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Abstract Purpose: To study the effect of near-vision reading task on optical quality of the eye when performed on a computer monitor and on printed paper, and to identify which of the two results in greater changes. Methods: Two groups of subjects performed a 30-min reading task in two different conditions: on a computer monitor and on printed paper. Ocular, corneal, and internal wavefront aberrations (Zernike coefficients up to 6 th order), root-mean-square of low- and high-order aberrations, spherical equivalent, vectoral components of ocular astigmatism (J45 and J0), and the compensation factor between internal and corneal aberrations were measured before and after the tasks. Their changes were analyzed in each group and between groups. Results: Statistically significant changes in wavefront aberrations and in root mean square of low- and high-order aberrations were observed in both groups which was significantly greater when the task was performed on printed paper. Partial loss of compensation mechanism and variation in spherical equivalent in a negative direction occurred after both reading tasks; however, it was statistically significant only with printed paper reading task. The vectoral components of ocular astigmatism did not show statistically significant changes in either groups. Conclusion: Near-vision reading tasks can change the optical quality of the eye, especially when the task is performed on printed paper.

Paper and cardboard elements can be used as a pro-ecological building material. To meet the safety and usage requirements paper elements need to be impregnated, however, most impregnation methods have a negative impact on the environmental performance of the elements. This article describes research that was conducted in order to determine the most effective technique of paperboard impregnation against water and humidity. Particular attention was given to biodegradable coatings, as several oil-based and wax-based wood impregnates were used. The samples were tested for 24 hours in immersion and for 48 hours in high air humidity. Water uptake (measured by the change in mass and thickness), delamination and deformation of samples were monitored. As a result, the basic characteristic of the tested impregnation methods was established – water and water vapour absorption, deformation or delamination after immersion. The lowest water and water vapour absorption was observed in samples impregnated with composed coatings of oils and waxes.

In this study, the use of bast fibers removed hemp (Cannabis sativa L.) stalks in pulp and paper production and some physical and optical properties of the produced papers were investigated. The chemical components and fiber morphological properties of hemp stalks free of bast fibers were determined and their suitability for pulp and paper production was examined. The holocellulose, cellulose and lignin contents of the hemp stalks were 79.7%, 52.0% and 22.2%, respectively, while fiber length, fiber width and lumen diameter were 0.60 mm, 28.8 µm and 13.4 µm, respectively. In line with these data, pulp production was carried out by cooking the hemp stalks with the Kraft cooking method. The yield, kappa number and viscosity values of pulp obtained from hemp stalks were determined as 48.2%, 39 and 1400 cm3/g, respectively. The breaking length and brightness values of the papers produced from these pulps were measured as 6.87 km and 33.34% ISO, respectively. Consequently, high yield and strength pulps can be produced from hemp stalks free of bast fibers, and since it has a low kappa number and high viscosity, it can be easily bleached.

A new generation of rapid, easy to use and robust colorimetric point of care (POC) nanocellulose coated-paper sensors to measure glucose concentration in blood is presented in this study. The cellulose gel containing the enzyme with co-additive is coated and dried onto a paper substrate. Nanocellulose gel is used to store, immobilize and stabilize enzymes within its structure to prolong enzyme function and enhance its availability. Here, we immobilize glucose oxidase within the gel structure to produce a simple colorimetric blood glucose sensor. Increase in blood glucose concentration increases the concentration of reaction product which decreases the system pH detected by the pH indicative dye entrapped in the nanocellulose gel. The sensor produces a color change from red to orange as pH decreases due to the enzymatic reaction of glucose into gluconic acid and hydrogen peroxide. This sensor can measure glucose concentrations of 7–13 mM (medical range for diabetes control) at temperatures of 4°C–40°C. Stability tests confirm that no denaturation of enzyme occurs by measuring enzyme activity after 4 weeks. A prototype device is designed to instantly measure the glucose concentration from blood in a two steps process: 1) red blood cell separation and 2) quantification of glucose by color change. This study demonstrates nanocellulose sensor as an economical, robust, and sensitive diagnostic technology platform for a broad spectrum of diseases.

We propose a printed 384‐well microtiter paper‐based fluorescent chemosensor array device (384‐well microtiter PCAD) to simultaneously categorize and discriminate saccharides and sulfur‐containing amino acids for food analysis. The 384‐well microtiter PCAD requiring 1 μL/4 mm2 of each well can allow high‐throughput sensing. The device embedded with self‐assembled fluorescence chemosensors displayed a fingerprint‐like response pattern for targets, the image of which was rapidly captured by a portable digital camera. Indeed, the paper‐based chemosensor array system combined with imaging analysis and pattern recognition techniques not only successfully categorized saccharides and sulfur‐containing amino acids but also classified mono‐ and disaccharide groups. Furthermore, the quantitative detectability of the printed device was revealed by a spike and recovery test for fructose and glutathione in a diluted freshly made tomato juice. We believe that the 384‐well microtiter PCAD using the imaging analysis system will be a powerful sensor for multi‐analytes at several categorized groups in real samples. [ABSTRACT FROM AUTHOR]

The purpose of this study was to evaluate a simple and low-cost colorimetric method based on Fe(III) chloride and potassium hexacyanoferrate(III) for determination of acetaminophen, ascorbic acid and phenylephrine, which can be used in small laboratories using restricted materials and resources. A paper based sensor using the reagent was introduced. Significance of different variables in determination of drugs were studied by Placket-Burman design and optimal values for concentration of hydrochloric acid, Fe(III) chloride and potassium hexacyano ferrate(III), 0.01 M, 0.004 M and 0.004 M, respectively were obtained. Without using any sophisticated instrument and only by image analysis the concentration of acetaminophen, ascorbic acid and phenylephrine was determined in pharmaceutical samples. In this way we were able to determine by analyzing the final color of the reactions. The linear range in ppm for all the analytes was obtained as 0.00–50.00 and limit of detection of 2.52, 2.48 and 2.48 were obtained for acetaminophen, ascorbic acid and phenylephrine, respectively. Percent relative standard deviation (RSD %) and percent relative error (RE %) of the proposed method for analysis of real samples of acetaminophen tablet were 4.77 and 7.64, ascorbic acid tablet, 4.73 and 1.41, and phenylephrine syrup, 2.44 and − 1.61, respectively. [ABSTRACT FROM AUTHOR]

