The main aim of this study is to determine the physical and chemical properties of biochar synthesized from different materials (straw rice, sawdust, sugar cane, and tree leaves) at different pyrolysis temperatures (400, 600, and 800 °C). The physical and chemical properties such as moisture content, water holding capacity, bulk density, and porosity; and pH, electrical conductivity (EC), organic matter, organic carbon, total nitrogen, potassium, phosphorus, calcium, magnesium, sodium, and sulfur were determined, respectively. The results show that the biochar yield decreased with increasing pyrolysis temperature, and the values of the analyzed properties varied depending on the type of biochar and pyrolysis temperature. The moisture content ranged from 1.11 to 4.18%, and the water holding capacity ranged from 12.9 to 27.6 g water g⁻¹ dry sample. The highest value of bulk density (211.9 kg m⁻³) was obtained from sawdust at a pyrolysis temperature of 800 °C. The porosity values ranged from 45.9 to 63.7%. The highest values of pH and EC (10.4 and 3.46 dS m⁻¹) were obtained from tree leaves at a pyrolysis temperature of 800 °C. Total organic matter ranged from 66.0 to 98.1%, total organic carbon ranged from 38.3 to 56.9%, and total nitrogen ranged from 0.4 to 1.9%. The highest values of phosphorus and calcium content (134.6 and 649.0 mg kg⁻¹) were obtained from sugar cane at a pyrolysis temperature of 800 °C. The magnesium, sodium and sulfur content had ranges of 10.9–51.7, 1124–1703 and 3568–12,060 mg kg⁻¹, respectively.

The main aim of this paper was to investigate the possibility of growing basil under three soilless systems (aeroponic, hydroponic and peatmoss slab systems). A model was developed to predict the nutrients consumption by basil plants. Shoot and root height, fresh and dry mass of whole plant, nutrients uptake, and oil content were studied during the growth period (after 4 and 7 weeks from transplanting). The results indicated that the shoot lengths of basil plants were 71.67 ± 2.89, 65.67 ± 1.15 and 62.33 ± 2.31 cm at the end of growth period for aeroponic, hydroponic and peatmoss slabs, respectively. The highest value of root height of basil plants was 37.67 ± 6.66 cm for aeroponic system. The dry mass of shoot of basil plants ranged from 28.48 ± 0.91 to 44.77 ± 0.97 and 72.98 ± 0.83 to 117.93 ± 1.40 g plant⁻¹ after 4 and 7 weeks from transplanting, respectively. The highest values of the N, P, K, Ca and Mg uptakes were 753.99 ± 5.65, 224.88 ± 3.05, 449.75 ± 4.59, 529.12 ± 6.63 and 112.44 ± 1.67 mg plant⁻¹ at the end of experimental period, respectively. The basil oil content ranged from 1.129 (1.11%) to 2.520 (1.80%) and 2.664 (1.42%) to 6.318 (1.44%) g plant⁻¹ after 4 and 7 weeks from transplanting, respectively at the same pervious order. The production costs of basil plant were 2.93, 5.27 and 6.24 EGP kg⁻¹ of plant. The model results were in a reasonable agreement with the experimental ones.

The bio-composite films based on Hydroxypropyl methylcellulose (HPMC) reinforced with silver nanoparticles (AgNPs) and Titanium oxide nanoparticles (TiO₂-NPs) were developed. Some physical and mechanical properties: Tensile strength (TS), elongation (E), Young’s elastic modulus (EM), water vapor permeability (WVP) and transparency were determined. Antibacterial properties of these films were also studied. The tensile strength values of HPMC film reinforced with Ag NPs and TiO₂-NPs and HPMC without nanoparticles were 39.24, 143.87 and 157.92 MPa, respectively. Elongation of the HMPC film was less than the HPMC film reinforced with AgNPs and TiO₂-NPs, the results were 2, 35 and 42%, respectively. Additionally, Young’s elastic modulus of HMPC film was determined to be 19.62 MPa and the HPMC film reinforced with AgNPs and TiO₂-NPs were 4.11 and 3.76 MPa, respectively. The values of WVP of HMPC film was higher than the HMPC film reinforced with AgNPs and TiO₂-NPs, where they were 0.5076 × 10⁻³, 0.4596 × 10⁻³and 0.4504 × 10⁻³(g/msPa), respectively. Nano-composite films demonstrated strong antibacterial activity against tested pathogen bacteria in the contact surface zone. The antibacterial activites of AgNPs (~ 10 nm) at 80 ppm were more active than 20 and 40 ppm against foodborne pathogen i.e.Bacillus cereusandEscherichia coli, the inhibition zone diameters were 9 and 10 mm, respectively. As well, TiO₂-NPs (~ 50 nm) at 80 ppm were more active than 20 and 40 ppm againstB. cereusandSalmonella Typhimurium, the inhibition zone diameters were11 and 10 mm, respectively.

