A highly efficient photovoltaic nanocomposite device is demonstrated by fabrication of structural clusters of silver nanoparticles (Ag NPs) on silicon solar cells via a boil deposition method. The efficiency of silicon solar cell was augmented by coating Ag NPs ultra-thin-film deposition on silicon solar cell. Chemically synthesized silver NP's, their consumption on a silicon thin layer and the operation of photovoltaic nanocomposite device were characterized by using several electron probe microscopic pectroscopic and spectrometric techniques viz. x-ray diffraction (XRD), scanning electron

We have investigated different nonidealities in Cu2ZnSnSe4-CdS-ZnO solar cells with 9.7% conversion efficiency, in order to determine what is limiting the efficiency of these devices. Several nonidealities could be observed. A barrier of about 300 meV is present for electron flow at the absorber-buffer heterojunction leading to a strong crossover behavior between dark and illuminated current-voltage curves. In addition, a barrier of about 130 meV is present at the Mo-absorber contact, which could be reduced to 15 meV by inclusion of a TiN interlayer. Admittance spectroscopy results on the

Recently, emerging vehicular applications are increasing the demand of vehicles which form significant burdens on network backhaul and represents a cause to the quality of experience (QoE) decay of the vehicular users. Proactive caching is a promising technique to mitigate the load on core networks by caching some of the expected data items. This work proposes a hierarchical proactive caching scheme which jointly considers caching in vehicles and roadside units (RSUs). Minimization of the vehicle communication latency is the main objective of our study. The optimization problem is formulated

We show that the four parameters of a single-dispersion Cole-Cole bio-impedance model can be extracted from an one time-domain measurement with a fixed frequency. In particular, a periodic triangle waveform current excitation signal is injected into the biological sample under study while measuring the voltage developed across this sample in a galvanostatic measurement setup. The voltage response due to this triangle-wave excitation is firstly analytically derived in closed form. After that the Flower Pollination optimization Algorithm (FPA) is applied to extract the unknown model parameters

This paper reports on the variations in the parameters of the single dispersion Cole bio-impedance model of Daucus Carota Sativus (carrots) under heating and freezing conditions. Experiments are conducted on six samples with recorded live bio-impedance spectra versus temperature. The Cole model parameters are extracted from the measured data using the Flower Pollination Algorithm (FPA) optimization technique and their variations are correlated with well-known bio-chemical and bio-mechanical variations. This represents a non-invasive method for characterizing and measuring the degree of change

This work explores a novel simple technique to investigate the shelf life of fruit using Electrical Impedance Spectroscopy (EIS). EIS is a non-destructive analysis that focuses on studying the electrical impedance variations during ripening of fruit. The purpose of this study is the use of a biodegradable natural plastic packaging for extending fruit and vegetable shelf life. Polyethylene Terephthalate is currently used for food packaging such vegetables, fruit and meat. It is a tough and flexible plastic material with high impact strength, but it has the disadvantages of synthetic plastics

Double-dispersion impedance models are important for the accurate fitting of spectral impedance measurements in Electrical Impedance Spectroscopy (EIS). While the Cole–Cole model is the most widely known, it is possible to define double-dispersion Cole–Davidson and Havriliak–Negami models as well. In this work, we show that more freedom can be exercised when these three models are combined together and that this combination can be done in various forms. Experimental results using a two-stage optimization algorithm applied on the suggested models are provided. © 2021, European Biophysical

The need for portable and low-cost bio-impedance analyzers that can be deployed in field studies has significantly increased. Due to size and power constraints, reducing the hardware in these devices is crucial and most importantly is removing the need for direct phase measurement. In this paper a new magnitude-only technique based on modified Kramers–Kronig transforms is proposed and tested. Comparison with impedance measurements of fresh and aging tomato samples using a precise industry standard impedance analyzer is carried out and explained. Error and noise analysis of the proposed

In this paper, different integer and fractional-order models are studied from electrical point of view, these models are used to fit the measured impedance data for different types of fruits and vegetables. Experimental work is done on eight different models for six types of fruits to verify the best fitting model. Electric impedance is measured in the range of frequencies (200 mHz–200 Khz) using a non-destructive method, where the tissues are not damaged by electrode insertion. Moreover, two integer order models have been extended to the fractional order domain where data analysis and fitting

A novel non-uniform Kramers–Kronig Transform algorithm for bioimpedance phase extraction is proposed and tested in this work. The algorithm error is studied and compared with a previously proposed phase extraction technique, also based on the Kramers–Kronig transform. Results using simulated datasets and experimental datasets confirm the excellent performance of the algorithm. © 2020, European Biophysical Societies' Association.