Nanocellulose has received enormous scientific interest for its abundance, easy manufacturing, biodegradability, and low cost. Cellulose nanocrystals (CNCs) and cellulose nanofibers (CNFs) are ideal candidates to replace plastic coating in the textile and paper industry. Thanks to their capacity to form an interconnected network kept together by hydrogen bonds, nanocelluloses perform an unprecedented strengthening action towards cellulose‐ and other fiber‐based materials. Furthermore, nanocellulose use implies greener application procedures, such as deposition from water. The surface chemistry of nanocellulose plays a pivotal role in influencing the performance of the coating: tailored surface functionalization can introduce several properties, such as gas or grease barrier, hydrophobicity, antibacterial and anti‐UV behavior. This review summarizes recent achievements in the use of nanocellulose for paper and textile coating, evidencing critical aspects of coating performances related to deposition technique, nanocellulose morphology, and surface functionalization. Furthermore, beyond focusing on the aspects strictly related to large‐scale coating applications for paper and textile industries, this review includes recent achievements in the use of nanocellulose coating for the safeguarding of Cultural Heritage, an extremely noble and interesting emerging application of nanocellulose, focusing on consolidation of historical paper and archaeological textile. Finally, nanocellulose use in electronic devices as an electrode modifier is highlighted. [ABSTRACT FROM AUTHOR]

Hydrogen sulfide (H2S) is known to participate in bacteria-induced inflammatory response in periodontal diseases. Therefore, it is necessary to quantify H2S produced by oral bacteria for diagnosis and treatment of oral diseases including halitosis and periodontal disease. In this study, we introduce a paper-based colorimetric assay for detecting bacterial H2S utilizing silver/Nafion/polyvinylpyrrolidone membrane and a 96-well microplate. This H2S-sensing paper showed a good sensitivity (8.27 blue channel intensity/μM H2S, R2 = 0.9996), which was higher than that of lead acetate paper (6.05 blue channel intensity/μM H2S, R2 = 0.9959). We analyzed the difference in H2S concentration released from four kinds of oral bacteria (Eikenella corrodens, Streptococcus sobrinus, Streptococcus mutans, and Lactobacillus casei). Finally, the H2S level in Eikenella corrodens while varying the concentration of cysteine and treatment time was quantified. This paper-based colorimetric assay can be utilized as a simple and effective tool for in vitro screening of H2S-producing ability of many bacteria as well as salivary H2S analysis. [ABSTRACT FROM AUTHOR]

Within the Master's course "Civil Engineering" at TU Darmstadt, a project has to be carried out. In the winter term 2018/2019 this was the design and fabrication of a bridge spanning 6 m and made entirely from paper. Students had to find bridge types suitable for the use of paper, develop and optimise cross sections and bracing systems and furthermore prove the load bearing capacity. This included the use of experimental methods explicitly. Finally, the bridge had to be erected crossing a small creek. No materials other than paper, cardboard and glue were allowed. [ABSTRACT FROM AUTHOR]

Herein, a novel modified polyvinyl alcohol(DA-IPVA) used as sizing agent was prepared by using diacetone acrylamide(DAAM)/adipic dihydrazide(ADH) as graft monomer and N-(isobutoxymethyl)acrylamide(IBMA) as self-cross-linking monomer. The effect of the amount of DAAM on the properties of emulsion, film and sizing paper was discussed. The surface micro-structure of the sizing paper was characterized by SEM and AFM. The addition of DAAM/ADH and IBMA endowed DA-IPVA with cross-linked active group and increased cross-linking density and hydrophobicity after ADH was added into the emulsion and the cross-linking structure was formed. The enhancing mechanism of surface sizing agent for paper was revealed. The DA-IPVA can be cross-linked on the surface and inside of the paper to form a dense network structure, which improves the bonding force between the fibers. When the mole fraction of DAAM of the cross-linking monomer is 8%, the surface sizing performance of the paper is obviously improved compared with the base paper. The dry and wet strength is increased by 266.5% and 334.3% respectively, and the folding resistance is increased 2946.67%. This study can have a profound impact on the development of the technology of cross-linking surface sizing agent for paper. [ABSTRACT FROM AUTHOR]

Direct fire, indirect heat, and extinguishing water cause great damage to cultural assets upon a fire disaster in a library or archive. Conservation and restoration of heat-damaged papers are particularly challenging due to the complexity and severity of the damage. Since valuable originals obviously cannot be used for the development of treatment methods and only to a limited extent for the analysis of the damage, it is necessary to produce model paper materials that have a high degree of similarity to fire-damaged papers, which was addressed in the present study. Three different heating methods were tested to produce model papers of different heating levels. Their altered optical, structural, and chemical properties were analyzed and compared with the results of original fire-damaged samples. The study points out pathways to enable the production of comparable sample materials. Heating between hot plates or in an oven produces papers that have properties quite similar to the originals in terms of surface area, paper structure, cellulose integrity, and interactions with water. Stack heating in the oven has proven to be a particularly effective manufacturing method for larger quantities of model papers. [ABSTRACT FROM AUTHOR]

Laser‐induced graphene (LIG) produced by irradiation of paper (paper‐LIG)holds substantial promise for flexible devices. This article presents paper‐LIG humidity and temperature sensors fabricated by single‐step irradiation of common filter paper with a pulsed UV laser (355 nm). The influence of the process parameters on the conversion of cellulose fibers into LIG is discussed based on the resulting morphology, structure, conductivity, and chemical composition, revealing a distinct barrier to transformation and a propagation behavior not seen under CO2 laser irradiation. The obtained material is constituted by a porous, electrically conductive network of fibers. The paper‐LIG relative humidity (RH) and temperature sensors with sensitivities of up to 1.3 × 10−3%RH−1 and ‐ 2.8 × 10−3 °C−1, respectively, are examined in terms of their linearity, reproducibility, and response time. A detailed discussion on the response mechanism is presented in the context of literature, pointing towards the absorption of water molecules in the interlayer spacing of graphene as the main reason for the increase in resistance with RH. Additionally, a contribution from variable range hopping along the ab plane of graphene at high RH is suggested. These results demonstrate the potential of paper‐LIG for low‐cost, sustainable, and environmentally friendly sensing. [ABSTRACT FROM AUTHOR]

