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In this research, thermal modeling has been done to investigate the effect of nanofluid on the performance of the linear parabolic collector. Therminol vapor/liquid phase fluid (VP-1) has been used as a base fluid; iron oxide nanoparticles have been used to produce mono-nanofluid; and iron oxide multi-walled carbon nanotubes nanocomposite has been used as nanoparticles to produce hybrid nanofluid. The fluid flow inside the absorber tube of the collector is assumed to be turbulent. The results show that when hybrid nanofluid and mono-nanofluid are used, the energy and exergy efficiencies of the collector are higher than those for the conditions of using the base fluid, but their amount is slightly lower with the use of hybrid nanofluid than when the working fluid is mono-nanofluid. According to the obtained results, the highest energy efficiency of the linear parabolic collector using nanofluid and mono-nanofluid is 70.2% and 70.4%, respectively, and the highest exergy efficiency is 35.7% and 35.9%, respectively. Despite this, the friction coefficient of mono-nanofluid compared to hybrid nanofluid was obtained on average about 9% higher. The results showed that the criterion for evaluating the performance of the collector (hydrodynamic thermal efficiency) when hybrid nanofluid is used is more than when mono-nanofluid is used. [ABSTRACT FROM AUTHOR]

This study examines the generation of irreversibility and the behavior of stagnation point hybrid nanofluid flow on a Riga plate. The effects of nonlinear thermally convective and solar radiation are incorporated in the modeled equations. The nanoparticles of (Cu) and (Al2O3) are mixed with Glycol (C3H8O2) to hybridized it. The leading equations have been changed to dimension-free form by using the set of appropriate variables and then have been evaluated by Artificial Neural Network (ANN) approach. It is revealed in this work that, the velocity panels are amplified with expansion in Grashof number and electromagnetic factor while declined with escalation in magnet/electrode factor and nanoparticles concentration. Upsurge, in Eckert number for both the scenarios (Ec < 0) and (Ec > 0), the radiation factor and nanoparticles concentration cause augmentation in thermal characteristics. Radiation factor has positive impacts on Bejan number and generation of Entropy. Moreover, Bejan number is retarded while entropy is augmented with growth in Brinkman number. It is also established in this work that the principle of entropy generation for hybrid nanoparticles supports the efficient delivery of drug in cancer treatment. [ABSTRACT FROM AUTHOR]

Magnetohydrodynamic free convection liquid considering Hall along with ion-slip current has many engineering usages. In addition, boundary layer flow of power-law fluids due to a stretching plane possesses sundry applications in biological sciences, geophysics, and petroleum industries. Further, hybrid nanofluids are important due to their high heat transfer capability. In view of such relevance, the goal of this investigation is to analyze Hall along with ion-slip effects on thermo-fluidic flow of magnetic power-law hybrid nanofluid so as to accomplish effective cooling in the desired thermal systems. Present investigation's novelty is adding hybrid nanostructure to power-law fluid flow influenced by Hall and ion-slip mechanism and implementation of modified Fourier's law featured with velocity and temperature gradients. The key results are that fluid velocity amplifies with rise in ion-slip and Hall parameters. Modified Prandtl numbers and Hall parameter ameliorate heat transfer rate while ion-slip parameter diminishes it. [ABSTRACT FROM AUTHOR]

Investigations on thin-film flow play a vital role in the field of optoelectronics and magnetic devices. Thin films are reasonably hard and thermally stable but quite fragile. The thermal stability of a thin film can be further improved by incorporating the effects of nanoparticles. In the current work, a stretchable surface is considered upon which hybrid nanofluid thin-film flow is taken into account. The idea of augmenting heat transmission by making use of a hybrid nanofluid is a focus of the current work. The flow is affected by variations in the viscous forces, along with viscous dissipation effects and Marangoni convection. A time-constrained magnetic field is applied in the normal direction to the flow system. The equations governing the flow system are shifted to a non-dimensional form by applying similarity variables. The homotopy analysis method is employed to find the solution to the resultant equations. It is noticed in this study that the flow characteristics decline with augmentation of magnetic, viscosity and unsteadiness parameters while they increase with enhanced values of thin-film parameters. Thermal characteristics are supported by increasing values of the Eckert number and the unsteadiness parameter and opposed by the viscosity parameter and Prandtl number. The numerical impact of different emerging parameters upon skin friction and the Nusselt number is calculated in tabular form. A comparison of current work with established results is carried out, with good agreement. [ABSTRACT FROM AUTHOR]

