glossy, American Bristol. NCC/PVA existence on the coated paper surface was confirmed with Fourier Transform Infrared Spectroscopy (ATR-FTIR). The impact of the coating, which was prepared at different concentrations, on the packaging materials was studied with respect to thickness, stiffness, water absorbability, contact angle and surface tension.

Photocatalytic materials have been widely used to remove dyes from printing and dyeing wastewater. However, difficulty in recycling of photocatalysts is the great concern in the real catalytic applications, which significantly raises the application cost. This study developed a low-cost catalyst by loading magnetic Ni onto filter paper (FP) via an easy going in-situ reaction. The characterization results displayed that the Ni particles were uniformly anchored onto the FP. The Ni@FP material presented a strong magnetic ability which was evidenced by a saturation magnetization (Ms) of 5.014 emu·g−1, a remanent magnetization (Mr) of 2.067 emu·g−1 and a coercivity (Hc) of 133.868 Oe. Meanwhile, the magnetic Ni@FP material displayed a recyclable advantage in photocatalytic degradation of methyl orange (MO) via an external magnetic field. There existed an optimal photocatalytic degradation rate of 93.40% within 5 min when MO concentration was 15 mg·L−1 at pH 8.0. Three cycle experiments confirmed that the Ni@FP possessed a satisfied stability and recycling ability. Moreover, the Ni@FP material presented a strong antibacterial activity which can prevent it from being contaminated by microorganisms. The versatility of the newly proposed photocatalyst in this study demonstrated its great application prospect in dyeing wastewater treatment.

Made available in DSpace on 2021-06-25T10:45:32Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-01-25 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Fundação de Amparo à Pesquisa do Estado de Minas Gerais (FAPEMIG) Lactose (LAC) is a disaccharide - major sugar, present in milk and dairy products. LAC content is an important indicator of milk quality and abnormalities in food industries, as well as in human and animal health. The present study reports the development of an innovative imprinted voltammetric sensor for sensitive detection of LAC. The sensor was constructed using electropolymerized pyrrole (Py) molecularly imprinted polymer (MIP) on graphite paper electrode (PE). The MIP film was constructed through the electrosynthesis of polypyrrole (PPy) in the presence of LAC (template molecule) on PE (PPy/PE). To optimize the detection conditions, several factors affecting the PPy/PE sensor performance were assessed by multivariate methods (Plackett–Burman design and central composite design). Under optimized conditions, the proposed analytical method was applied for LAC detection in whole and LAC-free milks, where it demonstrated high sensitivity and selectivity, with two dynamic linear ranges of concentration (1.0–10 nmol L−1 and 25–125 nmol L−1) and a detection limit of 0.88 nmol L−1. The MIP sensor showed selective molecular recognition for LAC in the presence of structurally related molecules. The proposed PPy/PE sensor exhibited good stability, as well as excellent reproducibility and repeatability. Based on the results obtained, the PPy/PE is found to be highly promising for sensitive detection of LAC. Analytical Chemistry Department Institute of Chemistry São Paulo State University (UNESP), 55 Prof. Francisco Degni St., São Paulo State Institute of Exact and Natural Sciences of Pontal Federal University of Uberlandia, 1600 20 St., Ituiutaba, Minas Gerais State Bioenergy Research Institute (IPBEN) São Paulo State University (UNESP), 55 Prof. Francisco Degni St., São Paulo State Analytical Chemistry Department Institute of Chemistry São Paulo State University (UNESP), 55 Prof. Francisco Degni St., São Paulo State Bioenergy Research Institute (IPBEN) São Paulo State University (UNESP), 55 Prof. Francisco Degni St., São Paulo State FAPESP: 2017/25329–6 FAPESP: 2018/12131–6 FAPESP: 2019/13818–8 CNPq: 408783/2018–4 CNPq: 443315/2014–0 CNPq: 447668/2014–5 CAPES: 88887.368610/2019–00 FAPEMIG: APQ-02078-15 FAPEMIG: APQ-02905-15

