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This research was designed to assess the yield and quality of ash prepared from different types of waste papers. Waste newspapers, writing papers, and cartons were selected for combustion to obtain the ashes and coded as WNPA, WWPA, and WCPA, respectively. The waste papers were incinerated simultaneously in separate but identical incinerators at 850 ℃. An experiment on the yield of the ashes was performed on two days before the ashes obtained were mixed based on the type of waste papers from which they were derived. The results showed that irrespective of the day and time, the WCPA was the most yielded (14.1%), followed by the WWPA (12.3%), and then the WNPA (11.9%). Also, it was found that all the ashes possessed flow properties acceptable for engineering applications. However, the WCPA would ensure the best performance if applied, especially as a partial replacement material for cement. While the WWPA was found to be richer than the WNPA, the WCPA was the richest in terms of the proportions of key oxides for strength development. In general, the percentages of various chemical components of each ash complied with the standard specifications for cement except in the case of losses on ignition of the WNPA and WWPA, which were about 0.53% and 0.02%, respectively, beyond the maximum stipulated value.

To improve the accuracy and efficiency of the aging life prediction and assessment of transformer oil-paper insulation, and to make up for the deficiencies of traditional characterizers, such as 2-furfural, carbon monoxide, and carbon dioxide, a method for the simultaneous determination of methanol, ethanol, $n-\mathbf{propanol}$, and $n$-butanol in oil with a single injection is established by headspace-gas chromatography-mass spectrometry. The measured results show that the determination limits of the four alcohol characterizers can be controlled to $\mathbf{10}\ \mu \mathbf{g}/\mathbf{kg}$ level. Based on this method, the change patterns of the above four alcohols with thermal aging time and degree of polymerization are obtained through thermal aging experimental research. Ethanol, $n$-propanol, and $n$-butanol in oil indicate nearly linear correlations with thermal aging time and degree of polymerization, similar to that of methanol. By analyzing 52 sets of measured data of 500 kV EHV transformers in operation, $n$-butanol is found to have excellent performance, and a new method to evaluate the aging state of oil-paper insulation employing $n$-butanol and methanol is proposed along with the aging attention value model. The measured data of 500 kV EHV transformers in operation indicate that the combination of $n$-butanol and methanol as the preferred characterizers can effectively compensate for the shortcoming of traditional characterizers in the early stages of aging, and the feasibility of the method is verified. Two possible pathways for the generation of $n$-butanol by cellulose cleavage during the aging of oil-paper are proposed from the chemical structure of cellulose.

It is more important to improve and complete the wastewater process in order to reuse and return it to the production line. In this study, the hydrogen peroxide/ozone process (Peroxone) was investigated as a supplementary step in paper mill wastewater treatment to reduce the amount of chemical oxygen demand and remove E. coli. In this regard, using the Box-Behnken Design method based on the response surface method to optimize and investigate the effect of three variables governing the ozonation process, including the amount of hydrogen peroxide consumed (ml), the amount of ozone input (mg/min) and ozonation time (min) were used. The results showed that the amount of ozone and hydrogen peroxide had the greatest effect for reducing COD (up to about 75%). Also, all three variables have played a significant role in increasing the efficiency of the Peroxone process and even completely eliminating E. coli. In determining the optimal conditions, the amount of ozone (146 mg/min), the amount of hydrogen peroxide (2ml) and the duration of ozonation (23 min), the lowest amount of residual COD (73 mg/L) and the highest efficiency (75% removal of E. coli) are predicted. The results showed that due to the interaction of ozone and hydrogen peroxide, the peroxone process performance was less efficient than the ozonation process alone.

Abstract We report an innovative and facile approach to fabricating an ultrasensitive plasmonic paper substrate for surface-enhanced Raman spectroscopy (SERS). The approach exploits the self-assembling capability of poly(styrene-b-2-vinyl pyridine) block copolymers to form a thin film at the air-liquid interface within the single microdroplet scale for the first time and the subsequent in situ growth of silver nanoparticles (AgNPs). The concentration of the block copolymer was found to play an essential role in stabilizing the droplets during the mass transfer phase and formation of silver nanoparticles, thus influencing the SERS signals. SEM analysis of the morphology of the plasmonic paper substrates revealed the formation of spherical AgNPs evenly distributed across the surface of the formed copolymer film with a size distribution of 47.5 nm. The resultant enhancement factor was calculated to be 1.2 × 107, and the detection limit of rhodamine 6G was as low as 48.9 pM. The nanohybridized plasmonic paper was successfully applied to detect two emerging pollutants—sildenafil and flibanserin—with LODs as low as 1.48 nM and 3.45 nM, respectively. Thus, this study offers new prospects for designing an affordable and readily available, yet highly sensitive, paper-based SERS substrate with the potential for development as a lab-on-a-chip device.