Time-dependent viscosity and thermal conductivity have been studied in relation to flow and thermal energy propagation along a vertical turning cone. Except the density variance, the other fluid's properties are assumed to be constant. Using the similarities procedure, the nonlinear system of differential equations is simplified to dimensionless ODEs. The resultant nonlinear ODEs system is computed while using fractional code FDE12, and the findings are quantitatively examined using the bvp4c approach for accuracy and consistency. In form of figures and tables, the behavior of momentum, energy, and mass is interpreted versus the physical constraints. The axial and radial velocity, both declines with the variation of unsteadiness parameter S. The axial velocity of the fluid is considerably increased when the mixed convection parameter is elevated, but the radial velocity is reduced. Similarly, when the variable viscosity increases, the velocity profile develops. [ABSTRACT FROM AUTHOR]

The current study aims at forming new prediction models to be employed in the approximating the possible uptake of a range of 10 heavy metals (HMs) (Cd, Co, Cr, Cu, Fe, Mn, Mo, Ni, Pb and Zn) by Hordeum vulgare tissues including roots, shoots and grains following its growth in soil amended with sewage sludge (SS) using conditions employed in greenhouses. The present study determined an insignificant difference between the actual and predicted quantities of the HMs in the three tissues using t values. The majority of the predicted quantities of the HMs were acceptable with the exception of Cd in the shoots, Cu in grains and Pb in roots. Consequently, it is possible to use these models in assessing the cultivation of barley plants in soil amended with SS in a safe way, while simultaneously monitoring any potential risks to the health of humans. [ABSTRACT FROM AUTHOR]

Rock masses slopes stability is a real problem and represents an important concern in Aseer Province, in order to avoid rock fall process on the main roads. For this reason, it is necessary to explore, inspect, investigate, and understand the natural stresses within these rock masses taking into a consideration the third dimension. In this sense, the state of stresses within the rock masses depends on the characteristics of Commonwealth Scientific and Industrial Research Organization (CSIRO) cell and the dimension of the overcoring hole. Furthermore, in order to achieve the 3D modeling, the characteristics of the rock masses mentioned before are introduced in the model using “Surfrac” program written in Pascal and FORTRAN, coupled with “Abaqus” software to simulate the stresses matrix in the model. As a result, the main findings of this research are summarized in three points: the first is dealing with the CSIRO cell itself, where the direction of the gauge is important during the measurement of stresses; in fact, the perpendicular gauges work better than those parallel to the hole axis. The second is evident from the model that the direction of hole must be perpendicular to the dip direction of the rock layers, allowing giving better results compared to others. The third is the selection of the measurement site requiring involving the regional stresses of the study area according to geological investigation. Finally, it is interesting to carry out geophysical exploration in the site to understand the local tectonic movement of rock masses. Moreover, a detailed map can highlight the main fractures and faults network and overlap them with the most important projects deployed in Aseer province for maintenance and monitoring. [ABSTRACT FROM AUTHOR]

This article presents a numerical simulation of hydrodynamics in a bubble column. Numerical simulations have been carried out using the Eulerian model which provides specific modeling adapted to gas-liquid flows and allows a reasonable representation of the two-phase flow structure (fields of mean velocities and volumetric fractions of the two phases) as well as the important modulation of turbulence in the two-phase flow. In these simulations, we tested the sensitivity of the coefficients of the closure model of the interfacial transfer (drag, lift and added mass) on the prediction of the fields of average velocities and volumetric fractions of the two phases. The results are compared with the experimental data available in the literature using an average bubble diameter approach. [ABSTRACT FROM AUTHOR]

