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Environmental negative impacts of the fossil fuels and intermittent feature of the renewable energies have made their hybrid configurations as a potential solution to overcome their both weaknesses. This research focuses on exergetic, and economic evaluation of a novel hybrid combined supercritical Brayton Cycle-Organic Rankine Cycle in which Solar PTC system and Biogas are considered as the energy Sources. The exhaust heat from the Bryton cycle runs the Organic Rankine cycle while either solar energy (during the daylight hours) or biogas energy (overnight hours) supply additional heat into the Brayton cycle. Sensitivity analyses were carried out in order to ascertain the influence that the system's input characteristics. The total exergy destruction of the system as well as its second law efficiency are computed. The process was not complete until exergoeconomics was used, and it was during this stage that the initial investment rate, the exorgoeconomic component, and the investment return rate are figured out. The findings of these analyses are compiled into a result report. It was concluded that combining the PTC system with the source of the biogas could be an effective way to achieve the desired level of heat delivery to the system.

Bioplastics are plastics derived from natural resources like corn starch, biomass, sugarcane bagasse, and food waste. Unlike fossil fuel-based plastics, they are bio-degradable entirely or partially. Therefore, bioplastics are relatively less harmful to the environment. Cellulose and starch-based bioplastics are already used for applications like packaging, cutlery, bowls, straws. However, their cost and performance cannot match the conventional plastics. The present study was aimed to produce bioplastic from food waste material. As a result, orange peel is chosen because of its high cellulose content and good availability. The bio-plastic film from orange peel was produced using simple laboratory techniques. Its identification for potential applications is the new area of work. The developed film blends with glycerol as a plasticizer have indicated consistent and promising results. This has excellent strength, flexibility, and disintegration in soiling conditions, morphologically having a rough surface, and confirms the film's bio-degradability nature. Characterization methods such as Fourier transform infrared (FTIR) spectroscopy, Thermal gravimetric analysis (TGA), powderX-ray diffraction (XRD), and Scanning electron microscope (SEM) analysis confirmed that the developed material's physicochemical and surface morphology belonged to bio-based plastic. A simple, novel, and economic process are described in the manufacturing of bio-based plastic.

Generally speaking, a Peltier module obtains a high value of COP only for a small range of applied DC voltage. Indeed, increment of DC voltage sharply reduces its COP. Hence, to get a high total COP for a large-scale commercial Peltier air cooler (for example input power of 1000 W) each individual Peltier module should work with a small input DC voltage. This means, a greater number of Peltier modules should be employed in a real cooler to reduce the allocate DC voltage for any individual Peltier module. However, this means higher capital, maintenance, operating and maybe final cooling cost. Hence, a size related cost economic analysis is required for cooling process using Peltier module which is experimentally presented in this research. Three Peltier air coolers with different sizes (but in the same range of total input power) are investigated from efficiency and economic cost viewpoints. Findings show that despite the higher capital and maintenance cost for case “c” (6 TEM), it still provides cheaper cooling compared to the other cases. However, it is noted that case “b” (4 modules) provides 100% lower cooling cost compared to the case “a” (2 modules) while case “c” (6 modules) provides only 35% lower cooling cost compared to the case “b”. This means, although increasing module number enhances the total COP of the cooler (for a given input power) and reduces the cooling cost, further increment of module number will finally augment the cooling cost of the cooler. Hence, an optimized number of modules can be selected for a large-scale cooling by simultaneous multi economic and cooling optimization. The quantitative and qualitative findings of this research can be useful for future marketing, and commercialization purposes of large-scale air-cooling process using Peltier module.

Covid-19 further revealed the significance of ventilation by air conditioning systems. Most common split heaters and resistance heaters recirculate the indoor air without ventilation process. Ventilation wastes energy consumption by the building. However, adding an air-to-air heat recovery unit seems a quick solution to reduce the wasted heat of the ventilation process. Nonetheless, recovery unit means further pumping power (pressure drop through the air-to-air heat exchanger), capital cost, additional fans and their electricity consumption, exergy costs and so on. Hence, the profitability of the recovery unit depends on outdoor temperature, desired indoor temperature, electricity price of the region, exergy loss and also the aforementioned factors. In this research the general standard Specific Exergy Costing theory is employed and simplified as an economic strategy for recovery ventilation. The model not only is able to predict the profitability of the ventilation process using air-to-air heat exchanger, but also it is an optimization tool for air-to-air heat recovery units as provided as a case study in this paper.

