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In this research paper, comprehensive thermodynamic modeling of an integrated energy system consisting of a multi-effect desalination system, geothermal energy system, and hydrogen production unit is considered and the system performance is investigated. The system's primary fuel is a geothermal two-phase flow. The system consists of a single flash steam-based power system, ORC, double effect water–lithium bromide absorption cooling system, PEM electrolyzer, and MED with six effects. The effect of numerous design parameters such as geothermal temperature and pressure on the net power of steam turbine and ORC cycle, the cooling capacity of an absorption chiller, the amount of produced hydrogen in PEM electrolyzer, the mass flow rate of distillate water from MED and the total cost rate of the system are studied. The simulation is carried out by both EES and Matlab software. The results indicate the key role of geothermal temperature and show that both total exergy efficiency and total cost rate of the system elevate with increasing geothermal temperature. Also, the impact of changing absorption chiller parameters like evaporator and absorber temperatures on the COP and GOR of the system is investigated. Since some of these parameters have various effects on cost and efficiency as objective functions, a multi-objective optimization is applied based on a Genetic algorithm for this system and a Pareto-Frontier diagram is presented. The results show that geothermal main temperature has a significant effect on both system exergy efficiency and cost of the system. An increase in this temperature from 260 C to 300 C can increase the exergy efficiency of the system for an average of 12% at various working pressure and also increase the cost of the system by 13%.

The current work proposes and investigates a novel multigeneration system (power, hydrogen, and energy) comprising a flash-binary geothermal power plant, a modified Kalian cycle, a low-temperature electrolyzer, and a reverse osmosis desalination setup. Indeed, the whole system has been devised regarding the multi-heat recovery technique and smart management of products through a structural modification. To emphasize the ability of the newly designed system in this work, the data of the Sabalan geothermal plant in Iran has been used as a case study. Subsequently, the feasibility of the proposed multigeneration system has been examined by the modified specific exergy costing (M-SPECO) method, characterizing the exergetic and cost aspects of the system. The M-SPECO method is recognized as an energy level-based cost scrutiny technique to evaluate energy conversion systems. Accordingly, the sensitivity study through single and dual parametric analyses has been implemented, wherein separator 1 pressure was the main parameter. Likewise, the non-dominated sorting genetic algorithm-II (NSGA-II) method has been applied to optimize the calculations and reveal the optimum conditions and results. In this way, the achieved optimum exergy efficiency of the system was calculated as 47.25%, followed by a value of 7.66 $/GJ for the modified overall unit cost of products.

The Reynolds number of turbine blades can be reduced by decreasing the surface roughness of the blades, which decreases energy loss in energy production systems. Due to the challenges of the polish...

The semi-analytical procedure combined with the trigonometric expansion and generalized differential quadrature (TE-GDQ) technique is developed to examine the asymmetric stability of functionally graded graphene platelet reinforced nanocomposite (FG-GPLRC) annular plates subjected to thermal loading. Uniform distribution and random orientation are supposed for GPLs in all laminas. The volume fraction between plies changes according to three types of functionally graded media. The equivalent Young’s modulus of the plate is determined by Halpin–Tsai micromechanical process. Then, the governing equations are extracted utilizing the Riessner plate theory as called FSDT and von-Karman kind of nonlinear geometrical relation. After calculating the pre-buckling path and the linearizing process, the stability relations can be derived using the adjacent equilibrium standard. Then, the TE-GDQ procedure is applied to the stability equations. Additionally, the obtained eigenvalue theme is solved; after that, the temperature variation for thermal buckling can be calculated. To illustrate the efficiency and accuracy of the exploited formulation and methods, a validation study is conducted. After validity, various parametric results are demonstrated to analyze the influence of the GPL volume fraction, type of reinforcement, and geometrical factors on the structure stability.

