Nutrient supply systems and their effect on the performance of the Nile Tilapia (Oreochromis niloticus) and Lettuce (Lactuca sativa) plant integration system.

The main aim of this work is to study the effect of different nutrient supply systems and their effect on the performance of the Nile Tilapia (Oreochromis niloticus) and Lettuce (Lactuca sativa var. crispa) plant integration system. To achieve that, five treatments having different culture systems (T1: Aquaculture (control), T2: Hydroponics (standard requirement: N = 210, P = 31, K = 234, Mg = 48, Ca = 200, S = 64, Fe = 14, Mn = 0.5, Zn = 0.05, B = 0.5, Cu = 0.02 and Mo = 0.01 ppm), T3: Aquaponics without nutrients addition, T4: Aquaponics with supplementary nutrients (KNO3, 101 g L-1, KH2PO4, 136 g L-1, Ca(NO3)2, 236 g L-1, MgSO4, 246 g L-1, K2SO4, 115 g L-1 and chelates for trace elements) in water (EC is 800 ppm) and T5: Aquaponics with supplementary nutrients spray on plants) were carried out. The previous systems were operated at three flow rates, namely, 1.0, 1.5 and 2.0 L h-1 plant-1. The various water quality parameters, plant growth and fish growth were studied. The result indicated that the highest values of N, P, k, Ca and Mg consumption rate were found with T2 and 1.5 L h-1 plant-1 of flow rate. The root length, fresh and dry of shoot and root for lettuce plants grown in T2 system was better than those grown in different culture system (T3, T4 and T5). Different culture systems showed significant effect on fish growth in terms of weight gain, specific growth rate and feed efficiency ratio. Higher growth rate was observed in treatment T3 as compared to other treatments. The production costs ranged from 2820.5 to 4885.4 LE ($ = 30.92 LE) for all culture systems.

Effect of drying system, layer thickness and drying temperature on the drying parameters, product quality, energy consumption and cost of the marjoram leaves.

The main aim of this work is to study the main factors affecting the quality of the dried product and the energy requirements through optimizing these factors. To achieve that different drying systems (solar, hybrid solar and oven dryings), layers thickness (1, 2 and 3 cm) and drying temperatures (50, 60 and 70 °C) were used. The obtained results indicated that, the accumulated weight loss of marjoram leaves ranged from 73.22 to 76.9%, for all treatments under study. The moisture content of marjoram leaves ranged from 273.39 to 333.17, 258.02 to 333.04 and 269.38 to 324.90% d.b. for hybrid solar, oven and solar drying systems, respectively. The highest value of the drying rate of marjoram leaves (223.73 gwater kg-1 h-1) was obtained when the marjoram dried by oven drying system at 70 °C at 1 cm layer thickness. The highest values of the basil and marjoram oil content (2.91%) was obtained when the marjoram dried under sun drying system. The energy consumption for drying marjoram decreases with increasing drying temperature and layer thickness for hybrid solar and oven drying systems. The cost of dried marjoram dried under hybrid solar drying system was lower than those of oven drying system, the highest cost (13.48 LE kg-1) was obtained at a temperature of 50 °C and a layer thickness of 1 cm.

Improvement of the production of bio-oil and biodiesel from Egyptian Jatropha seeds by using microwave and ultrasonic.

Bio-diesel is used for engine as a replacement of diesel fuel which is characterized by lower emission, low pollution and renewable some of fuel. This study focus on how to enhance the production of bio-oil from Jatropha seeds by using microwave and ultrasonic as pre-treatments. To achieve that, the effects of extraction temperature (60, 80, 100 and 120 °C) and extraction screw speed (60, 90 and 120 rpm) on oil extraction yield and quality, extraction energy requirements and extraction time and were studied. Studying the effect of pretreatments by microwave and ultrasonic on the yield, energy and time of extraction were studied. The results most important indicate that the highest oil yield (25.1%) was recorded at 120 °C extraction temperature and 60 rpm screw speed. The energy required for extraction ranged from 8 to 11.5 W.h depending on temperature and speed of extraction. The results indicated that using both pretreatments improve the oil yield by 5.03% for microwave and by 6.75% for ultrasonic. Finally, the results concluded that to produce 1 kg of biodiesel you need 1.1 kg raw oil and consume from 2052.5 W.h energy requirement.

Biochar production under different pyrolysis temperatures with different types of agricultural wastes.

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.

Study on the plant and fish production in the aquaponic system as affected by different hydraulic loading rates.

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.

Effect of loading rate and source of energy on the drying parameters of the basil during drying.