Abstract This study identifies important factors for designing an effective biomimetic paper‐based fog harvesting substrate by examining the harvesting properties of different surfaces, including glass, polyethylene, and superhydrophobic paper. In laboratory‐scale fogging tests, the wetting behavior of the substrates is characterized, and the importance of the tilt angle of the respective surface relative to the fog flow is elaborated. Because successful fog harvesting requires both efficient accumulation of water droplets on the surface (by condensation and collision) and sufficient but not excessive roll‐off of the liquid, the amount of water finally collected is clearly related to the pinning effect, which should prevent the smallest droplets from being carried away by the wind but must not lead to full and permanent wetting of the surface. Coalescence is identified as a major phenomenon to improve droplet roll‐off. In this context, superhydrophobic paper indicates to be a more effective water collector than glass or polyethylene, especially when oriented vertically, since it allows the droplets to roll off very efficiently. Finally, the addition of glass particles to the superhydrophobic coating is proposed as a means of enhancing pinning and improving the fog harvesting efficiency.

Since the last two decades, the use of natural fiber reinforced polymer composites has garnered significant application considerations over the synthetic fiber reinforced composites due to their numerous advantages and unique properties. Likewise, epoxy resin has attracted the interest of many researchers for composite synthesis, basically because of its chemical stability, thermal and mechanical characteristics. Hence, the primary aim of this study was to investigate the influence of dombeya fiber and paper particulate on the physical and mechanical properties of dombeya fiber and paper particulate-reinforced polymer composites for structural applications. Dombeya fiber and paper particles are renewable and biodegradable materials, thereby making them environmentally friendly materials to replace synthetic materials. Hand lay-up technique was utilized to fabricate the hybrid-reinforced biocomposites after which they were subjected to mechanical, wear, density, and moisture absorption properties. The surface morphology of the fractured surface was also analyzed to investigate its microstructural features. It was discovered from the results that hybrid biocomposites demonstrated improved properties over the unreinforced composite, with composites from 9-wt% dombeya fiber-paper particles reinforced biocomposite exhibiting the most suitable properties with commensurate density with the unreinforced epoxy matrix. These obtained characteristics support the material as a suitable material for biomedical apparatus application such as orthopedic implants, surgical instruments, and bone fixation devices.

Power transformers are critical equipment responsible for the transmission and transformation of electrical energy, and they are an important component of power system. Under the combined effects of electric field, thermal field, and mechanical stress, insulation degradation is prone to occur in oil-paper insulation structures. Among them, the “liquid-solid” interface formed by oil and oil-immersed pressboard is the weak point in transformer insulation, and extensive operational experience has shown that creeping flashover of insulating pressboard is a common fault in power transformers. Creeping flashover of insulating pressboard can rapidly destroy the insulation structure, leading to irreversible damage to the transformer and posing a serious risk of transformer accidents. In recent years, many scholars have conducted in-depth research on the characteristics and mechanisms of creeping flashover in oil-paper insulation structures using various experimental methods. They have obtained significant findings that have important theoretical and practical implications for optimizing the structure of power transformers and improving their reliability. This paper first introduces the characteristics of the electromagnetic environment inside the power transformer and the common forms of creeping flashover accidents in engineering. Then, classified according to the uneven degree of electric field and creepage distance of test electrodes used in relevant research, and the test methods and flashover characteristics of small size (

Abstract Paper, an inexpensive material with natural biocompatibility, non‐toxicity, and biodegradability, allows for affordable and cost‐effective substrates for unconventional advanced electronics, often called papertronics. On the other hand, polymeric elastomers have shown to be an excellent success for substrates of soft bioelectronics, providing stretchability in skin wearable technology for continuous sensing applications. Although both materials hold their unique advantageous characteristics, merging both material properties into a single electronic substrate reimagines paper‐based bioelectronics for wearable and patchable applications in biosensing, energy generation and storage, soft actuators, and more. Here, a breathable, light‐weighted, biocompatible engineered stretchable paper is reported via coaxial nonwoven microfibers for unconventional bioelectronic substrates. The stretchable papers allow intimate bioconformability without adhesive through coaxial electrospinning of a cellulose acetate polymer (sheath) and a silicone elastomer (core). The fabricated cellulose‐silicone fibers exhibit a greater percent strain than commercially available paper while retaining hydrophilicity, biocompatibility, combustibility, disposable, and other natural characteristics of paper. Moreover, the nonwoven stretchable cellulose‐silicone fibrous mat can adapt conventional printing and fabrication process for paper‐based electronics, an essential aspect of advanced bioelectronic manufacturing.

