Volume 18 Issue 4

Tricin is a complex compound with chemical bonds to phenylpropane units of lignin in gramineous plants, and it is predominantly bound to lignin by β-O-4 ether bonds. Thioacidolysis cleaves the alkyl aryl ether bonds, which releases tricin from the tricin-lignin complex and maintains the natural structure of the tricin. In this study, milled wood lignin (MWL) was isolated from wheat straw by Bjӧrkman’s method, and the MWL was subjected to thioacidolysis to release tricin from the MWL. Medium-pressure preparative liquid chromatography was used for further purification. FT-IR and ¹H-NMR analyses showed that the purified fraction was composed mainly of tricin-type flavonoids. The extracted tricin had strong scavenging capacity against 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radicals, with a half maximal inhibitory concentration (IC₅₀) of 51.9 mg/L. Drug sensitivity paper testing showed that the extracted tricin inhibited the growth of Escherichia coli. The bacteriostatic circle diameters of tricin from wheat straw MWL and quercetin standard were 9.17 and 7.52 mm, respectively. A 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay showed that the tricin from wheat straw MWL had possible inhibitory effect on lung cancer A549 cells, with a maximum inhibitory performance of 44.5%.

An environmentally friendly approach was studied for improving the fire retardancy of beech wood using a steam explosion process coupled with a phosphorylation reaction. Raw beech, steam-exploded, or bleached wood was subjected to phosphorylation employing etidronic acid (HEDP) and urea, and the resulting chemical composition and thermal behavior were analyzed using techniques such as elemental analysis, Fourier transform infrared spectroscopy, ionic chromatography, and pyrolysis combustion flow calorimetry. The thermal performance of beech wood underwent significant enhancements after the steam explosion treatment combined with soda impregnation. It resulted in a striking reduction in heat release rates (HRR), especially its peak (pHRR) and time-to-pHRR (T_pHRR) values (from 139.5 W/g and 365 °C to 40 W/g and 247 °C) and an increase in residue from 10.5% to 41.3%. The results demonstrate that the process created a self-extinguishing and non-flammable material that exhibited noteworthy flame retardancy improvement.

Differences in the pyrolysis characteristics of leaves of sweet cherry tree (Prunus avium L.) under rain-shelter cultivation (RS) or under open-field cultivation (CK) were analysed using thermogravimetry (TG), derivative thermogravimetry (DTG), and differential scanning calorimetry (DSC) at three heating rates of 10, 20, and 30 °C·min^-1. There were two obvious mass loss peaks at 280 °C and 330 °C, which were manifested by the slow pyrolysis of hemicellulose in the low temperature region and the rapid pyrolysis of cellulose in the high temperature region, respectively. The curve in the pyrolysis range after 440 °C was stable, and the mass change corresponded to the pyrolysis of a small amount of macromolecular organic extracts and inorganic salts. When the temperature reached 600 °C, approximately 69% and 73% of the CK and RS leaves were thermally destroyed, respectively. The Coats-Redfern method was used for kinetic calculations to obtain an activation energy of 29.8 to 36.1 kJ·mol^-1 in the first-order pyrolysis kinetics stage. The second-order pyrolysis kinetics stage can fit the pyrolysis process well. A significant difference was observed in the pyrolysis characteristics or the kinetics between CK and RS, which were related to the heating rate and the hemicellulose content, cellulose content, and lignin ratio in each sample.

Paper coated with natural materials has advantages over paper coated with fossil resources, including easy recycling, renewable components, and cost-effective formulation. Coating the paper surface with thyme oil has antibacterial and antioxidant properties and is known to improve packaging product quality. In the current study, the water resistance of the materials was measured by the Cobb30 values. The base paper, the starch-coated paper, and the thyme oil and starch-coated paper had Cobb30 values of 20, 17.5, and 15.7 g/m², respectively. The tensile strength index of uncoating and coating paper samples was, respectively (machine direction M.D.) 64.3 and 64.7, and (cross direction C.D.) 32.2 and 37.2. The bursting strength index results were 72.7 and 84.0. Hence, according to the tensile strength results, the treated paper burst strength values were higher than the base paper samples. The starch and thyme oil coatings formed a film layer on the paper surface, which may have helped impart better burst-strength properties. Besides, compared to the untreated base papers, the surface of the coated papers was denser and smoother, with a less porous structure, according to SEM results. In addition, resistance features of papers that are desired in the end-use of paper are shown in this work based on paper strength property tests.

Salix psammophila was converted to value-added chemicals in the presence of 1-butyl-3-methylimidazolium chloride ([Bmim]Cl) and water by the hydrothermal liquefaction method. [Bmim]Cl acted as both liquefier and catalyst, while water served as both co-solvent and reactant. The optimal reaction parameters for the highest liquefaction yield were determined by an orthogonal experiment. The possibility of application of the recycled [Bmim]Cl was investigated. FT-IR spectra results of the fresh used, the firstly reused, and the secondary reused IL [Bmim]Cl confirmed the high stability of [Bmim]Cl. Moreover, an explanation of the possible liquefaction mechanism for S. psammophila was also provided. This study may provide fundamental data for S. psammophila conversion and application.