The basil leaves were dried different sources of energy at different loading rates. Using hybrid solar drying compared to the conventional source of energy such as fossil and propane. Drying parameters were studied. Also, product quality was assessed under study treatments. The results indicated that the higher accumulated weight loss of basil leaves (75.56%) were obtained at 25 kg m-2 loading rate and solar drying system. The highest rate of the decrease in moisture content of basil leaves was happened at the 45 kg m-2 loading rates. Meanwhile, the lowest rate of the decrease in moisture content of basil leaves was found at 15 kg m-2 loading rates. The highest drying rate of basil leaves (219.54 gwater kg-1 h-1) was obtained at the loading rate of 15 kg m-2. The highest values of total chlorophyll and color of basil leaves 745.9 and 36.35 were found for solar dryer. The lowest values of total chlorophyll and color of basil leaves 703.5 and 31.66 were found for diesel dryer. The drying efficiency ranged from 33.98 to 40.33% for all batch loads. The highest essential oil yield obtained for solar dryer, the lowest essential oil yield occurred for diesel dryer. The highest value of volatile compounds with found for solar dryer. The total costs for basil drying were 19.73, 26.70 and 23.93 LE h-1 for solar, diesel and propane dryers, respectively. Also, the total costs of basil drying were 8.77, 13.15 and 12.27 LE kg-1 dried for solar, diesel and propane dryers, respectively.

Enhancing bio-oil yield extracted from Egyptian castor seeds by using microwave and ultrasonic.

Energy scarcity and conventional energy problems are the main reason of finding a renewable source of energy which is cheap and environmental friendly, therefore, biodiesel production is one of the most promising solutions of this problem. Also, Egyptian castor is one of the most important crops for oil production compared with other commonly used oil crops. The main aim of this study is to enhance the production of bio-oil from Egyptian castor seeds by using microwave and ultrasonic as pre-treatments. To achieve that, the effects of extraction screw speed (20, 40 and 60 rpm) and temperature (100, 150, 200 and 250 °C) on oil extraction yield and quality, extraction energy requirements and extraction time and were studied. Also, the effect of pretreatment conditions of microwave at three levels of power (Low, Med and High) and different times (1, 2 and 3 min) and pretreatment condition ultrasonic with different temperatures (40, 60 and 80 °C) and different times (15, 30 and 45 min) for castor seeds before extraction with the optimum condition of the screw press on oil extraction yield from castor seeds, extraction energy, extraction time and quality of the oil extracted. The results indicate that the optimum conditions oil extraction by screw press were 200 °C extraction temperature and 60 rpm screw speed. It could be seen that the extraction oil yield, extraction energy requirements and extraction time were 35.59%, 18.68 and 1.86 min, respectively. Microwave pretreatments had better on oil yield and energy required for extraction compared to ultrasonic pretreatments, where, microwave pretreatments recorded high oil yield and lower energy requirements compared to the ultrasonic pretreatments. Oil yield ranged from 32.67 to 37.41% compared to 13.29 to 39.83% in literature. The time required for extraction was ranged from 1.77 to 2.00 and 1.79 to 2.21 min for microwave and ultrasonic pretreatments, respectively. The pretreatment improved properties of the extracted oil.

Effect of adding nano-materials on the properties of hydroxypropyl methylcellulose (HPMC) edible films.

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 × 10-3 and 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 cereus and Escherichia 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 against B. cereus and Salmonella Typhimurium, the inhibition zone diameters were11 and 10 mm, respectively.

Mathematical model for predicting oxygen concentration in tilapia fish farms.

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.

Evaluation of fish feeder manufactured from local raw materials.

An automatic feeder for fish feeding was manufactured and evaluated successively. Feed pellet size, air flow rate and feeder screw speed were the most important factors affecting the performance and efficiency of the automatic feeder. It was tested at 3 sizes of pellets (1, 2 and 3 mm), 3 air flow rates (10, 15 and 20 m3 min-1) and 5 screw speeds (180, 360, 540, 720 and 900 rpm). The automatic feeder productivity, efficiency, specific energy consumption and costs were determined. The obtained results indicated that the automatic feeder productivity increases with increasing feed pellets size, air flow rate and rotational speed of screw treatments under study, the automatic feeder efficiency increased with increasing rotational speed of screw until it reached the highest value at 540 rpm and then remain constant at 720-900 rpm and after that decreased with increasing speed. Meanwhile, the specific energy consumption of automatic feeder decreased with increasing feed pellets size, air flow rate and rotational speed of screw treatments under study. The total cost of using automatic feeder ranged from 0.09 to 0.16 EGP kg-1 ($ = 15.63 EGP) for all treatments under study. This feeder will save time, effort and cost for fish industry.

Production of basil (Ocimum basilicum L.) under different soilless cultures.

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.