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The rapid economic growth and environmental concerns have led to high demands on paper and paper-based products in terms of variety, quantity, quality, and specialty. Enhancement and functionalization with additives are constantly required. Moving away from traditional petroleum-based additives, researchers have attempted to use “green” nanoadditives by introducing renewable environmentally friendly nanocellulose. This article studies the functions of nanocellulose as bio-additives (enhancer, retention and filtration reagent, and coating aid) in paper and paper products, and overviews the research development of nanocellulose-based additives and their applications in the paper industry for both efficient production and paper functionalization. The review shows that (1) a variety of nanocellulose-based bioadditives have been reported for various applications in paper and paper-based products, while commercially viable developments are to be advanced; (2) nanocellulose was mostly formulated with other polymer and particles as additives to achieve their synergistic effects; (3) major interests have concentrated on the nanocellulose in the specialty papers as representing more value added products and in the efficient utilization of recycled fibers, which remains most attractive and promising for future development. This report shall provide most useful database information for researchers and industries for paper recycling and enhancement, and paper-based products innovation and application.

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.

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.

This study optimizes a novel surfactant-assisted green liquor dregs (GLD) pretreatment of paper mill sludge (PMS), both of which are wastes from the kraft pulping industry, using a combined Response Surface Methodology (RSM) design. Optimized conditions give a maximal reducing sugar release of 16.38 g/L. A substantial reduction in heavy metals aluminum, chromium, cobalt, arsenic, lead, and copper after pretreatment illustrates the enhancement of substrate digestibility by reducing toxic elements. Separate hydrolysis and fermentation (SHF) and simultaneous saccharification and fermentation (SSF) for hydrogen production are assessed. SSF produced a hydrogen yield of 3.72 mL/g, displaying a 36.26% increase from pretreated PMS compared to SHF. These findings provide insights into possible methods of reducing process duration, energy input, and costs incurred with waste disposal within the paper industry. Furthermore, improved hydrogen yield using an SSF process demonstrates the potential beneficiation of pulp and paper GLD and PMS wastes.

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.

A simple electrochemical approach has been strategically developed for in situ generations of ZnO nanoparticles using Zn rods as electrodes and hydrogen peroxide as the oxidant without the formation of any by-product. These ZnO nanoparticles were extended for remediation of pollutants present in paper mill effluents, and separation efficiency was found to be above 90% for hydrocarbons, 92% for lignin, 99% for phenol, and 93% of chemical oxygen demand (COD), as confirmed by gas chromatography-mass spectrometry and COD analysis. It was also observed that the experimental setup could successfully remove 99% of the color from the sample. These ZnO nanoparticles have been proven in the past to be antibacterial and were explored for its ability to inhibit the growth of both Gram-positive and Gram-negative bacteria in the effluent samples after the removal of toxic pollutants. Therefore, we proposed an electrochemical reaction for the in situ synthesis of ZnO nanoparticles for remediation of paper mill effluent as well as inhibit the bacterial growth in the treated effluent sample.

A wide variety of biomass is available all around the world. Most of the biomass exists as a by-product from manufacturing industries. Pulp and paper mills contribute to a higher amount of these biomasses mostly discarded in the landfills creating an environmental burden. Biomasses from other sources have been used to produce different kinds and grades of biomaterials such as those used in industrial and medical applications. The present review aims to investigate the availability of biomass from pulp and paper mills and show sustainable routes for the production of high value-added biomaterials. The study reveals that using conventional and integrated biorefinery technology the ample variety and quantity of waste generated from pulp and paper mills can be converted into wealth. As per the findings of the current review, it is shown that high-performance carbon fiber and bioplastic can be manufactured from black liquor of pulping waste; the cellulosic waste from sawdust and sludge can be utilized for the synthesis of CNC and regenerated fibers such as viscose rayon and acetate; the mineral-based pulping wastes and fly ash can be used for manufacturing of different kinds of biocomposites. The different biomaterials obtained from the pulp and paper mill biomass can be used for versatile applications including conventional, high performance, and smart materials. Through customization and optimization of the conversion techniques and product manufacturing schemes, a variety of engineering materials can be obtained from pulp and paper mill wastes realizing the current global waste to wealth developmental approach.

In the present study, adsorption of colour and other pollutants from agro-based paper mill effluent onto fabricated coal fly ash nanoparticles (CFA-N) have been investigated. Response surface methodology was applied to evaluate the operational conditions for maximum ouster of colour from effluent by nano structured CFA-N. Maximum reduction in colour (92.45%) and other pollutants were obtained at optimum conditions: 60 min interaction time, 60 g/L adsorbent dosage and 80 rpm agitation rate. The regression coefficient values (adjusted R2 = 0.7169; predicted R2 = 0.7539) established harmony between predicted and the experimental data. The adsorption equilibrium results matched perfectly with both Langmuir and Freundlich isotherms with maximum adsorption capacity of 250 platinum–cobalt/g. Additionally, the efficacy of CFA-N was also assessed in a continuous column mode. Furthermore, the feasibility of treated effluent for irrigation purpose was checked by growing the plant Solanum lycopersicum. Overall, the findings demonstrated the outstanding role of inexpensive and abundantly available CFA-N in treatment of paper mill effluent to the required compliance levels. HIGHLIGHTS Nano fly ash was successfully utilized for removal of colour and other pollutants from agro-based paper mill effluent.; RSM using BBD was used to optimize the operational conditions.; Quadratic models have been established for the response variables.; Fixed-bed column adsorption studies illustrated the feasibility of nano fly ash for pilot-scale applications.; The reusability of treated effluent for irrigation was examined.

