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This paper considers real-time parameter variations of dish Stirling solar thermal system (DSTS) and combined solar parabolic trough-thermal power system (HTP)-based hybrid power system pertaining to frequency containment. A maiden attempt has been made by considering a detailed modelling of variable speed DSTS system for load frequency control (LFC), which shares the total load along with a battery energy storage system (BESS) and HTP in the proposed hybrid power system. Frequency oscillations resulting from the variations in load demand and/or power output variation of DSTS due to intermittent solar insolation in the hybrid power system needs to be contained employing an appropriate technique. To this end, a novel tilt integral-sliding mode controller (TISMC) optimized by improved African vulture optimization algorithm (IAVOA) has been introduced. Improvement in the existing AVOA has been made by introducing a joint opposite selection (JOS) operator, which shows better performance in exploitation and exploration phases of minimizing frequency error. The performance of the proposed controllers is compared with proportional (P), proportional-integral (PI), proportional-integral-derivative (PID) and proportional-integral-Sliding mode controller (PISMC) for LFC. Finally, performance of the proposed technique is validated in real-time system using OPAL-RT OP4510. From the MATLAB simulation and OPAL-RT results, it has been observed that the IAVOA-based TISMC is the best controller for controlling frequency deviations of the proposed hybrid power system. [ABSTRACT FROM AUTHOR]

The chemical corrosion resistance properties of newly developed oxide (mullite-, cordierite)-bonded SiC ceramics prepared using mixture of waste fly ash and metal oxide additives were investigated in environments containing Na2SO4 at temperature 1000 °C for 8 h. The thermal shock resistance to cooling were evaluated as a function of quenching cycles. The changes in weight, flexural strength, and morphology due to thermal and chemical corrosion were examined. The mechanisms of flexural strength degradation due to chemical and thermal corrosion were analyzed, and the results were compared with literature data. In the hot corrosion by Na2SO4, the cordierite component was severely attacked in the cordierite-bonded SiC ceramics resulted ~ 34% strength degradation after 8 h corrosion; on the contrary, mullite-bonded SiC ceramics exhibited ~ 4% improvement of flexural strength. The chemical and thermal shock resistance results suggest a potential advantage of porous SiC ceramics prepared using waste fly ash for several industrial applications. [ABSTRACT FROM AUTHOR]

A theoretical investigation is done in this multicomponent dusty plasma with non-thermal ions, relativistic electrons and mobile dusts through reductive perturbation technique by deriving Korteweg–de Vries (KdV) equation. Role of ions, dusts and relativistic electrons streamings are investigated in this multicomponent plasma to form compressive and rarefactive KdV solitons. Interestingly, for some pairs of streamings of ions, dusts and relativistic electrons, only compressive solitons are seen to produce whereas for some other pairs rarefactive KdV solitons with some interesting characteristics are seen to produce. In this theoretical investigation, mobile dust particles play a very crucial role in the formation of compressive and rarefactive KdV solitons. Application of this multicomponent plasma model in astrophysical and space plasma is briefly discussed. [ABSTRACT FROM AUTHOR]

The low-cost cordierite-bonded porous SiC ceramic membranes were successfully synthesized at 1300°C for 1 h in the air by in-situ solid-state reactions of SiC with a mixture of fly ash, α-Al2O3 and MgO (FAM). The effects of sintering temperature and FAM content on porosity, mechanical strength, phase compositions, microstructure and permeability were carefully investigated. The ceramics prepared at 1300°C with a 20 wt% FAM mixture showed a very high mechanical strength of 85.8 MPa at a porosity of 28 vol%. The addition of pore former effectively improved the porosity and permeability properties without significantly degradation of mechanical strength. The membrane exhibited 98.4% oil removal efficiency from synthetic oil–water emulsion (1000 mg l–1), which suggests that the membranes are suitable for oil–water separation and other microfiltration applications. The use of fly ash successfully reduced the sintering temperature for the fabrication of ceramic membranes and provided an efficient way of utilizing waste resources. [ABSTRACT FROM AUTHOR]

In this new investigation of higher-order nonlinear dust ion acoustic (DIA) waves with negative dust charges and weakly relativistic ions and electrons in the plasma, only compressive DIA solitons of interesting characters are established through the modified Korteweg–de Vries equation which is derived through standard perturbation technique. Important characteristics of amplitudes and width of relativistic DIA solitary waves are investigated in this new investigation for different plasma parameters. It is found that the amplitude of the solitons increases for smaller streaming speed to ions and electrons with the increment of dust-to-ion density ratio, whereas it is opposite for higher streaming speed of ions and electrons. It is also found that the amplitude of the compressive solitons remains unaffected and linearly increases with the enhancement of dust charges in the plasma. Finally, application of this study to astrophysical and space plasma is discussed briefly. [ABSTRACT FROM AUTHOR]

Large integration of renewable energy in hybrid power system in isolated mode of operation make frequency control a challenging task. This paper investigates the performance of Cuckoo Search Algorithm (CSA) and Firefly Algorithm (FA) based frequency control strategy of such a hybrid power system, which is a unique work. The generating units of the system are plug in hybrid vehicle (PHEV), wind turbine generators, a diesel engine generator (DEG) and battery energy storage system (BESS). The proportional plus integral (PI)/proportional integral derivative (PID) controllers are employed with PHEV, DEG and BESS to adjust the total active power generation in accordance to the load demand. Addition of PHEV reduces the reliance on the DEG or BESS as a result of variability and uncertainty of wind power. Different disturbance conditions such as step perturbations, random variations of load as well as wind output power, have been considered in the case studies under Matlab simulation to assess the performance of CSA and FA based control strategy. Analysis indicates that CSA based PID controller provides better response compare to GA, PSO and FA based PI/PID controller and CSA based PI controller. Sensitivity analysis has been carried out to check the robustness of FA and CSA optimized PI/PID controller gains. [ABSTRACT FROM AUTHOR]

Porous SiC based materials present high mechanical, chemical and thermal robustness and thus have been largely applied to water-filtration technologies. In this study, circular disc shaped SiC microfiltration membranes were prepared by dry pressing of commercially available SiC powder with yttria and alumina as additives followed by a low-cost oxide bonding technique. The membranes fabricated were characterized using standard characterization techniques like Scanning Electron Microscopy (SEM), Powder X-ray Diffraction (PXRD), porosity and pore size distribution analysis and compared with the membrane prepared by liquid phase sintering route from the same powder composition. Finally, water permeation studies were carried out in a standard membrane module and clean water flux was determined. These membranes were found well suited for treatment of oily waste water and grey water. The membrane prepared by oxide bonding method effectively removed ~ 89-93% of COD, ~ 77-86% of oil/grease and 88.4-92% of TSS from kitchen waste water and the removal efficiency are better compared to the membrane prepared by liquid phase sintering method. The effects of corrosions on the membranes were investigated in strong acid and alkali solution at 90 °C. The membranes prepared by oxide bonding method showed better corrosion resistance with retention of mechanical strength. [ABSTRACT FROM AUTHOR]