Volume 18 Issue 2

The utilization of plant extraction products from Oeneanthe pimpinelloides (Apiaceae family) seeds were investigated in terms of their use as an insecticide control of packaging materials. The aim was to investigate their insecticidal effects against the flour beetle Tribolium castaneum. The Oeneanthe pimpinelloides seeds were extracted with methanol. By using the liquid-liquid extraction method, the hexane extract (II) was separated from the methanol extract (I) and hexane and methanol were evaporated. Then, the chemical composition of each sample was determined via gas chromatography–mass spectrometry. The methanol extract predominantly contained tetrahydrofuran, 1-methoxy-2-propanol, 1-methoxy, 2-butoxyethanol, 1-phenylethanone, cyclohexene carboxylate derivative, (3-phenyl-2-propynylidene) cyclopropane, diphenyldiazene, and dihydroxypropyl ester components, while the hexane fraction contained nonane, 1-octanol, decane, undecane, tridecane, alkyl benzene, benzene sulfonic acid, benzoxazine, and hexadecanoic acid components, as well as some derivatives of them. Each fraction was dissolved in DMSO for impregnation on filter paper. The insecticide effects of the paper samples were determined against Tribolium castneum. According to the results, the mortality started after 3 d for each fraction. After 4 d, the hexane fraction indicated total mortality in comparison with the methanol fraction, which showed partial mortality (3/5).

Certain bamboo species have mechanical properties that are compatible with construction material. Despite this, their low shear strength, the presence of nodes in their culms, and their circular geometry inhibit the expansion of the use of this material as construction material. One technique that can solve these problems is glued laminated bamboo (GLB). Based on such findings, this paper aims to evaluate the physical and mechanical properties of glued laminated bamboo of the Dendrocalamus giganteus species. Two glues were used: resorcinol-formaldehyde (PRF) and polyvinyl acetate (PVAc). The following physical and mechanical characterization tests were performed on glued laminated bamboo: water absorption, density, compression parallel to fiber direction, tension parallel to fiber direction, shear parallel to the glue layer, shear parallel to fiber direction, and bending. The results, analyzed using statistical models, showed that the GLB has physical and mechanical properties comparable to those of hardwoods.

Biodegradation of digestate liquid fraction was performed in the activated sludge system with acetic acid, flume water, and molasses as external carbon sources. High-throughput sequencing was used to gain in-depth insight into the activated sludge microbial community. The type and amount of carbon source in influent (COD/TN ratio) significantly influenced microbial community structure, especially at the genus level, and thus the biodegradation performance of digestate liquid fraction. The highest total nitrogen and chemical oxygen demand removal efficiencies averaging 85.3% and 88.3%, respectively, were achieved in series with acetic acid and flume water and COD/TN ratio of 10.7 and 11.2, respectively. The microbial diversity in these series averaged at 3.08 and 3.65. The dominant bacteria at the phylum level in series with acetic acid were Proteobacteria and Bacteroidota, and at the genus level Azospira, while in series with flume water they were Bacteroidota and Firmicutes, and Macellibacteroides, respectively.

The compacting force in the biomass pelletizing process has remarkable effects on energy consumption, equipment life, and pellet quality. This paper presents an experimental study on the mechanical behavior for the pelletizing process of rice straw, wheat straw, and wood shavings, under different levels of technological parameters, including moisture content, compacting velocity, and particle size. Effects of these parameters on the constant coefficients in the three equations were analyzed. The relationship between the coefficients and the pelletizing process was considered. Results showed that Peiyun Huang equation was more suitable for the whole compacting process compared with the other two equations, which meant it was feasible to estimate the required input of the pelletizing system by measuring the product density based on the Peiyun Huang equation. No specific relationships between the coefficients and pellet quality and energy consumption were observed. It is infeasible to predict the pellet quality and energy consumption only by the mechanical properties of the biomass in densification process.

The embedment strength performance of the self-tapping screw (STS) connector, used as a cross-laminated timber fastener, was evaluated considering tree species’ density and load direction as parameters. The STS had a diameter of 8, 10, and 12 mm. Considering the characteristics of the STS, the embedment strength of the threaded area and the shank area were compared. A larger diameter of the STS resulted in a higher yield load in all directions of the respective wood. The effective embedment area can estimate a more accurate value for the embedment strength. The embedment strength of the longitudinal cross section as the embedment area was higher than that of the radial and tangential sections. For the loading direction, the ratio of the embedment strength parallel and perpendicular to the grain of the specimens was 0.40 to 0.58 by wood species. The embedment strength predicted based on the specific gravity and diameter of the fastener differed considerably by 38% to 56% from the actual embedment strength of STS using the effective embedment area. This paper provides data for setting the adjustment factors predicting the embedment strength of STS connection.