In the present work, the boiling heat transfer coefficient (BHTC) and fluid flow characteristics of graphene oxide nanoplatelets (GONPs) nano-suspensions in an annular heat exchanger (AHEX) were experimentally investigated. The BHTC, pressure drop (PD) and the friction factor (FF) of the heat exchanger was quantified, and effects of various operating conditions including heat flux (HF), flow rate (FR), the temperature of the nano-suspension and the mass concentration (MC) of the GONPs on the HTC and the PD of the system was assessed. Results showed that by increasing the HF, the weight concentration of the GONPs, and the temperature of the working fluid, the BHTC of the system increases. Also, the presence of GONPs can augment the friction forces, viscosity, and, as a result, increase the PD and the FF of the system. For all the experiments, the BHTC of the system was more significant than water. A comparison between water-perfluorohexane and water- n-pentane nano-emulsions revealed that water-n pentane has better thermal performance and lower PD in comparison with perfluorohexane despite the presence of the GONPs within the bulk of the nano-emulsion.

In this paper, two available variants of the Schrödinger equation are studied. These two nonlinear models are characterized by considering two nonlinearity types, including Kerr and power-laws, and the conformable derivative. The integration method used in this manuscript is the generalized exponential rational function method, which is an efficient method for solving equations with partial derivatives. The technique introduces a wide range of analytical solutions for these specific structures that were not proposed in the previous literature. To investigate the behavioral characteristics and physical features of these solutions some 2D and 3D figures have been demonstrated. The method employed in this paper was able to inspect the analytical solutions for the considered equations without having the usual complexities in some other known analytical techniques. This property is one of the strengths of the present contribution. Further, the utilized method can be easily adopted for solving other nonlinear models arising in mathematical physics.

Undoubtedly, all applied sciences are closely corresponding to differential equations, especially partial differential equations. This contribution aims to examine the efficiency of a modified version of the generalized exponential rational function method in solving some well-known nonlinear evolution equations. The investigated models in this article include the Zakharov–Kuznetsov, the cubic Boussinesq, and the modified regularized long-wave equation. In the structure of these solutions, various familiar elementary functions, including exponential, trigonometric, and hyperbolic functions are used. This important feature makes it easy to use these solutions in real applications. Numerical behaviors corresponding to the obtained solutions have been demonstrated through some three-dimensional diagrams in the article. This technique can be also adopted in determining wave soliton solution to other equations with partial derivatives.

New definitions always have more capabilities in describing phenomena than the more classic and well-known concepts because they usually appear to fill the gaps in existing concepts. In this paper, we employ a new stochastic fractional system that models interactions in a mutualism–parasitism food web. The main idea of piece-wise differential and integral operators is to separate the time under study into separate time domains in which the model behaves different behaviors. The idea was recently proposed by Atangana et al., and is gradually being used to solve a variety of application models. In order to demonstrate the valuable capabilities of this approach, many numerical simulations are provided in this paper. These results are mainly obtained from studying the role of the parameters in the model on its overall behavior. The results confirm that the piece-wise approach to the problem is a wise idea with more effectiveness rather than considering the whole situation is studied by a single operator. It is recommended to use these modified operators in modeling other applied problems with similar features.

Filled square cross-section shape is the common conventional structure for n-type and p-type legs of thermoelectric generators. However, other cross-section shapes with hollow structure can significantly increase the output power of thermoelectric generator. However, mechanical strength and economic considerations may still remain as the significant challenges and factors. Hence, in this research, different hollow cross-section leg shapes are investigated for thermoelectric generator from all thermal, economic, exergetic and mechanical viewpoints simultaneously through a 3D validated numerical simulation. Output voltage/power, energy-efficiency, exergy efficiency, Von-Mises stress, and the dollar/watt value are calculated for all mentioned structures and optimum conditions are identified. As a sample result, the triangular shape leg is able to generate up to 100% more power and better conversion/exergy efficiency (compared to the rectangular) at maximum input heat flux while mechanically less reliable design. Many other remarkable and interesting findings are provided in this manuscript.

