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Excessive copper (Cu2+) causes adverse effects on human health and the ecological environment. Traditional methods for detecting Cu2+ have drawbacks such as high detection costs, complex operating conditions, and being time consuming. Therefore, there is an urgent need to develop simple detection methods to better meet specific health and environment quality needs. In this work, a paper-based fluorescence sensor was prepared (herein referred to as the as-prepared method) by immersing filter paper in aqueous polyethyleneimine (PEI) solution, and its potential use in Cu2+ detection was investigated. The results showed that the as-prepared paper samples, with fluorescence properties obtained by aggregation-induced luminescence of PEI, have selective recognition of Cu2+ based on the internal filtration effect, and the lowest detection limit is 0.03 μM. In addition, the relative error of this method is in the range of 1.80~2.23%, which is relatively comparable to the national standard method (0.63~630 μM), demonstrating high accuracy. Therefore, paper-based sensors with a simple preparation method have potential applications in the detection of Cu2+ in water.

Wet-strength paper production is of great significance due to its prominent importance in everyday consumer activities. Production of these paper types is very challenging for the manufacturer since they have to meet very specific demands. Wet-strength paper products include bags that come in contact with moisture and wet products, hygienic and kitchen towels, paper towels, packaging products (packages for liquids, aseptic dishes, and a variety of packaging for food), and other special purposes items (teabags, coffee filters, paper money, etc.) Throughout this research, the focus was on the effects a wet strength agent has on the tensile strength of paper. The wet strength property of paper is the ratio between the strength of paper in the wet and dry state. The strength in the dry state comes from the hydrogen bonds present in natural cellulose, while the strength of paper in the wet state requires waterproof (covalent) bonds created by the use of a wet strength agent. The wet strength agent used is a cationic PAE resin. The aim of the work is to determine the optimal amount of agent needed in relation to the required value of the tensile strength property of the paper. The investigation of these influences was carried out on Semi Extensible Standard Kraft type of paper in Natron-Hayat.

In recent years, due to environmental awareness regarding the harmfulness of polymeric materials, there has been a growing interest in using papers, especially those from alternative raw materials. The importance of using all available raw materials is imperative today. Raw materials that were once viewed as waste are now of great importance because they have the ability to replace raw materials that are used irrationally or are lacking. Cereal straw is a lignocellulosic material that could be used in the paper industry and in the production of increasingly prevalent paper packaging. The aim of this research was to analyze the relationships between the qualitative parameters of straw-based printed papers containing 30% agricultural residues (wheat, barley, or triticale). The influence of two qualitative parameters (ink penetration depth and optical ink density) on the print-through was observed using multiple regression analysis on straw-based papers produced at the laboratory level. Throughout the research, 100% recycled wood paper was used as a reference sample. The results of the regression analysis showed that none of the variables individually make a statistically significant contribution to the prediction of the dependent variable in a linear context, that is, they indicate a non-linear interaction between the variables and the specific conditions under which the dependent variable reaches local extremes and changes in the gradient. Considering the results of the regression analysis and the visualization of the relationship, the model was additionally tested with other independent variables (paper type). From the results obtained, it can be concluded that the alternative straw-based paper with 30% barley pulp has the best interaction between ink and paper, which is the most similar to the reference sample in terms of printability, while the alternative straw-based paper with 30% wheat generally differs significantly from the reference paper when all three prints are considered.

This article traces the history of the relationship of papermaking and paper to libraries over time. Paper was first made in China and is traditionally considered one of that nation's four greatest inventions, along with gun powder, printing, and the compass. Papermaking was often associated with archives in its early development in China, as well as when it was introduced to Japan, where it came to be a part of some Shinto and Buddhist temples, and later governmental agencies. Under Islam, the availability of paper was linked to increased literacy and growth of libraries. In early modern Europe, before the widespread use of wood in the papermaking process, libraries and archives were part of an "economy of paper" with paper at times being in short supply. In the modern era, the world of papermaking did not intersect much with the world of the library, which made progress with the problem of brittle books, one of its greatest challenges, slow, though recent efforts of government, industry, scientists, and representatives of the library have produced positive results. The damage caused by wood-based paper in libraries was mirrored by the environmental damage caused by wood-based papermaking in communities. The history of papermaking and libraries demonstrates the importance of understanding the technologies which support the library, while also advocating effectively to the representatives of all its sources of support in ways which promote the values of the library and its associated community. [ABSTRACT FROM AUTHOR]

