Volume 20 Issue 1

Aperture plugging is a phenomenon that limits both the capacity and efficiency of pulp screens, which are critical components of the pulping, recycling, and papermaking processes. An understanding of when and how plugs begin to form can help avoid screen plugging, thus increasing papermaking and recycling efficiency. Small scale, fiber-optic pressure sensors were installed within screen cylinder apertures close to where plugging occurs to understand the mechanism of plug formation. Rotor pressure pulses within the aperture were measured during the plugging event. The pulse shape and magnitude during normal operation showed good agreement with past studies in which traditional pressure transducers were installed on the screen cylinder. However, prior to the onset of aperture plugging, the fiber-optic sensors showed that the variability of the pressure pulses increased and pulse magnitude within the slot decreased. The authors demonstrated that combining these variables by quantifying pulse variability using standard deviation and dividing that by pulse magnitude gave a result that was a strong predictor of aperture plugging.

In this paper, CiteSpace (6.1.R6) software was used to visualize and analyze the number of papers, terminology, countries, institutions, and collaborative networks of authors in the field of biogas upgrading in the years 2009 to 2023 to provide theoretical references for related researchers and departments. The progress of biogas upgrading research is divided into three phases: 2009 to 2011 (Phase I), 2012 to 2015 (Phase II), and 2016 to 2022 (Phase III). The first phase laid the theoretical foundation for the later phase, which included the fields of biomethanation and variable pressure adsorption. The physical/chemical biogas upgrading technology in the second phase gradually matured. The number of research papers published in the third phase increased rapidly, and with the rapid increase in the number of published research papers, which accounted for 73.2% of the total amount of research and statistical literature, this phase of biogas upgrading technology research is even more mature. In addition, the field of biogas upgrading has a small network of cooperation among researchers, and no close cooperation exists among the countries and research institutions involved. Under the trend of carbon emission reduction, “life cycle assessment” and “biomethanation” clusters have become the current research frontiers in the field of biogas upgrading.

This study assessed the feasibility of using major agricultural residues specifically bagasse, rice straw, wheat straw, and coir fiber to produce single-layer particle boards. These boards of densities 300, 400, and 500 kg/m³ were developed using melamine urea formaldehyde resin. Comprehensive evaluation of the boards included determination of their sound absorption coefficient (SAC), thermal conductivity, and noise reduction coefficient (NRC), as well as various physical properties and modulus of rupture. Additionally, the impact of board density on the SAC across a frequency range of 50 to 5000 Hz was examined. The coir boards displayed superior SAC, particularly at 3000 Hz. Rice straw boards at a density of 300 kg/m³ exhibited the lowest thermal conductivity (0.098 W/m-K). Density of 300 kg/m³ was optimal for achieving the highest SAC and lowest thermal conductivity in agro residue particle boards. As the density of the boards increased, SAC decreased, whereas thermal conductivity (K) increased, indicating that lower-density boards are more effective as sound and thermal insulators. Furthermore, all particle boards demonstrated promising sound absorption capabilities, achieving classifications of D and E under ISO 11654:1997, making them viable for interior applications in the building industry.

Despite prefabricated wood light-frame construction’s technical viability and ability to address labor shortages and industry productivity issues, its adoption remains limited. As an alternative to steel and concrete in non-residential buildings of four storeys or less and dwellings of five and six storeys, they represent only 23% and 6% of market shares, respectively. Based on a purposive sample of 40 interviews with diverse construction industry professionals in Quebec (Canada), the representations of prefabricated wood light-frame construction was highlighted. A thematic analysis identified the motivations and barriers to prefabrication adoption and the reasons for these positions more precisely. This work examined whether these perceptions differ significantly according to main professional activity. The findings confirm existing literature while providing deeper insights into motivations and barriers, revealing new viewpoints. Respondents primarily cited expertise as the most critical barriers. Availability of labor, cost, productivity, and construction quality were identified as key motivators, while manufacturing capacity and coordination were perceived with mixed opinions. Analyzing response profiles suggests that different stakeholders generally have similar perceptions. This research will aid in refining policies and strategies to encourage the widespread adoption of prefabricated wood light-frame in construction practices.

N-doped ultra-microporous activated carbon was made from Chenopodium quinoa Willd. straw in the Tibetan Plateau region and cesium chloride as activator and used for H₂ adsorption and storage. Its structure was characterized by the Brunauer-Emmett-Teller (BET) method and other techniques. The results showed that the adsorbent had a well-developed microporous structure, and its specific surface area was as high as 804 m² ·g^-1. Its major pore sizes were all distributed in the ultra-micropores of 0.62 nm. The adsorbent also had a high H₂ adsorption storage capacity, which could reach 12.2 cm³·g^-1 at an adsorption pressure of 1 MPa and an adsorption temperature of 298 K. This study provides a new way to improve the high value utilization of Chenopodium quinoa Willd. straw and solid hydrogen storage and provides corresponding evidence that CsCl can be used as an activator for ultra-microporous activated carbon.