The selective detection of halides in aqueous samples is crucial for addressing environmental and physiological concerns. Consequently, the development of an affordable, portable, and user-friendly sensing platform for rapid halide detection holds substantial promise. In this study, we present a novel paper-based nanosensor as an appealing alternative for selectively detecting halides in water. This nanosensor leverages the optical properties of silver nanoparticles (ranging from 50 to 250 nm) embedded in epoxy resin and printed on filter paper. We elucidate the colorimetric behavior of this nanosensor in response to specific halides (chloride, bromide, and iodide) upon contact. Importantly, this sensor discerns, through a single measurement, the presence of these halides in aqueous media with remarkable selectivity. The nanosensor manifests distinct color changes in reaction to different halides, particularly at elevated concentrations (ranging from 2 to 400 mM), surpassing the saturation levels observed in other proposed sensors. These discernible color changes are due to the oxidation of silver nanoparticles, changing their morphology and aggregation density, and can be readily detected and analyzed directly from a captured image. Consequently, it demonstrates considerable potential for integration into automated qualitative monitoring devices based on chromaticity analysis.

A thermoelectric generator (TEG) is one of the important energy harvesting sources for wearable electronic devices, which converts waste heat into electrical energy without any external stimuli, such as light or mechanical motion. However, the poor flexibility of traditional TEGs (e.g., Si-based TE devices) causes the limitations in practical applications. Flexible paper substrates are becoming increasingly attractive in wearable electronic technology owing to their usability, environmental friendliness (disposable, biodegradable, and renewable materials), and foldability. The high water-absorbing quality of paper restricts its scope of application due to water failure. Therefore, we propose a high-performance flexible waterproof paper-based thermoelectric generator (WPTEG). A modification method that infiltrates TE materials into cellulose paper through vacuum filtration is used to prepare the TE modules. By connecting the TE-modified paper with Al tape, as well as a superhydrophobic layer encapsulation, the WPTEG is fabricated. The WPTEG with three P–N modules can generate an output voltage of up to 235 mV at a temperature difference of 50 K, which can provide power to portable electronic devices such as diodes, clocks, and calculators in hot water. With the waterproof property, the WPTEG paves the way for achieving multi-scenario applications in humid environments on human skin.

Oil–paper insulation is the critical insulation element in the modern power system. Under a harsh operating environment, oil–paper insulation will deteriorate gradually, resulting in electrical accidents. Thus, it is important to evaluate and monitor the insulation state of oil–paper insulation. Firstly, this paper introduces the geometric structure and physical components of oil–paper insulation and shows the main reasons and forms of oil–paper insulation’s degradation. Then, this paper reviews the existing condition assessment techniques for oil–paper insulation, such as the dissolved gas ratio analysis, aging kinetic model, cellulose–water adsorption isotherm, oil–paper moisture balance curve, and dielectric response technique. Additionally, the advantages and limitations of the above condition assessment techniques are discussed. In particular, this paper highlights the dielectric response technique and introduces its evaluation principle in detail: (1) collecting the dielectric response data, (2) extracting the feature parameters from the collected dielectric response data, and (3) establishing the condition assessment models based on the extracted feature parameters and the machine learning techniques. Finally, two full potential studies are proposed, which research hotspots’ oil–paper insulation and the electrical–chemical joint evaluation technique. In summary, this paper concludes the principles, advantages and limitation of the existing condition assessment techniques for oil–paper insulation, and we put forward two potential research avenues.

As air pollution escalates, the need for air filters increases. It is better that the filters used be based on natural fibers, such as non-wood fibers, which cause low damage to the environment. However, the short fiber lengths, low apparent densities, and high volumes of non-wood materials can make it challenging to prepare filter paper with the required mechanical and physical properties. In that context, this study focused on utilizing bamboo fibers to fabricate filter paper by employing the anthraquinone soda pulping method. The pulp underwent bleaching and oxidation processes, with the incorporation of cationic starch (CS) and polyvinyl alcohol (PVA) to enhance resistance properties, resulting in the creation of handmade filter papers. The findings revealed that the tear, burst, and tensile strength of filter paper increased with the oxidation and addition of CS and PVA. Air permeability increased with addition of PVA and combination of CS and PVA. FTIR demonstrated the conversion of hydroxyl groups in cellulose chains to carboxyl groups due to oxidation. SEM images illustrated alterations in the fiber structure post-oxidation treatment, with CS reducing pores while PVA and the CS-PVA combination enlarged pore size and enhanced porosity. The BET surface area surface area expanded with oxidation and the addition of the CS-PVA blend, indicating heightened filter paper porosity. Notably, the combined inclusion of CS and PVA not only augmented mechanical strength but also increased porosity while maintaining pore size.