One of the essential steps to design energy conversion-based systems is choosing an efficient working fluid under the design goals to access stable products with high efficiency and overcome environmental issues. In this regard, the current paper is motivated to devise and evaluate a novel geothermal-driven multigeneration system under the effect of various working fluids. The proposed system consists of a flash-binary geothermal power plant, an organic flash cycle (OFC), a power/cooling subsystem (an organic Rankine cycle (ORC) and a thermoelectric generator incorporated with a compression refrigeration cycle), and freshwater and hydrogen production units utilizing a humidification-dehumidification desalination unit and a low-temperature electrolyzer. Considering the design potential of the OFC and ORC, four different environmentally-friendly working fluids, i.e., R123 and R600 in the OFC and R1234yf and R1234ze(e) in the ORC are selected and classified in four groups to introduce the best one, under the energy, exergy, and economic (3E analysis) approaches. Also, the whole system is optimized through a genetic algorithm, respecting the optimal solution for the energy efficiency and unit exergy cost of the products. According to the results, R123/R1234ze(e) shows the highest cooling, hydrogen, freshwater production rates, and energy efficiency. Likewise, the maximum power generation and exergy efficiency belong to R600/R1234ze(e). Moreover, R600/R1234yf has the lowest unit exergy cost of products.

Smart use of clean energy sources for achieving higher performance and designing cost-effective systems is recognized as an essential solution for reducing fossil fuel consumption. In this regard, this study supports a comprehensive evaluation and multi-criteria optimization of a novel poly-generation plant embracing geothermal energy from thermodynamic and thermoeconomic perspectives. Hence, the utilization of modified subsystems and smart use of multi heat recovery processes are projected and appraised. In this regard, the plant consists of a double-flash binary geothermal subsystem, an organic Rankine cycle in combination with an ejector refrigeration cycle considering a zeotropic working fluid (a mixture of pentane and R142b), a heating production heat exchanger, and a proton exchange membrane electrolyzer with the combined production of cooling, heating, power, and hydrogen. The crucial thermodynamic and thermoeconomic variables are investigated against key parameters and concluded that the sensitivity of outcomes is more evident with the variation in zeotropic working fluid composition and the vapor quality at the heating production heat exchanger's outlet. The attained results at the optimum mode demonstrated, the energy and exergy efficiencies of the plant as well as total unit costs of products are as being 44.5%, 35.8%, and 18.8 $/GJ, respectively.

Switching from fossil fuels to biofuels is an effective option for small-scale power production and cogeneration systems. The target of the current study is to propose and investigate a novel seasonal combined cycle driven by a biogas-fueled gas turbine from thermodynamic and economic viewpoints. Regarding the high-temperature of the turbine's exhaust gases, an integration of Rankine and ejector refrigeration cycles is configured. The bottoming cycle is designated for winter and summer conditions, independently. Hence, a combined cycle capable of operating as a cogeneration system producing electricity/heating or electricity/cooling, individually, is designed. Moreover, a parametric study based on assessing the impact of key parameters on the essential variables and a multi-criteria optimization trough a genetic algorithm are performed to attain the facilities of the proposal. According to the results, the capability of the whole system in winter conditions is significantly higher than that for summer conditions due to the higher heating capacity. Also, the evaluated variables are more affected by change in the environment temperature in both seasons. Additionally, the optimal overall energy, exergy and levilized cost of products are calculated as 79.2%%, 45.6%, and 21.7 $/GJ for summer and 70.7%, 37.0%, and 17.6 $/GJ for winter, respectively.

Most of the gas species in the air entering the fuel cell through the cathode electrode is nitrogen. Nitrogen recognizes as the only reactant inside the fuel cell stack that remains unchanged during its internal chemical and electrochemical processes. Owing to this specific behavior of nitrogen, this study investigates the performance of two types of solid oxide fuel cells with different electrolytes (oxygen-ion conducting and proton conducting) and their electricity generation applications under the influence of changes in nitrogen ratio of the air entering the cathode electrode. Also, the role of simultaneous changes in nitrogen ratio with two main fuel cell design parameters, precisely, current density and fuel utilization factor, on the performance of the fuel cell is scrutinized. Moreover, this study compares the performance of two different electrolytes in the fuel cell structure and their application under identical conditions from thermodynamic, economic, and environmental prespectives. According to the results, with increasing input nitrogen ratio, the voltage output of each cell, energy and exergy efficiencies, electricity generation rate, and exergoeconomic factor of the applications decrease, while the unit cost of electricity and carbon dioxide emission increase. The sensitivity of the reduction in performance is higher in nitrogen ratios above 0.7.

