Research Articles

The percentage depth doses of various wood-based phantom materials were  evaluated using Monte Carlo GATE simulation at 6MV photon beam. Several elemental compositions of phantom materials developed over the years were collected retrospectively, and the data were used to build each phantoms’ specific geometries and compositions in a Monte Carlo GATE algorithm. Upon the construction of the linear accelerator in GATE, the percentage depth doses were measured for each of the phantom materials, and results were recorded accordingly. The output revealed that all of the samples pass the 3 %/2 mm comparison by gamma index at 96.8%. The findings of this work supported the potential of wood-based phantom material in radiotherapy and medical physics application.

Agricultural waste is a growing global concern, with about 30% of food that is currently wasted in Brazil. Melon (Cucumis melo), which is widely cultivated in semi-arid regions, generates significant residues, including seeds, peels, and pulp, that are often discarded improperly, causing environmental impacts. These by-products have a rich lignocellulosic composition, making them promising raw materials for biofuels, bioplastics, and other valuable renewable compounds. Importantly, their use does not compete with the food supply, aligning with circular economic principles. This study evaluated the potential of seeds from five melon varieties as lignocellulosic biomass. The seeds underwent pretreatment by drying under controlled conditions and grinding to produce a homogeneous powder for analysis. Moisture, ash, and lignocellulosic components (cellulose, hemicellulose, and lignin) were assessed. Data were analyzed using ANOVA and Tukey’s test to identify significant differences among varieties. The caipira and cantaloupe varieties exhibited notably high holocellulose and lignin contents. Elevated holocellulose levels enhance the structural integrity of sustainable materials, while lignin contributes antimicrobial properties and serves as a precursor for high-value compounds such as resins, antioxidants, and bio-based polymers.

Camellia oleifera shell was pyrolysed at 300 to 750 °C to investigate biochar and bio-oil yields under different conditions, and the relationships between pyrolysis temperature and the product yields were established. The thermal decomposition behavior, biochar characteristics, and bio-oil composition were analyzed. The fixed carbon content of C. oleifera shell reached 22.2%, exceeding common biomass materials. Biochar yield decreased from 57.9% to 31.7% as temperature increased from 300 °C to 750 °C, while bio-oil yield increased from 14.4% to 37.1%. The established temperature-dependent yield models demonstrated excellent predictive capability (R²=0.99). Final carbonization levels under heating rates of 5, 10, and 15 °C/min were 35.4%, 29.4%, and 27.2%, respectively. Biochar pore volume increased with pyrolysis temperature, while specific surface area and average pore diameter exhibited an initial rise followed by decline. Specific surface area increased as temperature rose, with predominant pore diameters distributed between 10 and 30 nm. Bio-oil composition analysis revealed acids as predominant components (40.9% to 49.9%), followed by phenols (20.2% to 27.3%), aldehydes (9.2% to 10.2%), ketones (8.4% to 11.8%), esters (3.4% to 3.6%), and alcohols (0.41% to 1.07%). This study provides guidance for optimizing pyrolysis conditions to obtain target products.