Wrapping paper has an irreplaceable role in the food industry, but the high hydrophilicity of cellulose-based wrapping paper limits its application. Here, we aim to develop a fluorine-free and stable method for preparing the superhydrophobic cellulose-based paper using KH570-modified-n-TiO2 and ε-polylysine (ε-PL) to construct a superhydrophobic surface by layer-by-layer self-assembly. The paper modified by (ε-PL/KH570-modified-n-TiO2)4 multilayers has superhydrophobic and self-cleaning properties after heat treatment. The water contact angle reaches up to 152.8° and the antibacterial rate is close to 100%. The high barrier properties to water vapor better prolong the shelf life of cherries. Therefore, the (ε-PL/KH570-modified-n-TiO2)4 multilayers modified paper can provide a new idea for food preservation. The advantage of the double-layer assembly is that even if the superhydrophobic layer of the wrapper is worn away and lost, the remaining ε-PL is still able to act as a bacterial inhibitor, ensuring that the food is not perishable. [ABSTRACT FROM AUTHOR]

The absolute dating of documents is still one of the most important challenges for forensic document examiners (FDE). The potential difference between the date on a questioned document and the actual year of production of the used paper can be only 1 to 5 years. Until now, there was no analytical method with this accuracy available. This study demonstrates a method for an absolute dating of paper by using the 14C bomb peak and dating the starch in the paper. Accelerator mass spectroscopy (AMS) radiocarbon measurements were performed on starch extracts and cellulose fibers from 50 paper samples with known production year from 1950 to 2018. For most of the paper samples, the measured 14C concentration values in the starch extracts were highly correlated with the data of the 14C bomb peak calibration curve. The differences between the calibrated ages and the actual harvest years of the starch‐containing plants were only up to 3 years. The 14C concentration in the paper fibers showed a lower but significant correlation with the production year of the papers and can be used to support the dating results of the starch extracts. In order to secure the accuracy of the dating, aside from the radiocarbon measurements of the extracted starch other analytical methods or data are used, like a detailed chemical analysis of the paper composition including fiber composition and the spectroscopic analysis of the purity of the starch extracts. In practice, only starch extracts without contaminations are used for the paper dating. [ABSTRACT FROM AUTHOR]

This article models a mode of feminist bibliography by "surface reading" paper. Taking Ben Jonson's Sejanus His Fall (1605) as a case study, this article reads watermarks as reminders of paper's three-dimensional materiality, whose surfaces and depths model the more and less legible forms of labor which contribute to paper's making. Watermarks here become a creative and critical prompt to recover the interventions of John Spilman (the papermaker whose output was used for Sejanus), Spilman's workers, and especially his female ragpickers. This article fuses close reading of literary texts and archival sources with bibliography and theory to demonstrate fresh affordances of watermarks—both as they alter our reading of Sejanus and as they intervene more broadly in the affective and political models with which we read. [ABSTRACT FROM AUTHOR]

In the present society, the recycling and reuse of valuable substances are of utmost importance for economic and environmental purposes. At the same time, there is a pressing need to develop new methods to protect the ecosystem from many human activities, including those that have contributed to an ever-increasing presence of pharmaceutical pollutants. In this study, a straightforward approach that applies a magnetic carbon composite for the effective removal of NSAIDs from biological fluids is reported. The composite was produced by recycling wasted handkerchiefs, to provide cellulose to the reactive system and then transformed into carbon via calcination at high temperature. The morphological and structural features of the prepared "Fe3O4@-activated carbon" samples were investigated via thermal analysis, X-ray diffraction, Raman spectroscopy, and scanning electron microscopy. Magnetic solid-state extraction was carried out to reveal the adsorption capabilities of the magnetic carbon composite and then combined with UHPLC–PDA for the determination and quantification of five NSAIDs (furprofen, indoprofen, ketoprofen, flurbiprofen, and indomethacin). The method developed herein proved to be fast and accurate. The adsorbent could be reused for up to 10 cycles, without any decrease in performance; thus, it contributes to an intelligent and sustainable economic strategy projected toward minimal waste generation. [ABSTRACT FROM AUTHOR]

Objective: To determine the cellulose, hemicellulose, and lignin production in six Cenchrus purpureus cultivars, with and without fertilization, harvested every 21 days during 168 days. Design/methodology/approach: The evaluated cultivars were CT-115, elephant grass, king grass, Maralfalfa, Roxo, and Taiwan, with and without fertilization. The experimental design was a randomized complete block with a split-plot arrangement and four replications. The fertilization dose was 141-43-20 of NPK. Forage was harvested every 21 days during six months in the rainy season. We tested the samples for dry matter (DM), ash, NDF, ADF, hemicellulose, cellulose, and lignin. We performed a nonlinear regression analysis. We determined biomass production with the estimated values and the percentage of each component. The goodness-of-fit indicators were: R², the coefficient of determination (R), and the model selection criterion (MSC). The parameters and goodness-of-fit coefficients were analyzed in ANOVA with the SAS software using the GLM procedure. Means were compared with Tukey's test. Results: The Maralfalfa cultivar presented a higher cellulose production (3,786 kg ha-1), similar (p>0.05) to the elephant grass and Taiwan cultivars, which presented values of 3,451 kg ha-1 and 3,329 kg ha-1, respectively, and different (p<0.05) from CT-115 and king grass, which produced more than 1 t ha-1 of cellulose. Limitations/implications: Cellulose production increased by the effect of fertilization. Findings/conclusions: The fertilized Maralfalfa, elephant grass, and Taiwan cultivars produced more than 4,000 kg ha-1 of cellulose, 3,000 kg ha-1 of hemicellulose, and 1,000 kg ha-1 of lignin. [ABSTRACT FROM AUTHOR]