In this study, ternary MWCNTs/CoFe2O4/FeCo nanocomposite coated with conductive PEDOT-polyaniline (PA@MW/F/C) co-polymers were synthesized by microwave-assisted sol-gel followed in-situ polymerization methods. The phases, crystal structures, morphologies, magnetic and electromagnetic features of the as-prepared samples were identified via XRD, SEM, XPS, VSM, and VNA respectively. Absorption characteristics were investigated in the frequency (12–18 GHz) Ku band. XRD, VSM and SEM analysis confirmed the partial reduction process of CoFe2O4 and successfully decorated magneto-dielectric particles with co-polymers. By measuring electromagnetic features of the samples, it was found that coating magneto-dielectric particles with conductive co-polymers improved the permittivity and dielectric constant, accordingly affecting the impedance matching characteristic and attenuation constant performance. Moreover, exchange coupling behavior was found significant impacts on the microwave absorption properties. PA@MW/F/C coated nanocomposite revealed the maximum reflection loss of −90 dB at 13.8 GHz with 4 GHz effective bandwidth and 1.5 mm thickness. Due to the enhanced interfacial polarization, impedance matching and exchange coupling effects of the as-prepared nanocomposite, it owns excellent microwave absorption properties, which can be applied as an absorber with distinguishing features (strong absorption, thin thickness, and broadest effective bandwidth).

Utilization of renewable energy resources and efficiency improvement of energy conversion systems are of great importance due to energy crisis and environmental issues. Renewable energy driven Triple Combined Cycle (TCC) is a relatively new idea in this respect. In this paper, a biomass gasification-fueled TCC is presented in which the conventional gas turbine, as the topping cycle, is combined with a Closed Brayton Cycle (CBC) and an Organic Rankine Cycle (ORC). The proposed TCC is integrated with LNG regasification process to exploit its cold exergy for compressor inlet cooling of the CBC. For the CBC three working fluids (namely: helium, nitrogen and carbon dioxide) are considered. There is a good thermal match between the LNG and these fluids in heat rejection process and they can be cooled down to temperatures of below 0 °C at the compressor inlet for net power augmentation. Thermoeconomic method is applied to evaluate the TCC performance and optimization using genetic algorithm is employed to minimize the Levelized Cost of Electricity (LCOE). In the economic analysis the cost rate of environmental impacts due to pollutant emissions is also considered. The results indicated the superiority of helium over the other investigated working fluids from the economic perspective for which the LCOE is found to be 51.38 $/MWh. However, as an interesting outcome it is found that, from thermodynamic standpoint using CO2 as the working fluid yields higher exergy efficiency by 6.7% than the helium.

Port Sudan city is a capital of the Red Sea State in the republic of Sudan in south-eastern Africa. The city has high consumption of power for street lighting. The lighting is needed for 12 h/day. This consumes about 11.5 Mw day. The aim of this paper is study the proposed system to reduce the streetlight power consumption use in Port Sudan City and to explore the renewable energy to work alternative energy sources. The present paper studies the proposed system called (all-in-one) street lighting system consisting of PV panel, lithium ion battery and light sensor with LED lamp, all connected and constructed in single unit. The proposed system is to be used in Port Sudan city to decrease the electricity consumption, especially in summer. The problem has been treated theoretically. The proposed system has been compared with two types of plant the first plant used 250W lamp Ac and the second plant used 100W LED lamp. The results show that the proposed system has low cost, about 80 USD and much better economically. The proposed system can solve the power loss in Port Sudan city, saving 11.5 Mw day for this city and more than 428,000 SUP/day. The results show that the proposed system could be utilized to reduce lighting consumption, save energy and developments on environment. We therefore recommended to uses the proposed system in many countries not only in Port Sudan City.

