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Publisher Copyright: © 2022, The Author(s). 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.

In this work, we present for the first time, a simplified fabrication of a laminated paper-based analytical device (LPAD) with a free-mobile app, Palette Cam, for image analysis. A filter paper is cut in a rectangular shape (9 × 3 cm) and placed between a top laminating sheet with punched holes and a bottom laminating sheet. The holes allow accessibility of liquid on the paper. Thermal lamination is then employed to complete the fabrication of LPAD. Our simplified design reduces a tedious alignment of small pieces of paper to the holes. We demonstrated the LPAD with an analysis of salicylic acid in pharmaceutical products. Each 4 μL of ferric reagent and sample was dispensed on the LPAD. Smartphone was used to capture images. The RGB (red green blue) color intensity from the Palette Cam was converted into a logarithm color ratio. Our LPAD is simplified, cost-effective and able to be a portable device.

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 for the detection of glucose in tear with the naked eye. The paper-based biosensor fabricated by laser CO2, and GOx/HRP enzymatic solution coupled with TMB was utilized as reagents. A sample volume of 10 µl was needed for the biosensor operation and the results were observable within 5 minutes. To evaluate the device performance, color intensity-based and distance-based results were analyzed by ImageJ and Tracker. Distance-based results showed a linear behavior in the range of 0.1–0.6 mM with an R2 = 0.967 and LOD of 0.2 mM. The results could be perceived by the naked eye without any need to further equipment or trained personnel in a relatively short time (3–5 minutes). Moreover, glucose concentration could be obtained non-invasively by tears collected by this µPAD.

Is it really better to print everything, including software models, or is it better to view them on screen? With the ever increasing complexity of software systems, software modeling is integral to software development. Software models facilitate and automate many activities during development, such as code and test case generation. However, a core goal of software modeling is to communicate and collaborate. Software models are presented to team members on many mediums and two of the most common mediums are paper and computer screens. Reading from paper or screen is ostensibly considered to have the same effect on model comprehension. However, the literature on text reading has indicated that the reading experiences can be very different which in turn effects various metrics related to reader performance. This paper reports on an experiment that was conducted to investigate the effect of reading software models on paper in comparison with reading them on a computer screen with respect to cognitive effectiveness. Cognitive effectiveness here refers to the ease by which a model reader can read a model. The experiment used a total of 74 software engineering students as subjects. The experiment results provide strong evidence that displaying diagrams on a screen allows subjects to read them quicker. There is also evidence that indicates that on screen viewing induces fewer reading errors.

Funding Information: Open access funding provided by FCT|FCCN (b-on). This work was financed by national funds from Fundação para a Ciência e a Tecnologia (FCT), I.P., in the scope of the projects LA/P/0037/2020, UIDP/50025/2020, and UIDB/50025/2020 of the Associate Laboratory Institute of Nanostructures, Nanomodelling and Nanofabrication–i3N and by FEDER funds through the COMPETE 2020 Program and National Funds through Portuguese Foundation for Science and Technology under projects POCI-01–0145-FEDER-007688, UID/CTM/50025 and by ERC AdG grant from the project DIGISMART (ERC-AdG-2017, GA 787410). J.C. would like to acknowledge FCT/MCTES for his present research contract with reference CEECIND/00880/2018. R.C. acknowledges funding from i3N-FCT I.P. through the PhD Grant UI/BD/151295/2021. S. S. and T. P. also acknowledge the funding from National Foundation for Science and Technology, through the PhD Grants SFRH/BD/149751/2019 and 2020.08606.BD, respectively. Publisher Copyright: © 2022, The Author(s). Laser-induced graphene (LIG) is as a promising material for flexible microsupercapacitors (MSCs) due to its simple and cost-effective processing. However, LIG-MSC research and production has been centered on non-sustainable polymeric substrates, such as polyimide. In this work, it is presented a cost-effective, reproducible, and robust approach for the preparation of LIG structures via a one-step laser direct writing on chromatography paper. The developed strategy relies on soaking the paper in a 0.1 M sodium tetraborate solution (borax) prior to the laser processing. Borax acts as a fire-retardant agent, thus allowing the laser processing of sensitive substrates that other way would be easily destroyed under the high-energy beam. LIG on paper exhibiting low sheet resistance (30 Ω sq−1) and improved electrode/electrolyte interface was obtained by the proposed method. When used as microsupercapacitor electrodes, this laser-induced graphene resulted in specific capacitances of 4.6 mF cm−2 (0.015 mA cm−2). Furthermore, the devices exhibit excellent cycling stability (> 10,000 cycles at 0.5 mA cm−2) and good mechanical properties. By connecting the devices in series and parallel, it was also possible to control the voltage and energy delivered by the system. Thus, paper-based LIG-MSC can be used as energy storage devices for flexible, low-cost, and portable electronics. Additionally, due to their flexible design and architecture, they can be easily adapted to other circuits and applications with different power requirements. Graphical Abstract: [Figure not available: see fulltext.] publishersversion published