Precise knowledge of the soil organic carbon (SOC) stocks under various land uses is needed to meet the Kyoto Protocol and for the sustainability of natural resources. The purpose of the present study was to (1) gauge the depth and spatial distribution of the soil bulk density (BD), soil organic carbon (OC) stocks, and soil organic matter (OM) among the various land uses in the northern Nile Delta in Egypt; (2) estimate the soil carbon sequestration rate (CSR) under different land uses in the region; and (3) establish baseline data for SOC stocks in future studies on the dynamics of SOC. The study area was divided into ten sampling zones to represent each land use in the northern Nile Delta. Each sampling zone was further divided into four sampling sites to represent virgin lands and fish farms, and twelve sites were used to represent three crop types and four cultivation histories. The crops included clover, (Trifolium alexandrinum L.), sugar beet (Beta vulgaris L.), and rice, (Oryza sativa L.) and the years spanned were 5, 15, 30 and 50. The effects of the crop type on the SBD, SOC content, and SOC stocks were significant. In general, the SOC stocks increase as the number of years of cultivation increased. Thematic maps were produced using Geographical Information Systems (GIS) mapping. The Inverse Distance Weighted (IDW) technique in ArcGIS10.4 software revealed that the spatial pattern of the SBD, OC content, and stocks conformed to the soil analysis results. The SOC stocks of the croplands and fish farms were 1.6 and 1.5 times higher, respectively, compared to those of virgin land. Rice cropland had the lowest SBD (1.34 g cm−3) and the highest OC stocks (7.46 g C kg−1). The conversion of virgin land into croplands or fish farms actively contributed to the carbon storage rate (CSR). [ABSTRACT FROM AUTHOR]

It is well known that high refractive index contrast is essential to the formation of an omnidirectional Photonic Band Gap (PBG). It is generally cited also that the width of the omnidirectional PBG of a dielectric mirror is determined by the refractive-index contrast. But in this work, we show that this condition is not really general criteria. Dielectric mirror with higher refractive index contrast does not necessarily mean that it has the largest omnidirectional photonic band gap. So, we investigate the necessary conditions on the high and low refractive indices of the quarter wave layers to have the largest omnidirectional bandwidth in the visible range. We present a profound study of the omnidirectional band center wavelength and the bandwidth behaviors versus the layers refraction indices. It is shown therefore that one can modulate omnidirectional photonic band gap center by modulating the optical phase of the mirror. [ABSTRACT FROM AUTHOR]

Hybrid nanofluids are capable of being used as a carrier for delivering drugs to targeted areas in the body. For this purpose, the Casson hybrid nanofluids (HNFs) flow is suggested between the gap of two tubes. The study involves analyzing blood-based hybrid nanofluids (HNFs) that consist of silver (Ag) and titanium dioxide (TiO2) nanoparticles for applications of drug delivery. Titanium oxide nanoparticles, or TiO2 NPs, have strong photoactivity, low toxicity, and excellent biocompatibility, making them promising candidates for cancer treatment. The attractiveness of silver nanoparticles (AgNPs) for cancer therapy is due to their unique properties. Graphic representations are provided based on the simulations of non-dimensional velocity, temperature, and skin friction under physical parameter variations, for the applications of drug delivery are investigated and discussed. The control volume finite element method (CVFEM), is used to solve the problem. The new strategy of artificial neural networks (ANN) is also used to solve the transform equations. Nanoparticles increase drug stability and extend shelf life by protecting them from degradation or inactivation. [ABSTRACT FROM AUTHOR]

In this work, we exploit photonic crystal heterostructures formed by the combination of periodic and Fibonacci structures to design promising optical devices acting in the visible and the near infrared domains. An hybrid structure of the type Bragg mirror-(Fibonacci)S is proposed to enhance the high reflection band through the one dimensional photonic crystal in the near infrared. The use of the configuration exhibits a large photonic band gap at any angle of incidence and for both polarizations. The proposed structure is a quarter wavelength omnidirectional mirror of 37 layers with a bandwidth larger than that of the periodic structure with an increasing ratio 3.7, and it covers all the optical telecommunication wavelengths 0.85, 1.3 and 1.55 µm. Then a second structure of the type Bragg mirror-(Fibonacci) S-Bragg mirror with varied optical thicknesses permits to confine strongly the light giving a rise to a microcavity through the visible range with strong mode localisation. Since different physical phenomena have their own relevant physical scales, we exploit the physical properties of the proposed structures in different wavelength domains to obtain different optical devices. The transmission spectra are determined by using a theoretical model based on the Transfer Matrix Method (TMM). [ABSTRACT FROM AUTHOR]