The coefficient of friction for different contacting materials against skin is mainly influenced by the nature of the materials (synthetic and natural fabrics), mechanical contact parameters (interfacial pressure and sliding velocities), and physiological skin conditions (ambient humidity and skin moisture content). In the present research work, seven different types of papers used in everyday life were analyzed. The physical properties of these materials were determined through tensile tests and friction tests. By comparing mechanical properties with coefficient of friction, it was possible to conclude that the coefficient of friction is strongly correlated with the mechanical properties.

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.

This work reports on the development and performance evaluation of newly developed paper sheets coated, on both sides, with thin films of biodegradable poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) for applications of food packaging. For this, PHBV/paper/PHBV multilayers were first prepared by the thermo-sealing technique, optimizing the process variables of temperature and time. Thereafter, the multilayer sheets were characterized in terms of their morphological, optical, thermal, mechanical, and barrier properties and compared with equivalent paper structures double coated with high-barrier multilayer films of petrochemical polymers. The results indicated that the double coatings of PHBV successfully improved the mechanical resistance and ductility, protected from moisture, and also reduced the aroma and oxygen permeances of paper, having a minimal effect on its optical and thermal properties. Finally, the compostability of the resultant multilayer sheets was analyzed, confirming that the presence of the PHBV coatings slightly delayed the aerobic biodegradation and disintegration of paper.

All-lignin coating formulations were prepared while combining water-soluble cationic kraft lignin (quaternized LignoBoost®, CL) and anionic lignosulphonate (LS). The electrostatic attraction between positively charged CL and negatively charged LS led to the formation of insoluble self-organized macromolecule aggregates that align to films. The structures of the formed layers were evaluated by atomic force microscopy (AFM), firstly on glass lamina using dip-coating deposition and then on handsheets and industrial uncoated paper using roll-to-roll coating in a layer-by-layer mode. Coated samples were also characterized by optical microscopy, scanning electron microscopy (SEM) coupled with energy dispersive spectroscopy (SEM/EDS), and contact angle measurements. It was suggested that the structure of all-lignin aggregates is the result of the interaction of amphiphilic water-soluble lignin molecules leading to their specifically ordered mutual arrangement depending on the order and the mode of their application on the surface. The all-lignin coating of cellulosic fiber imparts lower air permeability and lower free surface energy to paper, mainly due to a decrease in surface polarity, thus promoting the paper’s hydrophobic properties. Moderate loading of lignin coating formulations (5–6 g m−2) did not affect the mechanical strength of the paper.

Most power transformers are oil-immersed transformers for which its insulation system consists of oil and cellulosic solid. The insulation liquid impregnates the solid-covering air spaces, which improves the efficiency of the insulation system. Not only does the oil ensure electrical insulation but it also works as coolants transferring the heat generated during transformer operation to the exterior of the transformer. Throughout normal operation conditions, transformers experience multiple stresses that degrade their insulation. Since the lifetime of oil-immersed transformers is defined mainly by the state of the insulation paper, it is critical to understand the behavior and degradation mechanisms of new insulation systems that try to overcome the drawbacks of mineral oil as well as to improve power transformer performances. The current increased prevalence of the nonlinear loads additionally stresses power transformers, which generates their premature ageing or even failure. Consequently, new materials and assessment methods are required to guarantee the suitable management of power transformer populations. In this Special Issue “Experimental and Numerical Analysis of Thermal Ageing in Power Transformers”, four papers have been published. The guest editor also describes briefly some challenges involved beyond the coverage of this Special Issue.

We developed a surfactant-free spray coating process to coat commercial cellulose-based paper with carbon nanotubes (CNTs) and prepared paper-CNTs current collectors for Li-ion batteries (LIBs). The paper-CNTs were used as current collectors for replacing conventional aluminum foil. Li-ion batteries assembled using paper-CNTs were coated with LiFePO4 as the active material and used as cathodes with Li as the anode, and the assembled LIBs showed a high energy density of 460 Wh kg−1 at a power density of 250 W kg−1. These electrodes were stable even at a current density as high as 600 mA g−1, and showed cycling stability for ~450 cycles at 150 mAh g−1. Furthermore, paper-CNTs based electrodes showed ~17% improvement in areal capacity compared to commercial aluminum-based electrodes suggesting that paper-CNTs can readily displace Al foils as current collectors.