Background: The prevalence and death rate arising from malaria infection, and emergence of other diseases showing similar symptoms to malaria require the development of malaria-specific and sensitive devices for its diagnosis. To address this, the design and fabrication of low-cost, rapid, paper-based analytical devices (µPAD) using surface-immobilized aptamers to detect the presence of a recombinant malarial biomarker—Plasmodium falciparum lactate dehydrogenase (rPfLDH)—is reported in this study. Methods: Test zones on paper surfaces were created by covalently immobilizing streptavidin to the paper, subsequently attaching biotinylated aptamers to streptavidin. Aptamers selectively bound rPfLDH. The measurement of captured rPfLDH enzyme activity served as the means of detecting this biomarker. Enzyme activity across three replicate sensors was digitally quantified using the colorimetric Malstat assay. Results: Screening of several different aptamers reported in the literature showed that aptamers rLDH7 and 2008s immobilized in this manner specifically recognised and captured PfLDH. Using rLDH7, the sensitivity of the µPAD sensor was evaluated and the µPAD sensor was applied for preferential detection of rPfLDH, both in buffered solutions of the protein and in spiked serum and red blood cell lysate samples. In buffered solutions, the test zone of the µPAD sensor exhibited a KD of 24 ± 11 nM and an empirical limit of detection of 17 nM, respectively, a limit similar to commercial antibody-based sensors exposed to rPfLDH. The specific recognition of 133 nM rPfLDH in undiluted serum and blood samples was demonstrated by the µPAD. Conclusion: The reported µPAD demonstrates the potential of integrating aptamers into paper-based malarial rapid diagnostic tests. [ABSTRACT FROM AUTHOR]

There is current interest in replacing petroleum-based additives in consumer paper products with abundantly available, renewable and sustainable biopolymers such as lignin-containing cellulose nanofibers (LCNFs) and cottonseed protein. This research characterized the performance of cottonseed protein isolate with/without LCNFs to increase the dry strength of filter paper. The application of 10% protein solution with 2% LCNFs as an additive improved the elongation at break, tensile strength and modulus of treated paper products compared to the improved performance of cottonseed protein alone. Improvements in tensile modulus and tensile strength were greatest for samples containing larger amounts of lignin and a greater degree of polymerization than for those with less lignin from the same biomass sources. [ABSTRACT FROM AUTHOR]

Up to now the literature dealing with the cartography of the former Duchy of Pomerania has assumed that wall map of the region by Eilhardus Lubinus (Eilhard Lubin) had two editions: the first dating from 1618 and the second from 1758. Detailed analysis of correspondence between the mapmaker and his patron, the Pomeranian Duke Philip II, and later letters relating to arguments over payment and paper supplies as well as of a recently discovered copy of the map (now at the University of Szczecin), however, point to the existence of a third edition. This, it is suggested, dates from 1619–1620 and was financed by Lubin himself. Research has also revealed that the paper on which this new exemplar was printed came neither from the Pomeranian dukes' paper mill (as for the 1618 edition) nor from the Unold paper mill in Wolfegg (as for the 1758 edition). [ABSTRACT FROM AUTHOR]

The pulp and paper industry is increasingly seeking a sustainable and conscientious development, minimizing the environmental impacts caused by it. Therefore, reducing efficiently the number of stages used in the bleaching process can mean less consumption of water and chemical reagents, contributing to the reduction of harmful waste to the environment. Thus, this study sought to evaluate the pulp quality and some physical-mechanical properties (smoothness, tear and tensile indexes) of two new bleaching sequences A*DP and A*E*DP and compare them with the reference D0(E+P)D1P. To do so, industrial eucalyptus Kraft pulp pre-delignified with oxygen was used. The bleached pulp was refined to 1200, 1800 and 2400, in PFI mill and tested according to TAPPI standards to determine smoothness, tear and tensile indexes. Based on the results obtained, it was verified that the sequences studied are viable for using in bleaching plants, which allowed a reduction in the chlorine dioxide consumption and presented satisfactory smoothness, tear and tensile indexes for paper. [ABSTRACT FROM AUTHOR]

The pulp and paper manufacturing industry is currently facing sweeping changes due to the fact that supply and demand are dominated by different global players. These changes have significant effects not only on the paper and pulp production of countries but also on world economies thanks to the high level of trade between countries around the world. Based on the historical development of paper, our study examines today's production around the world economies, shows the latest commercial trends in the paper and pulp trade, and makes a prediction on the effects of the data belonging to this sector on the trade of countries through using panel regression models. According to our results, we determined a significant relationship between the total world paper and cardboard production in Turkey and the European Union and the amount of pulp. On the other hand, a partial relationship was found between the European Union and Turkey's paper production. In addition, we concluded that the amount of pulp used in paper and cardboard production was the factor causing the total paper production in the European Union and Turkey. In other words, we have established as a result of the analysis that as the amount of pulp used in paper and cardboard production increases, paper and cardboard production also increases at the same rate. [ABSTRACT FROM AUTHOR]

The British Library's Stein collection contains about 14,000 scrolls, fragments and booklets in Chinese from a cave in the Buddhist Mogao Caves complex near Dunhuang in north-west China. This article describes storage and access solutions for the collection in the context of a busy research library and the currently ongoing Lotus Sutra Manuscripts Digitisation project. The article presents the various technical and organisational challenges that its rehousing presents to the library conservators. Restricted by the existing storage facilities, budget limitations and tight project deadlines, the conservators must provide housing that is adequate for the scroll format, is practical and prevents dissociation, but is also cost- and time-effective. With the best storage practice in mind, they have developed original solutions, balancing the specific housing requirements and constraints. These storage solutions allow the conservators to ensure the long-term safety and accessibility of the collection while laying down a foundation of standardisation that will ensure a homogeneity of approaches for future projects. [ABSTRACT FROM AUTHOR]

An awareness of the problems associated with the use of plastics can provide new opportunities for the paper industry. We have to try to enhance the public awareness of the environmental value of papers by using diverse advertising approaches. We have to collaborate to make paper more viable to replace plastics in many uses. The collaboration not only between industry and academia but also between countries and associations is essential to advance the age of paper.