This study reports the three-dimensional (3D) flow of Ag-MgO hybrid nanofluid (HNF) over a spinning disc of flexible thickness in the presence of modified Fourier law. The HNF is contained of silver and magnetic nanoparticulate in the base fluid engine oil. The energy transition has been examined in the involvement of melting heat propagation. The highly nonlinear system of partial differential equations (PDEs) is processed by adopting the proper similarity conversions to attain the coupled ODE system. The obtained system of modeled equations is numerically solved by employing the Parametric Continuation Method (PCM). The nature of various constraints, as opposed to the velocities, energy, and mass transmission, is portrayed and described. In comparison to the simple nanofluid flow, the hybrid nanoliquid flow's velocity and heat conduction are observed to have a significant influence. As a result, the functionality of the hybrid nanoliquid is significantly superior to that of the conventional nanofluid. The positive variation in power-law exponent n and Reynold number Re significantly enhances the fluid velocity. The effect of both melting coefficient and thermal relaxation term reduces fluid temperature. [ABSTRACT FROM AUTHOR]

The hybrid nanofluid is extensively used in manufacturing commercial applications due to its high exceptional capacity to increase the heat transfer rate. As a result, in the existence of nonlinear convection, the hybrid nanofluid is considered to flow on an inclined plane. The nonlinear convection has many applications in real life and is more relevant to the natural flow avoiding the flow restrictions. The focus has been executed on the thermal and mass Grashof numbers to analyse the fluid motion in the presence of these parameters for nonlinear nature. Moreover, the hybrid nanofluid flow analysis has been done to investigate the heat transfer analysis. The modelled equations are solved through an analytical approach. The heat and mass transfer rates and drag force are calculated under the influence of various physical parameters. The new parameter of the Grashof numbers improves the fluid motion for its larger values, and consequently, the fluid rapidly falls down from the inclined plane. The obtained outputs show that hybrid nanofluids are more effective in heat transfer analysis as compared to other conventional fluids. [ABSTRACT FROM AUTHOR]

Among all direct and indirect water-based evaporative air coolers, Maisotsenko indirect evaporative cooler (MIEC) is the only one which can supply sub wet-bulb air temperature while adding no moisture to the product air. For any given MIEC, four thermal/fluid parameters including dry channel flow rate, wet-to-dry-side air flow ratio, ambient air temperature and ambient relative humidity impact the performance of the MIEC. Sub-wet bulb supply temperature while having maximum cooling capacity happen only for a specific range of the mentioned thermal/fluid parameters. For any ambient condition and dry side air flow, a magic value of air-flow-ratio can maximize the cooling capacity of the cooler. Thousands of data is required to provide a simultaneous multi-aspect analysis of each parameter (while other parameters vary as well) to identify all possible curve behaviors and secrets of this technology. That is why, for the first time in this research, a strong machine learning (ML) model, is developed for MIEC cooler using 625 validated analytical/experimental-based training data (full factorial design). This model is employed to generate around 3600 unseen data to fully clarify the impact of each parameter (on supply temperature, total cooling capacity, useful cooling capacity and wet-bulb effectiveness) while other parameters are variable too. This strategy makes it possible to see all hidden extremum or peak point where the performance of the cooler is maximized or minimized. Interesting results are found in this research. For any ambient condition, there is an extremum point of the air flow ratio at which the total cooling capacity is maximized. The results indicate that as the dry side air flow increases, this extremum value decreases. For instance, under an ambient condition of 18 °C and 9 % relative humidity, the extremum point of the air flow ratio is 0.45 when the dry side air flow is 0.8 L/s and 0.25 when the dry side air flow is 4.8 L/s. In real-world commercial cooler, this can be simply happened by appropriate re-adjusting the dry and wet side fan speeds. • Maisotsenko evaporative cooler can supply sub-wet-bulb temperature. • Machine Learning model is developed for this technology. • All possible behaviours of this cooler were recognized. • The cooling capacity is maximized under specific range of fluid-flow factors. • Magic number of air flow ratio is identified, analysed and reported. [ABSTRACT FROM AUTHOR]

