فهرست مطالب z. rafiee

Including several health-giving characteristics, saffron is widely used in treatment of diseases. Furthermore, it creates color, taste and aroma in foods. However, use of saffron bioactive compounds in foods is associated with limitations. Encapsulation of these compounds with various methods, including nanoliposomes, is one of the appropriate solutions to solve these problems. The aim of this study was to prepare saffron extract loaded in nanoliposomes and assess physicochemical characteristics of the produced particles.

 Nanoencapsulation of saffron extract was carried out with nanoliposomes using thin layer hydration. Soy lecithin with various concentrations (22.5, 45 and 90 mg/10 ml) and saffron concentrations (2.5 and 2.5 mg/ml) was prepared. Release rate of saffron extract from nanoliposomes in aqueous media was assessed at 72 and 100 °C.

The optimal sample (treatment with 90 mg/10 ml lecithin and 2.5 mg/ml saffron extract) included particle size of 82 nm, polydispersity index of 0.4, zeta potential of -27.6 mV and encapsulation efficiency of 90.1% with stability of 99%. After 20 min, produced nanoliposomes were able to preserve 40% of the saffron extract at 72 °C (p < 0.05).

Nanoliposomes are good carriers to preserve medicinal compounds of saffron and can be used to produce functional products with mild processing.

Improving transient voltage stability is one of the most important issues that must be provided by doubly fed induction generator (DFIG)-based wind farms (WFs) according to the grid code requirement. This paper proposes adjusted DC-link chopper based passive voltage compensator and modified transient voltage controller (MTVC) based active voltage compensator for improving transient voltage stability. MTVC is a controller-based approach, in which by following a voltage dip (VD) condition, the voltage stability for the WF can be improved. In this approach, a voltage dip index (VDI) is proposed to activate/deactivate the control strategy, in which, two threshold values are used. In the active mode, the active and reactive power are changed to decrease the rotor current and boost the PCC voltage, respectively. Based on the control strategy, in a faulty grid, DFIG not only will be able to smooth DC-link voltage fluctuations and reduces rotor overcurrents but also it will increase the voltage of point of common coupling (PCC). Therefore, it improves transient voltage stability. The simulation results show the effectiveness of the proposed strategy for improving voltage stability in the DFIG.</span></span></span></div>

Selection of Ground Motion Prediction Equation (GMPE) is one of the key elements within a seismic hazard analysis. A variety of available GMPE models makes this selection a scientific challenge. Therefore, the stability assessment of an optimized GMPE model is investigated in this paper by employing a new Re-Sampling Analysis (RSA) methodology (Azarbakht et al., 2014). The Boore and Atkinson 2008 GMPE is examined in this paper. The multi-objective Genetic Algorithm (GA) is employed in order to minimize the Log-likelihood (LLH) measure as well as maximise the RSA. The ground motion database, in this study, consists of 15348 ground motion spectra resulting from 58 seismic events. The magnitude range is between 5 and 7.4, and all the records have the distance less than 200 km. The analysis is performed for peak ground acceleration. The results are compared with the eight most common NGA GMPEs. The obtained results show that the optimum coefficients for the BA2008 model improve it in such a way that the LLH is least among the models, and the RSA measure is adequate. It is worth mentioning that all the results in this paper are constrained to the given assumptions as well as the considered methodologies and database. The results may change by using different databases and enrichment of the data during future researches.

The aim of this study was to extract phenolic compounds from olive leaves of Cronaiky, Roghani and Mishen varieties by maceration and Microwave-assisted extraction (MAE) methods. Our result revealed that effect of extraction method and variety was statistically significant.