Volume 19 Issue 1

Wild (or lowbush) blueberries (Vaccinium angustifolium Ait.) undergo severe drought impacts due to climate warming because they grow in sandy soils with poor water retention. The feasibility was studied for using biochar in a forest biomass-fueled combined heat and power (CHP) plant to amend the sandy soils. The chemico-physical properties (e.g., bulk density, moisture content, porosity, pH) of the biochar were measured. An acid treatment method (1% to 3% acidic or citric acid solution) was developed to decrease the biochar pH from 11.4 to neutral or lower, aiming to aid in weed control in wild blueberry fields. The water holding capacity (WHC) of sandy soils (S) mixed with biochar (B) (Type I) and sandy soils mixed with both biochar and fertilizer (Type II) at four ratios of 100S:0B (control), 50S:50B, 30S:70B, and 10S:90B were measured. The biochar generated from the CHP plant had comparable physical properties (such as bulk density, porosity, pH, and surface area) with woody biochar made from pyrolysis. The acid treatment method significantly lowered the pH to a range of 5.0 to 6.5. The 50:50 mixing ratio for both Type I and Type II increased the water holding capacity by about 20% compared with control groups.

In NIR spectral modeling, the method of screening wavelengths with consistent stable signals (SWCSS) is based on a standard-free algorithm. However, the wavelengths selected by SWCSS may contain invalid information. In this paper, the Competitive Adaptive Reweighted Sampling (CARS) wavelength optimization algorithm was used in conjunction with SWCSS to eliminate the uninformative variables in the wavelengths selected by SWCSS. The SWCSS-CARS method was based on three near-infrared spectrometers (Lengguang 1, Lengguang 2, and Lengguang 3), with Lengguang 1 as the master and the other two instruments as the targets, using a total of 84 sample spectra of five types of pulpwood and their lignin contents as the research objects. Compared with the full spectrum, the number of wavelengths was reduced from 1601 to 24 in the model built using the coupling algorithm. For target 1, the value of RPD was improved from 1.9247 to 3.1880; for target 2, t the value of RPD was improved from 1.7415 to 3.2508. The wavelengths selected by the SWCSS-CARS coupling algorithm were able to build stable, robust models.

Recent research has explored the potential of rice husk biochar as a low-cost adsorbent for the removal of contaminants from aqueous solutions, including aldrin, mercury (Hg²⁺), lead (Pb²⁺), and cadmium (Cd²⁺). Experimentation involved adding varying doses of biochar to wastewater with different contamination levels, agitating the mixture for 60 min, and filtering the solutions for analysis. The experiment revealed impressive removal efficiencies: 100% for aldrin, 99.92% – 99.99% for Hg²⁺, 95.90% – 99.52% for Pb²⁺, and 88.60% – 99.46% for Cd²⁺. In binary and quaternary mixtures, Hg²⁺ showed higher removal efficiency than Pb²⁺ and Cd²⁺, with the exception of aldrin. The adsorption order was identified as aldrin > Hg²⁺ > Pb²⁺ > Cd²⁺. The Freundlich adsorption isotherm best described heavy metals in the mono and quaternary component adsorption, while the Langmuir adsorption isotherm was a better fit for the binary component. Consequently, the study highlights rice husk biochar as an efficient, sustainable, and environmentally friendly option for wastewater treatment.

The group composition of alcohol extracts from balsamic poplar leaves Populus balsamifera L, growing in the Krasnoyarsk Krai, Krasnoyarsk (Russia) were examined in this work. Leaves selected in different phases of the growing season were used: June, July, August – fresh, September – fallen leaves. Poplar leaves contain up to 56% of extractive substances, alcohol-soluble substances account for up to 67% of the extract amount. Alcohol extracts were fractionated using solvents with increasing polarity: petroleum ether (boiling point 40 to 70 °C), diethyl ether, ethyl acetate, butanol. The results showed that the alcohol extracts of poplar leaves are dominated by substances extracted with ethyl acetate (up to 60%). The study of the component composition of volatile compounds of individual fractions of alcohol extracts was performed on an Agilent chromatography-mass spectrometer. The presence of various groups of compounds was established: hydrocarbons, alcohols, acids, ketones, etc., including biologically active substances such as megasterol acetate, ℽ-sitosterol, sitosterol, 3,7,11,15-tetramethyl-2-hexadecene-1-ol, diethyltoluamide, 4-methoxy-3-nitrobiphenyl, and other compounds that it can be used in different applications.

Phosphoric acid-hydrogen peroxide (PHP) pretreatment is an effective method to obtain a cellulose-enriched fraction from biomass. In this study, artificial neural network (ANN) was used to predict PHP pretreatment efficiency of cellulose content (C-C), cellulose recovery (C-R_y), hemicellulose removal (H-R_l), and lignin removal (L-R_l) under various conditions of pretreatment time (t), temperature (T), H₃PO₄ concentration (C_p), and H₂O₂ concentration (C_h). The final optimized topology structure of the ANN models had 1 hidden layers with 9 neurons for C-C and 10 neurons for C-R_y, 10 neurons for H-R_l, and 12 neurons for L-R_l. The actual testing data fit the predicted data with R² values ranging from 0.8070 to 0.9989. The relative importance (RI) revealed that C_p and C_h were significant factors influencing the efficiency of PHP pretreatment with total RI values ranging from 12% to 62.6%. However, their weights for the three components of biomass were different. The value of T dominated hemicellulose removal effectiveness with an RI value of 78.6%, while t did not seem to be a main factor dominating PHP pretreatment efficiency. The results of this study provide insights into the convenient development and optimization of biomass pretreatment from ANN modeling perspectives.

