Background: The improvement of the thermal conductivity of nanofluids is practical for different processes such as drug delivery, manufacturing of crystals, polymer processing, food and drink, cancer treatment, oil and gas, paper making and for many more. The bioconvection phenomenon has engrossed the attention of numerous researchers for its many applications in biotechnology, mechanical and electrical engineering. Bioconvection nanofluids are more prominent in the fields of biomedicine, pharmacy, nanodrug delivery, biomedical, automotive cooling and the military. Purpose: The major purpose of the current work was to determine the numerical and statistical analysis of a novel thermal radiation and exponential space-based heat source on the bioconvective flow of a pseudoplastic 3D nanofluid past a bidirectional stretched Riga surface. The behavior of the Arrhenius activation energy (AAE) and thermal radiation are also disclosed. Methodology: Suitable similarity transformations were used to transmute the partial differential equations of the flow-modeled phenomena into the structure of ordinary differential ones. The numerical solutions for the renewed set of ODEs were tackled by the bvp4c shooting algorithm built-in MATLAB software. Furthermore, the statistical analysis was computed by applying response surface methodology (RSM). Research implications: The numerical analysis is valid for the incompressible three-dimensional, magnetized flow of a pseudoplastic bioconvection nanofluid through a bidirectional surface with Riga plate aspects in the occurrence of activation energy. Social implications: The flow across three dimensions has quite important implementations in various fields, for example, polymer production, material production technology, the manufacturing of nano-biopolymer computer graphics, industry, powered engineering, aeroplane configurations, etc. The current analysis is more applicable in nanotechnology. Results: The consequences of flow control parameters over flow profiles were studied and explained under the graphic structures. Numerical outcomes were computed and discussed in detail. From the results, it was noted that the velocity field was increased via a larger mixed convection parameter. The temperature distribution was boosted via the thermal Biot number. The concentration of nanoparticles declined via the greater Lewis number. Furthermore, the motile microorganisms field was reduced via the Peclet number. Originality: Until now, no investigation has been recognized to examine the consequences of the bioconvection flow of three-dimensional pseudoplastic nanofluids past a Riga plate containing motile microorganisms utilizing the shooting method called bvp4c. Conclusions: From the results, it was concluded that nanofluids are more helpful for heat transfer increments. Furthermore, from the experimental design observed, the response declined via the thermophoresis parameter, which was significant from the ANOVA observed model.

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Gyrotactic Motile Microorganisms Impact on Pseudoplastic Nanofluid Flow over a Moving Riga Surface with Exponential Heat Flux

The water-energy-food nexus and COVID-19: Towards a systematization of impacts and responses.

Seawater or brackish water desalination is largely powered by fossil fuels, raising concerns about greenhouse gas emissions, particularly in the arid Middle East region. Many steps have been taken to implement solar resources to this issue; however, all attempts for all processing were concentrated on solar to electric conversion. To address these challenges, a small-scale reverse-osmosis (RO) desalination system that is in part powered by hybrid photovoltaic/thermal (PVT) solar collectors appropriate for a remote community in the Kingdom of Saudi Arabia (KSA) was designed and its power requirements calculated. This system provides both electricity to the pumps and low-temperature thermal energy to pre-heat the feedwater to reduce its viscosity, and thus to reduce the required pumping energy for the RO process and for transporting the feedwater. Results show that both thermal and electrical energy storage, along with conventional backup power, is necessary to operate the RO continuously and utilize all of the renewable energy collected by the PVT. A cost-optimal sizing of the PVT system is developed. It displays for a specific case that the hybrid PVT RO system employs 70% renewable energy while delivering desalinized water for a cost that is 18% less than the annual cost for driving the plant with 100% conventional electricity and no pre-heating of the feedwater. The design allows for the sizing of the components to achieve minimum cost at any desired level of renewable energy penetration.

https://www.mdpi.com/1660-4601/18/3/1001/pdf

Design and Energy Requirements of a Photovoltaic-Thermal Powered Water Desalination Plant for the Middle East.

This paper simulates a nano-PCM (NPCM) in a circular enclosure where an inverted triangle is placed in its middle. Inside the barrier is a li-ion battery pack (LIIBP) with a triangular arrangement. The desired NPCM is made by adding graphene nanoparticles (NPs) in PCM, CaCl2.6H2O. There are 12 blades (BLs) on the middle LIIBP. The unsteady simulations are performed in two modes of melting and freezing of NPCM using the finite element method. The charging and discharging process of the PCM is investigated while the LIIBP temperature is kept constant. Simulations are done by employing COMSOL Multiphysics software. The percentages of molten material, average Nu, TAve, and local temperature are studied by altering the blade length (LBL) during the melting and freezing of NPCM. The results demonstrate that under the identical circumstances, the melting time of NPCM is longer than the freezing period. An enhancement in the LBL intensifies the TAve of the NPCM in the melting process and reduces the TAve in the freezing process. Enhancing the LBL increases the amount of NPCM at constant times from the beginning of the melting and freezing processes. The complete melting time of NPCM in a longer BL is less than that in bladeless mode. The same behavior is observed for freezing time. 