Silver nanoparticle (AgNP)-decorated cellulose filter paper (FP), a low-cost point-of-use (POU) water disinfection system, can supply affordable and safe drinking water for people in desperate need, especially in rural areas in developing countries. However, owing to the unstable immobilization of AgNPs, silver can leach into the treated drinking water from the FP and exceed the World Health Organization (WHO) drinking water limit (

In society, there is widespread and growing acceptance of the value of cooperation between industry and universities being collaborative Research and Development (R&D) domain and industrial policy the fuel of knowledge-based economies. In this paper, different domains of cooperation between the University and Industry as well as their generated benefits for each partner are identified. These benefits have been assigned to each domain of cooperation, showing a large number of benefits associated to collaborative R&D. Leading us to make a statement - collaborative R&D is the key cooperation domain for sustainable long-term university-industry partnerships. Suggestions are given about how to continue this research study.

Many organic residues are being wasted since they are not given a comprehensive management; anaerobic digestion is an alternative to reduce the impact of these residues, and to produce biogas. The chapter includes the state of art about biogas and energy production, and later, the analysis of a study case focusing on the use of pulp and paper wastes to produce biogas. The study was carried out through anaerobic digestion at a bench scale using three temperature phases to treat primary and secondary sludge, establishing operational parameters such as temperature, retention time, and organic loadings. Monitoring of volume, methane concentration in the biogas, volatile solids reduction, volatile fatty acids during the process, the performance of the process in function of methane produced per volatile solids removed is calculated. This case study shows that it is feasible to use the sludge from the company’s wastewater treatment plant (WWTP) for the generation of biogas, thus reducing waste management problems.

Paper is a common material that is promising for constructing microfluidic chips (lab-on-a-paper) for diagnostics and drug delivery for biomedical applications. In the past decade, extensive research on paper-based microfluidics has accumulated a large number of scientific publications in the fields of biomedical diagnosis, food safety, environmental health, drug screening and delivery. This review focuses on the recent progress on paper-based microfluidic technology with an emphasis on the design, optimization and application of the technology platform, in particular for medical diagnostics and drug delivery. Novel advances have concentrated on engineering paper devices for point-of-care (POC) diagnostics, which could be integrated with nucleic acid-based tests and isothermal amplification experiments, enabling rapid sample-to-answer assays for field testing. Among the isothermal amplification experiments, loop-mediated isothermal amplification (LAMP), an extremely sensitive nucleic acid test, specifically identifies ultralow concentrations of DNA/RNA from practical samples for diagnosing diseases. We thus mainly focus on the paper device-based LAMP assay for the rapid infectious disease diagnosis, foodborne pathogen analysis, veterinary diagnosis, plant diagnosis, and environmental public health evaluation. We also outlined progress on paper microfluidic devices for drug delivery. The paper concludes with a discussion on the challenges of this technology and our insights into how to advance science and technology towards the development of fully functional paper devices in diagnostics and drug delivery.

We present a short review of several fundamental results, which have been obtained within frameworks of one trend of the wide spread of investigations, carried out during 1970 –2010s under the leadership of doctor of science, corresponding member of the National Academy of Sciences of Belarus P. D. Kukharchik, whose scientific interests were connected with the study of physical properties of heterogeneous dielectric and metal-containing industrial materials by the methods of holography, holographotomography, digital radiography, microwave and infrared introscopy. In this review, by the example of several base problems, we describe the semi-analytical methods of rigorous theoretical simulation of electromagnetic fields, arising under electromagnetic diffraction by slots in perfectly conducting screens of arbitrary thickness in absence and in the presence of plane dielectrics in the plane and cylindrical geometries of electromagnetic propagation. It demonstrates application of the these methods to simulation of processes of moisture measuring of paper sheet using microwave cavities with slots, which are employed on enterprises of pulp and paper industry.