Laminated veneer lumber (LVL) and laminated veneer board (LVB) panels from jabon wood (Neolamarckia cadamba) were impregnated with fire retardation substances, namely diammonium phosphate (DAP) and sodium silicate (SS). Prior to testing, the boards were conditioned in relative humidity (RH) of 65% and a temperature of 25 °C. The moisture content (MC), bending strength tests in flat wise position, and bonding tests were conducted in accordance with the Japanese Agricultural Standard (JAS:2008). Density tests and hardness tests were conducted in accordance with ASTM D143 standard (2003) in 50 mm x 50 mm. Thickness-swell shrinkage tests were conducted in accordance with the standard BS EN 317:1993, and fire resistance was tested under PS 1-19 standard. The use of 20% DAP and SS solution on jabon wood using impregnation methods affected some of the properties of the panels, especially the moisture content, density, and bonding strength of LVL and LVB compared to the control panels.  Both DAP and SS impregnation increased the density. The treatments showed promise for resisting fire, as well as increasing the moisture content and increasing the density compared to the control.

Through-tenon joints are widely used in ancient timber buildings. To study the influence of the gaps between mortise and tenon shoulder on the seismic performance of through-tenon joints, a 1:3.52 scaled model was constructed and used for low cyclic loading test. Finite element analysis was conducted to study the mechanical behavior of the through-tenon joint. The seismic performance parameters of the model such as moment-rotation hysteresis curves, envelope curves, degradation of rigidity, and energy dissipation capacity were compared. The analyses showed similar changing characteristics, which indicated that the finite element analysis results were reliable. Based on the results, 7 through-tenon joint finite element analysis models with different gaps between mortise and tenon shoulder were established. The seismic performance of each of the through-tenon joints with different gaps between mortise and tenon shoulder were studied. The moment-rotation hysteresis curve of the through-tenon joint had an obvious pinching effect, and the through-tenon joint had good rotational loading capacity and good deformation ability. The peak rotational loading capacity, initial stiffness, and energy dissipation capacity of the joint decreased, while the gap between mortise and tenon shoulder increased.

Flow and spontaneous imbibition phenomena in porous media are important for various industrial applications, including printing and medical lateral flow assays. Their quantitative characterization is important to better understand and select the appropriate raw materials. However, standard methods often require time-consuming tests, and/or expensive equipment. Different time scales must be considered, limiting the range of possible characterization tools. A novel experimental approach based on image analysis for characterizing spontaneous imbibition processes is presented. Hence, ultra-fast diffusion may be quantitatively characterized. Models are issued from the literature to consider physical phenomena at small (milliseconds) and medium range (seconds) of time scales.  The obtained experimental data fit with theoretical results, providing valuable insights into the understanding of fluid flow behavior at different time scales. Furthermore, the identification of some physical properties for either the fluid, or the substrate, based on the theoretical models are possible, as the contact angle, which remains to be otherwise challenging.  This study contributes to bridging the gap between spontaneous imbibition and capillary phenomena at different time scales, their modeling, and a characterization of material and/or fluid properties paving the way for enhanced understanding and control of fluid behavior in porous media. Different papers are considered to illustrate the method.

Montmorillonite (MMT) was used to improve the performance of starch and nano-ZnO was added to act as antibacterial agent for developing a starch-based active packaging material via solution mixing and casting methods. The effect of MMT and ZnO on the performance of starch films was investigated, and then the composite films were used for cherry preservation. The results indicated that the addition of MMT could improve the mechanical and water-vapor barrier properties of starch films, but it had only a slight impact on optical properties. However, the addition of nano-ZnO could reduce the optical, mechanical, and water vapor barrier properties of composite films. In preservation applications, compared to the other films, the composite films containing nano-ZnO could be beneficial to maintain quality and nutritional value of cherries by slowing down the growth of bacteria and thereby delaying weight loss, decreasing hardness, and decreasing pH and soluble solid content, resulting in a better preservation effect. Therefore, a starch-based active packaging film with good properties and preservation effect was developed with nano-ZnO and MMT, which could be applied in the field of preservation.

Researchers have recently been interested in employing nanoparticles (NPs) obtained from herbal extracts through green synthesis for various applications. This study investigated the detoxification of aflatoxins, which are toxic substances produced by molds Aspergillus flavus and Aspergillus parasiticus. The present work examined the levels of aflatoxins in hazelnut and peanut puree. Turkish black tea extract (BTE), Turkish green tea extract (GTE), green synthesized black tea-based iron oxide nanoparticles (BTFeONPs), and green tea-based iron oxide nanoparticles (GTFeONPs) were produced for aflatoxin removal. Characterizations and various antioxidant and antimicrobial activities of the tea extracts and iron oxide nanoparticles (FeONPs) were investigated. The aflatoxin levels of hazelnut puree used for this study were 6.57 ± 0.06 µg/kg for aflatoxin B₁ and 13.03 ± 0.16 µg/kg for total aflatoxin, whereas the aflatoxin levels of (AFLB₁) peanut puree were 7.79 ± 0.15 µg/kg for AFLB₁ and 15.21 ± 0.12 µg/kg for total aflatoxin. Using soluble BTE resulted in a 40 to 50% decrease in aflatoxin levels in hazelnut and peanut purees, while soluble GTE led to a 30 to 45% decrease. Meanwhile, using BTFeONPs and GTFeONPs resulted in a 33 to 48% and 40 to 50% decrease, respectively, in aflatoxin levels in hazelnut and peanut purees.