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The gas flow through sheet-like porous materials such as paper can show marked lateral variations due to a heterogeneous, locally varying microstructure. Hence, reliable predictions of such lateral flux variations require an appropriate consideration of local variations in the microstructure. The flow through such sheet-like materials is commonly described with Darcy's law in which permeances are formulated in terms of microstructure properties, such as porosities, tortuosities, or hydraulic radii. This work proposes an extension of existing permeance models that directly considers the variation and the cross-dependence between local microstructure properties. The extended model is applied to local air fluxes through a paper sheet to exemplarily reveal the joint impact of local porosities and local tortuosities on the air flux. The key extension is to consider a joint distribution of porosity and tortuosity. The latter is constructed from the univariate property distributions using a copula approach and yields local tortuosities including their variation for any encountered local porosity. These values jointly enter any permeance model that qualitatively captures the dependence of the air flux on the porosity. To assess the merit of the model, variations in the air flux and in the pore space properties are independently determined from the same measured microstructure of paper. Air flux variations are provided by computational fluid dynamics simulations on multiple, nonoverlapping segments taken from the microstructure. A statistical analysis of the entire microstructure provides the distribution of local porosity, tortuosity, and thicknesses. Our model quantitatively explains that porosity-dependent variations in the tortuosity, in particular the ones associated with high-volume pathways, decisively determine air flux variations. Article Highlights: Computational fluid dynamics simulations determine local variation of air flow through an actual microstructure of paper. Construction and use of the copula approach to model joint distribution of local porosities and tortuosities is explained. Existing permeance models equipped with variations in porosity and porosity dependent tortuosity capture most variations in air flow. [ABSTRACT FROM AUTHOR]

Land-reflected signals from a geosynchronous communication satellite broadcasting in P-band (367.5 MHz) were captured in low Earth orbit (LEO) using a simple dipole antenna. A delay-Doppler map (DDM) was generated through autocorrelation. Estimates of the specular point delay were obtained from the lag of the second peak in the DDM with a bias of 239.4 m and a standard deviation of 44 m (12 m over a frozen lake) with respect to a predicted orbit model. Relative magnitudes of the first and second DDM peaks fell within the range of values predicted using dielectric models for the frozen ground and lake. Finally, retrievals of surface reflection coefficient were generated using a range of realistic values for the transmitter link budget $G/T$ , and these also fell within the range of possible values for the antenna gain pattern. Given the lack of calibration and the large uncertainties in the receiver orbit and attitude, this agreement is sufficient to conclude a successful demonstration of the fundamental principle of single-antenna reflectometry in P-band. P-band reflectometry may offer a new approach to remote sensing of sub-canopy and root-zone soil moisture. [ABSTRACT FROM AUTHOR]

In 1969, circa 1,000 fragments of the Qur'an were found in the space between two ceiling covers in the Holy Shrine of Imam Riḍā in Mashhad, Iran. Some of these were among the oldest Qur'ans produced in Iran. Three volumes in that cache are the only remaining parts of a fourteen-volume Qur'an, copied in Ramaḍān 327/939, endowed to the Holy Shrine by Kishvād b. Amlās. The volume is in vertical format and was copied on paper. Presently, it is the oldest known dated Qur'an manuscript on paper in the world. The similarities of the script and illumination to some undated and unsigned Qur'ans give us some hints about the Kufic script and illuminations in central Iran. The present article discusses the codicological and paleographical features of this copy. [ABSTRACT FROM AUTHOR]

Purpose: Photos are powerful tools to attract individuals' attention and convey service experiences. Yet exactly how visual cues in a photo contribute to the perceptions of the staged servicescape, and how these perceptions inspire online booking/reservation behaviors, remains underexplored. Addressing the gap, this study aims to uncover (1) how perceptual information mediated by an online photo contributes to the formation of consumers' holistic perceptions of the service environment and (2) how such consumers' holistic perceptions further influence customers' online purchasing behaviors. Design/methodology/approach: This research adopts an innovative crowdsourcing approach and refers to field data on consumers' online hotel booking behaviors to examine relationships among inferred servicescape dimensions, consumers' holistic perceptions of the mediated servicescape and their actual online booking/reservation behaviors (e.g. page-view and meta-click behaviors). Findings: Confirmatory factor analysis and path analysis indicated that five mediated servicescape dimensions (i.e. color, lighting, furnishings, layout and style) contribute significantly to consumers' perceptions of the mediated servicescape (CPMS) and exert different impacts on CPMS. Connecting the crowdsourced rating and consumer behavioral data, CPMS is found to influence consumers' aggregated page-view and meta-click behavior, especially in the US market. Originality/value: Building upon servicescape theory, the medium theory and the online booking literature, this research proposes a novel conceptual framework of CPMS to theorize the process by which visual cues in online photos contribute to CPMS and subsequent online purchase behaviors. Findings from this research extend Bitner's servicescape framework to mediated service contexts and provide practical implications for promoting service businesses. [ABSTRACT FROM AUTHOR]