Biowaste-to-biogas processes have been introduced to design a valuable and green renewable plant to achieve a sustainable society and environment. The biomethane production process through biogas upgrading instead of designing a combined heat and power (CHP) system can be more attractive. This study presents a life cycle analysis (LCA) from both cost and environmental standpoints for four biowaste-to-biogas/biomethane process scenarios. Biogas production is achieved through anaerobic co-digestion of the organic fraction of municipal solid waste (OF-MSW) and secondary sewage sludge (S-SS), incorporating a pre-treatment process based on the dark co-fermentation process (DCFP). Each scenario offers distinct methods for utilizing the hydrogen-rich gas and biogas, with varying degrees of energy recovery and efficiency. Two sensitivity studies were conducted under various utilizations of the recovered biomethane and the anticipated electricity mix. Scenario SC-1 (CHP-from-biogas) was found to be the most co-friendly favorable in eight out of eleven impact categories (under the CML/IA technique). Further, biogas upgrading-integrated options exhibited lower impacts. Replacing biomethane instead of petrol in scenarios with upgraded biogas was identified as the most effective approach against climate change. Financial analysis indicated that all layouts are economically viable, each demonstrating a positive NPV over a 20-year period (up to $11.57 million). • Life cycle analysis for different biowaste-to-biogas/biomethane scenarios. • Anaerobic co-digestion process of MSW organic fraction and secondary sewage sludge. • Different method for utilizing the hydrogen-rich gas stream and biogas. • Biogas upgrading-integrated options exhibited less impact in the respective items. • Economically viable, all option demonstrating a positive NPV over a 20-year period. [ABSTRACT FROM AUTHOR]

The environmental impact assessment of organic fraction of municipal solid waste (OF/MSW)-to-biofuel structures is essential prior to scaling them up to identify worrisome impacts on ecosystems, resources, human health, and climate. The current article aims to address a sustainable and comprehensive guide for analyzing the environmental impacts (based on the life cycle analysis (LCA)) of different OF/MSW-to-biofuel structures. To analyze different structures, three pre-treatment procedures (namely, hot water/acetone organosolv/acid), two different hydrolysis treatment ways (acidic/enzymatic), and different fermentation alternative methods (ethanolic/acetone-ethanol-butanol fermentations) were considered. The findings of the research indicated that scenarios based on acetone-ethanol-butanol fermentation cannot address a favorable environmental performance (due to the insufficiency of the avoided effects of the output products to compensate the environmental burdens caused by acetone pre-treatment). In contrast, scenarios based on ethanolic fermentation integrated with hot water or acid-based pre-treatment process can address superior environmental performances compared to scenarios based on acetone-ethanol-butanol fermentation and ethanolic (with acetone pre-treatment). Comprehensively, Scenario S-4 (as most eco-friendly Scenario) yielded the greatest net environmental savings with reductions of −857.16 potentially disappeared fraction/m2 per year, −214.3 kg CO 2 equivalent per ton of/MSW, and −3.33 GJ per ton of/MSW processed. [Display omitted] • Sustainable guide for the environmental impacts of MSW organic fraction-to-biofuel. • Different pretreatment, hydrolysis treatment, and fermentation alternative methods. • Environmental analysis is based on the life cycle analysis methodology. • Superior environmental result under ethanolic fermentation-hot water pretreatment. • Potential scalability of the biorefinery in the context of future developments. [ABSTRACT FROM AUTHOR]

In this article, the solar hydrogen storage is modeled and hourly investigated with TRNSYS software. The Photovoltaic (PV) panel is employed for green power generation that is consumed in the electrolyzer subsystem and produced hydrogen. Additionally, the required electricity at the lack of enough solar irradiation is supplied from the grid. The performance of the system is comparatively analyzed for three main cities. Results show that the maximum power generation by PV panel is about 1670 kW in June which approximately is the same for two cities. The energy and Faraday efficiency of electrolyzer changes between 0.85-0.89 and 0.89–0.92 respectively. The amount of hydrogen production reaches 1235 m3/h for one of them in May. The total amount of hydrogen production is 13,181 m3/year in Yazd, 13,143 m3/year in hot city, and 13,141 m3/year in most populated city. • Transient simulation of power to hydrogen system using TRNSYS. • Influence of various places on hydrogen production rate. • Designing a hydrogen storage system with a solar energy source. • Analyzing the performance of the electrolyzer from an energy viewpoint. [ABSTRACT FROM AUTHOR]