The dimensional absorbency properties of paper towels were studied, focusing on three- and two-dimensional absorption mechanisms. Key factors affecting these absorption mechanisms were identified through a series of experiments and principal component analysis (PCA). The results showed that the water absorption capacity, driven by capillary action (porosity), exhibited differences between two-dimensional surface absorption (in the X and Y directions) and three-dimensional bulk absorption (including the Z direction, or thickness). Porosity analysis revealed that three-dimensional absorbency is highly correlated with porosity, whereas two-dimensional absorbency has a relatively low correlation and is influenced by fiber properties such as length and width, as well as mass-related characteristics including fines content and freeness. The findings highlight the need to balance these dimensional properties to achieve optimal absorbency in paper towel products. Additionally, this study provides a foundation for developing more efficient paper towels and offers valuable insights into the complex mechanisms of paper towel absorbency, which will aid in the development of improved hygiene paper products.

This study investigates the enhancement of mechanical characteristics of hybrid polymer composites reinforced with Palmyra Palm Leaflet (PPL) and Coconut Sheath Leaf (CSL) fibers by integrating Tamarind Shell Powder as a filler material. The composites were fabricated with varying ratios of PPL and CSL fibers, and their tensile strength, flexural strength, interlaminar shear strength (ILSS), impact strength, hardness, and water absorption were evaluated. Results indicated that the composite with 20% PPL and 10% CSL exhibited superior mechanical performance, achieving the highest tensile strength of 42.22 MPa, flexural strength of 94.35 MPa, ILSS of 7.52 MPa, and impact strength of 5.98 J. Hardness values peaked at 84.12 SD for the same composition. Moreover, the integration of Tamarind Shell Powder significantly improved the mechanical properties compared to composites without filler, which showed lower values across all parameters. Water absorption tests revealed an increase in water uptake with filler incorporation, though within acceptable limits for practical applications. Scanning Electron Microscopy (SEM) analysis further supported these results by revealing enhanced fiber-matrix bonding and better dispersion of the filler, resulting in fewer voids and defects. This research highlights the potential of bio-based fillers in optimizing the mechanical performance of hybrid composites for sustainable engineering applications.

The decay, mold, and termite resistance of high-density fiberboard (HDF) formed using combinations of wood and chicken feather fibers (CFF) bonded with polyurethane resin was investigated. Laboratory and underground field exposure tests showed that HDF containing 50% to 100% CFF by weight were moderately to highly resistant to the white-rot fungus Pycnoporus sanguineus (L.) Murrill and the subterranean termite Coptotermes gestroi Wasmann. Moderate to heavy mold growth was observed on HDF containing 25% to 100% CFF when inoculated with a mixed strain of Aspergillus niger, Penicillium chrysogenum, and Trichoderma viride. In general, HDF consisting of wood fibers and CFF was resistant to decay and subterranean termite but susceptible to mold growth. The susceptibility HDF to mold may require the use of a biocide to improve mold resistance.

Oriented strand board (OSB) panels are widely used as the best web solution for wooden I-joists. Many previous studies have focused on testing various new web materials, but few have examined the contribution of other web shapes to the I-joists’ behavior. The use of corrugated wood-based panels as I-joist web has been investigated. The aim of this study was to analyze the sensitivity of the joist in bending tests to the elastic properties of the corrugated web using a numerical approach with the finite element method. Joists with a corrugated web were manufactured and tested in long- and short-span bending tests and compared to traditional I-joists with an OSB web. The results obtained were encouraging. Results show that the in-plane shear modulus is the most critical elastic property in the behavior of the joist and is estimated at 1300 MPa to reproduce the same behavior of the corrugated web joist as that experimentally tested. The numerical approach also enabled determination of the corrugated web’s shear failure mode. This mode of failure manifested itself as interactive buckling, followed by the creation of diagonal tension lines.

Assessing the toxicity of textile samples in terms of risks to human well-being and health is a significant issue. In this study, 11 textile materials were tested using two procedures: the sperm motility inhibition test using bull spermatozoa and the acute immobility test using Daphnia magna. A comparative analysis was carried out considering the advantages of each toxicity assessment method. The bull sperm test was shown to be less sensitive and more complicated to carry out than the Daphnia magna immobility test. In addition, the inclusion of both dyes and synthetic fibres significantly influenced textile toxicity, with aqueous extracts from dyed textiles showing higher toxicity levels when tested alongside undyed textiles. The toxicity index for dyed textiles ranged from 37% to 62% in the motility inhibition test, while the Daphnia magna test showed an acute immobility parameter of 100% with the uncontaminated control medium.