Tropical species are widely used in construction, and their physical and mechanical properties have been important characteristics with direct impact on the design of structures, especially the strength and stiffness of wood applied in them. Tests to obtain both parameters are conducted under ABNT NBR 7190 (1997) guidelines in Brazil, being rarely found in some research centers because of the higher costs of testing equipment. For instance, the toughness test depends on equipment with a pendulum, whose device requires accuracy and maintenance for reliable analyses. This paper aims to estimate toughness through another property more easily found, given by the compression strength parallel to the grain. For this, 20 tropical wood species of the South American region were used to obtain initial values of these properties. The characteristic values of the compression strength parallel to the grain as well as linear and quadratic regression models were obtained. Statistical analysis was performed and confirmed that a linear model gave better predictions than a quadratic model.

Biodegradable transparent wood was fabricated by introducing epoxy resin E51 modified with the silane coupling agent (KH550) into bleached poplar veneer. The light transmittance of transparent wood was modulated by KH550 content. The silane coupling agent KH550 was able to change the compatibility of epoxy resin and wood substrate, thereby affecting the performance of transparent wood. In this study, the effect of KH550 on the properties of transparent wood and its mechanism were investigated. The light transmittance, tensile strength, and elongation at break of transparent wood showed an increasing and then decreasing trend with increased KH550 dosage. When the mass ratio of the coupling agent KH550 to the epoxy resin was 1:20, the transparent wood made by impregnating wood substrate with epoxy resin modified by KH550 had the best performance, with the fast degradation starting temperature of 338 °C, 81.07% light transmittance at λ = 780 nm, 59.92 MPa tensile strength, and 3.47% elongation at break. This work provides a new way for preparing high performance transparent wood.

Polygonatum sibiricum (P. sibiricum) and Polygonatum odoratum (P. odoratum) are commonly known Chinese herbal medicine sources. Although they had similar medical effects, the difference between these varieties was verified in this study. Liquid chromatography with tandem mass spectrometry (LC/MS/MS) was used to determine their chemical composition. P. sibiricum has seven chemical components, whereas P. odoratum has only five. Based on the DPPH radical scavenging activity analysis results, half maximal inhibitory concentration (IC₅₀) values of P. sibiricum and P. odoratum were 4.23 and 18.3 mg/mL, respectively. The results of ABTS⁺ radical scavenging activity analysis showed that the IC₅₀ values of P. sibiricum and P. odoratum were 4.77 and 19.3 mg/mL, respectively. Moreover, P. sibiricum had higher total phenolic content (10.0 mg of gallic acid / g of extract), and better reducing ability than P. odoratum. Again, P. sibiricum showed better tyrosinase inhibition ability than P. odoratum, and the IC₅₀ values were 9.68 and 15.4 mg/mL, respectively. P. sibiricum was concluded to have better biofunctionality than P. odoratum.

Calibration transfer between near infrared (NIR) spectrometers is a subtle issue in the chemometrics and process industry. Similar instruments may generate strongly different spectral responses, and regression models developed on a first NIR system can rarely be used with spectra collected by a second apparatus. In this work, two novel methods based on Structural Equation Modeling (SEM), called Enhanced Feature Extraction Approaches for factor analysis (EFEA-FA) and Enhanced Feature Extraction Approaches for spectral space transformation (EFEA-SST), were proposed to perform calibration transfer between NIR spectrometers. They were applied to a NIR nondestructive testing model for solid wood panels mechanical properties. Four different standardization algorithms were evaluated for transferring solid wood panels quality databases between a portable NIRS (InGaAs)-array spectrometer (NIRquest512) and a HSI Camera (SPECIM FX17). The results showed that EFEA-SST yielded the best model evaluation metrics (R² and Root Mean Square Error of Prediction (RMSEP)) values for tensile strength (RMSEP=11.309, R²=0.865) parameters, while EFEA-FA gave the best fit for flexural strength (RMSEP=10.653, R²=0. 912). These results suggest the potential of two novel quality parameters prediction methods based on spectral databases transferred between diverse NIRS spectrometers.

Producing tissue paper is an energy-demanding process; a significant amount of energy is expended when removing water by vacuum, mechanical pressing, and thermal drying. Because the water is most energy-demanding to remove in drying, making the preceding step of vacuum dewatering more efficient would benefit the whole process. This article focuses on developing a laboratory-scale method for verifying the nature of diminishing returns of water removal and investigating efficiency strategies of the vacuum dewatering. The theoretical concept of successive vacuum suction boxes with progressing vacuum levels was tested at the laboratory scale in order to show quantifiable results of the previously solely theoretical concept. The results confirmed that vacuum dewatering can be improved by adding progressively higher vacuum levels and that such a practice can benefit both outgoing dryness levels and expended vacuum pump energy. To truly examine the power of progression of vacuum levels, rewetting can be included in the calculations, by using an approximate value collected from pilot or full-scale measurements. For any new fiber mix, pulp type, vacuum level setup, basis weight, etc. the vacuum levels, rewetting, and dwell times need to be tuned to that specific case.