This paper discusses the results of the micro-Raman analysis performed on paper-like graphene oxide (GO) samples consisting of many functionalised graphene layers and annealed at moderate temperatures (≤500 °C) under vacuum conditions (p ≃ 10−4 mbar). The analysis of the standalone samples revealed that the obtained material is characterised by a noticeable disorder level but still stays below the commonly accepted threshold of high or total disorder. GO formed in a simple way showed two spectral bands above 1650 cm−1 recorded very rarely or not at all and their origin has been discussed in detail. The results also confirmed the metastable character of multilayer GO after the annealing process at moderate temperatures as the C/O ratio was kept between 2 and 3 and the spectral features were stable within the annealing temperature range.

Invasive alien plant species (IAPS) may cause threats to native biodiversity in ecosystems. Researchers have been investigating all the possible ways that they can be used effectively for other purposes. Since IAPS are capable of forming cellulose fibre nets, in this research, papers were made from three different types of IAPS (Japanese knotweed, giant goldenrod, and black locust). This research examined these IAPS papers and their effectiveness when used as printing substrates. In comparison to commercial office paper, the differences in basic, surface, optical, and microscopic properties were measured. As a widely used technology, inkjet printing was applied. We tested a commonly used sans-serif typeface (which has been established as being more legible than other typefaces in previous research) in three different type sizes (i.e., 8, 10, and 12 pt). According to the results, paper made from IAPS could offer some usable properties and acceptable legibility, especially when printing typefaces with specific attributes, such as moderate counter size, higher x-height, and minimal differences in the letter stroke width, are used. An appropriate typographic tonal density should be achieved in combination with an adequate letter size, e.g., 10 pt type size when a sans-serif typeface is used.

This review explores circular economy principles in regard to ethanol production from paper-mill sludge. Environmental sustainability and renewability over fossil fuels make second generation ethanol an attractive energy source in a rapidly growing population and consumption world. Paper sludge (PS), a by-product of the pulp and paper (P&P) industry, can no longer be recycled for paper production and is mainly disposed of in landfills. Therefore, it poses a major environmental challenge. However, it has shown potential as a valuable raw material for ethanol production, along with other pulp and paper products, due to its abundant availability and high cellulosic content. This waste-to-energy (WtE) technology for ethanol production is proposed as an alternative, aligning with circular economy concepts to maximize resource efficiency and minimize waste. This review underlines the circular economy aspects of bioethanol production within paper mill sludge management systems. Circular economy principles applied to ethanol production from PS offer a promising avenue for sustainable biofuel development that not only addresses waste management challenges but also enhances the overall environmental performance of biofuel production. Furthermore, economic benefits are described, highlighting the potential for job creation and community development.

In recent times, there has been a notable surge in the interest in promoting environmentally conscious products, particularly within the building industry where the focus has shifted towards sustainable materials. In this study, as a sustainable building material, ceiling tiles have been fabricated as a composite board containing waste materials, namely waste paper, sawdust, recycled polyethylene terephthalate (PET), and epoxy resin, and characterized comprehensively through physical and mechanical tests, density, thickness swelling (TS), modulus of elasticity (MOE), modulus of rupture (MOR), and flexural strength (FS) for product stability. A total of nine composites were fabricated with different ratios through molding techniques, and the characterization results were compared to determine the optimized stable ratio of composite composition. The composition of 25% waste paper, 15% sawdust, 10% recycled PET, and 50% epoxy resin presented the maximum FS compared to the other composite ratios. Water absorption (WA) and thickness swelling were evaluated after immersion durations of 1–24 h. The findings revealed that as the density increased, the sawdust content within the matrix decreased from 25–35%. Concurrently, an increase in recycled PET content resulted in decreased water absorption and thickness swelling. Significantly, the MOE, MOR, and FS demonstrated optimal values at 864.256 N/mm2, 12.786 N/mm2, and 4.64 MPa, respectively. These observations represent the excellent qualities of this hybrid composite board, particularly in terms of sustainability, stability, and water absorption capacity. Moreover, its lightweight nature and ability to support ceiling loads further enhance its appeal for construction applications. This study not only advances the discourse on sustainable construction materials but also fosters opportunities for broader acceptance and innovation within the industry.

