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Photovoltaic system is widely installed to increase the share of renewable energy as well as to reduce the environmental impact of fossil fuel based energy. Photovoltaic (PV) is one of the most potential renewable energy based power generation systems. Monitoring of PV system is very important to send information that allows owners to maintain, operate and control these systems to reduce maintenance costs and to avoid unwanted electric power disruptions. Different monitoring systems have been introduced with the time following different requirements. Circuit complexity, availability of friendly graphical user interface, easy to understand system architecture, maintenance facility and customization ability for end user differ from system to system along with cost issues. This paper provides an overview of architectures and features of various PV monitoring systems based on different methods. There are various technologies for PV monitoring and control, developed as for commercial use or research tasks. It has been seen that a large portion of the work is done on classifications, for example, Internet based Monitoring using Servers, TCP/IP, GPRS and so forth. There are various methodologies for data acquisition, for example, PLC (Power Line Communication), PIC, Reference cell, National Instruments etc. Various requirements are considered while selecting a proper monitoring system for an application. Review of various monitoring technologies with system attributes and working structures have been discussed to get a clear view of merits and demerits of existing PV monitoring systems. All the systems discussed in this paper have pros and cons, and these systems were developed following different requirements. In the end, a particular cost effective monitoring system using Arduino microcontroller has been proposed considering both research and user level requirements from perspectives of cost, availability of parts/modules and features, compatibility with sensors and end-devices etc. [ABSTRACT FROM AUTHOR]

This contribution investigates the impact of adding transition metal of Ti to CeO y samples at various concentrations referring to 0, 15.84, 24.46, 34.46, 36.23, 38.46, 45.38% and pure TiO y , correspondingly. The samples were fabricated by the magnetron sputtering technique. X-ray diffraction (XRD) configurations demonstrate the presence of α-Ce 2 O 3 and Ce 2 O 3 phases with increased Ti contents in the systems. X-ray photoelectron spectroscopy (XPS) experimentation confirms the purity of the S1-sample (CeO 2) and the purity of the S8-sample (TiO 2). Further XPS analysis reveals that Ti incorporation in the doped systems functions as a reducing agent because of the existence of α-Ce 2 O 3 and Ce 2 O 3 phases. Moreover, based on UV–vis spectroscopy results, the studied samples exhibit indirect optical energy band-gaps reduced from 2.6 to 2.35 eV with the increase of Ti concentrations of 0–45.38% in (S1-S7), respectively. In reference to bandgap 2.35 eV, a slight rise in band gaps was detected for S3 sample. However, an observable increase in the band gap of 2.9 eV occurred for S8 (pure TiO 2). Optical analysis of the calculated energy loss parameters demonstrates that all the studied samples reveal small amounts of energy loss. Our results suggest that the improved optical properties of Ti-doped CeO y films could serve for various optical applications. [ABSTRACT FROM AUTHOR]

Herein, the closed field unbalanced magnetron sputtered CrNiN, CrNiSiN, and CrNiAlN coatings are studied to gain insights into their structural, morphological, optical, and mechanical properties. Detailed characterizations of the thin films have been carried out through X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), ultraviolet–visible–near infrared (UV–Vis) spectroscopy, nanoindentation, finite element modeling (FEM), and water contact angle measurements. XRD confirmed the hexagonal close-packed hcp-Cr 2 N (211) phase and face-centered cubic fcc-CrN (200) phase. The SEM images confirmed the compact, dense, and uniform distribution of gains in the coating structures. The average crystallite size of CrNiN coatings was 515 nm. The addition of substituents (Si and Al) to the CrNiN coatings resulted in increasing the crystallite sizes to 605 nm (for CrNiSiN) and 811 nm (for CrNiAlN) as well as grain size from 1.32 to 2.335 μm. XPS analysis was conducted to estimate the atomic constituents and measure the high-resolution XPS spectra of Ni2 p photoelectron lines. The elastic modulus and hardness of the coatings are between 361 and 459 GPa, and 23.1–26.8 GPa, respectively. The Si, and Al additions enhanced both Young's modulus and the hardness of the coatings. Results of FEM modeling demonstrated the stress distribution within the coatings on steel and silicon substrates at different film thicknesses. The maximum stress level was increased by 30% at the coatings' upper portion, while that of the interface was reduced by 60%. The water contact angle values lay within the range of 102.4°–112.4°. [Display omitted] • Hexagonal close packed CrN phase was detected and existence of Cr, Ni, Al, Si, and N were confirmed via XPS analysis. • An average grain size of 515 nm was recorded for CrNiN thin films. • The doublet separation energy of 10.8 eV between the Cr2 p 3/2 and Cr2 p 1/2 levels was detected. • A very high Young's modulus of 458.7 GPa was attained by CrNiN thin films. • Water contact angle of CrNiN thin films lies within the range of 102.4–112.4°. [ABSTRACT FROM AUTHOR]