A new biodegradable cellulose derivative-non-isocyanate polyurethane (NIPU) was prepared, and densities, viscosities, and surface tension of NIPU were measured by density bottle method, capillary viscometer and BZY-2 type full automatic surface tension meter respectively from 298.15 to 318.15 K. The results showed that densities, viscosities and surface tension were related to temperature and concentration. The viscosity and surface tension decreased with the increase in temperature at the same concentration; at the same temperature, viscosity and surface tension were positively correlated with concentration. And the experimental data were correlated by the correlation equations of viscosity and temperature, they showed a good agreement with the fitting results of the related equations. [ABSTRACT FROM AUTHOR]

The three cellulosic key chromophores, 2,5-dihydroxy-[1,4]-benzoquinone, 5,8-dihydroxy-[1,4]-naphthoquinone and 2,5-dihydroxy-acetophenone, are nearly ubiquitous in cellulosic materials because of their special structures and resonance stabilization with highly delocalized double bonds that renders them thermodynamically very stable and resistant towards bleaching. All of these compounds possess acidic hydroxyl groups. The current work explores the derivatization of these OH groups by a phosphitylation agent followed by 31P NMR analysis, an approach that is very frequently used for quantitative OH group analysis and differentiation in lignins and lignin derivatives. The chemical shifts are reported and structural peculiarities of the chromophore derivatives are discussed. The 31P NMR approach adds to the toolbox of methods applicable in cellulose chromophore analysis, bleaching and aging studies. [ABSTRACT FROM AUTHOR]

Paper has gained popularity as a packaging material due to its reduced environmental impact compared with non-degradable alternatives. However, its flammability poses safety risks, prompting research on enhancing its flame retardancy. This work introduces a diffusion-driven self-assembly strategy (DDSAS) to create a functional graphene oxide (GO) coating on various packaging papers. DDSAS involves infiltrating the paper's cellulose microfiber network with branched polyethyleneimine (b-PEI), which binds firmly to cellulose microfibers. Electrostatic interactions between GO and b-PEI then drive GO assembly into a densely stacked, layered structure on the paper surface. This GO structure provides a physical barrier against flames and generates incombustible gases (CO2, H2O, NO2, and NO) when heated, diluting the surrounding oxygen concentration and acting as a heat insulation layer. These factors increase the flame retardancy of treated papers ten-fold. Additionally, the gradual reduction of GO upon heating forms reduced graphene oxide (rGO) on the paper, significantly increasing its electrical conductivity. As a result, the flame-retardant papers not only prevent the fire from spreading but can also act as fire sensors by triggering an alarm signal at the early stages of contact with fire. In summary, this work offers a rational strategy for designing and manufacturing flame-retardant paper packaging materials. [ABSTRACT FROM AUTHOR]

Introduction. Social restrictions due to COVID-19 have made it difficult to obtain research data and literature to support publication activities. Universitas Airlangga (UNAIR) provides Remotex facilities or remote repository access, where academics can read and download journals of international repute. This paper aims to analyze whether there is a relationship between RemoteXs access by faculty and the number of publications on Scopus. Methodology. This study uses statistical data on the number of times the repository is accessed by the faculty. a sample of the number of papers was also taken from the Scopus website. Data were analyzed by the Pearson Correlation method. Results and discussion. The results of the study show that the number of lecturers' accesses has no correlation with the number of publications. Meanwhile, the total repository access at the faculty is strongly correlated with the number of publications. Conclusion. There is no relationship to how many times the number of RemoteXs access publications on Scopus. However, there is a relationship with the faculty, this is because of the doctoral program in the faculty that is required for publication.

Abstract In order to improve the sensitivity and accuracy of oil‐paper insulation partial discharge detection by the fibre‐optic Fabry–Perot (FP) ultrasonic sensor, this work studied the ultrasonic signal’s frequency characteristics of typical oil‐paper insulation partial discharges and the vibration characteristics of the FP sensor’s diaphragm in the liquid environment. Based on the works above, a multifrequency FP sensor array is proposed, consisting of several FP sensors with different resonant frequencies to detect partial discharges. The experimental results show that the liquid environment has a significant effect on the vibration characteristics of the FP sensor’s diaphragm, and the sensitivity and accuracy of partial discharge detection can be improved based on the multifrequency FP sensing array, which can also be applied in the pattern recognition and localisation of partial discharges.