We report a paper-based photodetector made from mixed cation organic perovskite halide MA1–xFAxPbI3 (MA = methylammonium (CH3NH3); FA = formamidium CH(NH2)2). The detector shows a substantial photo...

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.

The development of diagnostic tools for measuring a wide spectrum of target analytes, from biomarkers to other biochemical parameters in biological fluids, has experienced a significant growth in the last decades, with a good number of such tools entering the market. Recently, a clear focus has been put on miniaturized wearable devices, which offer powerful capabilities for real-time and continuous analysis of biofluids, mainly sweat, and can be used in athletics, consumer wellness, military, and healthcare applications. Sweat is an attractive biofluid in which different biomarkers could be noninvasively measured to provide rapid information about the physical state of an individual. Wearable devices reported so far often provide discrete (single) measurements of the target analytes, most of them in the form of a yes/no qualitative response. However, quantitative biomarker analysis over certain periods of time is highly demanded for many applications such as the practice of sports or the precise control of the patient status in hospital settings. For this, a feasible combination of fluidic elements and sensor architectures has been sought. In this regard, this paper shows a concise overview of analytical tools based on the use of capillary-driven fluidics taking place on paper or fabric devices integrated with solid-state sensors fabricated by thick film technologies. The main advantages and limitations of the current technologies are pointed out together with the progress towards the development of functional devices. Those approaches reported in the last decade are examined in detail.

The fabrication of low-cost, flexible, and recyclable electronic devices has been the focus of many research groups, particularly for integration in wearable technology and the Internet of Things (IoT). In this work, porous zinc oxide (ZnO) nanostructures are incorporated as a UV sensing material into the composition of a sustainable water-based screen-printable ink composed of car-boxymethyl cellulose (CMC). The formulated ink is used to fabricate flexible and foldable UV sensors on ubiquitous office paper. The screen-printed CMC/ZnO UV sensors operate under low voltage (≤2 V) and reveal a stable response over several on/off cycles of UV light exposure. The devices reach a response current of 1.34 ± 0.15 mA and a rise and fall time of 8.2 ± 1.0 and 22.0 ± 2.3 s, respectively. The responsivity of the sensor is 432 ± 48 mA W−1, which is the highest value reported in the literature for ZnO-based UV sensors on paper substrates. The UV-responsive devices display impressive mechanical endurance under folding, showing a decrease in responsivity of only 21% after being folded 1000 times. Their low-voltage operation and extreme folding stability indicate a bright future for low-cost and sustainable flexible electronics, showing potential for low-power wearable applications and smart packaging. publishersversion published

This study investigates the efficacy of using discarded textile (cotton and polycotton) and paper waste (newspaper and corrugated cardboard) as substrates to form sheets with optimum tensile strength. The effect of alkali treatment (sodium hydroxide (NaOH) and sodium bicarbonate (NaHCO3)), compressive loads (200 N and 500 N), and the use of binding agents (blackstrap molasses, sodium alginate, and cornstarch) were studied to optimize the tensile strength of homogeneous sheets. The alkali treatment using 5% NaOH for 5 h of soaking demonstrated the highest increase in tensile strength of 21% and 19% for cotton and newspaper, respectively. Increasing compressive load from 200 N to 500 N showed the highest increase in tensile strength of 37% and 42% for cotton and newspaper, respectively. Remarkably, among the binders, cornstarch at 20% concentration obtained an increase in tensile strength of 395%, 320%, 310%, and 185% for cotton, polycotton, corrugated cardboard, and newspaper sheets, respectively. The optimum results obtained from this study will be utilized to develop biodegradable seedling pots using discarded textile and paper waste.

Waste-to-energy or value-added products have been increasingly considered in many pulp and paper mills (PPMs) worldwide. However, developing appropriate conversion technologies is a major challenge in transforming PPMs wastes into biofuels or value-added biomaterials. In the present study, a long-term (320 d) anaerobic digestion of primary sludge of a thermomechanical pulp mill (TMP) was carried out for the first time in a thermophilic anaerobic membrane bioreactor (ThAnMBR). Effect of organic loading rate (OLR) in the range of 2.5–6.8 kg-COD/m3 d and hydraulic retention times (HRT) of 3–8 d on the process performance was investigated. Under various OLRs, stable biogas productions were obtained, and the best results were achieved with lower OLR (2.5 kg-COD/m3 d) and higher HRT (8 d), at biogas yields of 189 L biogas/kg MLSS fed. However, it was found that biogas production and sludge biomass degradation decrease when the organic loading rate increases. The proportion of sludge reduction ranged from 28.9 to 46.7% depending on the applied OLRs. Despite varying OLRs, stable membrane performance was obtained, where the required membrane flux was easily maintained during the reactor operation. In this study, also the properties of digestate and membrane permeates were studied under different operating conditions, and they fluctuated to some extent with OLR. ThAnMBR is a promising new technology for pulp and paper mill primary sludge treatment.