The academic community has witnessed a notable increase in paper publications, whereby the rapid pace at which modern society seeks information underscores the critical need for literature mapping. This study introduces an innovative automatic model for categorizing articles by subject matter using Machine Learning (ML) algorithms for classification and category labeling, alongside a proposed ranking method called SSS (Scientific Significance Score) and using Z-score to select the finest papers. This paper’s use case concerns industry productivity. The key findings include the following: (1) The Decision Tree model demonstrated superior performance with an accuracy rate of 75% in classifying articles within the productivity and industry theme. (2) Through a ranking methodology based on citation count and publication date, it identified the finest papers. (3) Recent publications with higher citation counts achieved better scores. (4) The model’s sensitivity to outliers underscores the importance of addressing database imbalances, necessitating caution during training by excluding biased categories. These findings not only advance the utilization of ML models for paper classification but also lay a foundation for further research into productivity within the industry, exploring themes such as artificial intelligence, efficiency, industry 4.0, innovation, and sustainability.

Expansive soil exhibits significant swellings and shrinkages, which may result in severe damage or the collapse of structures built upon it. Calcium-based admixtures, such as lime, are commonly used to improve this problematic soil. However, traditional chemical additions can increase significant environmental stress. This paper proposes a sustainable solution, namely, the use of lignin fiber (LF) from the paper industry to partially replace lime as an amendment for expansive soils. Both the macroscopic and microscopic characteristics of the lignin fiber-treated expansive soil are extensively studied. The results show that the mechanical properties of expansive soil are improved by using lignin fiber alone. Under the condition of an optimal dosage of 8%, the compressive strength of lignin fiber-modified soil can reach 193 kPa, the shear strength is increased by 40% compared with the untreated soil, and the water conductivity is also improved with the increase in dosage. In addition, compared with 2% lime-modified soil, the compressive strength of 8% lignin fiber- and 2% lime composite-treated expansive soil increased by 50%, the cohesion increased by 12%, and the water conductivity decreased significantly. The microstructure analysis shows that at an 8% lignin fiber content, lignin fibers interweave into a network in the soil, which effectively enhances the strength and stability of the improved soil. Simultaneously, the fibers can form bridges across the adjacent micropores, leading to the merging of pores and transforming fine, dispersed micropores into larger, connected macropores. Lime promotes the flocculation of soil particles, forming larger aggregates and thus resulting in larger pores. The addition of fibers exerts an inhibitory effect on the flocculation reaction in the composite-improved soil. In conclusion, lignin fibers are an effective addition used to partially replace calcium admixture for the treatment of expansive soil, which provides a sustainable and environmentally friendly treatment scheme for reducing industrial waste.

The dynamic mechanical behavior and cushioning performance of honeycomb sandwich panels, which are extensively employed in product cushioning packaging due to their exceptional energy absorption capabilities, were examined using a combination of experimental and numerical methods. Several factors, such as maximum acceleration–static stress, cushioning coefficient–static stress, and other curves, were analyzed under various impact conditions. The simulated stress–strain, deformation modes, cushioning coefficients, and other parameters demonstrate consistency with the experimental results. The acceleration, maximum compression, and cushioning coefficient obtained from the experiment and simulation calculation were 30.68 g, 15.44 mm, and 2.65, and 31.96 g, 14.91 mm, and 2.79, respectively. The results indicate that all error values were less than 5%, confirming the precision and reliability of the model. Furthermore, the model was utilized to simulate and predict the cushioning performance of honeycomb sandwich panels with different cell structures and paper thicknesses. These results provide a solid basis for enhancing the design of subsequent honeycomb element structures.

Natural and synthetic esters are increasingly being chosen instead of mineral oil for environmental and fire safety reasons. However, their use in power transformers is limited due to insufficiently well-understood ageing processes affecting their properties and the properties of cellulosic materials impregnated with them. The research results presented in many scientific papers prove that the use of esters slows the ageing process of cellulosic materials. This article presents the results of research aimed at answering the question of whether the effect of slowing the ageing process will also occur in the case of insulation with very low initial moisture. The answer to this question will allow us to better understand the role of water in the ageing process of the transformer’s insulation system. The thermal ageing process was carried out at a temperature of 150 °C in closed systems. The degree of cellulose polymerisation was taken as a measure of the degree of paper ageing. Great attention was paid to measuring the water content in both paper and electro-insulating liquids at various stages of their ageing. Furthermore, measurements of the properties of electro-insulating liquids were made, which are considered markers of ageing. The test results obtained indicate that in the case of a dry insulation system, corresponding to the initial moisture of the new units, the type of liquid used to impregnate the cellulosic material does not significantly affect its depolymerisation process. However, in the case of paper impregnated with natural esters, a lower dynamic of moisture increase in insulation was observed.