The purpose of this work is the study of laser cleaning of historical paper. The effect of laser exposure of the paper reflectance, fracture resistance and acidity was investigated. The paper surface roughness before and after laser treatment was analyzed by optical and scanning electron microscopy. It was shown that use of multi-pulse micromachining in combination with high-speed scanning of laser beams provides high safety for paper cleaning. The optimal parameters of laser radiation for effective and safe cleaning are a power density of about 2 × 105 W/cm2 at a wavelength of 1.06 μm, pulse repetition rate is 20 kHz; and a beam scanning speed of 200 mm/s–500 mm/s. The selective laser cleaning method for books and documents was proposed. Selective cleaning is achieved by means of high-precision control of the trajectory of movement of laser beams.

In this paper, the implementation of artificial neural networks (multilayer perceptron [MLP] and radial base functions [RBF]) and the upgraded Markov chain model have been studied and performed to identify the human behavior patterns during rock, paper, and scissors game. The main motivation of this research is the design and construction of an intelligent robot with the ability to defeat a human opponent. MATLAB software has been used to implement intelligent algorithms. After implementing the algorithms, their effectiveness in detecting human behavior pattern has been investigated. To ensure the ideal performance of the implemented model, each player played with the desired algorithms in three different stages. The results showed that the percentage of winning computer with MLP and RBF neural networks and upgraded Markov model, on average in men and women is 59%, 76.66%, and 75%, respectively. Obtained results clearly indicate a very good performance of the RBF neural network and the upgraded Markov model in the mental modeling of the human opponent in the game of rock, paper, and scissors. In the end, the designed game has been employed in both hardware and software which include the Zana intelligent robot and a digital version with a graphical user interface design on the stand. To the best knowledge of the authors, the precision of novel presented method for determining human behavior patterns was the highest precision among all of the previous studies.

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.

Thailand has an increasing demand for housing and infrastructure. This leads to increased amounts of construction and demolition (C&D) wastes. Most of the C&D wastes are reusable and recyclable. However, without proper waste management these wastes are mostly dumped into landfills without being sorted. This study utilizes a system dynamics (SD) approach to examine the feasibility of the reverse logistics implementation in C&D waste management in the long term. The focus material is paper waste, as it is one of the major wastes that can be recycled and remanufactured. The dynamic model consists of three reverse logistics options, including landfill, recycled, and remanufactured options. Costs involved in the implementation are labor, transportation, landfilling, recycling, and remanufacturing costs. Benefits, on the other hand, include sales of recycled and remanufactured products, energy savings, and green image savings. The simulation results reveal that the reverse logistics program should be implemented for at least three years to achieve positive net profit. The implementation should also be continued until the end of year 9 to be worth the investment, with the internal rate of return exceeding 12%.It is also suggested that the recycling and remanufacturing options should be promoted in long term in order to save landfill space and promote green image of the industry

An important step in the conservation of old paper documents is the analysis of both the medium and the ink, in an attempt first to determine the extent of deterioration and degradation and then to choose the best preservation and restoration solutions. Our paper focuses on the analysis of three old documents displayed at the ‘Poni-Cernătescu’ Museum in Iaşi City, Romania by optical microscopy (OM), scanning electron microscopy and energy dispersive X-ray spectroscopy (SEM-EDX), micro-FTIR spectroscopy and FT-Raman. Thus, the morphology and chemical composition of the paper media and the type of ink, as well as the cellulose crystallinity index were determined. PCA (Principal Component Analysis) was also used while relying on spectra collected by FTIR spectroscopy. We were able to determine the extent of degradation of the documents by corroborating all these findings.