International audience; This paper focuses on the problem of the hierarchical multi‐label classification of research papers, which is the task of assigning the set of relevant labels for a paper from a hierarchy, using reduced amounts of labelled training data. Specifically, we study leveraging unlabelled data, which are usually plentiful and easy to collect, in addition to the few available labelled ones in a semi‐supervised learning framework for achieving better performance results. Thus, in this paper, we propose a semi‐supervised approach for the hierarchical multi‐label classification task of research papers based on the well‐known Co‐training algorithm, which exploit content and bibliographic coupling information as two distinct papers' views. In our approach, two hierarchical multi‐label classifiers, are learnt on different views of the labelled data, and iteratively select their most confident unlabelled samples, which are further added to the labelled set. The success of our suggested Co‐training‐based approach lies in two main components. The first is the use of two suggested selection criteria (i.e., Maximum Agreement and Labels Cardinality Consistency) that enforce selecting confident unlabelled samples. The second is the appliance of an oversampling method that rebalances the labels distribution of the initial labelled set, which reduces the reinforcement of the label imbalance issue during the Co‐training learning. The proposed approach is evaluated using a collection of scientific papers extracted from the ACM digital library. Performed experiments show the effectiveness of our approach with regards to several baseline methods.

1/f noise represents the dominant source of noise in the low-frequency range in several physical systems, including field-effect transistors. Its investigation can provide very important information on the fabrication process, highlighting the steps that are more prone to the introduction of defects. Here, 1/f noise in bilayer MoS2 transistors on paper with inkjet-printed Ag contacts and hBN die- lectric is investigated. These devices are promising building blocks for future low-cost, flexible, and easily recyclable disposable electronics. The analysis of 1/f noise, performed following Hooge’s empirical approach, results in a Hooge parameter ≈1–10, which is comparable to those reported for bilayer MoS2 transistors on SiO2. The present results indicate that the noise properties of the investigated devices are stable against substrate bending and are mainly determined by the printing of the dielectric, while not being sensibly affected by the use of the paper substrate. These results are promising for the further development of low noise 2D material-based flexible electronics on paper.

To explore whether the brain contains pattern differences in the rock–paper–scissors (RPS) imagery task, this paper attempts to classify this task using fNIRS and deep learning. In this study, we designed an RPS task with a total duration of 25 min and 40 s, and recruited 22 volunteers for the experiment. We used the fNIRS acquisition device (FOIRE-3000) to record the cerebral neural activities of these participants in the RPS task. The time series classification (TSC) algorithm was introduced into the time-domain fNIRS signal classification. Experiments show that CNN-based TSC methods can achieve 97% accuracy in RPS classification. CNN-based TSC method is suitable for the classification of fNIRS signals in RPS motor imagery tasks, and may find new application directions for the development of brain–computer interfaces (BCI).

Paper waste in the mockups design with regular, irregular, and amorphous patterns is a critical problem in digital printing presses. Paper waste reduction directly impacts production costs, generating business and environmental benefits. This problem can be mapped to the two-dimensional irregular bin-packing problem. In this paper, an iterated local search algorithm using a novel neighborhood structure to detect overlaps between amorphous shapes is introduced. This algorithm is used to solve the paper waste problem, modeled as one 2D irregular bin-packing problem. The experimental results show that this approach works efficiently and effectively to detect and correct the overlaps between regular, irregular, and amorphous figures.

Ample interest for more efficient utilization of bio-based residues has emerged in the Nordic pulp and paper (P&P) industry, which uses virgin wood as feedstock. Although different bioenergy retrofit technologies for production of liquid, solid, and gaseous bioenergy products have been applied in the existing P&P mills, the number of installations remains small. The lack of profound knowledge of existing bioenergy retrofits hinders the replication and market uptake of potential technologies. This review synthesises the existing knowledge of European installations and identifies the key drivers and barriers for implementation to foster the market uptake of potential technologies. The bioenergy retrofits were reviewed in terms of technical maturity, drivers, barriers and market potential. Based on this evaluation, common drivers and barriers towards wider market uptake were outlined from political, economic, social, technical, environmental, and legal perspective. Technologies already commercially applied include anaerobic fermentation of sludge, bark gasification, tall oil diesel and bioethanol production, whereas lignin extraction, biomethanol production, hydrothermal liquefaction and hydrothermal carbonization are being demonstrated or first applications are under construction. The findings of this review show that a stable flow of residues at P&P mills creates a solid base for retrofitting. New innovative bio-based products would allow widening the companies' product portfolios and creating new businesses. Also, European Union's (EU) legislation drives towards advanced biofuels production. Wider uptake of the retrofitting technologies requires overcoming the barriers related to uncertainty of economic feasibility and unestablished markets for new products rather than technical immaturity.

Despite the potential in fabrication of microfluidic paper-based analytical devices (μPADs) for point-of-care testing (POCT) kits, the development of simple, accurate, and rapid devices with higher sensitivity remains challenging. Here, we report a novel method for 3D-μPAD fabrication with enclosed channels using vat photopolymerization to avoid fluid evaporation. In detail, height of the enclosed channels was adjusted from 0.3 to 0.17 mm by varying the UV exposure time from 1 to 4 s for the top barrier, whereas the exposure time for the bottom and side barriers was fixed. As a result, sample flow in the enclosed channels of 3D-μPADs showed lesser wicking speed with very scant evaporation compared to that in the hemi channels in the 3D-μPADs. The stoppage of evaporation in the enclosed channels significantly improved the gray intensity and uniformity in the detection zone of the 3D-μPADs, resulting in as low as 0.3 mM glucose detection. Thus 3D-μPADs with enclosed channels showed enhanced sensitivity compared to the 3D-μPADs with hemi channels when dealing with a small volume sample. Our work provides a new insight into 3D-μPAD design with enclosed channels, which redefines the methodology in 3D printing.