This article performs an analytical study on the damping vibration behavior of metal foam nanocomposite plate reinforced with graphene oxide powders (GOPs) in thermal environment. The GOPs are dispersed through the thickness of the structure according to three functionally graded (FG) and one uniform distribution patterns. The Halpin–Tsai micromechanical model is chosen for estimating the effective material properties of the structure having GOPs as reinforcement phase. Also, different porosity types are taken into account for the metal foam matrix. The plate is resting on a three-parameter viscoelastic medium containing Winkler and Pasternak layers in combination with viscous dampers which can dissipate the oscillation of the structure in some special cases. The Governing differential equations are derived via Hamilton’s principle on the basis of refined higher order shear deformation theory and then solved with employing Galerkin solution method to obtain the natural frequencies of the proposed structure. Moreover, various boundary conditions (B.Cs) including simply supported, fully clamped and different combinations of these B.Cs are considered in this study. The influences and confrontation of different significant parameters such as GOPs’ weight fraction, foundation parameters, aspect and side-to-thickness ratios, porosity coefficients, thermal environment, and FG patterns are investigated through various graphical and numerical results. Our findings declare that the dynamic behavior of the graphene oxide powder reinforced metal foam (GOPRMF) plate remarkably depends on these parameters.

To enhance the quality of machined parts, virtual machining systems are presented in this study. In the turbine blades, the minimization of the surface roughness of the blades can decrease the Reynolds number to decrease the loss of energy in power generation. Due to difficulties of polishing process in minimizing the surface roughness of machined blades, the optimized machining parameters for minimizing the surface roughness is an effective solution for the problem. In this study, a virtual machining system is developed to predict and minimize the surface roughness in 5-Axis machining operations of gas turbine blades. To minimize the surface roughness, the machining parameters were optimized by the Genetic algorithm. To validate the developed system, the turbine blades were machined using a 5-Axis CNC machine tool and the machined blades were measured using the CMM machine to obtain the surface roughness of machined parts. So, a 41.29% reduction in the measured surface roughness and a 42.09% reduction in the predicted surface roughness are obtained using the optimized machining parameters. The developed virtual machining system can be applied in the machining process of turbine blades to enhance the surface quality of machined blades and thus improve the efficiency of gas turbines.

Regarding the low energy density of solid biomass, it usually is converted to gaseous bio-fuels to be utilized in power generation systems. In this regard, the biomass gasification and digestion are of two major conversion routes. The main goal of this research is to make a comparison between biomass gasification and digestion to fuel a power and hydrogen cogeneration plant. The proposed plant is composed of a micro-scale gas turbine and an absorption power cycle for exhaust waste heat recovery of the gas turbine. The generated power by the absorption cycle is utilized in an alkaline electrolyzer for hydrogen production. Thermodynamic, economic and electrochemical models are developed to simulate and investigate the systems performances from exergy, economic and environmental standpoints. Also to determine the best operating conditions, tri-objective optimization is conducted based on maximizing the exergy efficiency and minimizing CO2 emission and product cost. The results indicate that the digester-based system yields higher values of power and hydrogen production, and exergy efficiency as well as lower value of CO2 emission compared to gasifier-based system. It implies that selection of the better system between the two considered ones depends on the user/designer special criteria.

This paper reported the microwave absorption properties of BaFe12O19, carbon-fiber@Fe3O4 composite, and graphene@BaFe12O19@Fe3O4 composite. The prepared samples showed no impurity or any secondary phase during the XRD analysis. The morphology of the samples has indicated the successful arrangement of the Fe3O4 nanoparticles on the carbon fiber, which created pores thereby enhancing the absorption of microwaves. Similarly, the BaFe12O19 and Fe3O4 were also efficiently decorated on the surface of the graphene sheets. The presence of non-magnetic carbon fiber and graphene causes a significant reduction in coercivity while maintaining reasonable saturation and remnant magnetization, thereby improving the microwave absorption capability of the prepared composites. The B/C/A combination with 5 wt% filler loading offers better microwave absorption capabilities in all thickness variations with RLmax having value greater than ?10 dB. Additionally, an increase in filler loading to 15 wt% for the B/C/A combination resulted in an increase in RLmax to 40 dB. The studies have demonstrated the synergic effect of the various components of the composites for efficient tuning of microwave absorption capabilities and the possibility of using the B/C/A combination for technological application.