The main aim of this research is to develop a mathematical model to predict the dissolved oxygen in recirculating aquaculture system. The oxygen consumption of the model through the fish respiration and nitrification and the oxygen addition of the model through oxygen generator and water pumping. The effect of different water temperatures (24, 26, 28, 30 and 32 °C) on the dissolved oxygen consumption through fish respiration, biofilter and nitrification and fish growth were studied. An experiment to measure oxygen consumed by fish respiration and biofilteration and fish growth with the growth period and to validate the model results was carried out. The oxygen consumption predicted by the model was in a good agreement with those measured by the system. The oxygen consumption by fish respiration ranged 12.04 to 47.53 g O₂ m⁻³ h⁻¹ experimentally, while it was from 12.01 to 46.06 g O₂ m⁻³ h⁻¹ theoretically. The predicted and measured oxygen consumption through biofilteration values ranged from 0.43 to 21.91 and 0.45 to 23.09 g O₂ m⁻³ h⁻¹, respectively. The individual fish weight from the system ranged from 3.00 to 209.52 g experimentally while it was from 3.00 to 226.25 g theoretically during the whole period.

Ice cream is a popular dessert product across the world. Structure, body, taste, and odor properties are created by adding non-milk ingredients and milk ingredients. The main aim of the study is to decrease the caloric value of ice cream by using sugar and fat replacements. Ice cream treatments were investigated based on microstructural, chemical, physical, microbiological, sensory, and calorific values. Four different ice creams were used (control ice cream (SC1), ice cream with stevia (SC2), ice cream with sucralose (SC3), and ice cream with sorbitol (SC4)). The chemical properties in all treatments of ice cream were significantly recorded (p < 0.05). The highest sucrose and fat levels were detected in the SC1 treatment compared with the other treatments (p < 0.05). The lowest fat and sugar amounts were observed in the SC2, SC3, and SC4 treatments (p < 0.05). The highest viscosity, overrun, and hardness values (p < 0.05) were detected in the control ice cream. Total aerobic mesophilic bacterial counts were not significantly recorded between different ice cream treatments (p < 0.05). The sensory scores were not significantly affected by sweeteners and bulk agents in the different treatments. The highest calorific value was calculated in the SC1 samples (p < 0.05). On the other hand, the lowest calorific value was calculated in SC2, followed by the SC3 and SC4 treatments. In scanning electron microscopy (SEM), the gel exhibited a homogeneous structure with a fine network within the SC2, SC3, and SC4 treatments, as it contained a cohesive structure with small-sized pores.

Aquaponics is the combined culture of fish and plants in recirculating aquaculture systems, considered to be an innovative, eco-friendly and sustainable technology. The effect of the hydraulic loading rate (HLR) on the performance of fish and plants in the aquapoinc system was the main aim of this study. Four hydraulic loading rates were applied, 1.2, 1.8, 2.4 and 3.0 m day⁻¹ under stocking density tilapia fish of 5 kg m⁻³ and lettuce population of 25 plant m⁻² for a period of January to March, 2023. Water parameters, plant and fish parameters were determined. The most important results revealed that the highest plant nutrients removal was at HLR of 2.4 m day⁻¹. The highest value of water parameters were found at the HLR of 2.4 m day⁻¹. Root length increased with increasing HLR. Fresh and dry shoot and root weight values were higher at 2.4 m day⁻¹ compared to other treatments under study. Meanwhile, fish growth parameter showed higher values at the HLR of 3.0 m day⁻¹ compared to other treatments. The highest values of weight gain, feed growth rate, specific growth rate and feed conversion ratio were 81.72 g, 1.36 g day⁻¹, 1.88% day⁻¹ and 1.20 g feed g⁻¹ fish, respectively, for all treatments under study.