Beech (Fagus sylvatica L.) and pine (Pinus sylvestris L.) wood specimens were heat-treated separately at three different temperatures (170 °C, 190 °C, and 210 °C) with steam treatment method (STM), oil treatment method (OTM), and hot-air treatment method (HTM). Then, the specimen surfaces were coated with water-based, polyurethane-based, and oil-based varnishes according to industrial applications. The study results show that both hardness and adhesion strength values of STM and HTM treated specimens were similar for both wood species. In contrast, these values were generally lower in OTM-treated specimens. For all applied methods, heat treatment temperature had no significant effect on hardness values. Varnish adhesion strength decreased in all heat-treated wood specimens compared to untreated specimens. Adhesion strength also decreased in STM- and HTM-treated specimens with increasing heat treatment temperature. Hardness values increased in all specimens coated with polyurethane- and water-based varnish compared to the specimens without varnish. However, hardness decreased in the specimens coated with oil-based varnish. In contrast, the highest adhesion resistance was determined in the specimens coated with oil-based varnish under all heat treatment conditions. In addition, the heat treatment method is more effective relative to the hardness values and the treatment temperature is more effective relative to the adhesion strength of varnished pine and beech specimens.

The effects of CeO₂, ZrO₂, Nb₂O₅, and ZnO catalysts supported on carbon nanotubes (CNT) relative to cellulose hydrothermal hydrogenolysis in the presence of Ni/CNT and pressured H₂ was studied in this work. The catalysts were characterized by inductively coupled plasma – optical emission spectrometry, X-ray diffraction, X-ray photoelectron spectrometry, transmission electron microscopy, NH₃ temperature programmed desorption (TPD), and CO₂-TPD. Glucose and its isomers were detected by mass spectrometry. The results showed that redox active CeO₂/CNT with strong Lewis acid and strong Lewis base sites was active in C-C bong cracking, isomerization, dehydrogenation, and hydrodeoxygenation reaction, yielding 36.3% ethylene glycol and 17.2% 1,2-propylene glycol. The ZnO/CNT with Bronsted base accelerated isomerization, retro-aldol condensation, and dehydrogenation, yielding 20.7% 1,2-propylene glycol, 17.8% ethylene glycol, and 12.7% tetrahydrofuran dimethanol. The Nb₂O₅/CNT and ZrO₂/CNT were inert to C-C bond cracking, whereas H⁺ in hot compressed water and the Bronsted acid in Nb₂O₅/CNT accelerated dehydration, yielding more sorbitol and sorbitans. The results provide reference for catalyst selection and product regulation in cellulose hydrogenolysis.

As the only renewable building material, wood has a strong carbon sequestration effect. Thus, timber structures have the natural advantages of saving energy and reducing emissions. Currently, the research objects of building energy consumption are rarely timber structures. To further control the operational energy consumption of timber structures, this paper takes six-story glued laminated timber beam-column frame and light wood-frame shear wall structures as the research objects. Building energy consumption research is conducted through testing the heat transfer coefficient of the envelope structure, air circulation ratio, and Building Information Modeling (BIM) technology on-site. The results show that the energy consumption of the building is consistent with the current energy consumption of small- and medium-sized office buildings, and the heat gain and loss of the building are mainly due to solar radiation and heat conduction of the envelope, respectively. The airtightness of the building has the greatest influence on the energy consumption of the building, and the type of building structure and window-to-wall ratio have little influence on the energy consumption of the building.

This article presents a methodology based on web mining techniques for estimating furniture prices using e-commerce data. Data on different public e-commerce sites in the United States were collected and analyzed using web mining methods. Deep learning and random forest algorithms were used to predict the prices of different types of furniture. Bookcase and dresser type furniture, which are widely used in price estimation, were selected. The inquiry identified a collection of eight distinctive attributes linked to furniture items, spanning measurements such as width, depth, and height, alongside features encompassing frame material, partition count, drawer count, color, and price. In preparation for constructing predictive models, a dataset comprising 300 instances was compiled for comprehensive analysis. Models developed based on web mining to predict furniture prices gave satisfactory results. During the testing phase, the random forest algorithm outperformed deep learning, achieving high goodness of fit values of 0.89 and 0.94 for bookcase and dresser furniture, respectively. The results indicate that price estimation for dresser furniture was more accurate than for bookcases in all models. The findings demonstrate that web mining techniques can be used effectively in competitive furniture pricing, with potential to save time and cost in pricing for furniture purchasing.

Cerrado is the second largest Brazilian morphoclimatic domain. Despite being a region of great ecological importance, it has been the target of constant threats caused by anthropogenic activities, mainly those related to agriculture and livestock farming. With a rich biodiversity still not fully known and constantly being devastated, the Cerrado lacks studies. The objective of this study was to microscopically analyze the wood of Cerrado tree species. Wood samples were collected from nine tree species in a Cerrado area located in Monte Carmelo, Minas Gerais. Microscopic analyses were carried out on permanent histological slides and macerated material, following IAWA Committee standards. This work provided information on species whose wood had not been previously described in the literature, such as Machaerium opacum and Eugenia dysenterica, as well as on previously described species.