Volume 21 Issue 1

Biobased aerogels derived from starch offer a promising pathway for developing sustainable biomaterials. This study examines the use of starch extracted from potato peels to develop aerogels intended for glycine storage and controlled release. The reaction of starch with glutaraldehyde, used as a crosslinker, was demonstrated using Fourier-transform infrared spectroscopy, revealing the formation of hemiacetal bonds. Crosslinking enhanced thermal stability of the aerogels, as shown by thermogravimetric analysis, and improved their resistance to disintegration upon hydration. Glycine, an essential amino acid with agricultural and industrial applications, was loaded into the aerogels, and the release kinetics were evaluated under controlled conditions. Moreover, glycine acts as a neutralizing agent for residual glutaraldehyde, ensuring the suitability of the aerogel for applications where glutaraldehyde toxicity could be a concern. Structural characterization through scanning electron microscopy confirmed the porous architecture of the aerogels and revealed the presence of glycine crystals within the pores. These findings underscore the potential of crosslinked starch aerogels as eco-friendly carriers for bioactive molecules, paving the way for their application in agriculture and other fields.

Lignin, as the most abundant renewable aromatic polymer on earth, holds immense potential as a feedstock for value-added products. However, its recalcitrant and heterogeneous structure presents significant challenges to efficient valorization. While microbial and enzymatic bioconversion offers a sustainable and specific route for lignin depolymerization, industrial implementation is often hindered by limitations such as low enzymatic efficiency, poor operational stability, and restricted substrate accessibility. This review systematically summarizes the current state of lignin bioconversion, focusing on the capabilities of various fungi and bacteria and the ligninolytic enzymes they produce, notably laccases and peroxidases. A key emphasis is placed on the emerging roles of “green” solvents, specifically ionic liquids (ILs) and deep eutectic solvents (DESs), in overcoming these limitations. These solvents not only enhance lignin solubility but also can activate and stabilize ligninolytic enzymes, thereby enabling more efficient depolymerization reactions. This review examines the mechanisms, advantages, and current challenges of integrating ILs and DESs into biomass lignin upgrading strategies. Finally, it discusses future research directions and potential application prospects.

A taishōgoto is a Japanese instrument that combines a guitar and an autoharp with the scale buttons positioned in a piano-like pattern. Its unique design, which combines a strung zither body with a keyboard mechanism akin to a typewriter, makes it relatively easy to achieve precise pitch while generating a rich, bright timbre full of overtones. For open string, the gradient of the partials frequency versus the partials indicates the value of 100.95 (i.e., G2) is half the fundamental frequency i.e.,195 Hz (i.e. G3). For harmonicity (fn/f0) versus the partials number, the gradient of ~0.5 shows that the partials consist of the harmonic and in-harmonics partials. For fret 3, the gradient of the partials frequency versus the partials is 229.46 (i.e., A3#), equivalent to the fundamental frequency (f0) of 232 Hz (A3#). The taishogoto regardless finds practical applications in spite of these limitations. It has been evolved into a variety of genres, such as jazz, world, and folk music, and it continues to be of interest to experimental composers who are experimenting with its unique tonal characteristics. The taishogoto thus has a special place between usefulness and artistry, history and modernity, and innovation and limitation.

The influence of environmental factors on variations in organic compound content of sapwood and inner bark of mature Persian oaks were investigated in the Zagros forests, western Iran. Trees with four levels of defoliation were selected: healthy, light, moderate, and severely defoliated. First, wood and bark flours were prepared based on standard TAPPI test methods. The extractives of the tissues were obtained using Soxhlet and acetone solvents. Subsequently, the extractives compounds were derivatized using a silane-based compound and then analyzed by gas chromatography-mass spectrometry. Six dominant compounds were detected in the wood and bark of healthy oaks, with 1,6-anhydro-β-D-glucopyranose (levoglucosan) and 1,2-benzenedicarboxylic acid (phthalic acid) being the most abundant components. In trees with light defoliation, five dominant compounds were identified, among which phthalic acid and salicylic acid were the most abundant components. In trees with moderate dieback, 6-aza-5,7,12,14-tetrathiapentacene (heteropentacene) and salicylic acid were found in the greatest quantities, while in trees with severe dieback, salicylic acid and phthalic acid were the dominant components in the wood and bark of Persian oak trees. Salicylic acid and gibberellin A3 were common components in all bark and wood samples, while other compounds differed between different classes of dieback.

Poplar wood (Populus deltoides), a fast-growing and abundant species, holds promise for sustainable material use, but its low density, poor dimensional stability, and weak strength restrict high-value applications. This study examined property enhancement through resin impregnation with phenol-formaldehyde (PF), melamine-urea-formaldehyde (MUF), and polyethylene glycol (PEG) at 5%, 10%, and 15% concentrations. Modified specimens were tested for weight percent gain, bulking, water absorption, dimensional swelling, modulus of rupture, modulus of elasticity (MOE), impact strength, and surface hardness, as well as machinability and carving performance using expert evaluation and Computer Numerical Control (CNC) surface quality. Given the laboratory-scale dimensions of the specimens, the resins achieved satisfactory penetration, as also reflected in the WPG values. The 15% PF treatment produced the greatest improvements, yielding a WPG of 26.3%, MOE above 10,000 MPa, and reduced surface roughness to 2.90 µm. Compared with untreated samples, PF-modified wood showed superior dimensional stability, machining resistance, and carving clarity, approaching the properties of hardwoods such as walnut and beech. MUF led to moderate benefits, whereas PEG mainly caused bulk increase without significant strength or moisture resistance improvements. Overall, PF impregnation effectively upgraded poplar wood, indicating its potential as a cost-effective alternative for decorative and structural applications.

The purpose of this study was to fit and compare semi-empirical thin-layer drying models and an artificial neural network (ANN) model to describe the drying kinetics of wood fiber in a near-infrared (NIR) dryer. The drying kinetics of wood fiber were evaluated using 18 semi-empirical models at three temperatures (105, 120, and 135 °C), utilizing a halogen moisture analyzer. The ANN model was designed with temperature and time as input factors and moisture content as the output variable. The findings revealed that the drying process was mainly controlled by a diffusion mechanism, and all the process occurred in two falling drying rate periods. The fitness of drying curves on semi-theoretical models based on statistical parameters, including RMSE, SSE, and R² showed that there was not much difference between equations with a maximum of two constant parameters and equations with more than two constant parameters. Therefore, using a simple model can help to reduce the time of the analysis and is beneficial to avoid using complex drying models. Also, the results showed that at higher drying temperatures (120 to 135 °C), both ANN and the best-performing semi-empirical models (Page and Henderson–Pabis) produced comparable accuracy, whereas at lower temperature (105 °C), ANN performed better due to its flexibility.