Application of thermoelectricity as the building air cooling system has not been commercialized yet. However, remarkable eco-friend characteristics of thermoelectricity encourages the researchers to enthusiastically work on different aspects of Peltier cooler to make its performance competitive with other cooling techniques. The contribution of this research is to explicitly clarify the real cooling cost made by a single popular and affordable thermoelectric module in the market under different working conditions and identify how the effective parameters can impact the cooling cost and performance of the cooler. To reach the aim of this research, a laboratory-scale thermoelectric air-water based cooler is fabricated to obtain the behavior of thermoelectric cooler under different air flow rates, room (air intake) temperatures, input power and so on. In the next step, the obtained results are employed to analyze the cost-effective features of the cooler under the mentioned working conditions. Based on the results, cost per kWh of cooling by a thermoelectric module can vary between 0.7 and 1.4 dollar depending on the range of mentioned parameters. It is interesting that, an extremum point is observed for input power of 23 W through which the cost of air cooling process is minimized and then is increased. Hence, number of employed thermoelectric modules in real big size cooler will be a key parameter to allocate an optimum input power for any individual thermoelectric module. Moreover, the cost of cooling is reduced for warmer air temperatures which shows the suitability of thermoelectric coolers for hot regions.

This study investigates the effects of melting phenomena and non-linear thermal radiation in Cross nanofluid bioconvection flow with motile microorganisms with a convective boundary over a cylinder. Brownian motion and thermophoresis diffusion are also taken into account in this mathematical model. A governing partial differential equation is used to represent the given flow phenomena. The proper dimensionless transformation is then employed to convert the PDE controlling system into an ordinary one. Bvp4c numerically solves redesigned ODE problems using a shooting strategy in the computational tool MATLAB. Figures versus velocity, temperature distribution, nanoparticle concentration, and microbe concentration profiles are used to analyze and expound on the notably involved aspects thoroughly. It has been demonstrated that increasing the estimates of a mixed convection parameter can enhance velocity. By increasing the Prandtl number, the temperature and concentration of nanoparticles decrease. A high Peclet value lowers the microorganism's profile.

Abstract The recent developments in the additive manufacturing to manufacture complex cost effective profiles is gaining popularity to test the strength of developed products through finite element method (FEM). Finite element analysis (FEA) is a potent tool for mechanical analysis. The combination of 3D printing and FEA is opening new opportunities to go further in the complexity of the product geometry. The autonomous underwater vehicle (AUV) propeller blade has a complex profile with multi-directional gradient and twist, which requires a multi-stage operation to manufacture, including the hubs. The AUV propeller is required to withstand the applied load and generate the required thrust to move AUV at the desired speed. The current study explores the performance of AUV propeller prepared by additive synthesis using Nylon 6 material. The design of the propeller blade was developed using SOLID WORKS and integrated to the CUBPRO (DUO) to obtain the required 3D printing parameters. A comparative investigation is made for Nylon material within the dimensional conformance with the 3D printed propeller blade. The stress-strain analysis of the Nylon AUV propeller is carried with the FEM. The analysis of error and the stress show that the Nylon material meets the performance criteria for AUV propeller.

Coronary artery disease (CAD) is stated as one of the most common causes of death all over the world. This article explores the influence of multi stenosis in a flexible and rigid left coronary artery (LCA) model using a multiphase blood flow system which has not yet been studied. Two-way fluid–solid interaction (FSI) is employed to achieve flow within the flexible artery model. A realistic three-dimensional model of multi-stenosed LCA was reconstructed based on computerized tomography (CT) images. The fluid domain was solved using a finite volume-based commercial software (FLUENT 2020). The fluid (blood) and solid (wall) domains were fully coupled by using the ANSYS Fluid-Structure Interaction solver. The maximum pressure drops, and wall shear stress was determined across the sever stenosis (90% AS). The higher region of displacement occurs at the pre-stenosis area compared to the other area of the left coronary artery model. An increase in blood flow velocity across the restricted regions (stenosis) in the LCA was observed, whereas the recirculation zone at the post-stenosis and bifurcation regions was noted. An overestimation of hemodynamic descriptors for the rigid models was found as compared to the FSI models.

A set of lab-scale experiments were designed and conducted to remedy Direct Blue 15 (DB15) dye using nontoxic halloysite nanotubes (HNT) with the view to be utilized in a textile industrial effluent (TIE). The DB15 adsorbed-HNT “sludge” was used as a reinforcing agent and plastic waste to fabricate the composite. To advance the knowledge and further understand the chemical phenomena associated with DB15 adsorption on HNT, different factors like pH value, adsorbate initial concentration, adsorbent dosage, and temperature on the composite were affected experimentally tested. To estimate the adsorption capacity of HNT, nine isotherm models were applied, and it was identified that the Brouers–Sotolongo adsorption isotherm model represented the best accuracy for predicting the adsorption behavior of the HNT. Likewise, the pseudo-second-order reaction was the predominant mechanism for the overall rate of the multi-step dye adsorption process. Additionally, it was demonstrated that the mass transfer during the process is diffusion-controlled, and thermodynamic assessments showed that the process is physisorption.