This paper examines changes and trends in tributary gifts (pangmul 方物) sent by Chosŏn regular envoys to the Ming Emperor during the 15th and 17th centuries. First, pangmul items sent by the Chosŏn to the Ming were partially inherited from the Koryŏ era. Second, it examines how King Sejong’s 1429 request that the Chosŏn court pay its tribute by means other than gold and silver led the court to offer specialty goods as tribute instead of precious metals. It then moves on to explore how economic scarcity resulting from the Imjin Wars of 1592 led Chosŏn pangmul to be composed mostly of folding fans and stationery items such as paper (kyŏngmyŏnji, paekmyŏnji, and oil paper), inkstones (hwayŏn), ink (chinmuk and yumaemuk) and writing brushes (hwangmopil)–the dynasty’s common, major export goods. After the war, the Chosŏn dynasty regained stability and returned to its pre-war pangmul practices. However, the pangmul were not completely fixed and showed tentative patterns, going back and forth between the practices of the 15th century and the new circumstances of the 17th century. In short, this paper explores how pangmul practices were not completely fixed, and how contingencies such as the war and the changing landscape of manufacturing in 16th-century Korea influenced the composition of Chosŏn pangmul.

From the moment of production, paper as a printing substrate is exposed to the process of natural ageing regardless of the type of cellulose fibres in its composition. Accordingly, the prints produced by the various printing techniques are also exposed to several factors that impair the quality of the print i.e. its colour over time. Therefore, it is very important to properly select the printing substrate for achieving a high quality of graphic products. For that purpose, three types of papers with hemp fibres were used as printing substrates which were printed with laboratory hand-operated instrument Esiproof using flexographic cyan (C), magenta (M), yellow (Y) and black (K) water-based inks. Prints were artificially aged in SunTEST XLS+ test chamber according to standard ASTM D 6789-02 for 48 and 96 hours. Based on changes in the reflectance spectra of each printed ink after exposure to electromagnetic radiation it was noticed how composition of printing substrate strongly influence on colour stability of prints due time. An increase of exposure time to electromagnetic radiation leads to a decrease in the value of the reflectance of the printing substrate and cyan, magenta and yellow prints. It was confirmed how electromagnetic radiation have the greatest impact on the reflectance of yellow print, while the black one is the most stabile regardless of the substrate it was printed on.

In this study, the effects of the lacquer applied to the printing materials which were printed by electrophotographic printing method on printing quality were investigated. In practice, printing materials with the same weight and different optical properties were used and the study was carried out in three stages. The optical and physical properties of the printing materials used in the first part were determined, in the second part, the printing of these materials by electrophotographic printing method and printability tests were performed. In the third chapter, matte and glossy lacquers were applied to these printed materials and printability tests were repeated. As a result of the study, it was observed that the application of gloss and matte lacquer caused a decrease in the printing density values and also the application of matte lacquer caused a decrease in the gloss values.

Abstract The low‐frequency polarisation information of oil‐paper insulation could be easily obscured by the conductance effect, and the contained polarisation information thus can not be readily extracted from the frequency domain spectroscopy (FDS). Given this issue, an alternative idea is reported to extract the low‐frequency polarisation information by using logarithmic‐derivative spectroscopy (LDS). The present findings proved that the parameters extracted by using the LDS can be applied for studying the low‐frequency polarisation behaviour under the moisture effect. In that respect, the novelty of this work is in the exploration of the LDS as a potential tool to extract feature parameters for analyzing the low‐frequency polarisation information of transformer oil‐paper insulation.

Abstract In recent years, there have been many cases of transformer failures caused by corrosive sulfides. At present, research mainly focuses on the single sulfide dibenzyl disulphide, but few research on multiple sulphur or the oil‐paper hybrid insulation. In this study, three typical sulfides dibenzyl disulfide, hexadecyl mercaptan and benzothiophene were selected to form seven sulfide‐oil‐paper models. Then relaxation calculations were carried out, and through molecular dynamics simulation, the synergistic effect of different sulfides on the properties of insulating paper and insulating oil was discussed. Results show that the coexistence of the three sulfides has the most severe weakening on the mechanical properties of cellulose, and it also causes great damage to hydrogen bonds. Hexadecyl mercaptan has a weaker effect on hydrogen bond destruction, but it will greatly aggravate the cellulose chain movement. The viscosity of insulating oil is generally increased by the influence of sulfide. Hexadecyl mercaptan is the main factor affecting the viscosity. Thiophene has little effect on the viscosity, ctive protection technology on sulphur corrosion.

The identification of sustainable materials as an alternative to plastic is fundamental for the protection of the environment and for the safeguard of marine ecosystems. The replacement of plastic with organic materials for fish storage might affect its shelf-life due to the high concentration of oxidizable fatty acids in fish flesh. This study investigated the effectiveness of two organic packaging materials, namely coconut fiber (Coc) and paper (Pap), as alternatives to the conventionally used polystyrene (Pol), on the shelf-life, hygienic parameters, and quality traits of anchovies refrigerated for one (T0), three (T1), or seven (T2) days. The hygienic quality of anchovies packaged in the organic Pap and Coc boxes was better than the traditional Pol, probably due to the higher porosity of the packaging, which allows a higher bacterial proliferation. Results of the T-BARS test showed a lower (p < 0.05) malondialdehyde concentration in fillets from the Pap group, which increased (p < 0.05) from the first to the seventh day of storage. The polyunsaturated fatty acids concentration did not differ between groups, but it decreased (p < 0.05) from T0 to T2. Coconut fiber and paper are worthy of further investigation since these packaging materials did not affect the shelf-life and fatty acid profile of anchovies during storage.