The growing need for reliable analytical tools to perform measurements at the point-of-need has prompted the development of novel sensors that are low cost, portable, sensitive, easy to use, and capable of multiplexed analysis. Miniaturization of the sensors into microfluidic platforms has become a promising approach to achieve these self-contained sensors. However, traditional microfluidics often require relatively expensive and complicated pumping mechanisms that increase the cost and limit the portability of the sensors. From a material perspective, paper is an attractive substrate for constructing point-of-need sensors because of its affordability, vast availability, and self-pumping ability, particularly when combined with electrochemical detection. In this mini-review, we discuss various strategies to achieve multiplexing or simultaneous detection of multiple analytes in electrochemical paper-based devices and provide a brief guide on selecting the detection strategy based on the electrochemical property of the analytes.

A novel nacre-like flame-retardant paper based on graphene oxide (GO), and phytic acid (PTA) is fabricated via evaporation-induced self-assembly. This facile method is time saving and low energy consuming. A facile approach is proposed to improve thermal oxidative stability of GO paper by in situ phosphorus doping during flame exposure. Then fire-alarm system is designed based on the high-temperature thermal reduction characteristic of GO. The GO paper functionalized with PTA (GO-PTA) can provide ultrasensitive, reliable and longtime fire early-warning signal. Fire alarm can be triggered at approximately 0.50 s when GO-PTA samples are attacked by fire. Phosphorus atoms are in situ doped into graphene layers during fire exposure, endowing GO-PTA paper with outstanding thermal oxidative stability, and thus alarm duration time of GO is greatly improved. The work develops advanced fire detection and early-warning sensors that provide reliable and continuous signals, which provide more available time for fire evacuation.

The sensitive quantitative analysis of trace heavy metallic elements (Cd, Mn, Cr, and Cu) in aqueous solutions was achieved successfully through the combination of filter paper enrichment with laser-induced breakdown spectroscopy. Filter paper was enriched with 0.4 mL aqueous solutions to form a homogeneous sample layer on the surface of the metallic target. Considering the limits of detection, the values deduced with calibration curves already exhibited the high performance of the proposed method at several hundred or 10 μg/L (Cd 0.165, Mn 0.035, Cr 0.012, and Cu 0.078 mg/L), lower than or comparable to those using other similar methods. The LIBS results agreed reasonably well with those from ICP-MS for real samples. All results showed that our method was suitable and accurate for rapid on-site detection of trace metals in aqueous solutions. This indicates that filter paper enrichment combined with laser-induced breakdown spectroscopy is a feasible approach to wastewater quality monitoring.

Simultaneous enhancement in water flux and removal efficiency during the filtration process remains a big challenge for separation membranes. The porous structure of the filter paper can provide many channels for water transportation, but the separation performance is generally poor. The purpose of this study is to develop a new kind of filter paper consisting of ultralong hydroxyapatite (HAP) nanowires, cellulose fibers (CFs) and double metal oxide (LDO) nanosheets, and to achieve the simultaneous enhancement of both water flux and removal efficiency for high-performance dye separation. In this work, a novel kind of LDO/HAP/CF nanocomposite filter paper consisting of ultralong HAP nanowires and CFs and LDO nanosheets has been developed for rapid water filtration and highly efficient dye adsorption. Positively charged LDO nanosheets can adsorb on the surface of negatively charged ultralong HAP nanowires and embed in the porous networked structure of the LDO/HAP/CF nanocomposite filter paper, which can provide a porous structure for rapid water transportation and can adjust the pore size of the nanocomposite filter paper. As a result, the pure water flux of the LDO/HAP/CF nanocomposite filter paper can be adjusted. The optimized pure water flux of the LDO/HAP/CF nanocomposite filter paper can reach 783.6 L m-2 h-1 bar-1, which is 1.51 times that of the HAP/CF filter paper without LDO nanosheets (518.6 L m-2 h-1 bar-1). More importantly, the adsorption capacity of LDO nanosheets is high for dye molecules, the rejection percentage of Congo red (CR) by the as-prepared HAP/CF filter paper is only 59.8%, and its water flux is 534.7 L m-2 h-1 bar-1. The optimized rejection percentage and water flux of the LDO/HAP/CF nanocomposite filter paper for CR are significantly enhanced (98.3% and 736.8 L m-2 h-1 bar-1, respectively) compared to those of the HAP/CF filter paper. The size of LDO nanosheets has a significant effect on the water flux and dye rejection percentage of the LDO/HAP/CF nanocomposite filter paper. The as-prepared LDO/HAP/CF nanocomposite filter paper is promising for the applications in highly efficient purification of wastewater containing dye molecules.