The use of flash-binary geothermal power plants is recognized as an appropriate concept for preparing a sustainable energy production facility. Hence, the target of the current research is to specify the exergetic and economic aspects of an innovative electricity and cooling cogeneration system comprising a dual-flash binary geothermal power plant and an ejector refrigeration unit. The essential point of this study is the smart use of the total capacity of a medium-temperature geothermal source to produce energy-based products and eliminate the weakness of the conventional setups, increasing the exergy and exergoeconomic performances. A parametric study has been implemented to analyze the effect of several main parameters on the vital variables including efficiencies, exergy destruction rate, sum unit exergy cost, investment cost rate, and exergoeconomic factor. Besides, a multi-objective optimization in different cases has been applied to the calculations through a non-dominated sorting genetic algorithm II (NSGA-II) to achieve an optimal design. The results showed that the performance of the system was more sensitive to changing the separators’ operating pressure of the plant. Likewise, the optimum exergy efficiency and optimum unit exergy cost of the system were found to be 12% and 0.0043 $/kWh through the exergy/cost multi-objective optimization case, correspondingly.

The presence of toxic heavy metal ions in the environment generating from industrial activities is one of the most drastic environmental threats that humanity is facing today. Herein, we theoretically study the removal of toxic heavy metals using the two-dimensional carbon materials such as pristine as well as Stone-Wales defect filled carbon cones. Our results show that carbon cones are promising materials to remove the Cd2+, Hg2+, and Pb2+cations in the solutions. Time-dependent density functional analysis also revealed “ligand to metal” excitations for the considered cation/carbon cone systems. The results of this study reveal that two-dimensional carbon cone is an important nanomaterial with possible unexpected properties. Therefore, many experimental and theoretical investigations are necessary to determine these properties.

Today, a new biomedical application of various nanomaterials is the utilization of them as drug delivery systems (DDSs) for several anti-cancer medicines to decrease their problems by carrying them to the target tumor cell zone. In the recent project, we have studied the efficiency of the pristine BC2NNTs and functionalized BC2NNTs as a DDS for chlormethine (CM) anti-cancer drug applying the density functional theory B3LYP/6-31G (d, p). It was detected that CM interacted weakly with the pristine BC2N nanotubes (−13.60 kcal mol−1). Therefore, the functionalized BC2NNTs were studied for CM interaction. In comparison to pristine BC2NNTs, in the adsorption and stabilization of the investigated compounds as well as their thermodynamic energy, our computations revealed that H bonds between active positions of carboxyl functionalized BC2NNTs and CM were the key factors. The fractional charge transfer, molecular electrostatic potential, and natural bond orbital analyses showed a considerable charge transfer from CM drug to the functionalized BC2NNTs. In addition, it was discovered to be stable in aqueous environments with amounts for solvent energies, which is appropriate for CM drug delivery uses. This project proposes a novel plan to achieve a high-density CM drug on the BC2NNTs’ surfaces.

Regarding the ability of solid oxide fuel cell-based energy conversion systems and modifying their design structure, the current study comprehensively investigates the potential of empowering a novel integrated solid oxide fuel cell-based power plant via liquefied natural gas together with geothermal energy, addressing this matter. Likewise, the newly designed system embraces an efficient design through multi-heat recovery based on two energy sources. In this regard, the sensitivity analysis and optimization (using a genetic algorithm) methods are utilized to assess the proposed system, taking into account the energy, exergy, exergo-economic, and environmental perspectives. The results indicate that as the current density of the cell increases, the net output power and energy efficiency of the system enhance. Among considered decision variables, geothermal water temperature and turbine pressure have the severest impacts on the output power and the corresponding unit cost. Moreover, optimization results reveal that the air heat exchanger and turbine have the highest exergy destruction costs with values of 4800 $/year and 4500 $/year, respectively. Furthermore, it is found that the emissions’ cost (0.000154 $/s) would be around 2% lower when the system is optimized by minimizing unit product cost rather than maximizing the energy or exergy efficiency of the system.