The present study reports on the development by thermoforming of highly sustainable trays based on a bilayer structure composed of paper substrate and a film made of a blend of partially bio-based poly(butylene succinate) (PBS) and poly(butylene succinate-co-adipate) (PBSA). The incorporation of the renewable succinic acid derived biopolyester blend film slightly improved the thermal resistance and tensile strength of paper, whereas its flexural ductility and puncture resistance were notably enhanced. Furthermore, in terms of barrier properties, the incorporation of this biopolymer blend film reduced the water and aroma vapor permeances of paper by two orders of magnitude, while it endowed the paper structure with intermediate oxygen barrier properties. The resultant thermoformed bilayer trays were, thereafter, originally applied to preserve non-thermally treated Italian artisanal fresh pasta, “fusilli calabresi” type, which was stored under refrigeration conditions for 3 weeks. Shelf-life evaluation showed that the application of the PBS–PBSA film on the paper substrate delayed color changes and mold growth for 1 week, as well as reduced drying of fresh pasta, resulting in acceptable physicochemical quality parameters within 9 days of storage. Lastly, overall migration studies performed with two food simulants demonstrated that the newly developed paper/PBS–PBSA trays are safe since these successfully comply with current legislation on plastic materials and articles intended to come into contact with food.

A paper-based microfluidic detection device for the detection of ethanol is demonstrated in this work. The method is based on a fluorophore consisting of short-chain conjugated molecular unit susceptible to the protonation of its terminal pyridine groups, along with a carboxyl-functionalized sidechain that acts as a binder and renders it water-soluble. The resulting fluorescent paper device yields large fluorescence changes when exposed to reactions that yield H2O2 in aqueous solutions. Using an enzyme-catalyzed rection that produces H2O2 from ethanol, we developed a two-zone, cut-out paper device containing a reaction zone in which the ethanol-containing analyte is placed, and an adjacent sensor zone where we observe a fluorescence color shift proportional to the ethanol concentration. The limit of detection of the fluidic ethanol biosensor was 0.05 v/v% and the dynamic range was 0.05-2 v/v%. This method was employed to detect the alcohol concentration of consumer vodkas using only a paper sensor and a smartphone camera. [ABSTRACT FROM AUTHOR]

Hydrophobic coatings are of utmost importance for many applications of paper-based materials. However, to date, most coating methods demand vast amounts of chemicals and solvents. Frequently, fossil-based coating materials are being used and multiple derivatization reactions are often required to obtain desired performances. In this work, we present a solvent-free paper-coating process, where olive oil as the main biogenic component is being used to obtain a hydrophobic barrier on paper. UV-induced thiol-ene photocrosslinking of olive oil was pursued in a solvent-free state at a wavelength of 254 nm without addition of photoinitiator. Optimum reaction conditions were determined in advance using oleic acid as a model compound. Paper coatings based on olive oil crosslinked by thiol-ene reaction reach water contact angles of up to 120°. By means of Fourier transform infrared spectroscopy and differential scanning calorimetry, a successful reaction and the formation of a polymer network within the coating can be proven. These results show that click-chemistry strategies can be used to achieve hydrophobic polymeric paper coatings while keeping the amount of non-biobased chemicals and reaction steps at a minimum. [ABSTRACT FROM AUTHOR]

BACKGROUND: This study aimed to investigate the outcome of using the human acellular dermal allograft patch compared with the conventional paper patch in traumatic tympanic membrane perforation. METHODS: This was a retrospective study including 41 patients (42 ears) treated with 22 human acellular dermal allografts and 20 paper patches for acute traumatic tympanic membrane perforation from April 2013 to June 2020. The procedure was performed by applying human acellular dermal allograft or paper patches after trimming of perforation margins under local anesthesia. Patient's age, sex, cause, duration, side, location, size of perforation, and the result of healing was analyzed. The audiologic or computed tomography data were also investigated when available. RESULTS: There was no significant difference in sex, age, affected side ratio, size and duration of perforation, recovery confirmation time, and audiogram results between the two groups. There was no significant difference in the size or duration of perforation between the success and failure groups. The human acellular dermal allograft and paper-patch groups showed no significant difference in the recovery confirmation time (70.7 ± 42.3 vs. 89.9 ± 119.4 days, P = .486) and recovery rate (95.5% vs. 85.0%, P = .333). However, the patch maintenance time of the human acellular dermal allograft group was statistically longer than the paper-patch group (32.9 ± 14.9 vs. 15.6 ± 19.9 days, P = .001). On multivariable regression analysis, patch material was the only parameter associated with patch maintenance time (P = .002). CONCLUSION: Treatment outcomes of traumatic tympanic membrane perforation using human acellular dermal allograft showed better or similar therapeutic efficacy compared to paper patch. The important advantage of this material is to stay in situ for a sufficient time without being detached until successful healing. [ABSTRACT FROM AUTHOR]

Improving the strength decrease caused by fungal metabolites is still an arduous task in the field of paper materials protection. A set of damaged Kangxi Dictionary from Qing Dynasty was chosen as samples in this work. The main goal of this work is to develop high-efficiency and eco-friendly media with the characteristics of antifungal and reinforcement, to preserve paper materials and continue the historical and scientific research value of cultural heritage. PHMG as an efficient antifungal was used in this work. For better behavior, the epoxy group of KH560 can be induced by the amino group in PHMG by ring opening reaction to form PHMG-KH560 colloidal complex. Spraying PHMG-KH560 on paper could establish Si-O-C bonding and increased the hydrogen bond between polymeric material and paper fibers, which simultaneously inhibited fungi and improved mechanical strength of the original paper, even after the artificial aging. PHMG-KH560 had certain antifungal activity against five fungi, such as Aspergillus versicolor, and Aspergillus Niger , and had better inhibitory effect on Cladosporium herbarum, Trichoderma viride , and Penicillium expansum. The ancient writing ink on the paper sprayed with PHMG-KH560 did not affect its visual beauty, which also indicated that the complex reagent was expected to be applied to the antifungal and reinforcement of paper materials. [ABSTRACT FROM AUTHOR]