A novel paper-based potentiometric platform for the simple and fast monitoring of water hardness is presented. First, potentiometric ion-selective electrodes for calcium and magnesium printed on a paper substrate were built and optimized. These sensors, which display near-Nernstian sensitivity, were used for the determination of the concentration of these cations and the calculation of the water hardness. Second, the incorporation of a solid-state reference electrode allowed building an integrated paper-based potentiometric cell for the determination of the hardness of artificial and real samples (mineral waters). The validation of the results shows good ability to predict hardness in the conventional scale. Truly decentralized measurements were demonstrated by integration of a miniaturized instrument and dedicated software in a portable device. The measurements were able to be performed in just under two minutes, including a two-point calibration. Since the method is simple to use and cost-effective, it can be implemented in domestic and industrial settings.

This review summarizes the state of the art of paper-based biosensors (PBBs) for coronavirus disease 2019 (COVID-19) detection. Three categories of PBB are currently being been used for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) diagnostics, namely for viral gene, viral antigen and antibody detection. The characteristics, the analytical performance, the advantages and drawbacks of each type of biosensor are highlighted and compared with traditional methods. It is hoped that this review will be useful for scientists for the development of novel PBB platforms with enhanced performance for helping to contain the COVID-19 outbreak, by allowing early diagnosis at the point of care (POC).

Writing and presenting results is important for any research work. Publishing is not enough; it should be written clearly and consistently for others to read and cite. We present a review of different techniques, for improving the writing in research papers intended for publishing. These include how to write the title, whether to use active or passive voice, how long sentences should be, how to present the uncertainty, understanding the International System of Units (SI) writing conventions, how to assign authorship, how to effectively use references, how to present the work, and how to publish it in a journal. This paper is a summary of the main and most recent recommendations in the scientific field on how to write a research paper to increase its impact.

Supercapacitors are favored by researchers because of their high power density, especially with the acceleration of people's life rhythm. However, their energy density, especially from the point of view of the whole energy storage device, is far lower than that of commercial batteries. In this work, a kind of customizable full paper-based supercapacitor device with excellent self-healing ability is fabricated by simple and low-cost screen printing, electropolymerization and dip coating methods. The resultant separator-free supercapacitor device exhibits both ultrahigh gravimetric and areal specific energy (power) densities of 39 Wh kg−1 (69 kW kg−1) and 692 μWh cm−2 (236 mW cm−2), achieving excellent supercapacitor performance. Notably, the addition of vitrimers endows the whole device with outstanding self-healing properties, which is helpful for enhancing the adaptability of the device to the environment. In addition, this kind of paper-based device also displays good photothermal and electromagnetic shielding performances. These striking features make paper matrix composites attractive in the fields of supercapacitors, medical photothermal treatment and electromagnetic shielding.

Photonic crystals film that possesses periodic dielectric structure have shown great prospect in developing environmentally friendly paper alternatives due to the unique properties of dye free and non-photobleaching, but their practical application is limited by the weak interaction between colloidal particles. Although some progress has been obtained, it is still a challenge to develop photonic paper with the desired mechanical and optical properties. Herein, multifunctional hard core/soft shell nanoparticles with controlled size are fabricated by semi-continuous seed emulsion polymerization method. Compared with convention colloidal particles, these core/shell nanoparticles can facile self-assemble into large-scale dense ordered structure film via dried at room temperature due to the relatively low glass transition temperature (Tg) of the shell layers. The facile fabrication route enables the continuous high-through put production of the photonic papers. The as-formed papers not only possess the capacity to solvent (water/ethanol) rewritable and multicolor painting, but also can rapidly reversible mechanochromic. Moreover, due to the good compatibility of core/shell interface, these photonic films possess excellent mechanical properties, demonstrating that this multifunctional film makes the fabrication of novel robust rewritable papers possible and enables visual monitoring of deformation degree.

In recent times, it has been witnessed that wireless systems based on IoT-based have developed rapidly in various sectors. The IoT (Internet of Things) is the network in which physical devices, equipment, sensors and other objects can communicate among themselves without human involvement. The WSN (Wireless Sensor Network) is a central component of the IoT, which has proliferated into several different applications in real-time. The IoT and WSNs now have various critical and non-critical applications impacting nearly every area of our everyday life. WSN nodes are usually small and battery-driven machines. Thus, the energy effective data aggregation techniques that increase the lifespan of the network are highly significant. Various approaches and algorithms for energy-efficient data aggregation in IoT-WSN systems were presented. This paper reviews the literature with specific attention to aspects of wireless networking for the preservation of energy and aggregation of data.

This paper introduces the background, concept and definition of the Industry Commons. It initiates a discussion on the positioning of the Industry Commons Ecosystem (ICE) with respect to current research directions in advanced manufacturing and production systems that shape advances in engineering and technology, novel business models and innovation breakthroughs. The potential value of data sharing across industrial domains is estimated at over $100 billion, particularly in view of optimising manufacturing processes. Data sharing across domains however faces a series of well-documented challenges associated with the lack of semantic interoperability and related standards, management of trust and sustainability. Solving bottlenecks in data sharing requires a systemic approach to data management, which can account for all aspects of data use, levels of application, attribution and dynamic exchanges. In this paper we propose a high-level ecosystem approach that integrates societal values with digital affordances of industry's cognitive-assisted processes, remote interfacing, hybrid applications and large-scale value networks. Early development of an Ontology Commons EcoSystem (OCES) is presented as the key enabling framework for Industry Commons interoperability and a series of enabling frameworks form the basis of future research directions in Trusted Data Sharing and Closed-Loop Lifecycle Management for greater sustainability.

