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AbstractA novel multifunctional conjugated polymer (RCP‐1) composed of an electron‐donating backbone (carbazole) and an electron‐accepting side chain (cyanoacetic acid) connected through conjugated vinylene and terthiophene has been synthesized and tested as a photosensitizer in two major molecule‐based solar cells, namely dye sensitized solar cells (DSSCs) and organic photovoltaic cells (OPVs). Promising initial results on overall power conversion efficiencies of 4.11% and 1.04% are obtained from the basic structure of DSSCs and OPVs based on RCP‐1, respectively. The well‐defined donor (D)‐acceptor (A) structure of RCP‐1 has made it possible, for the first time, to reach over 4% of power conversion efficiency in DSSCs with an organic polymer sensitizer and good operation stability.

This paper addresses the study of vibrations induced by turbulent boundary layers (TBLs) flowing over plate-like structures. The aim is here to propose a predictive method in order to evaluate the vibroacoustical behaviour of a plate excited by TBL pressure fluctuations. The ultimate goal is to develop tools for predicting internal cabin noise in an aircraft during flight. Hence TBL is considered. Different TBL models are discussed and compared. A prediction method well suited for mid-high frequencies is also presented. The method called simplified energy method (SEM) is based on local energetic considerations and extends the well-known statistical energy analysis (SEA). Two different SEM formulations are presented. The first one is of heat conduction type, whilst the second is radiative. The TBL source model was integrated in the local energy proposed formulations. When applied to a simple Kirchhoff-Love simply supported plate, SEM allows prediction of averaged energy quantities. Comparisons are drawn between heat and radiative formulations. Good concordance was observed between energy results and pure analytical calculations of the structural response under TBL excitation over a wide frequency range.

Abstract Energy harvesting in natural environment has attracted a great deal of attention to generate stable and continuous electrical energy. In this work, we proposed an advanced pyroelectric energy harvesting system by using form-stable phase change material (PCM) composites. The PCM composite connected pyro-electrode generated electrical polarization due to the change of external environment. Polyethylene glycol (PEG) and 1-tetradecanol (1-TD) composites with different phase transition field induced the temperature difference during light-on/-off process. Poly(vinylidene difluoride) (PVDF) was utilized for pyroelectric energy harvesting. The PVDF based pyro-electrode was applied changing the conditions of solar light irradiation and heat air flow. The PCM composites controlled the temperature fluctuation effectively and generated stable output electrical voltage and current. Numerical simulation was carried out to provided in-depth insight into the underlying physics of the system. We envisage that the developed thermal energy harvesting system can pave a way towards high-throughput and sustainable energy harvesting.

Cu(In,Ga)Se-2-based solar cells buffered with indium sulfide grown by numerous techniques have reached efficiencies comparable to those achieved by standard devices buffered with (CBD)CdS. The present paper firstly recalls some of the properties of the indium sulfide single crystal and Points Out the disagreements concerning the thin films properties inventoried in the literature. Secondly, the influence of the presence of some "foreign elements" within file indium sulfide on its properties is presented. It is shown that these "foreign elements", even at low concentration levels, are possibly at the origin or the thin films properties deviations compared to the single crystal. The impact of these contaminants on the solar cells performance is finally discussed.

Abstract In this work, earth-abundant CZTSSe thin film solar cells were fabricated by sulfo-selenization of the Mo/Zn/Cu/Sn/Cu metallic precursors. The influences of morphological and compositional properties of the absorbers on performance of solar cells were investigated by tuning Cu content in the films. The Raman analysis showed that absorbers consist of a kesterite CZTSSe phase with ZnSe as a minor secondary phase. X-ray photoelectron spectroscopy (XPS) analyses revealed that the surfaces are Cu depleted and Zn enriched compared with the bulk composition of the absorbers. The results indicate that during sulfo-selenization the Cu diffused into the film and the Zn towards the film surface. The performance of the solar cells initially improved with the increasing of the Cu content and then decreased. By tuning the Cu content in the absorbers, the minority-carrier life time improved from 0.8 to 1.6 ns. The power conversion efficiency increased from 5.1 to 8.03% with fine controlling of Cu composition of the CZTSSe absorbers. The diode-ideality factors are higher than 2, suggesting an increased interfacial recombination in the devices. The high ideality-factors A and low minority carrier life times may originate from surface and bulk related defects, which in turn limits the Voc and the achievable high conversion efficiency for the CZTSSe thin film solar cells.

This paper deals with the optimization of the daily operation of Polerood hydropower station being constructed in the north of Iran. Dynamic Programming method (DP) is applied as the preferred optimization tool owing to the fact that it guarantees the optimal solution and is applicable to the present problem. Produced profit and peak-shaving are the two objectives considered separately in this study. The results show that the optimal water management of the case study through charging and discharging the reservoir at the appropriate times led to 4% increase in the produced profit. In another part of this study, the optimal performance strategies regarding to the two objectives (produced profit and peak-shaving) are compared. The observed similarity between the two performance strategies implies the substantial dependence of the electricity price and the network demand level. The paper ends with the profitability study of the project and the sensitivity analysis of the results to various economic parameters. Article History: Received December 15th 2017; Received in revised form April 18th 2018; Accepted September 16th 2018; Available onlineHow to Cite This Article: Feshalami, B.F. (2018) Optimal Operating Scenario for Polerood Hydropower Station to Maximize Peak Shaving and Produced Profit. International Journal of Renewable Energy Development, 7(3), 233-239.https://doi.org/10.14710/ijred.7.3.233-239

Abstract The quest for more efficient solar absorbers has resulted in the development of numerous coating techniques for the absorption panel itself. The Chrome-Black coating is an electroplated black-chrome coating on a copper substrate which combines the properties of high visible absorption (α), low infra-red emission (ϵ) and excellent temperature stability in both air and vacuum environments. Results obtained show that surfaces may be produced both with high α ϵ ratios, for example α = 87 per cent, ϵ = 3 per cent and α ϵ = 28 and with high absorption, for example α = 92 per cent, ϵ = 8 per cent and α ϵ = 11 . These results were obtained assuming an air-mass-2 spectral distribution and a 50°C black body weighting for absorption and emission respectively. All samples are known to be stable to at least 300°C. This type of coating would be expected to have good anticorrosion properties and this has been confirmed by electro-chemical oxidation and reduction testing. A comparison is made between the topography of this coating and of sputtered metal surfaces.

A membrane assisted process for green hydrogen production from a bioethanol derived feedstock is here developed and evaluated, starting from the conventional Steam Methane Reforming (SMR) process. Such a process is suitable for centralized hydrogen production, and is here analyzed for a large-scale H2 production unit with the capacity of 40.000 Nm3/h. The basic Steam Ethanol Reforming (SER) process scheme is modified in a membrane assisted process by integrating the Pd-membrane separation steps in the most suitable reaction steps. The membrane assisted process, configured in three alternative architectures (Open architecture, Membrane Reactor and Hybrid architecture) was evaluated in terms of efficiencies and hydrogen yields, obtaining a clear indication of improved process performance. The alternative membrane assisted process architectures are compared to the basic SER process and to the benchmark SMR process fed by natural gas, for an overall comparative assessment of the efficiency and specific CO2 emissions and for an economic analysis based on the operating expenditures.