Abstract Tissue paper softness relies on two major factors, the bulk softness, which can be indicated by the elasticity of the sheet, and surface softness. Measurement of surface softness is complicated and often requires a multi-step process. A key parameter defining surface softness is the topography of the surface, particularly the crepe structure and its periodicity. Herein, we present a novel approach to measure and quantify the tissue paper surface crepe structure and periodicity based on the detection of waviness along the sample using laser scanning confocal microscopy (LSM) and X-ray tomography (XRT). In addition, field emission scanning electron microscope (FESEM) was used to characterize the tissue paper surface. We demonstrate that surface topography is directly correlated to the erosion of the doctor blade, which is used to remove the dry tissue paper from the Yankee cylinder. Because of its accuracy and simplicity, the laser confocal microscopy method has the potential to be used directly on the production line to monitor the production process of the tissue paper. XRT revealed more structural details of the tissue paper structure in 3D, and it allowed for the reconstruction of the surface and the internal structure of the tissue paper. Graphic abstract

Today, the paper industry is faced with a global deficiency of raw wood materials, so alternative sources of virgin cellulose fibres are playing an important role in paper production. Agricultural countries produce large quantities of crop farming by-products such as straw, which is an interesting alternative raw material for cellulose fibres. Straw is used in many industries because of its numerous advantages: animal food industry, biofuel industry, construction industry and as artistic material. The potential use of straw production residues is of great importance in paper and printing industry. The focus of this research is on triticale straw, which was used as a non-wood fibre source for paper production. Namely, triticale straw was converted into semi-chemical pulp and was combined with recycled wood pulp in order to produce alternative laboratory papers. The usability of this kind of laboratory papers in printing industry was analysed based on line reproduction quality. This research evaluated and analysed line reproduction quality based on four line attributes: width, blurriness and raggedness. The results of this research proved that triticale pulp in laboratory papers has equal influence on line printing quality as the recycled wood pulp.

Korean hand papermaking is a renowned cultural tradition in the Korean peninsula. It is still practiced while scientific analysis of paper itself from a large data set is rare. In this study, a set of more than three hundred Korean handmade papers, collected in a reference collection book Hanji: Korean handmade paper, were chemically investigated, and their property data such as colour, pH, grammage, thickness, tensile strength, folding endurance were statistically analysed in order to determine general features for Korean papers. The influence of different paper sheet formation methods (Heullimtteugi vs Gadumtteugi) were revealed by multivariate data analysis and the chemical profiles of raw materials were studied by pyrolysis–gas chromatography/mass spectrometry (Py-GC/MS). The Korean handmade paper samples display colour gamut in the colour space L* (69.9–95.9), a* [(−3)-3], b* (0–20), most have neutral/alkaline pH values. Paper density, fiber orientation and physical properties are influenced by the sheet formation techniques. For instance, Gadumtteugi tends to produce papers with strong fiber orientation while Heullimtteugi produces papers with more evenly distribution of fibers. In addition, Py-GC/MS analysis results show that paper mulberry fibers contain less intensity lignin monomers and more terpenic compounds in comparison with gampi and mitsumata fibers. This study provides paper analysis from large sample set, statistics reveal that the material preparing and making craft determined the paper structure which reflected in their physical properties. These properties influenced paper performance and applications in art creations as well as relics conservation and restoration. The characterized paper sample database could be used for handmade paper studies in East Asian region. Consequently, this study contributes to a better understanding of contemporary Hanji properties as well as improves knowledge on handmade papers from the Korean peninsula.