Colored paper is an important industrial paper grade that has applications in various industrial sectors. The increase in coloring efficiency is a key in decreasing the use of dyes, thus can be considered as a "green" process concept; the coloring efficiency depends on the dye retention and dispersion. This work explores the use of nanocellulose, specifically, TEMPO-oxidized cellulose nanofibers (TOCNF), on the coloring efficiency of the preparation of colored paper. Two dyes (i.e. direct blue GL and reactive red 195 (RR195)) were used. Thanks to the large specific surface area and abundant active sites of TOCNF, its use largely improves the direct blue GL retention during the process. The coloring difference (∆E* ab) reached 5.334 with the addition of 13.6 wt% TOCNF and 1.8 wt% direct blue GL in the pulp furnish. The functional group in the dye is a vital factor in determining the dye retention when one chooses TOCNF to enhance the coloring efficiency in the production of colored paper. Furthermore, TOCNF significantly improved the strength properties of both direct blue GL and RR 195 dyed papers. This work demonstrates the potential of nanocellulose in the production of colored paper in improving the coloring efficiency, thus decreasing the environmental impact of the manufacturing process. [Display omitted] • Nanocellulose (i.e. TOCNF) adopted for colored paper preparation • Coloring efficiency improved by TOCNF due to the dye retention improvement • -COO− in TOCNF deteriorating its combination with negatively-charged dye [ABSTRACT FROM AUTHOR]

The prevalence of diabetes has increased over the past years. Therefore, developing minimally invasive, user-friendly, and cost-effective glucose biosensors is necessary especially in low-income and developing countries. Cellulose paper–based analytical devices have attracted the attention of many researchers due to affordability, not requiring trained personnel, and complex equipment. This paper describes a microfluidic paper-based analytical device (μPAD) for detecting glucose concentration in tear range with the naked eye. The paper-based biosensor fabricated by laser CO2; and glucose oxidase/horseradish peroxidase (GOx/HRP) enzyme solution coupled with tetramethylbenzidine (TMB) were utilized as reagents. A sample volume of 10 μl was needed for the biosensor operation and the results were observable within 5 min. The color intensity–based and distance-based results were analyzed by ImageJ and Tracker to evaluate the device performance. Distance-based results showed a linear behavior in 0.1–1.2 mM with an R2 = 0.9962 and limit of detection (LOD) of 0.1 mM. The results could be perceived by the naked eye without needing additional equipment or trained personnel in a relatively short time (3–5 min). [ABSTRACT FROM AUTHOR]

A current challenge regarding microfluidic paper-based analytical devices (µPAD) for blood plasma separation (BPS) and electrochemical immunodetection of protein biomarkers is how to achieve a µPAD that yields enough plasma to retain the biomarker for affinity biosensing in a functionalized electrode system. This paper describes the development of a BPS µPAD to detect and quantify the S100B biomarker from peripheral whole blood. The device uses NaCl functionalized VF2 filter paper as a sample collection pad, an MF1 filter paper for plasma retention, and an optimized microfluidic channel geometry. An inverted light microscope, scanning electron microscope (SEM), and image processing software were used for visualizing BPS efficiency. A design of experiments (DOE) assessed the device's efficacy using an S100B ELISA Kit to measure clinically relevant S100B concentrations in plasma. The BPS device obtained 50 μL of plasma from 300 μL of whole blood after 3.5 min. The statistical correlation of S100B concentrations obtained using plasma from standard centrifugation and the BPS device was 0.98. The BPS device provides a simple manufacturing protocol, short fabrication time, and is capable of S100B detection using ELISA, making one step towards the integration of technologies aimed at low-cost POC testing of clinically relevant biomarkers. [ABSTRACT FROM AUTHOR]

Correctness and reliability of molar mass data by viscometry in organometallic solvents (cuen, cuoxam, cadoxen) are compromised by the alkalinity of these solvents which causes immediate depolymerization especially in the case of pulps with higher carbonyl content (oxidative damage). The viscosity values thus correspond to the molar mass after the beta-elimination reactions that underly these degradative processes, which is sometimes significantly smaller than the molar mass determined by gel permeation chromatography (GPC) in the non-degrading solvent system DMAc/LiCl. Despite this well-known drawback, viscosity measurements have become a standard approach for molar mass measurements due to their ease and fastness, especially in the pulp and paper industries. A potential way to reduce the inherent error of these molar mass determinations via viscosity measurements is a reductive treatment prior to dissolution of the pulp in the organometallic solvents, which converts the labile, alkali-sensitive carbonyl structures back to the respective alcohols. Using sodium borohydride (NaBH4) on different types of cellulosic pulps, we demonstrate the beneficial effects of such a reduction step on the determined degree of polymerization (DP) for all three common solvents: cuen, cuoxam and cadoxen. Molar mass distributions and profiles of carbonyl groups were determined by GPC and by carbonyl selective fluorescence labeling ("CCOA method"). Such a reductive treatment was especially valuable for hemicellulose-containing pulps. While the decreased measurement error according to the new protocol is beyond doubt, an immediate acceptance in the pulp and paper industries is at least questionable, because the new, more correct data would not agree with the old – wrong, but consistent – numbers accumulated over years and decades. In the long run, however, the new, improved protocol will prevail here as well due to its lower error rate. [ABSTRACT FROM AUTHOR]

In order to develop high power lithium ion batteries (LIBs), urgent requirements including adequate safety, higher current density and superior cyclic stability are proposed for separator. Tissue paper, composed of packed cellulose fibers, possesses lower production cost, easier accessibility, superior wettability together with outstanding thermostability, and is thus a candidate to be the substrate for high performance separator. To address the issue of structural failure usually encountered by single polymer as binder during long term cycling, crosslinked binder was constructed on tissue paper to adhere nano-SiO2 through chemical reactions between poly (vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) and hyperbranched polyethyleneimine (PEI) in this work. The effects of crosslinking degree on physical properties and electrochemical performance were studied thoroughly. When the feed ratio of PVDF-HFP and PEI is fixed at 10:1, the crosslinked composite separator displays excellent electrolyte uptake and wettability, superior ionic conductivity, better interfacial compatibility as well as higher Li+ transference number (0.56), thus offering battery with prominent rate capabilities. Besides, this crosslinked composite separator exhibits satisfying dimensional stability even treated at 250 °C, better flame retardancy, enhanced mechanical behavior, wider electrochemical window and outstanding cycle stability. Accordingly, tissue paper-based crosslinked composite separators can meet higher requirements put forward by high power LIBs. [ABSTRACT FROM AUTHOR]