Effect of nano phase change materials on the cooling process of a triangular lithium battery pack

In this paper, a gentle air flow is simulated among cylindrical lithium-ion battery (LIIB) cells using COMSOL software. A circular PCM compartment is placed around the battery cells. The hot air from cooling the battery is used to heat the house. By changing the battery position in three modes in PCM in the air speed range of 1 × 10−3 to 5 × 10−3m/s, the volume fraction of solid PCM, the average PCM temperature (TAve−PCM), the maximum battery temperature (Tmax−b) and the exhaust air temperature at different times from 0 to 1000 seconds are analyzed. The percentage of time energy provided by this system of the total energy required for this residential house has also been examined. The results of this study show that over time at high speeds, the Tmax−b of the LIIB first increases and then decreases. The passage of time also reduces the amount of TOutlet. If the LIIB is placed on the air inlet side of the PCM instead of the air outlet side, the Tmax−b is reduced by 1.53 degrees at high speeds. Placing the LIIB on the left side of the PCM causes the output temperature (TOutlet) to be higher and also increases the amount of solid PCM by up to 5% in 1000 seconds compared to placing the LIIB on the right side. Using 50 cells of LIIB and air flow of 0.005 m/s in this system can provide up to 22% of the required energy for heating the building in a winter day. 

Combining an active method and a passive method in cooling lithium-ion batteries and using the generated heat in heating a residential unit

Background Flat plate solar collectors (FPSCs) can meet the needs of low-temperature process industries by providing a hot flow stream. In this regard, the addition of nanoparticles can improve the energy-saving potential of the FPSCs. In this study, the effectiveness of using copper oxide (CuO) nanoparticles in a solar-assisted hot process stream was investigated. Methods Using transient-based numerical approaches, the efficacy of loading CuO nanoparticles at 0.1 vol.% into water on collector heat gain was examined. Using effectiveness–NTU method, the nanofluid efficacy was challenged by adding a two-pipe heat exchanger to diminish heating power usage in a hot process stream. Findings The results revealed that if a water-filled solar-assisted hot process stream was used, the energy-saving will be 670, 383 and 225 kWh m 2 . year at 60, 120 and 240 lit hr under Najran climate conditions. Taking into account energy-saving of 712, 415.5 and 242.5 kWh m 2 . year for nanofluid, it was found that incorporating CuO into a solar-assisted hot process stream has been successful. Owing to using CuO, the effectiveness of the solar-assisted hot process stream was improved within the range of 6-12.8%.

Challenging of using CuO nanoparticles in a flat plate solar collector- Energy saving in a solar-assisted hot process stream

Influences of a helical absorber tube on the thermal performances of a double-fluid parabolic trough solar collector (PTSC) occupied by non-Newtonian nanofluid are investigated numerically. The problem geometry includes a double-fluid parabolic trough solar receiver with high insulation and a non-circular adsorbent tube. The finite volume method, SIMPLE algorithm, and k-ε model were used for numerical solutions. The result showed that the double-fluid solar receiver was equipped with a helical absorber tube filled with nanofluid with a volume fraction of 4% and nanoparticles diameter of 50nm flowing in the absorber tube, and an annulus glass cover is introduced as the optimal model in this paper. For single-flow PTSC, the value of ηmax nanofluid- and water-based PTSCs are 47.5% and 43.1%, respectively, at a flow velocity of Re=5000. In double-flow PTSC, the value of ηmax at 1 and 4 vol.% is 56.5% and 58.2%, respectively, at the flow velocity of Re=5000. Finally, a deep learning method is employed to examine the parameters affecting the efficiency, including the concentration and diameter of nanoparticles and Re number. The results indicate the ANN has acceptable performance in prediction of the efficiency of the double-fluid parabolic trough solar collector occupied by non-Newtonian nanofluid. 

Numerical study on performance of double-fluid parabolic trough solar collector occupied with hybrid non-Newtonian nanofluids: Investigation of effects of helical absorber tube using deep learning

Saeed Alqaed

Papers

Challenging of using CuO nanoparticles in a flat plate solar collector- Energy saving in a solar-assisted hot process stream

Design and Energy Requirements of a Photovoltaic-Thermal Powered Water Desalination Plant for the Middle East.

Effect of nano phase change materials on the cooling process of a triangular lithium battery pack

Combining an active method and a passive method in cooling lithium-ion batteries and using the generated heat in heating a residential unit

Numerical study on performance of double-fluid parabolic trough solar collector occupied with hybrid non-Newtonian nanofluids: Investigation of effects of helical absorber tube using deep learning