The global proposal of 'carbon neutrality' puts forward higher innovation demand for the cleaner energy production. The potential for employing "green" methanol produced from hydrogen obtained by water electrolysis and collected CO 2 from a gas-fired power station is examined in this study. The consumption of electricity for renewable methanol production is 1.045 times as much as that for traditional methanol production, the traditional method consumes 2.5 times as much thermal energy as the renewable methanol process. In addition, the total direct and indirect CO 2 emissions from renewable methanol production are almost one-third of the emissions from the traditional method. The total cost of setting up the units of a renewable and a traditional methanol production plant with an annual capacity of 100,000 tons is $50.1 million and $46.806 million in this study case, respectively. If the methanol price hits $310 per ton, renewable methanol production will be highly economically viable. But if electricity and gas prices rise or CO2 emission tax is imposed, renewable and conventional methanol production plants will lose their economic feasibility. Therefore, in order to deal with this risk, the establishment of special high-tech parks is of great significance to reduce costs and stabilize the sustainable development of relevant industries. • Introducing a new methanol synthesize plant from CO 2 hydrogenation. • Techno-economic assessments of the introduced plant and propose the construction idea of high-tech park. • The sustainable-based methanol synthesize is compared to the conventional methanol production method. [ABSTRACT FROM AUTHOR]

The purpose of this paper is focused on introducing a new layout of an electricity and liquid hydrogen cogeneration power plant and evaluating its performance from the exergo-economic and environmental stand points. The system is based on the combination of a biomass gasification gas turbine cycle, a Rankine cycle, an electrolyzer unit, and a hydrogen liquefaction cycle. A parametric model is firstly developed to study the sensitivity of the system performance on the main design parameters (including biomass flow rate ṁ biomass , gas turbine inlet temperature T GT , compressor pressure ratio PR, and steam turbine inlet pressure P SRCT). Afterward, the optimal operation of system is selected using by a multi-objective optimization approach. The observations revealed that m ˙ biomass is the most effective design parameter. The optimal design parameters are obtained as ṁ biomass = 1.94 kg/s, T GT = 1421 K, PR = 5.52, and P SRCT = 3886 kPa, which results in the maximum electricity and hydrogen production of 3377 kW and 14.8 kg/h together with minimum total cost rate of 86.61 $/h. At this condition, the optimal environmental index is 1.09 kg CO₂ /kWh. • Optimizing proposed system is determined. • The subsystems are biomass unit, SRC, and PEM electrolyzer. • Tri-objective optimization and economic analyses are applied. [ABSTRACT FROM AUTHOR]

In this work, an innovative integrated system that is incorporated from solid oxide electrolysis cells and an oxygen separator membrane is assessed and optimized from the techno-economic aspects to respond to oxygen, hydrogen, and nitrogen demands for hospitals and other health care applications. Besides, a parametric comparison is conducted to apprehend the weights of parameters changes on the performance of criteria. Relying on the assessments, from the hydrogen production of 1 kg/s, 23.19 kg/s of oxygen, and 50.22 kg/s of nitrogen are produced. The parametric study shows that by raising the working temperature of the electrolyzer, the cell voltage variation has descending trend and the power consumption of the system is decreased by 19%. Finally, the results of multi-criteria optimization on the Pareto front reveal that in the optimal case, the system payback period is attained at about 5.32 years and the exergy efficiency of 92.47%, which are improved 16.6% and 16.2% compared to the base case, sequentially. Consequently, this system is proposed to consider as a cost-effective and reliable option towards its vital and valuable productions, in the pandemic period and after's. • An innovative SOEC-based system was designed to generate O 2 , H 2 and N 2 in COVID-19 pandemic period. • The system was scrutinized based on the thermodynamic and economic points of view. • Effects of the key operation parameters was investigated on the systems performance. • NSGA-II algorithm was utilized to optimize the designed system. • The exergy efficiency of the system and pay-back period factor were determined. [ABSTRACT FROM AUTHOR]