Volume 20 Issue 1

The optimal amount of biogas slurry was determined to improve both the yield of Brassica chinensis L. (BL) and soil quality. An experiment was set up with six sets of drip irrigation gradients (1:3 mix of biogas and water) of 12 (BS-1), 15 (BS-2), 18 (BS-3), 21 (BS-4), 24 (BS-5), and 27 (BS-6) L. Each treatment was repeated three times and irrigated eight times. The radius of drip irrigation was 1.2 m, and the dripping speed was 2 L/h. The highest plant height, fresh weight, dry weight, soluble sugar content, and protein content of 25.2 cm, 16.7 g, 1.10 g, 0.61 g/100 g, and 1.90 mg/g, respectively, were obtained under the BS-5 treatment. Soil total nitrogen, available phosphorus, and organic matter content under the BS-4 treatment increased 5.29%, 230.75%, and 1.00%, respectively, compared with those before drip irrigation treatment. The soil available potassium content was highest under the BS-3 treatment and had increased 20.4% compared with that before drip irrigation treatment. The most remarkable influence on the yield and quality of BL was observed when the drip irrigation amount was 24 L. Drip irrigation with 21 L of biogas slurry is conducive to improving soil physical and chemical properties.

Releases of CO₂ from forest soils was studied relative to different timber harvesting techniques, slope classes, and stand age. Three timber harvesting techniques (suspended skidding (SS), skidding by using a skidding cone (SC), and cable-pulling (CP)) were used in young and mature black pine stands at three different slopes (0 to 20% – S1, 20% to 33% – S2, and > 33% – S3). Soil respiration measurements were carried out at five-day intervals (1^st, 5^th, and 10^th day) and 6 months later after the timber harvesting techniques. The soil respiration increased on the first day, decreased on the 5^th and 10^th days, and reached its lowest level on the 6th month. The SC technique in the young stands showed the highest soil respiration value on the slopes indicating that the cone placed on the head of the log during the skidding operations does not deform the soil. In the mature stands, all timber harvesting techniques and the undisturbed sites showed lower values than in the young stands on the S1. On the S2, mean value was higher in the mature stands. In contrast to the young stands, the undisturbed stands had the highest soil respiration.

Timber-concrete composite (TCC) beams are formed by integrating timber beams and concrete slabs into a cohesive structural unit using shear connectors. This integration capitalizes on the tensile strength of timber and the compressive strength of concrete, resulting in excellent load-bearing capacity, bending stiffness, vibration comfort, sound insulation, and fire resistance. The long-term behavior of TCC beams must be emphasized, considering the significant time-dependent behaviors of timber, concrete, and the connection system. This work analyzed the long-term mechanical behavior of TCC beams and systematically reviewed the current research on the long-term performance. The primary focus was on the experimental studies of the shear performance of the shear connectors and the mechanical performance of TCC beams under long-term loads. Furthermore, theoretical methods and numerical simulation analyses for evaluating the long-term performance of TCC beams were analyzed. Strengths and weaknesses of existing theoretical methods are identified, and further research and development in the calculation method of TCC beams under long-term loads is proposed.

Nanoemulsions were formulated as hydrogels, incorporating extract from jackfruit leaf (JLE) and consisting of a blend of xanthan gum and fish gelatin (XAN-GEL). Utilizing the spontaneous emulsification technique, single xanthan gum (XAN), single fish gelatin (GEL), and XAN-GEL blends  were hydrated at a mass ratio (0.5 to 2.5% w/v) and were prepared and subsequently assessed for various parameters such as droplet size, polydispersity index (PDI), zeta potential, colloidal stability, and viscosity. Additionally, plain nanoemulsion (NE) and carbomer were synthesized as control samples for comparative analysis. The droplet size, PDI, and zeta potential values of the developed nanoemulsion and gelled nanoemulsion fell within the ranges of 131 to 223 nm, 0.23 to 0.33, and -27.3 to -47.3 mV, respectively. Notably, all formulations exhibited stability except for the lower amount of XAN ratio blends at 1.0% (MD) and 0.5% (ME). Furthermore, all stable nanoemulsion gels demonstrated shear thinning behavior, and the highest amount of XAN ratio blends at 2.0% (MA) enhanced the viscosity of the nanoemulsion by fine tuning the rheological characteristics of the targeted gelled nanoemulsion suitable for future topical drug delivery application.