The difunctionalization of unsaturated hydrocarbons, the incorporation of two functional groups onto an unsaturated carbon-carbon bonds, is one of the most active and popular topics in modern organic chemistry due to its significance in the rapid and highly atom economical synthesis of complex molecules from simple starting materials within a single click. Among various difunctionalization reactions, difunctionalizing carboxylations utilizing CO2 as a renewable and environmental friendly C1 feedstock has attracted more and more attention in recent years. In this regard, several interesting strategies have been developed in the last two decades for the preparation of branched carboxylic acids and their derivatives through the alkylative/arylative carboxylation of the corresponding unsaturated hydrocarbons using CO2 as a carboxyl source. Thus, it is an appropriate time to summarize those advances. The purpose of this Mini-Review is to focus on the most important advances and developments on the attractive research field with particular emphasis on the mechanistic features of the reaction pathways. Notably, we have organized this review based on the type of bond where the CO2 insertion occurs.

One of the widespread applications of nano-materials which is currently investigated is in drug delivery vehicles for various anticancer drugs for reducing their serious side effects which is usually done through their transportation into targeted tumor cells. In this study, the performance of a pristine NC3 carbon-like nanotube (NC3NT) was scrutinized as a vehicle to deliver 5-aminosalicylic acid (5-ASA) through density functional theory (DFT) at B3LYP-D3 theory level with 6-31G (d, p) basis set. The adsorption energies (Eads) for the ASA@NC3NT complexes were approximately −18.62 in the gas phase whereas they were approximately 29.73 kcal mol−1 in the water phase. The more negative Ead values in the solvent phase show that the NC3NT has the ability to enhance the solubility of 5-ASA and change the interaction between them in the aqueous phase. Based on fractional and NBO charge transfer analyses, the charge transport from the 5-ASA molecules to the surface of the NC3NT is significant. Moreover, the electronic spectra related to the ASA/NC3NT complexes have a blue shift towards shorter wavelengths of approximately 19 nm based on the ultraviolet–visible analysis. We can conclude, based on our calculations, that the above-mentioned nanotube could be employed as a vehicle for delivering 5-ASA.

Through the present investigation, the thermal and power output of novel-shaped solar panels are evaluated. For the cooling of the mentioned forms, forced air flow was utilized. Three novel shapes, of Pyramid, Hexagonal, and Conical which had the equal lateral surface were considered. For the simulation, an open source CFD software was utilized. The lateral surfaces were put under identical amount of heat flux. Air as the coolant fluid was injected with constant inlet temperature from the trapdoors at the bottom of different shaped structures. Three different values of heat flux and air injection rate were evaluated for each shape. The outcomes presented that the conical shaped solar panel exhibits better thermal performance than other geometries. Furthermore, conical form finds the least temperature that was about 10.5 ?C less than that of the pyramidshaped panel. Furthermore, it was revealed that the corners of pyramid and hexagonal-shaped solar panels have higher temperature. Also, it was found that the efficiency of conical shaped panel was up to 8.4% more than that of pyramid-shaped panel.

Abuse of the cathinone (CA) drug has been related to several deaths worldwide. In this paper, the sensing characteristics of the pristine BC3 nanosheet (BC3N) as well as the Au@BC3N are scrutinized towards CA using TPSS, B3LYP, M06-2X, PBEPBE, and B97D density functionals. It is found that the decoration of Au enhances the reactivity of BC3N toward CA to a great extent, and raises the sensing response of BC3N from 0.12 to 415.1. Correspondingly, a short recovery time of approximately 1.01 s is anticipated for the CA desorption from the surface of Au@BC3N. The interaction between CA and the Au@BC3N is slightly strengthened by the water solvent, whereas the sensing response decreases. We deduced that doping BC3N by Au makes it an encouraging sensor for detecting CA.

An innovative biomass gasifier integrated plant was proposed for combined heating and power production in the current paper. The plant consists of an s-CO2 cycle, gasifier, combustion chamber, and a domestic water heater for heating purposes. The system was studied from different perspectives, i.e., energetic, exergetic, exergo-economic, economic, and environmental (4E). For this purpose, simulation of the proposed plant was carried out by EES software; then, by utilizing COMFAR III software, the economic sensitivity investigation was conducted to detect the influence of financial parameters on the system's economic features after installation of the plant. Results of economic evaluation unfolded that installing the proposed plant is affordable from the economic point of view. Besides, a sensitivity analysis was conducted to calculate the main performance indicants, including an environmental impact indicator. The proposed system was optimized by a robust Multi-Objective Bat Optimization Algorithm . For determining the final optimum solution, TOPSIS, LINMAP, and Shannon entropy methods were used in the optimization process. Optimization results were also compared to the conventional multi-objective optimization methods to detect the suitable optimization method. The findings of the comparison confirmed that the bat algorithm's performance had been better, based on Taylor and Violin diagrams. Besides, scatter plots of effective parameters are presented to define the suitable operating ranges. The results show that the optimum exergy efficiency, Levelized CO2 emissions, and total product cost are 38.42%, 0.4757 t/MWh, and 7.517 $/GJ obtained. The total product cost was reduced significantly from 10.01 $/GJ to 7.517$/GJ at the expense of a slight diminish in exergetic efficiency of about 2% through the use of the bat algorithm. Also, the annual greenhouse gas emission made by the proposed system was reduced by about 9% after the optimization process.