Surface hydrophobicity and grease resistance of paper may be achieved by the application of coatings usually derived from fossil-oil resources. However, poor recyclability and environmental concerns on generated waste has increased interest in the study of alternative paper coatings. This work focuses on the study of the performances offered by two different biopolymers, poly(3-hydroxybutyrate-co-3hydroxyvalerate) (PHBV) and polycaprolactone (PCL), also assessing the effect of a plasticizer (PEG) when used as paper coatings. The coated samples were characterized for the structural (by scanning electron microscopy, SEM), diffusive (water vapor and grease barrier properties), and surface properties (affinity for water and oil, by contact angle measurements). Samples of polyethylene-coated and fluorinated paper were used as commercial reference. WVTR of coated samples generally decreased and PHBV and PCL coatings with PEG at 20% showed interesting low wettability, as inferred from the water contact angles. Samples coated with PCL also showed increased grease resistance in comparison with plain paper. This work, within the limits of its lab-scale, offers interesting insights for future research lines toward the development of cellulose-based food contact materials that are fully recyclable and compostable.

This work reports a modification of a fibrous cellulose material (paper) by the addition of polyacrylonitrile (PAN) fibres doped with 10,12–pentacosadiynoic acid (PDA). The fibres are sensitive to ultraviolet (UV) light. When the paper containing PAN–PDA is irradiated with UV light it changes colour to blue as a consequence of interaction of the light with PDA. The colour intensity is related to the absorbed dose, content of PAN–PDA fibres in the paper and the wavelength of UV radiation. The features of the paper are summarised after reflectance spectrophotometry and scanning microscopy analyses. All the properties of the modified paper were tested in accordance with adequate ISO standards. Moreover, a unique method for assessing the unevenness of the paper surface and the quality of printing was proposed by using a Python script (RGBreader) for the analysis of RGB colour channels. The modification applied to the paper can serve as a paper security system. The modified paper can act also as a UV radiation indicator.

Currently, there is an increasing interest in the use of biopolymers in industrial applications to replace petroleum-based additives, since they are abundantly available, renewable and sustainable. Cottonseed protein is a biopolymer that, when used as a modifier, has shown improved performance for wood adhesives and paper products. Thus, it would be useful to explore the feasibility of using cellulose nanomaterials to further improve the performance of cottonseed protein as a paper strength agent. This research characterized the performance of cottonseed protein isolate with/without cellulose nanofibers (CNFs) and cellulose nanocrystals (CNCs) to increase the dry strength of filter paper. An application of 10% protein solution with CNCs (10:1) or CNFs (50:1) improved the elongation at break, tensile strength and modulus of treated paper products compared to the improved performance of cottonseed protein alone. Further analysis using scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) indicated that the cottonseed protein/nanocellulose composites interacted with the filter paper fibers, imparting an increased dry strength.

This study examines the possibility of using paper based on lint cellulose with addition of licorice cellulose for printing. The physical, mechanical and printing characteristics of paper, were studied towards this end. The addition of licorice cellulose components into the lint cellulose composition changed the surface nature and paper structure, which are defining phenomena of humidification, adsorption, adhesion, ink penetration and swelling. A reduction of paper sponginess by 15% increases the resolution capability - smoothness. This stimulates the provision of image high legibility. According to the research of the results of paper whiteness and opacity which define paper printing properties, it is possible to conclude that the research paper is fit for printing of single-color outputs. The use of licorice cellulose in cellulose-paper industry will solve the problem concerning not only raw materials but the ecology at the same time due to utilization of licorice root waste and use of hydrogen peroxide instead of carcinogenic sodium hypochlorite.

The debate on the environmental effects of everyday packaging materials has long reached the scientific community. The quest is on to design cheap but also sustainable and eco-friendly packaging solutions. A hot contestant material within the application is the ever-present wood-based paper. In addition to meeting logistic requirements, paper packaging must protect the packaged goods from environmental influences, while keeping aroma molecules in the food. To quantify both aspects in depth, exploration of adsorption of organic molecules on paper is required. As paper is a rather complex material, adsorption and desorption experiments can be notoriously difficult to interpret. This paper will demonstrate that the adsorption of organic molecules on a cellulose surface can be investigated simply by using temperature programmed desorption (TPD) experiments. The experiments show that both non-polar and polar molecules (n-decane and deuterated methanol) readily adsorb onto cellulose films. During desorption one finds the polar molecule bound to the cellulose surface more heavily than the non-polar molecule.