This study explored a corn quality detection method based on surface-enhanced Raman spectroscopy (SERS) and electronic nose technology. The content of aflatoxin (AFB1) and ochratoxin (OTA) in corn samples was detected by fluorescence immunoassay as the basic data for the experiment. Subsequently, the SERS curve of the corn samples was measured, and the electronic nose was used to analyze the odor of the samples. Combining the relationship between SERS curves, electronic nose data, and the toxin content in corn, a prediction model was established by using the random forest (RF) method. The results showed that the model’s coefficient of determination of the test set for predicting AFB1 reached 0.70, and the model’s coefficient of determination of the test set for predicting OTA reached 0.74. This experiment showed that SERS and electronic nose technology can effectively detect the mycotoxin content in corn samples, which provides a new method to predict the toxin content in corn.

Drilling resistance amplitude was used to estimate properties such as density, modulus of elasticity (MOE), and modulus of rupture (MOR) in Phyllostachys makinoi bamboo. The purpose of this study was to replace subjective visual estimation with a scientific method, using drilling resistance to estimate bamboo maturity, thereby providing a basis for selecting high-quality bamboo materials. The results indicated significant linear correlations between both average and maximum drilling amplitudes and bamboo density, MOE, and MOR. The coefficients of determination (R²) for average and maximum drilling amplitude with bamboo density ranged between 0.55 and 0.56, and a significant linear correlation was also observed between average and maximum drilling amplitudes (R² = 0.75). Additionally, the profile curve of drilling resistance amplitude varied significantly across the thickness of the bamboo culm. From the culm surface inward (bamboo skin, flesh layer, and cavity layer), the amplitude rose rapidly, reaching a peak at approximately 28% of culm thickness, then gradually decreased, with a secondary reduction observed around 67% of the thickness, eventually reaching the hollow core. Based on these findings, maximum drilling amplitude could serve as an indicator of bamboo density and may be applied as a minimally destructive technique for evaluating bamboo quality.

Pyrolysis of biomass residues can generate savings in the value chains of forest products due to the potential uses of its products in the forestry sector. The aim of this study was to determine the performance during slow pyrolysis process and the yields of different products of two types of residues, wood chips and solid wood board-ends from Gmelina arborea. Results showed no significant differences in yields of charcoal (26 to 28%), wood vinegar (28 to 30%) and non-condensable gases (37%), but bio-oil yield was higher for the solid wood board-ends residues (7.7%). The evaluation of energy charcoal characteristics and wood vinegar was similar for two types of residues.  So, results suggest that two types of residues provided similar charcoal, condensable and non-condensable gases yields, but solid board-ends are recommended to obtain higher yield of bio-oil and complete the process in less time. Charcoal and vinegar characteristic were affected by type of residues.

The storage stability of binders before their application is a crucial factor in the wood panel industry, as it impacts the mechanical properties, quality control, economic efficiency, and market competitiveness of the final products. In the present study, the long-term stability of two canola protein isolate (CPI) and two canola meal (CM) adhesive variants was investigated. The protein-based adhesives were prepared and tested on one-layer particleboards after one week, one month, two months, three months, and four months of storage of the formulations. Results indicate that the CPI-based outperformed the CM-based variants in terms of internal bonding strength (IB), modulus of rupture (MOR), and modulus of elasticity (MOE) due to the higher protein concentration of the CPI over the CM. While the IB strength of the CM-bonded particleboards was lower than the EN 319 requirement after the first four weeks of storage (0.34 N/mm² and 0.29 N/mm² for nitrite and bisulfate-crosslinked respectively), that of the CPI-bonded was still superior to the EN 319 after four months (0.44 N/mm² and 0.3 N/mm² for nitrite and bisulfate-crosslinked respectively). This indicates that the nitrite-crosslinked variants had a more robust chemical formulation, leading to stronger and more durable bonds.