Utilization of hybrid renewable resources in supplying clean energy is a new idea which helps to fulfill individual drawbacks of each renewable source. In this work, an innovative triple combined power cycle driven by hybrid biomass-solar energies is proposed, analyzed and optimized from the exergy, economics, and environmental standpoints. In order to fulfill the intermittent nature of solar energy, it is used for hydrogen production (via Proton Exchange Membrane (PEM) electrolyzer supplied by electricity from Photovoltaic-Thermal (PVT) panels) which is injected into a post-firing combustion chamber of the gas turbine. The proposed system consists of a biomass fueled gas turbine combined with a closed Brayton cycle and a Rankine cycle as the bottoming cycles. To examine the system performance, thermoeconomic evaluation is carried out and multi-objective optimization is performed to find the optimum operating conditions based on Levelized Cost Of Electricity (LCOE) and CO2 emission. The results revealed that, incorporation of solar-based hydrogen production with the biomass-based gas turbine results in a significant decrease in CO2 emissions and biomass consumption as well as increase in power generation capacity. However, it brings about a decrease of exergetic efficiency (due to the large exergy destruction in PVT and PEM electrolyzer) and an increase of LCOE (due to the additional expenditures imposed by PVT panels and PEM electrolyzer). Under the best operating conditions based on multi-objective optimization, the proposed triple combined cycle attains exergy efficiency of 30.44% with a LCOE of 61.37 $/MWh, and CO2 emission of 0.4579 kg/kWh.

Nickel-based superalloys, especially GTD-111, are widely used in the aerospace industry. Due to the high amount of Cr, the IN625 superalloy can be a good option for the surface protection of GTD-111. In this study, IN625 powder was cladded on GTD-111 using a pulsed Nd: YAG laser. This study aimed to investigate the effect of laser process parameters such as power, scan speed, and powder feed rate on microstructure development, defects, and hardness of the cladded samples. The results of this study showed that with increasing laser power from 150 to 300 W, the solidification structure tends to form equiaxed grains due to the decreasing GR from 30,751 to 20,058 °C/s and G/R from 1230to 802 °C/mm2. While at the laser power of 300 W, the tendency to form liquated cracks is increased due to the expansion of HAZ and the consequent increase in the reaction of crack-sensitive phases such as γ′, γ-γ′, and MC within the matrix. The tendency to form an equiaxed/coaxial region in the clad zone (CZ) decreased with an increase in the powder feeding rate. The inclination to form lateral porosity increased due to the reduction of the laser time interaction with the sample surface. On the other hand, by increasing the scan speed from 4 to 7 mm/s, the tendency to form cracks in the interface of the clad-substrate and HAZ increases due to the increased stresses caused by cooling. Unlike scanning speed and laser power, with increasing powder feeding rate, the distance between dendritic arms at the bottom of the coating has decreased from 1.12 to 1.02 μm. In this study, it was found that with increasing the heat input, the solidification rate decreases and as a result, more time is created for increasing the coating dilution. The distance between the dendrites subsequently increases and coarsening of carbide particles also occurs.