The article analyzes the separation of fats from paper waste packaging. The method is based on interaction with boiling water and greaseproof paper. The cooking process is considered the formation of emulsions according to different slots. The research data are presented and discussed obtained from the analysis of ready-made samples. 20 different fat-coated paper samples have been prapared for research. Ten of them have been selected for printing paper, and another dozen cartons. The half of the samples analyzed are covered with vegetable fat, the remaining samples are vegetable fat. It was found that the carton samples were less opposed to the separation of fat. During the experiment, it was determined that by cooking the cardboard samples coated with olive oil for 5 minutes, 30% of the total fat content was removed. The most effective samples of this type were heated for a long time. Santrauka Straipsnyje nagrinėjamas riebalų atskyrimas nuo popieriaus pakuočių atliekų. Metodas remiasi verdančio vandens ir riebalų sąveika su suterštu popieriumi. Nagrinėjamas virimo procesas, emulsijų susidarymas atsižvelgiant į skirtingus laiko tarpsnius. Pateikiami ir aptariami tyrimų duomenys, kurie gauti išnagrinėjus pasiruoštus mėginius. Iš viso pasiruošta 20 skirtingų riebalais padengto popieriaus pavyzdžių. Dešimčiai iš jų pasirinktas spausdinimo popierius, kita dešimtis – kartonas. Pusė analizuojamų mėginių padengti augalinių riebalų sluoksniu, likę mėginiai – gyvulinių riebalų sluoksniu. Pastebėta, kad kartono mėginiai mažiau priešinosi riebalų atskyrimui. Nustatyta, kad, 5 min. virinant kartono mėginius, padengtus alyvuogių aliejumi, pasišalino 30 % viso riebalų kiekio. Efektyviausia tokio tipo mėginius virti ilgą laiką, nes, panardinus mėginius 15 min. į verdantį vandenį, pasišalino daugiau nei pusė buvusių riebalų kiekio – 55 %. Reikšminiai žodžiai: atliekos, emulsija, popierius, popieriaus pakuotės, riebalai, šiluma, vanduo, virimas.

The study on reading habits among higher secondary school students is a paper thought to access the use of library service and reading habits of higher secondary school students the findings from the table are differentiated into various categories and the table shows that the most of the students are very much enjoyable in reading books with fervor. therefore the study concluded that the reading habits of secondary school students should be given rapt attention because of the imminent danger of losing reading habits in the era of information & communication technology. the study recommends that there must be a fixed time for reading a variety of reading material that will appeal to students and that adopting different methods to arouse the interest of students could enhance their reading habit. [ABSTRACT FROM AUTHOR]

One of the main problems faced by libraries, archives and collectors is the mold degradation of the paper-based documents, books, artworks etc. Microfungi (molds) emerge in regular storage conditions of such items (humidity, usually over 50%, and temperatures under 21 °C). If the removal of the visible mycelium is relatively easy, there is always the problem of the subsequent appearance of mold as the spores remain trapped in the cellulosic, fibrillary texture, which acts as a net. Moreover, due to improper hand hygiene bacteria contamination, old books could represent a source of biohazard, being colonized with human pathogens. An easy and accessible method of decontamination, which could offer long term protection is therefore needed. Here, we present a facile use of the ZnO nanopowders as antimicrobial agents, suitable for cellulose-based products, conferring an extended antibacterial and anti-microfungal effect. The proposed method does not adversely impact on the quality of the cellulose documents and could be efficiently used for biodegradation protection.

We examined changes in the number of authors per paper for science and technology papers (agricultural sciences, engineering and technologies, medical sciences, and natural sciences) in Korea. We employed the Scopus database to examine the change in the number of authors in papers, which were published from 2000 to 2015 in the 234 Korean academic journals indexed on Scopus. We found that the global trend of growth in the number of authors per paper is evident in Korea as well. While there was little evidence of a correlation with the citation per paper, a positive correlation was found between with the field-weighted citation impact, another measure of a paper’s impact, in medical and natural science papers. In terms of the type of collaboration, we found that international collaboration papers had the highest number of authors, followed by national and institutional collaborations. The number of authors per paper was highest for those published in the top 10% journals by Source Normalized Impact per Paper, followed by Scopus-indexed journals, while papers published in Korea Citation Index had the lowest number of authors per paper. We propose that the rise in the number of authors per paper in Korean papers may be ascribed to many Korean research programs encouraging group research and the widespread availability of the internet, which has stimulated joint research efforts and encouraged international collaboration.