Activating flux is made up of inorganic material mixed with a volatile medium. The objective of this study is to identify and review the literature in activating flux, and different type of welding techniques. For that purpose, a structured review method is adopted and the Scopus database is used as a primary source for the selection of papers. The papers were identified using the string term of “Activating flux” OR “Activated flux” in the title of papers. And a total of 238 papers were identified for the study. Besides the above few other papers were also reviewed and the materials used, the type of flux used, and the findings of different combinations were highlighted in the form of tables. The findings of the study provide a comprehensive understanding of the different type of welding techniques focusing on TIG welding, and the different combination of flux used and their impact was summarized.

Thermal papers are replacing the conventional form of printing and are being extensively used across the globe. This study encompasses a non-destructive approach to examine thermal papers by using ATR-FTIR spectroscopy and Video Spectral Comparator (VSC), where the former technique helps in characterizing and discriminating different samples and the latter helps in deciphering the faded prints on thermal paper. The qualitative analysis of the spectroscopic data based on peak to peak comparison and quantitative analysis using chemometrics has been done to obtain high discriminating power. Multivariate analysis using HCA gave a discriminating power of 83.82% and PCA showed a variance of 95.64%. The strength of the study is portrayed through the decipherment of artificially and naturally faded thermal papers using VSC and analyzing the effect of different storing conditions on their rate of fading.

The aim of the study was to use black liquor produced during the soda pulping process in a pulp and paper mill to increase methane production during pulp and paper industry sludge treatment and decrease the treatment cost. The effects of black liquor on sludge solubilization and methane production were assessed and the economic feasibility of the process was evaluated. Black liquor and NaOH were found to be equivalent in the thermochemical pretreatment process to solubilize sludge and disintegrate flocs. However, adding black liquor increased the background chemical oxygen demand and volatile fatty acid concentration and increased the amount of methane produced by approximately 7-30%. A start-up delay was emphasized by first-order kinetics model due to black liquor addition while methane production remained stable. Economic assessments of five scenarios were performed. It was found to be economically feasible to use black liquor to replace NaOH for the thermal pretreatment process. The surplus methane generated suggested that co-digestion of sludge and black liquor allows surplus bioenergy to be produced during the thermochemical pretreatment anaerobic digestion process.

The use of online learning and subsequent online testing has expanded rapidly in pharmacy programs across the United States. Numerous published studies have compared online learning with traditional methods in pharmacy. However, no such studies have been published in pharmacy. This study's objective is to compare first-professional year student preferences for computer-based vs. traditional paper-and-pencil testing for a required social and administrative pharmacy class.All students enrolled in the class were invited to complete one brief survey at the end of the semester to determine their testing preference.Of the 138 first-professional year students completing the survey, 79% (109 of 138) preferred computer-based testing, 9% had no preference, 6% (8 of 138) preferred paper-and-pencil testing, and the remainder (8 of 138) stated it depended on what was being tested. Ninety-one percent of students did not perceive the testing method to impact their grades. Students preferred computer-based testing over traditional paper-and-pencil as a convenient testing method (mean 4.73 vs. 3.4, P.001), providing immediate feedback (mean 4.87 vs. 1.91, P.001), and as a more effective testing method (mean 4.57 vs. 3.96, P.001).First-professional year students preferred computer-based over traditional paper-and-pencil testing for a social and administrative science class, with the method of testing not perceived to impact grade. This finding is timely, given the recent required transitioning of all pharmacy classes and subsequent testing to an online format due to the coronavirus disease of 2019 pandemic.

The authors of the title paper (Journal of Optics 49:181–186, 2020) claim to have grown a so-called urea potassium dichromate (UPDC) by slow evaporation of an aqueous solution containing equimolar amounts of urea and potassium dichromate and characterized it based on a unit cell study. A critical analysis reveals that the claims in the title paper are erroneous. Hence, we reinvestigated the crystal growth reaction and determined the structure of the product crystal. Based on these studies, we prove that due to no chemical reaction between the reagents fractional crystallization of potassium dichromate (K2Cr2O7) occurs and not formation of any so-called UPDC crystal. Taking the title crystal as an example we show the importance of reporting single-crystal structure for new compound characterization.

This letter presented a pencil-on-paper-based ecofriendly capacitive touchpad fabricated through a low-cost lab- and solvent-free fabrication process. Economical, readily available, and biodegradable materials, such as pencil and paper, have been used for sensor fabrication. A touchpad based on five such sensors has been developed and evaluated by using it as a user control interface to on/off LEDs and displaying results on LCD and mobile app. The graphite sensors in the user interface have been shielded from the direct interaction of humans and the environment using changeable cling film to make the interface reliable and reusable. The interface can be used in different conditions and users by changing the shielding film. Simultaneously, the system's functionality will remain consistent and functioned similarly to the conventional touch sensors and buttons. These recyclable and easily arrayed touch sensor-based keypads can contribute to future developments in disposable and lightweight interfaces for human–machine interface, medical and healthcare applications, smart packaging, security monitoring, and consumer products.

Paper electronics have been fast developed in recent years due to their degradability and recyclability; however, most of them are barely equipped with logic functions, impeding them from becoming autonomous on-paper systems. To provide a working unit for logic implementations, a paper field-effect transistor (FET) with a clay-graphite channel that demonstrated negative differential resistance (NDR) is fabricated in this study. The device exhibited a p-type semiconductor characteristic with an optical bandgap of ∼1.97 eV according to photoluminescence analysis, resulting from considerable defective graphite mixed with clay in the channel. Considering that the NDR behavior is theoretically predicted to be tunable by the contact resistance, we fabricated FETs with different contact resistances and observed that the NDR behavior occurred in devices with relatively lower contact resistance. The NDR effect is also tunable by varying the gate voltage, which matches well with simulation results. The possible mechanism for the NDR behavior is the decrease in carrier drift velocity induced by band-to-band tunneling, associated with impurities-induced trapping states and gate-induced confined states. This work provides a promising and easy pathway to develop digital components using paper electronics in the near future.