Paper is the most abundant and inexpensive polymeric structure of cellulose available. Paper has micro-porous capillary-like networks which are responsible for flow of solvents instead of pumps or electronic power, making paper an ideally usable tool. Microfluidic paper-based analytical devices use fabricated paper devices on which hydrophilic zones are formed within hydrophobic barriers. Hydrophilic zones act as regions for actual analytical purposes, whereas hydrophobic zones act to demarcate separate zones from one another. Clinically, these devices have been proved to be excellent point-of-care-devices in diagnosis which can bypass use of costly and time-consuming laboratory techniques. In the presented review, the basic principles and components involved in the design of paper-based devices were then summarised in understandable manner. Further, various applications in different fields were also compiled in the form of text under different sections and tables. Paper-based analytical devices may serve as an excellent tool in variety of analytical works as these techniques are simple, rapid, economic, and require less human power or trainings. They have prominent applications in analysis of biological fluids, drugs/metabolites, food stuffs, colorants, biomarkers, and several other fields.

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.

Here, we propose a printed 96-well microtiter paper-based chemosensor array device (PCSAD) to simultaneously detect metal ions for river water assessment. Colorimetric chemosensors for metal ions have been designed based on molecular self-assembly using off-the-shelf catechol dyes and a phenylboronic acid (PBA) derivative. The colorimetric self-assembled chemosensors consisting of catechol dyes and a PBA derivative on a 96-well microtiter paper substrate demonstrated various color changes according to the disassembly of the ensembles by the addition of nine types of metal ions. An in-house-made algorithm was used to automate imaging analysis and extract color intensities at seven types of color channels from a captured digital image, allowing for rapid data processing. The obtained information-rich inset data showed fingerprint-like colorimetric responses and was applied to the qualitative and quantitative pattern recognition of metal ions using chemometric techniques. The feasibility of the 96-well microtiter PCSAD for environmental assessment has been revealed by the demonstration of a spike-and-recovery test against metal ions in a river water sample.

TiO2 nanoparticles can improve the electrical performance of oil paper insulation. In this study, 10 nm TiO2 nanoparticles were prepared and dispersed into transformer oil, and then immerse pressboards in it to obtain nanofluid impregnated pressboards (NP). Its thermal aging was accelerated together with the reference sample at 130°C for 36 days. Analyzing the acid value in the oil, polymerization degree, surface topography, AC breakdown strength, surface flashover characteristics and surface potential decay characteristics. It was observed that TiO2 nanoparticles can reduce the acid value and improve AC breakdown strength of oil. However, the degree of polymerization and surface appearance of NP and oil impregnated pressboards (OP) during thermal aging did not differ significantly. During the aging process, the energy level of pressboard surface traps shifted first towards the shallow and then gradually towards the deep. During all the aging stages, the surface flashover voltage of NP was always higher or close to that of OP. The mechanism of TiO2 nanoparticles improving the breakdown and surface flashover characteristics of oil–paper insulation during thermal aging is discussed from the perspective of water molecules and aging by‐products adsorption and introduction of shallow traps by nanoparticles. [ABSTRACT FROM AUTHOR]

Calcium hydroxide nanoparticles dispersed in ethanol or 2-propanol have been proposed for deacidification treatments of cellulose-based supports and are currently adopted by many paper and paintings conservators. There is however a risk inherent in this treatment: the dispersion would acquire a highly alkaline pH in the presence of moisture, absorbed by the dispersing alcohol solvents or by the cellulose-based support. Consequently, conditions of potential risk would be created for the structural integrity of the cellulosic supports, for some organic film-forming materials and some colouring matter. The simple tests conducted in this study clearly demonstrate that this risk is real, and suggest a cautious attitude in evaluating the suitability of these nano-dispersions for the treatment of some works of art. [ABSTRACT FROM AUTHOR]