A key challenge in prevention of global warming is how to increase energy efficiency, to be able to deal with increased fossil CO2 emissions from rising energy usage. Increasing energy efficiency will decrease energy usage and is in a key role in emission mitigation. The focus is the pulp and paper industry, which is energy-intensive. Development of industrial energy efficiency has been studied before but the role of industrial transformation is still mostly unknown. The knowledge must be improved, to be able to predict future developments in the most effective way. In this research, impact of various production unit closures and start-ups on energy efficiency of the Finnish pulp and paper industry were studied utilizing statistical analysis. Results indicate that about 20% of the Finnish pulp and paper industry energy efficiency improvement between 2011 and 2017 is caused by the major structural changes. The rest, 80% of the progress, was mainly due to improved technology and more optimal operational modes. Additional findings suggest that modern mill start-ups have a significantly greater potential to reduce energy consumption than old mill closures.

Managing a large fleet of ageing assets has become a technical challenge faced by many electricity utilities in developed countries. Asset managers are increasingly interested in techniques that can help extend the useful lifetime of a transformer. Oil regeneration is one of such techniques. In this paper, oil regeneration experiments were performed on a 6.4/0.4 kV retired distribution transformer to investigate the effect of oil regeneration on improving paper conditions. Oil regeneration was conducted in two stages, with the first stage aimed at ‘cleaning the oil’ and the second stage targeted at ‘cleaning the paper’. Oil samples were collected at regular intervals throughout the process and paper samples were obtained from the transformer before and after each oil regeneration stage. It was found that oil regeneration restores oil parameters, including moisture and acidity, similar to those of new oils at the end of stage 1. Analysis of paper samples indicated a reduction in paper moisture at the end of stage 2 by nearly 40%, while low molecular weight acids (LMA) in paper exhibited a reduction by around 30% on average. It is found that the extended oil regeneration period, i.e., stage 2, is necessary to improve the paper condition and hence to reduce the paper ageing rate.

The goal of this study was to analyze the effects of cellulose fibers loading by precipitation in-situ of calcium carbonate over the properties of printing paper obtained from mixtures of the softwood and hardwood fibers. The effects of fibers with in-situ loading were analyzed comparatively with conventional paper loading respectively, by adding precipitated calcium carbonate into fiber stock. The effectiveness of the methods was evaluated by various analyses and investigations: calcium carbonate content, Scanning electron microscope (SEM) images, X-ray diffraction, optical and mechanical properties of the paper sheets. The evaluation of the effects on paper properties led to the conclusion that, at the same filler content, the in-situ loading method gives higher opacity and brightness than conventional methods. The utilization of cellulose fibers with in-situ loading as additive, shown as a modification of the ratio between fibers with in-situ loading and fibers without loading, regardless of whether they are softwood or hardwood fibers, allowed us to optimize printing paper properties, especially regarding the relationship between optical and strength properties.

Paper and prints on it are analyzed as composite materials. Printing, varnishing and lamination are described in terms of the formation of the composite material. The article discusses why and how the properties of a print should differ from the properties of paper.Article in Lithuanian

Paper with antimicrobial properties was developed through in situ growth of ZnO nanorods. The targeted application for this type of paper is in health centers as wallpaper, writing paper, facemasks, tissue paper, etc. The paper was tested on three model microbes, Gram-positive bacteria Staphylococcus aureus, Gram-negative bacteria Escherichia coli and common airborne fungus Aspergillus niger. No viable bacterial colonies or fungal spores could be detected in the areas surrounding test samples of the antimicrobial paper. Gram-negative bacteria Escherichia coli were found to be inhibited in an area that is 239% and 163% the area of the paper sample under different room lighting conditions, i.e., halogen and fluorescent lamp illumination, respectively. For Gram-positive bacteria Staphylococcus aureus the zones of inhibition surrounding the paper samples are 102% and 70%, and for Aspergillus niger, 224% and 183% of the sample area, under similar lighting conditions.