Flexible paper-based surface enhanced Raman spectroscopy (SERS) substrate has attracted great attention in the sensitive detection of analytes in recent years. However, due to its inherent hydrophilic surface, the nanoparticles will not be concentrated very well on the surface of the paper. This reduces the reproducibility and sensitivity of the paper-based substrate. Herein, we demonstrate flexible hydrophobic paper-based substrate using silver nanocubes loaded on polymethylhydrosiloxane modified filter paper (AgNCs@SiO2/PMHS modified filter paper) to realize high sensitivity and reproducibility. The hydrophobic filter paper was obtained by dip-soaking the filter paper into PMHS solution, resulting in increased contact angle to ~112.5°. The AgNCs@SiO2/PMHS modified paper substrate shows high analytical enhancement factor (AEF) of 6.55 × 106, which is 2.2-fold enhancement compared to AgNCs@SiO2/normal paper substrate, and a low detection limit of 0.1 nM rhodamine 6G and 0.89 nM adenine. The high SERS enhancement factor and sensitivity is attributed to the high hotspots density created in the hydrophobic surface as a result of the excellent uniformity and superior sample collection efficiency compared to the normal filter paper-based substrate. Besides, the substrate shows excellent spot-to-spot and substrate-to-substrate reproducibility, with relative standard deviation (RSD) of 6.05% and 9.22%, respectively. Moreover, the AgNCs@SiO2/PMHS modified filter paper substrate achieved good stability; the Raman signal intensity only drops by 25.88% after 3 months of exposure to air. Therefore, this flexible hydrophobic AgNCs@SiO2/PMHS modified filter paper substrate with low cost fabrication and label-free SERS detection is a promising SERS platform for analytical and biological sensing applications.

Graphene-based papers have recently triggered considerable interests in developing the application as thermal interface materials (TIMs) for addressing the interfacial heat transfer issue, but their low through-plane thermal conductivity (κ⊥), resulting from the layer-by-layer stacked architecture, limits the direct use as TIMs. Although various hybrid graphene papers prepared by combining the graphene sheets and the thermally conductive insertions have been proposed to solve this problem, achieving a satisfactory κ⊥ higher than that of commercial TIMs (>5 W m−1 K−1) remains challenging. Here, a strategy aimed at the construction of heat pathways along the through-plane direction inside the graphene paper for achieving a high κ⊥ was demonstrated through the simultaneous filtration of graphene sheets with two different lateral sizes. The as-prepared graphene paper presented a hierarchical structure composed of loosely stacked horizontal layers formed by large graphene sheets, intercalated by a random arrangement of small graphene sheets. Due to the heat pathways formed by small graphene sheets along the through-plane direction, the hierarchically structured graphene paper exhibited an improved κ⊥ as high as 12.6 W m−1 K−1 after a common graphitization post-treatment. In the practical test, our proposed paper as an all-graphene TIM achieved an enhancement in cooling efficiency of ≈ 2.2 times compared to that of the state-of-the-art TIM, demonstrating its superior performance to meet the ever-increasing heat dissipation requirement.

Membrane heat exchangers were used for moisture and heat recovery from a hot and humid natural gas stream in indirect contact with an air stream. A plate membrane module with spiral channels on each side was designed to configure gas and air streams in co-current and counter-current flow. Two types of membranes, a commercial kraft paper, and a laboratory-made thin-film composite membrane, were used as the module core. The thermal efficiency and the water recovery from the humid gas were calculated and compared under different operating conditions. At a unit flow ratio of air/gas, the greatest effectiveness was achieved at a methane flow of 100 cm3/min, but water recovery increased at higher gas flows. For the counterflow configuration, an air/methane flow ratio of 2 was sufficient to achieve the highest total effectiveness and water recovery; however, larger air/gas ratios were beneficial to improve heat and moisture transfer for the co-current configuration. The highest water recovery by the kraft paper and composite membrane was achieved (approximately 15 mgH2O/cm2.h) for the input gas with the highest humidity. The dehumidification performance of kraft paper as a porous and hydrophilic membrane was slightly better than that of the composite membrane containing a dense hydrophilic polymer thin film in most cases. A relatively low heat transfer coefficient was found for the module, which was increased by using higher gas flow rates at higher humidity conditions.