In order to completely understand the trend of pressure variations inside High Pressure (HP) fuel pipeline of Combination Electronic Unit Pump (CEUP) fuel injection system and study the impact of two major physical properties of fuel i.e., density and dynamic viscosity on pressure a 1D nonlinear dynamic mathematical model of fuel pressure inside pipeline using Wave Equation (WE) has been developed in MATLAB using finite difference method. The developed model is based on the structural parameters of CEUP fuel injection system. The impact of two major physical properties of the fuel has been studied as a function of pressure at various operating conditions of diesel engine. Nearly 13.13 bars of increase in pressure is observed by increasing the density from 700 kg/m 3 to 1000 kg/m 3 . Whereas an increase of viscosity from 2 kg/m.s to 6 kg/m.s results in decrease of pressures up to 44.16 bars. Pressure corrections in the mathematical model have been incorporated based on variations of these two fuel properties with the pressure. The resultant pressure profiles obtained from mathematical model at various distances along the pipeline are verified by correlating them with the profiles obtained from simulated AMESim numerical model of CEUP. The results show that MATLAB mathematical results are quite coherent with the AMESim simulated results and validate that the model is an effective tool for predicting pressure inside HP pipelines. The application of the this mathematical model with minute changes can therefore be extended to pressure modeling inside HP rail of Common Rail (CR) fuel injection system.

During a fuel injection cycle pressure inside Combination Electronic Unit Pump (CEUP) fuel injection system varies from low (~50 bars) to very high (~1500 bars) in fractions of seconds depending on the operating conditions. Physical properties of fuel including density, acoustic wave speed and bulk modulus also vary as a function of rapidly varying fuel pressure. A detailed analysis of these key fuel properties with our improved frequency dependent model with viscous damping developed in MATLAB is presented for both diesel and biodiesel fuel Rapeseed Methyl Ester (RME). Quantitative analysis of developed model confirms that model predictions are quite realistic and accurate across range of operating conditions of diesel engine.

An efficient controller based on joint between original proportional-integral-derivative (PID) controller and fast genetic algorithm (FGA) is proposed to enhance the transient response of high order synchronous machine. PID controller has several advantages in practical design of synchronous machine compared with another controller。The transient response parameters with PID controller of synchronous machine are reasonable, but they susceptible to the local minima problem and not adequate. Therefore, FGA is used to overcome this problem and to enhance the transient response. Performance of the proposed controller is tested through a high order synchronous machine model and then compared with the original PID controller. In this paper the weak coupling relationship between the automatic voltage controller (AVR) and automatic generation control (AGC) in the synchronous machine has been proved to simplify the overall model. The results demonstrate that, the proposed controller is an efficiency and better than a conventional PID controller.

High pressure (HP) fuel pipeline is one of the vital components of Combination Electronic Unit Pump (CEUP) fuel injection system besides pump and injector. Effect of four key fuel properties including density, viscosity, acoustic wave speed and bulk modulus on pressure wave profile has been investigated using a 1D viscous damped mathematical model. Wave equation (WE) based mathematical model has been developed in MATLAB using finite difference method. Dynamic variations of these fuel properties during fuel injection cycles have also been incorporated in mathematical model by utilizing empirical formulas. The results show that these four key fuel properties not only vary with the pressure during fuel injection process but also define the trend of pressure wave propagation inside HP fuel pipeline.

Diesel fuel pressure wave inside Combination Electronic Unit Pump (CEUP) pipeline has been investigated using a 1D viscous damped mathematical model considering the effect of four key fuel properties including density, viscosity, acoustic wave speed and bulk modulus. Wave equation (WE) based mathematical model has been developed in MATLAB using finite difference method. Mathematical model results at various operating conditions of diesel engine have been verified by comparing with those of AMESim numerical model of CEUP and quantified through Root Mean Square Errors (RMSE) and Index of Agreements (IA). Dynamic variations of these fuel properties during fuel injection cycles have also been incorporated in mathematical model by utilizing empirical formulas. Predicted results show that simulated results which consider fuel properties dynamic variations as a function of pressure are more coherent to AMESim numerical model results.

The overall reliability of the underwater unmanned vehicle(UUV) system is improved. This paper mainly study sensor fault diagnosis of UUV. On the basis of analyzing the abnormal sensor model of UUV, put forward the corresponding method of fault diagnosis. The improved gray model GM(2,1) theory is introduced into the fault diagnosis of underwater unmanned vehicle. On the sensor sample date sequence gray model is established. Through analyzing the actual output signal and the output signal of this model, detect sensor fault in real time.