This study applied various scientific analyses to one fragment of paper and three pigments excavated from earthenware found in the Hoeamsa Temple site at Yangju, Korea, which is believed to have been built in the early twelfth century. Radiocarbon dating of the paper fragment suggests a manufacture date between 1460 and 1646 (at a 95% confidence interval). It was estimated to have been used during the early and middle period of the Joseon dynasty (1391–1776), when the Hoeamsa Temple site was rebuilt. In addition, by staining the fiber of the paper fragment with Graff "C" stain, the paper's raw material was identified as paper mulberry through dislocation, cross-marking, and transparent membrane, which are characteristics of the bast fiber. Efforts were made to identify their material properties and manufacturing techniques of the three types of pigments. Color difference analysis was performed by distributing the pigments in large areas to reveal characteristic differences according to the color difference of the pigment. We found that green-type pigments are malachite and atacamite, red-type pigments are hematite based on the element Fe, and white-type pigments are quartz and muscovite based on the elements Si and Al. In addition, as the size distribution of the three types of pigments is wide and has a multi-peak distribution curve, it was concluded that the pigments were used without purification. [ABSTRACT FROM AUTHOR]

Paper, nanocellulose, and other polysaccharide-based materials can be excellent candidates for food packaging barrier layers, except that they tend to be vulnerable to moisture. This article reviews published research describing various chemical treatments having the potential to render hydrophobic character to such layers. Emphasis is placed on systems in which hydrophobic monomers are used to treat either particles or sheets comprised largely of polysaccharides. A goal of this review is to identify combinations of materials and procedures having promise for scale-up to industrial production, while providing effective resistance to moisture. The idea is to protect the underlying polysaccharide-based barrier layers such that they can continue to impede the transfer of such permeants as oxygen, greases, flavor compounds, and water vapor. A further goal is to minimize any adverse environmental impacts associated with the treatments. Based on the research articles considered in this review, promising hydrophobic treatments can be achieved involving silanes, ester formation, other covalent interactions, plasma treatments, and to some extent by various treatments that do not require formation of covalent bonds. The article is designed such that readers can skip ahead to items of particular interest to them. [ABSTRACT FROM AUTHOR]

Aims: The purpose of this study was to evaluate the effects of ambient or altered environmental conditions on the inactivation of SARS‐CoV‐2 applied to materials common in libraries, archives and museums. Methods and Results: Porous and non‐porous materials (e.g. paper, plastic protective book cover) were inoculated with approximately 1 × 105 TCID50 SARS CoV‐2 (USA‐WA1/2020), dried, placed within test chamber in either a stacked or unstacked configuration, and exposed to environmental conditions ranging from 4 to 29°C at 40 ± 10% relative humidity. The amount of infectious SARS‐CoV‐2 was then assessed at various timepoints from 0 to 10 days. Ambient conditions resulted in varying inactivation rates per material type. Virus inactivation rate decreased when materials were stacked or at colder temperatures. Virus inactivation rate increased when materials were unstacked or at warmer temperatures. Conclusions: SARS‐CoV‐2 at ambient conditions resulted in the inactivation of virus below limit of quantitation (LOQ) for all materials by Day 8. Warmer temperatures, for a subset of materials, increased SARS‐CoV‐2 inactivation, and all were

The features of the primary preparation of hemp straw stalks suitable for obtaining cellulosecontaining materials and paper are considered in the article. The primary processes of the preparation of hemp raw materials for pulp production, which include harvesting, storage of straw stalks, transportation, and primary processing of raw materials suitable for obtaining cellulose-containing materials, are described. Methods of shortening stems and fibers applied in the pulping process are studied in detail. Technological methods of shortening straw stalks of technical hemp and cleaning raw materials from grains and garbage impurities are mentioned. The necessity of applying the processes of stalks crushing and wet purification of chopped straw stalks of technical hemp is proved. [ABSTRACT FROM AUTHOR]

Featured Application: An improvement in adhesion (gluing) in the printing production process. In this study, the effect of air plasma on the surface properties of printed and coated cardboard was investigated. The material was activated by low-pressure cold plasma for 1, 10, 20, and 30 s. Wettability changes on the surface were examined by contact angle measurements using the sessile droplet technique. The differences in the surface free energy were calculated using the Lifshitz–van der Waals/acid–base and Contact Angle Hysteresis approaches. Optical profilometry was used for the surface roughness evaluation and an X-ray photoelectron spectroscopy analysis was performed to find changes in surface chemistry. Adhesive strength tests were carried out to estimate the adhesion changes after the material's modification. It was found that the water and formamide contact angles increased after the plasma treatment while the diiodomethane contact angle did not change. As a result of the modification, the surface free energy also increased significantly and the surface roughness increased. The pull-off tests confirmed the improvement in the material's surface properties. Moreover, it was demonstrated that the optimal effect can be obtained after just 10 s of the plasma process. [ABSTRACT FROM AUTHOR]

As a green material, cellulose is widely used in friction triboelectric nanogenerators (TENGs). However, the weak polarity of the cellulose fibers surface leads to its weak contact electrification performance, which is not conducive to its utilization in TENGs. In this study, epoxy chloropropane and ethylenediamine were grafted onto cellulose fibers to form paper and were assembled with an Fluorinated ethylene propylene film. The output voltage, current, and surface charge density were 34.9%, 26.7%, and 16.7% higher than those of ordinary paper, respectively. When 20% nano TiO2 filler was added to the paper made from amino-modified cellulose fibers, the output voltage, current, and surface charge density of the TENG increased by 70.9%, 226.7%, and 122.2%, respectively, compared with ordinary paper. As the air humidity of the TENG increased from 60 to 90%, the output voltage, current, and surface charge density were maintained at 53.7%, 38.9%, and 61.0%, respectively. When a 5 × 107 Ω resistor was connected to the working circuit, its output power reached 13.78 μ W cm2. This showed that cellulose as a green material has wide application prospects in the field of TENG. [ABSTRACT FROM AUTHOR]