The development of all-bio-based composites is one of the relevant aspects of pursuing a carbon-neutral economy. This study aims to explore the possibility to reinforce polylactic acid by the combination of cellulose and chitin nanofibers instead of a single reinforcement phase. Polylactic acid colloidal suspension, cellulose and chitin nanofiber suspensions were mixed using only water as mixing medium and subsequently dewatered to form paper-like sheets. Sheets were hot pressed to melt the polylactic acid and form nanocomposites. The combination of cellulose and chitin nanofiber composites delivered higher tensile properties than its counterparts reinforced with cellulose or chitin nanofibers alone. Cellulose and chitin appear to complement each other from the aspect of the formation of a rigid cellulose nanofiber percolated network, and chitin acting as a compatibilizer between hydrophobic polylactic acid and hydrophilic cellulose.

It is becoming increasingly more important to provide a low-cost point-of-care diagnostic device with the ability to detect and monitor various biological and chemical compounds. Traditional laboratories can be time-consuming and very costly. Through the combination of well-established materials and fabrication methods, it is possible to produce devices that meet the needs of many patients, healthcare and medical professionals, and environmental specialists. Existing research has demonstrated that inkjet-printed and paper-based electrochemical sensors are suitable for this application due to advantages provided by the carefully selected materials and fabrication method. Inkjet printing provides a low cost fabrication method with incredible control over the material deposition process, while paper-based substrates enable pump-free microfluidic devices due to their natural wicking ability. Furthermore, electrochemical sensing is incredibly selective and provides accurate and repeatable quantitative results without expensive measurement equipment. By merging each of these favorable techniques and materials and continuing to innovate, the production of low-cost point-of-care sensors is certainly within reach.

In this work, we present a systematic study on solid Surface Enhanced Raman Scattering (SERS) substrates consisting of Au and Ag nanoparticles (NPs) loaded on filter paper with the dip-coating method. The aim of this work is to explore how a series of parameters (e.g., concentration of colloidal solution, different porosity of filter paper, and the presence of an aggregating agent) affects the analytical performance of paper-based SERS substrates. All the substrates developed in this study have been analyzed with two non-resonant probe molecules, 4-mercaptobenzoic acid (4-MBA) and adenine, in terms of (i) inter-sample repeatability, (ii) intra-sample repeatability, (iii) sensitivity, and (iv) overall SERS performance in terms of analyte quantification. Moreover, the issue of how to evaluate the repeatability for a solid SERS substrate is carefully discussed.

The article experimentally investigates the properties of offset print friction and determines static and kinetic coeffi­cients of friction. Conventional and UV inks have been found to increase the static friction coefficient and re­duce the kinetic friction coefficient between paper and print. The roughness pro­perties of two different types of paper and prints using conventional and UV inks have been examined and compared thus determining that conventional inks strongly increase the roughness of print surface and that the influence of UV inks depend on the type of paper. Santrauka Nagrinėjamos popieriaus ofsetinių atspaudų trinties savybės ir nustatyti statinis bei kinetinis trinties koeficientai. Nustatyta, kad įprastiniai ir UV dažai didina atspaudo į popierių statitinio trinties koeficiento dydį ir mažina kinetinio koeficiento dydį. Atliktas dviejų rūšių popieriaus su įprastais ir UV dažais šiurkštumo palyginamasis tyrimas ir nustatyta, kad įprasti dažai atspaudų paviršiaus šiukštumą stipriai didina, o UV dažų poveikis priklauso nuo popieriaus rūšies. Reikšminiai žodžiai: atspaudai; įprasti dažai; popierius; šiurkštumas; trintis; UV dažai.

