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The aim of this paper is to use the second derivative of Chebyshev polynomials (SDCHPs) as basis functions for solving linear and nonlinear boundary value problems (BVPs). Then, the operational matrix for the derivative was established by using SDCHPs. The established matrix via mixing between two spectral methods, collocation and Galerkin, has been applied to solve BVPs. Consequently, an error analysis is investigated to ensure the convergence of the technique used. Finally, we solved some problems involving real-life applications and compared their solutions with exact and other solutions from different methods to verify the accuracy and efficiency of this method. [ABSTRACT FROM AUTHOR]

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This study investigated the incidence and occurrence of virus-like symptoms in solanaceous plants, peppers (Capsicum spp.), potatoes (Solanum tuberosum) and tomatoes (Solanum lycopersicum) in Egypt. In this study, a total of 640 samples collected from different Governorates in Egypt. 640 samples were tested using DAS-ELISA, with 86.87% of samples showing positive reactions. It was also, revealed that Potato virus Y (PVY) was the most prevalent virus (16.41%), followed by Potato leaf roll virus (PLRV) (11.87%), Alfalfa mosaic virus (AMV) and Pepper mild mottle virus (PepMMoV) both (10.94%), However, Tomato spotted wilt virus (TSWV) was detected at low frequency (4.22%). Some samples were found coinfected with two or three different viruses (i. e. PVY+ ToMV, TMV+ PepMMoV+ TYLCV). Results demonstrated that potato was the most infected plans (37.65%) followed by tomato (27.97%) and then by pepper (21.25%). Potato was the most infected plant (37.65%), followed by tomato (27.97%), and then pepper (21.25%). Collected pepper leaf and fruit with negative results in all tested antisera were selected for identification the virus isolates which suggestive to be Tomato brown rugose fruit virus (ToBRFV) on the basis of symptomatology, host range, modes of transmission and particle morphology. RT-PCR was used to confirm the identity of the virus isolate. Among twenty-five plants species and cultivars, the virus isolate reacted positively with fourteen plants species. The virus was transmitted mechanically and by seed 1:2.5%. Examination of leaf tissue extracts of infected pepper plants by electron microscope revealed rod–shaped particles of 261-348 nm in length, in the range of the Tobamovirus group. Concerning varietal susceptibility, Helsinki and Mycelia pepper cultivars were highly susceptible (70%) followed by California Wonder (50%) and Vita Z 461 (40%). On the other hand, Vita Z Dragon cultivar was the lowest susceptible one (30%). RT-PCR analysis indicated that the virus isolate is ToBRFV. [ABSTRACT FROM AUTHOR]

This paper presents a practical and efficient method to incorporate energy analysis into conventional time domain transient stability simulation for producing a first swing stability index. The proposed method is a variation of the PEBS approach, utilizing a numerical Transient Energy Function and a pseudo-fault-on trajectory starting from the dominant potential energy peak point of the postfault system trajectory. The transient stability index not onl provides additional insight into the stability studies, but also has the potential of speeding up the stability limit derivation process by reducing the number of program runs.

In this work, mixing polyvinyl alcohol (PVA), chitosan (CS) and polyaniline (PANI) to prepare composite nanofibers with improved adsorption capacity using electrospinning technique has been studied, Thereby overcoming the difficulty of producing PANI nanofibers. The morphologies of the prepared nanocomposites were fully examined by SEM, Fourier transform infrared spectroscopy and X-ray diffraction measurements. Results indicated that the blended PVA/CS/PANI-based nanofibers exhibited better size morphology with smaller diameter than (PVA/PANI) and pure polyaniline. Batch experiments were conducted using the prepared (PVA/PANI/CS) composite to study its affinity for dye decolorization. Different factors affecting the adsorption process such as contact time, initial dye concentration, temperature and pH were optimized. The maximum percentage removal was found to be 96% at 300 rpm using adsorbent dose of 60 mg and temperature of 25°C and initial dye concentration 50 ppm. Also, the adsorption isotherms, kinetics and thermodynamics for the removal process were studied. The adsorption process followed Freundlich isotherm and pseudo-first order kinetics. [ABSTRACT FROM AUTHOR]