The membraneless-gas separation microfluidic paper-based analytical device (ML-GS μPAD), consisting of donor, spacer, and acceptor layers, was developed to monitor total ammonia in fish pond water. The principle of the analysis involved the addition of sodium hydroxide solution to the sample zone in the donor layer containing ammonia/ammonium, and the produced ammonia gas diffuses through the spacer to the detection zone in the acceptor layer containing red rose extract to produce a color change from pink to blue corresponding to the ammonia/ammonium concentration. Under optimum conditions, the proposed method provided good linearity of ammonia in the range concentration of 0-100 mg L

The existence of pesticide residues in the hydrosphere, biosphere, and anthroposphere can cause acute or chronic diseases and deteriorate the environment. Therefore, efficient detection of pesticide residues is of great significance to prevent food poisoning, control food pollution, and protect human lives by recognizing their distribution and concentration. Herein, a novel smartphone-coupled three-layered paper-based microfluidic chip is proposed as a facile platform to detect the pesticides. The stereoscopic capillary-driven fluid transport is enabled by the three-layered microfluidic chip configuration. The detection mechanism is based on the enzyme inhibition reaction and the chromatic reaction. The detection results are obtained by a smartphone and figured out by colorimetric quantitative analysis. Taking advantages of the above merits, we demonstrate the utilization of this smartphone-coupled three-layered paper-based microfluidic chip for the effective analysis of typical pesticides (profenofo and methomyl). The linear ranges of profenofo and methomyl are 0.27-2.1 μmol L

Research on text comprehension in relation to the reading medium (paper or screen) has mainly involved undergraduate or high school students. To advance current knowledge on the effects of reading medium, this longitudinal study focused on beginner readers, specifically, the role of precursors in first graders’ comprehension of narrative and expository linear texts from reading on paper and computer screen. Working memory and inference skills as cognitive precursors and basic digital skills were measured at the end of preschool (T1); reading text comprehension and word reading, as a control variable, were measured at the end of the first grade (T2). Sixty-three children participated in total. The first graders read four texts, one narrative and one expository, on both paper and computer screen, in a counterbalanced order. Results showed no main effects of the reading medium or text genre, but the interactive effect of these variables was significant. At T2, the children had higher comprehension scores after reading narrative than descriptive texts from paper. In addition, reading from the screen was preferred at post-test, after all texts were presented. As precursors, working memory and inference skills predicted both printed and digital text comprehension. In contrast, basic digital skills predicted only digital text comprehension after controlling for medium, text genre, and word reading.

Point-of-care testing (POCT), as a portable and user-friendly technology, can obtain accurate test results immediately at the sampling point. Nowadays, microfluidic paper-based analysis devices (μPads) have attracted the eye of the public and accelerated the development of POCT. A variety of detection methods are combined with μPads to realize precise, rapid and sensitive POCT. This article mainly introduced the development of electrochemistry and optical detection methods on μPads for POCT and their applications on disease analysis, environmental monitoring and food control in the past 5 years. Finally, the challenges and future development prospects of μPads for POCT were discussed.