The hydrolysis-condensation of trialkoxysilanes under strictly controlled conditions allows the production of silsesquioxanes (SSQs) with tunable size and architecture ranging from ladder to cage-like structures. These nano-objects can serve as building blocks for the preparation of hybrid organic/inorganic materials with selected properties. The SSQs growth can be tuned by simply controlling the reaction duration in the in situ water production route (ISWP), where the kinetics of the esterification reaction between carboxylic acids and alcohols rules out the extent of organosilane hydrolysis-condensation. Tunable SSQs with thiol functionalities (SH-NBBs) are suitable for further modification by exploiting the simple thiol-ene click reaction, thus allowing for modifying the wettability properties of derived coatings. In this paper, coatings were prepared from SH-NBBs with different architecture onto cotton fabrics and paper, and further functionalized with long alkyl chains by means of initiator-free UV-induced thiol-ene coupling with 1-decene (C10) and 1-tetradecene (C14). The coatings appeared to homogeneously cover the natural fibers and imparted a multi-scale roughness that was not affected by the click functionalization step. The two-step functionalization of cotton and paper warrants a stable highly hydrophobic character to the surface of natural materials that, in perspective, suggests a possible application in filtration devices for oil-water separation. Furthermore, the purification of SH-NBBs from ISWP by-products was possible during the coating process, and this step allowed for the fast, initiator-free, click-coupling of purified NBBs with C10 and C14 in solution with a nearly quantitative yield. Therefore, this approach is an alternative route to get sol-gel-derived, ladder-like, and cage-like SSQs functionalized with long alkyl chains.

Flexible poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate)/polypyrrole/paper (PEDOT:PSS/PPy/paper) thermoelectric (TE) nanocomposite films were prepared by a two-step method: first, PPy/paper nanocomposite films were prepared by an in situ chemical polymerization process, and second, PEDOT:PSS/PPy/paper TE composite films were fabricated by coating the as-prepared PPy/paper nanocomposite films using a dimethyl sulfoxide-doped PEDOT:PSS solution. Both the electrical conductivity and the Seebeck coefficient of the PEDOT:PSS/PPy/paper TE nanocomposite films were greatly enhanced from 0.06 S/cm to ~0.365 S/cm, and from 5.44 μV/K to ~16.0 μV/K at ~300 K, respectively, when compared to the PPy/paper TE nanocomposite films. The thermal conductivity of the PEDOT:PSS/PPy/paper composite film (0.1522 Wm−1K−1 at ~300 K) was, however, only slightly higher than that of the PPy/paper composite film (0.1142 Wm−1K−1 at ~300 K). As a result, the ZT value of the PEDOT:PSS/PPy/paper composite film (~1.85 × 10−5 at ~300 K) was significantly enhanced when compared to that of the PPy/paper composite film (~4.73 × 10−7 at ~300 K). The as-prepared nanocomposite films have great potential for application in flexible TE devices.

In the paper the folding quality in the printing house “BALTO”is investigated. The concept of quality, paper folding process,combined folding machine parameters and printing papers aredescribed. In the paper the percent of folding defects is determined,the spoilage dependence on paper characteristics, foldingmachine settings and other factors are investigated. Resultswere presented as histograms and were analyzed using statisticalmethods. Santrauka Surinkta statistinė informacija apie UAB BALTO spaustuvėje lankstymo metu padaromą brokuotą produkciją. Stebėjimai atlikti dirbant su skirtingomis popieriaus rūšimis ir popieriaus gramatūromis. Gauti rezultatai buvo pateikti histogramomis, kurios analizuojamos pasitelkiant statistinius metodus. Vertinant rezultatus, papildomai buvo sudaryta statistinių skirstinių lentelė. Nustatyta, kurios popieriaus rūšys ir gramatūros lankstomos kokybiškiau ir kokios popieriaus charakteristikos tai lemia. Reikšminiai žodžiai: popierius, popieriaus charakteristikos, lankstymas, brokas.

Paper and prints on it are analyzed as composite materials. Printing, varnishing and lamination are described in terms of the formation of the composite material. The article discusses why and how the properties of a print should differ from the properties of paper. Santrauka Popierius ir atspaudai analizuojami kaip kompozicinės medžiagos. Aprašomas atspaudų spausdinimas kaip kompozicinės medžiagos susidarymo procesas spausdinant, lakuojant ir laminuojant. Aptariama, kodėl ir kaip turėtų keistis atspaudo savybės, lyginant su popieriumi. Raktiniai žodžiai: kompozicinė medžiaga; popierius; popieriaus fizikinės savybės

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In this article the author discusses the rules for writing a case study paper. The author states that case study papers offers documentation of the investigation, analysis, and/or performance of a geotechnical project and it present information that will advance geotechnical and geoenvironmental engineering practice.