The first-ever use of halloysite nanotube (HNT), a relatively low-cost nanomaterial abundantly available with minor toxicity for removing brilliant green dye from aqueous media, is reported. The factors affecting adsorption were studied by assessing the adsorption capacity, kinetics, and equilibrium thermodynamic properties. All the experiments were designed at a pH level of around 7. The Redlich-Peterson isotherm model fits best amongst the nine isotherm models studied. The kinetic studies data confirmed a pseudo model of the second order. Robotic investigations propose a rate-controlling advance being overwhelmed by intraparticle dispersion. The adsorbent features were interpreted using infrared spectroscopy and electron microscopy. Process optimization was carried out using Response Surface Methodology (RSM) through a dual section Fractional Factorial Experimental Design to contemplate the impact of boundaries on the course of adsorption. The examination of fluctuation (ANOVA) was utilized to consider the joined impact of the boundaries. The possibilities of the use of dye adsorbing HNT (“sludge”) for the fabrication of the composites using plastic waste are suggested.

Being an energy source of another origin, the compression ignition (CI) engine’s typical design parameters might not suit Simarouba oil methyl ester (SuOME). Present experimental investigation targets are determining the effects of engine design parameters, including fuel injection pressure and nozzle geometry, on the engine, concerning performance and emissions such as carbon monoxide (CO), unburnt hydrocarbon (HC), oxides of nitrogen (NOx), and smoke opacity, with SuOME as fuel. Comparisons of brake thermal efficiency (BTE) and different emissions from the engine tailpipe were performed for different fuel injection pressures and a number of injector holes and diameter of orifices were opened in the injector to find the optimum combination to run the engine with SuOME. It was observed that the combined effect of an increase in injection pressure of 240 bar from 205 bar, and increasing number of injector holes from three to six with reduced injector hole diameters from 0.2 to 0.3 mm, recorded higher brake thermal efficiency with reduced emission levels for the SuOME mode of operation compared to the baseline standard operation with SuOME. For 240 bar compared to 205 bar of injection pressure (IP) for SuOME, the BTE increased by 2.35% and smoke opacity reduced by 1.45%. For six-hole fuel injectors compared to three-hole injectors, the BTE increased by 3.19%, HC reduced by 9.5%, and CO reduced by 14.7%. At 240 bar IP, with the six-hole injector having a 0.2 mm hole diameter compared to the 0.3 mm hole diameter, the BTE increased by 5%, HC reduced by 5.26%, CO reduced by 25.61%, smoke reduced by 10%, while NOx increased marginally by 0.27%. Hence, the six-hole FI, 240 IP, 0.2 mm FI diameter holes are suitable for diesel engine operation fueled by Simarouba biodiesel.

Water desalination by membrane distillation (MD) can be affected by a wide range of operating parameters. The present work uses combinational approach of Analytical Hierarch process (AHP) and Fuzzy Analytical Hierarchy process (Fuzzy-AHP) to identify the most important parameters in the MD desalination. Five process parameters and key-performance indicators, named derivable outputs (DOs), are considered, along with the critical factors affecting these DOs in the current study. The DOs and the critical influencing factors (CIFs) are selected based on their experimental feasibility. The investigation involves five DOs, which are liquid entry pressure, thermal power consumption, permeate quality, permeate flux, and pumping (feed circulation) power. A total of twenty-five critical influencing factor were associated with the DOs. The identification of the DOs and CIFs was based on the literature review, and further analyses were performed. Both methods, AHP and Fuzzy-AHP, determined six extremely important CIFs in the desalination MD, which are feed temperature, feed concentration, or feed salinity; feed flow rate; membrane hydrophobicity; pore size; and membrane material. Moderately important CIFs are found to be four by both methods. These common CIFs are feed solution properties, membrane thickness, feed channel geometry, and pressure difference along the feed channel. Finally, the least preferred CIFs are four common in both methods that are MD configuration, duration of test, specific heat of feed solution, and viscosity.