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This study aimed to evaluate the effect of adding liquid extract of algae (Hypnea musciformis, Grateloupia acuminata, and Sargassum muticum) (HGS) and Magnesium oxide nanoparticles (MgO NPs) using this extract to rear water of Oreochromis niloticus, on improving culture water indices, growth performance, digestive enzyme, hemato-biochemical characters, immune, antioxidative responses, and resistance after challenged by Aeromonas hydrophila with specific refer to the potential role of the mixture in vitro as resistance against three strains bacteria (Aeromonas sobria, Pseudomonas fluorescens, P. aeruginosa) and one parasite (Cichlidogyrus tilapia). The first group represented control, HGS0, whereas the other group, HGS5, HGS10, and HGS15 mL−1 of liquid extract, as well as all groups with 7.5 μg mL−1 MgO-NPs added to culture water of O. niloticus, for 60 days. Data showed that increasing levels at HGS 10 and HGS15 mL−1 in to-culture water significantly enhanced growth-stimulating digestive enzyme activity and a significantly improved survival rate of O. niloticus after being challenged with A. hydrophila than in the control group. The total viability, coliform, fecal coliform count, and heavy metal in muscle partially decreased at HGS 10 and HGS15 mL−1 than in the control group. Correspondingly, the highest positive effect on hemato-biochemical indices was noticed at levels HGS 10 and HGS15 mL−1. Fish noticed an improvement in immune and antioxidant indices compared to control groups partially at HGS 10 and HGS15 mL−1. Interestingly, fish cultured in rearing water with the mixture provided downregulated the related inflammatory genes (HSP70, TNF, IL-1β, and IL-8) partially at HGS15 mL−1. In vitro, the mixture showed positive efficiency as an antibacterial and partially antiparasitic at HGS 10 and HGS15 mL−1. This study proposes utilizing a mixture of (HGS) and (MgO-NPs) with optimum levels of 10–15 mL-1 in cultured water to improve water indices, growth, health status, and increased resistance of O. niloticus against bacterial and parasitic infection.

A computational fluid dynamics (CFD) study is conducted for silicon ingot irradiation facility in a typical material testing reactor (MTR). The ingots are placed inside the irradiation device in staggered and in-line bundles. The configurations are varied according to the variations of longitudinal and transverse pitches Sl and St, respectively. For in-line bundles, Sl and St are changed in the range of 1.1, 1.2, 1.3, 1.4, and 1.5 of the ingot diameter. For staggered bundles, Sl is changed in the range of 1.1, 1.2, 1.3, 1.4, and 1.5 of the ingot diameter while St is changed in the range of 0.95, 1.0, 1.05, 1.1, and 1.15 of the ingot diameter. The silicon ingot volumetric heat generation Qv is allowed to change around its nominal value in the range of 0.25, 0.5, 0.75, 1.0, and 1.25 W/g. The effects of rotation of ingots during irradiation at velocities of 15, 30, and 60 rpm are investigated. The computational fluid dynamics code ANSYS FLUENT is employed to carry out the calculations. The temperature profile inside the silicon ingot during irradiation is of significant importance for uniform doping. Therefore, the impact of heat generation and bundle pitches on the temperature profile through the ingot is calculated and reported for all cases of this study. The results show that the maximum ingot temperature does not exceed the limits for each bundle at maximum heat generation. Two correlations for average Nusselt number for both aligned and staggered configurations are generated to describe heat transfer rates during natural convection regime. The rotation of ingots during irradiation showed considerable enhancement of heat transfer rates.

The main objective of nuclear reactor safety is to maintain the nuclear fuel in a thermally safe condition with enough safety margins during normal operation and anticipated operational occurrences. In this research, core flow bypass is studied under the conditions of the unavailability of safety systems. As core bypass occurs, the core flow rate is assumed to decrease exponentially with a time constant of 25 s to new steady state values of 20, 40, 60, and 80% of the nominal core flow rate. The thermal hydraulic code PARET is used through these calculations. Reactor thermal hydraulic stability is reported for all cases of core flow bypass. Keywords: Thermal–hydraulics, MTR reactors, Core flow bypass

Heat transfer deterioration (HTD) phenomena in supercritical water is one of the most thermal hydraulic critical issues for supercritical reactors. The onset of heat transfer deterioration and bouncy effect have been studied in details, however limited work has been done on the mechanism of HTD occurrence. In this work, three dimensional analysis of velocity and temperature boundary layers under heat transfer deterioration conditions is conducted. The effect of thermo physical water properties changes inside the fluid boundary layer and its effect on the heat transfer coefficient is studied. Analogy between HTD and critical heat flux condition in subcritical boiling is observed and reported. Under HTD conditions, clotting or sudden stopping of the flow inside the tube is predicted due to the severe variation in density and other thermo physical properties in the tubes radial direction.

Sewage treatment plants (STP’s) throughout Malaysia are facing escalating issues on sewage disposable and environmental impact. Investigation on the sewage sludge for possible fuel formulation as renewable energy is being considered. The characterization of waste sludge on its volatility, High Heating Value and Energy output value will provide a preliminary finding for usage as potential biomass fuel. Co-combustion of sewage sludge and coal provide another formulation for potential biomass fuel depend on its technical viability and economical input.