Background Display signage is ubiquitous and essential in hospitals to serve several clerical, operational, and clinical functions, including displaying notices, providing directions, and presenting clinical information. These functions improve efficiency and patient engagement, reduce errors, and enhance the continuity of care. Over time, signage has evolved from analog approaches such as whiteboards and handwritten notices to digital displays such as liquid crystal displays, light emitting diodes, and, now, electronic ink displays. Electronic ink displays are paper-like displays that are not backlit and show content by aligning microencapsulated color beads in response to an applied electric current. Power is only required to generate content and not to retain it. These displays are very readable, with low eye strain; minimize the emission of blue light; require minimal power; and can be driven by several data sources, ranging from virtual servers to electronic health record systems. These attributes make adapting electronic ink displays to hospitals an ideal use case. Objective In this paper, we aimed to outline the use of signage and displays in hospitals with a focus on electronic ink displays. We aimed to assess the advantages and limitations of using these displays in hospitals and outline the various public-facing and patient-facing applications of electronic ink displays. Finally, we aimed to discuss the technological considerations and an implementation framework that must be followed when adopting and deploying electronic ink displays. Methods The public-facing applications of electronic ink displays include signage and way-finders, timetables for shared workspaces, and noticeboards and bulletin boards. The clinical display applications may be smaller form factors such as door signs or bedside cards. The larger, ≥40-inch form factors may be used within patient rooms or at clinical command centers as a digital whiteboard to display general information, patient and clinician information, and care plans. In all these applications, such displays could replace analog whiteboards, noticeboards, and even other digital screens. Results We are conducting pilot research projects to delineate best use cases and practices in adopting electronic ink displays in clinical settings. This will entail liaising with key stakeholders, gathering objective logistical and feasibility data, and, ultimately, quantifying and describing the effect on clinical care and patient satisfaction. Conclusions There are several use cases in a clinical setting that may lend themselves perfectly to electronic ink display use. The main considerations to be studied in this adoption are network connectivity, content management, privacy and security robustness, and detailed comparison with existing modalities. Electronic ink displays offer a superior opportunity to future-proof existing practices. There is a need for theoretical considerations and real-world testing to determine if the advantages outweigh the limitations of electronic ink displays.

Paper mill sludge biochar (PMSB) was produced via pyrolysis in a muffle furnace at 750 °C. Subsequently, PMSB was soaked in the HCl solution and washed by deionized water to obtain minerals and organic materials. The organics were named as demineralized paper mill sludge biochar (DPMSB). It was found that PMSB and minerals had larger pore diameters than DPMSB. Also, the removal efficiencies of Cu, Zn and As were above 95.00% by using PMSB and minerals because of the large pores, abundant carbonates and OH groups, while the removal efficiencies of Cu, Zn and As by using DPMSB were 40.92%, 87.93% and 94.99%, respectively, owing to the H + competition to Cu and Zn adsorption but more micropores to enhance As adsorption. The adsorption behavior of PMSB showed that the adsorption isotherms of Cu, Zn and As could be well simulated by the Freundlich model, and the pseudo-second-order model fitted the adsorption kinetics of Zn and As, and the Elovich model fitted the adsorption kinetics of Cu. Moreover, the optimal dosages of PMSB to adsorb Cu, Zn and As were 0.3, 0.3 and 0.1 g/L, respectively. And the pH values of the solution for the efficient adsorption of Cu, Zn and As were 4.00, 6.00 and 2.00, respectively. This work provided basic data for the potential commercial application of PMSB for heavy metals removal from wastewater.

The design of a cheap, simple, and handy sensing system for rapid quantitation of pharmaceuticals becomes mandatory to ease drug development procedures, quality control, health care, etc. This work describes a simple, innovative, and easily manufactured paper-based device using a correction pen as a plotter for hydrophobic/lipophobic barriers and graphene quantum dots for recognition and quantification of the hemostatic drug carbazochrome, via fluorescence turn-off mechanism mediated by the inner filter effect. A smartphone-based all-in-one device fitted with an inexpensive 365 nm flashlight as a UV light source and a free image processing software was developed for rapid and reliable interpretation of the fluorescence change from the paper-based device upon introduction of the drug. The simple and convenient steps permit the analysis of many samples in a very short time. The smartphone-based all-in-one device featured excellent sensitivity for carbazochrome with a limit of detection equals to 12 ng/detection zone and good %recovery (100.0 ± 0.4). The reliability of the device was ascertained by favorable statistical comparison with the analogous optimized conventional fluorimetry method and a reference HPLC method. The device has been successfully applied for versatile quantitation of carbazochrome in tablets and on manufacturing equipment surfaces with excellent recoveries. The device offers many green aspects that definitely assist the implementation of the sustainability concept to analytical laboratories. The cost-efficiency, reliability, and ease of fabrication as well as the greenness and user friendship qualify the device for wide application in low-income communities.

CdSe/ZnS quantum dots (QDs) and 3,3,5,5-tetramethylbenzidine (TMB) were incorporated into a filter paper to produce a paper-based colorimetric device for Hg2+ detection. Under visible light, the CdSe/ZnS QDs acted as a photocatalyst to oxidize TMB, resulting in blue colorization on the paper. Moreover, Hg2+ could enhance the photocatalytic activity of CdSe/ZnS QDs and consequently caused an increase in the color intensity of the paper. The color change of the paper-based device can be directly identified by naked-eye observation or captured by a smartphone and analyzed using image processing software for quantitative analysis. Under optimal conditions, a low detection limit of 0.09 µM was achieved. This device was applied for real samples, including tap water and cosmetics, and achieved satisfying results.

As a kind of industrial hazardous solid waste, paper mill sludge (PMS) was hard to treated by conventional process because of its high moisture, high organic content and and high environmental risk. The hydrothermal liquefaction (HTL) shows excellent potential for the conversion to a wide variety of organic matter with high water contents including various kinds sludge into fuels or value-added chemicals. In this paper, the liquefaction potential for PMS under different reaction temperatures were investigated, and the products were classified into several main components based on the results of GC-MS. The results showed that the highest yield of bio-oil was 44 % (wt/wt dry PMS without ash) at 340 °C with simply compound composition. And the bio-oil product has above 26 % long chain hydrocarbon and 22 % cycloketones. It has potential for conversion to biomass platform compounds. It can be used as bio-fuel for heat recovery of alkali recovery system of paper mill. So, adjusting different reaction temperatures of HTL, the properties of products can meet the different requirements for platform chemical and/or bio-oil fuel.