During the storage of celluloid pictures for animation films over half a century, an interleave paper adhered to acrylic paint. The purpose of this study is to establish a methodology to cleanly remove the paper from the paint. A layered film, a replica of the celluloid pictures, adhered with paper was prepared and immersed in water or ethanol. The effect of these solvents on the peeling behavior was investigated using a peel test. The maximum peel force for the dry layered film in was distributed at ~0.5 N, independently of the peel speed. The peel force was significantly reduced after the layered film was immersed in pure water or ethanol. A morphological observation revealed that the dry paper was peeled off via the cohesive failure of the paper. After the layered film was immersed in pure water, the paper was also peeled off via cohesive failure. The layered film immersed in ethanol was peeled off at the paper/paint interface. To clear the effect of the volume change in the paint on peel behavior, the relative volume was determined via image analysis. The relative volume of paint was 1.56 in pure water and 1.37 in ethanol. It can be considered that the large difference in the volume of paint induces a large shear stress at the paint/paper interface. [ABSTRACT FROM AUTHOR]

The manufacturing of paper with new functional properties is a current problem today. A method of modifying the surface layer of paper by the partial dissolution of cellulose on its surface is proposed. N-Methylmorpholine-N-oxide (NMMO) is proposed for use as a solvent, the regeneration of which provides an environmentally friendly process. It was shown that among the possible hydrate forms of the solvent, the monohydrate and higher-melting forms are optimal for modifying the paper surface. The temperature–time modes of processing were revealed and the weight gain and density increase in the course of modification were estimated. The structural and morphological features of the original and modified paper were studied by X-ray imaging and scanning microscopy. The NMMO surface treatment makes it possible to vary the air permeability of the paper, making it practically non-permeable. The capillary and pore system were radically transformed after the partial dissolution of cellulose and its coagulation, as the formed cellulose film isolates them, which leads to a decrease in surface absorbency. The processing conditions allowing for the optimization of the optical and strength properties of the modified paper samples are revealed. The resulting paper with a modified N-methylmorpholine-N-oxide surface layer can be used for printing valuable documents. [ABSTRACT FROM AUTHOR]

BACKGROUND: Deinking is an important part of paper recycling that involves the removal of ink particles from the paper fibres. This industrial process is important so that the fibres can be recirculated back into paper production, which enables better sustainability as fewer fresh fibres are needed. In this study, we examined five different alternative fibre materials from different agricultural residues and industrial processes for the pilot production of papers. Papers containing fibres from invasive plants (Japanese knotweed), dedicated crops (miscanthus, acacia), agricultural residues (tomato stems), and industrial waste (jute - fibres from coffee bags) were printed with water-based flexo inks and deinked with two separate processes (chemical and enzymes). Mechanical (break and tensile index, breaking length) and optical properties (ISO whiteness, brightness and CIE L*a*b* values) were measured and ink elimination IR700 and deinking efficiency was calculated for the two deinking processes. RESULTS: Enzymatic treatment improved the mechanical properties of deinked pulp in comparison with the classic chemical treatment. Mechanical strength for almost all papers increased slightly (breaking length up to 20% in tomato and jute), and the optical result (brightness) increased similarly for both processes due to the bleaching action of the colour-shaded samples, whereas the deinking efficiency showed mixed results between chemical- and enzyme-type deinking (with chemical achieving better elimination measured at 700 nm) in the typical range of ink elimination values (15-35%) for flexographic inks. This indicates further optimization of the deinking with enzymes is needed due to different alternative fibre compositions and variations of residues in the delignification processes. CONCLUSION: Using a combination of adjusted enzymatic treatment as a precursor for deinking of paper-based packaging materials sourced from alternative fibres showed promising results regarding mechanical properties, whereas the optical properties need to be improved with cellulase optimization or by using mixes of different enzymes. These kinds of paper materials printed with flexo inks were found to be successfully deinkable with the chemical ISO-based deinking protocol. [ABSTRACT FROM AUTHOR]

The development of self-powered UV photodiode on green substrate is still a challenge. In this study, highly conductive Al doped ZnO (AZO) film was sputter-deposited on paper substrate at room temperature; subsequently, paper-based Schottky photodiodes were successfully fabricated by following Au-ZnO-Al and Au-ZnO-AZO-Al structure designs, respectively. These UV light-based devices operate successfully without external power. Au-ZnO-AZO-Al photodiode shows improved response and faster speed compared to Au-ZnO-Al photodiode. The one-dimensional Poisson simulation results demonstrate that the improvement is attributed to the strong electric field in the ZnO-AZO n-n+ high-low junction, thus, enhancing the collection rate and drifting speed of the photogenerated carriers. In addition, AZO can form favorable ohmic contact with the Al electrodes, further improving the device performance. The photo-response of the paper-based photodiode device shows high reproducibility and stability. Based on these outstanding results, we conclude that these paper-based electronic devices have great potential to replace conventional petroleum-based flexible electronic devices, thus, contributing to the green/sustainable development. [ABSTRACT FROM AUTHOR]