In this paper, we analyze the intelligent subdesign of the simulated marking system through an in-depth study of it. This paper proposes a correlation analysis-based quantification of N-element sense values and a rationality enhancement-based scoring fitting algorithm for English essays. This paper also extracts word features, sentence features, and chapter structure features in essays to fit English composition scores. Since not all students can complete the essays according to the topic requirements, a triage scoring model is used to separate the normal essays from the low-scoring essays. Statistically, it was found that the essay scores also showed a certain normal distribution. The standard support vector regression algorithm is prone to data skewing problems, so this paper addresses this problem by using a rationality enhancement method that gives a corresponding penalty factor according to the distribution of the dataset. The results show that the English essay scoring fitting algorithm proposed in this paper can well improve the prediction accuracy of some data and solve the problem of skewed data where the scores show a normal distribution. This paper designs and implements an online mock examination system that incorporates an intelligent scoring system for essays, enabling it to meet the needs of teachers and students for online examinations and intelligent scoring.

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

With the arrival of the Internet and social media, at the same time as masses of humans have benefitted from the full-size reassets of records available, there was an full-size boom with inside the upward push of cyber-crimes, mainly targeted closer to women. According to a 2019 file with inside the Economics Times, India has witnessed a 457% upward push in cybercrime with inside the 5 years span among 2011 and 2016. Most speculate that that is because of effect of social media inclusive of Facebook, Instagram and Twitter on our day by day lives. While those simply assist in growing a legitimate social network, advent of consumer debts in those websites normally desires simply an email-id. A actual lifestyles man or woman can create more than one fake IDs and for this reason impostors can effortlessly be made. Unlike the actual international state of affairs in which more than one policies and guidelines are imposed to become aware of oneself in a completely unique manner (as an instance at the same time as issuing one’s passport or driver’s license), with inside the digital international of social media, admission does now no longer require this kind of checks. In this paper, we study the one-of-a-kind debts of Instagram, specifically and try and verify an account as fake or actual the use of Machine Learning strategies specifically Logistic Regression and Random Forest Algorithm.

Flexible photodetectors functionalized by transition metal dichalcogenides have attracted great attention due to their excellent photo-harvesting efficiency. However, the field of optoelectronics still requires advancement in the production of large-area, broad band and flexible photodetectors. Here we report a flexible, stable, broad band and fast photodetector based on a MoS2/WSe2 heterostructure on ordinary photocopy paper with pencil-drawn graphite electrodes. Ultrathin MoS2/WSe2 nanohybrids have been synthesized by an ultrahigh yield liquid-phase exfoliation technique. The thin sheets of WSe2, and MoS2 contain two to four layers with a highly c-oriented crystalline structure. Subsequently, the photodetector was exploited under ultra-broad spectral range from 400 to 780 nm. The photodetector exhibits excellent figure of merit such as on/off ratio of the order of 103, photoresponsivity of 124 mA W−1 and external quantum efficiency of 23.1%. Encouragingly, rise/decay time of about 0.1/0.3 s was realized, which is better than in previous reports on paper-based devices.

Electrochemiluminescence (ECL) is a powerful technique with the advantages of high sensitivity and a wide dynamic range. However, most of previous strategies based on ECL could only detect one analyte so that it is inevitable to investigate the selectivity and influences of interferences. Herein ECL integrated with paper chromatography was showed to be a potential platform for separation and detection of two environmental hormones (bisphenol A, BPA, and dibutyl phthalate, DBP). In our approach, carbon conductive tape was attached to an ITO glass and then modified with multi-walled carbon nanotubes (MWCNTs) and CdSe quantum dot (CdSe QDs) to fabricate the working electrodes for ECL detection. The synthesis of CdSe QDs was optimized based on their photoluminescence spectra and the ECL intensities. The modified electrode was then coupled in the paper-based analytical devices consisting of the filter paper modified with chitosan. Based on their quenching effect on the ECL emission of CdSe QDs, excellent linear relationships could be obtained between decreased ECL intensities and both the concentrations of DBP and BPA. Besides, DBP and BPA could be separated based on their retention time by tilting the filter paper for 30° and then detected with ECL. This study suggested that paper-based analytical devices could be potentially applied for separation and detection of multiple targets due to their ease of fabrication and convenient operation.

The rapid development of the portable and wearable devices has inspired the ever-growing pursuit of flexible energy storage equipment which can power these devices. Here, rice paper (RP) was integrated with a homemade LGS-polypyrrole (LGS-PPy) ink and commercial pen ink in order to construct a flexible electrode of a supercapacitor via a facial dip-coating method. The obtained RP/LGS-PPy ink/Pen ink composites showed a high areal specific capacitance of 1568 mF/cm2 at 0.2 mA/cm2, owing to the uniform deposition of a LGS-PPy layer which was covered by the pen ink coating. Furthermore, the assembled symmetric supercapacitor fabricated from the RP/LGS-PPy ink/Pen ink electrode exhibited impressive electrochemical performances in terms of specific capacitance (317.5 mF/cm2 at 2 mA/cm2), power density (846 μW/cm2 at the energy density of 23.5 μWh/cm2), and life times (82.1% capacitance retention after 5000 cycles). In addition, the capacitance of the as-prepared device remained essentially unchanged even after bending at 180°, thus demonstrating this device's outstanding flexibility. The low cost of raw materials, robust fabrication strategy as well as the moderate performances make the RP-based supercapacitor a promising candidate for future flexible energy storage devices.