Crocin loaded nano-emulsions: Factors affecting emulsion properties in spontaneous emulsification

Spontaneous emulsification may be used for encapsulating bioactive compounds in food and pharmaceutical industry. It has several advantages over high energy and other low energy methods including, protecting sensitive compounds against severe conditions of high energy method and its ability to minimize surfactant, removal of cosurfactant and thermal stability compared with other low energy methods. In this study, we examined possibility of encapsulating highly soluble crocin in W/O micro-emulsions using spontaneous method which further could be used for making double emulsions. Nonionic surfactants of Span 80 and polyglycerol polyricinoleate (PGPR) were used for making micro-emulsions that showed the high potential of PGPR for spontaneous method. Surfactant to water ratio (SWR) was evaluated to find the highest amount of aqueous phase which can be dispersed in organic phase. Droplet size decreased by increasing SWR toward the SWR = 100 which had the smallest droplet size and then increased at higher levels of surfactant. By increasing SWR, shear viscosity increased which showed the high effect of PGPR on rheological properties. This study shows in addition to W/O micro-emulsions, spontaneous method could be used for preparing stable O/W micro-emulsions. © 2015 Elsevier B.V

Electropolymerized Coatings of Poly (o-anisidine) and Poly (o-anisidine)-TiO2 Nanocompsite on Aluminum Alloy 3004 by using the Galvanostatic Method and Their Corrosion Protection Performance

Poly (o-anisidine) (POA) and also poly (o-anisidine)-TiO2 (POA-TiO2) nanocomposite coatings on aluminum alloy 3004 (AA3004) have been investigated by using the galvanostatic method. The electrosynthesized coatings were characterized by FT-IR, SEM- EDX, SEM and AFM. The corrosion protection performances of POA and also POA-TiO2 nanocomposite coatings were investigated in 3.5% NaCl solution by using the potentiodynamic polarization technique and electrochemical impedance spectroscopy (EIS). The corrosion rate of nanocomposite coatings was found ∼900 times lower than bare AA3004. The results of this study clearly ascertain that the POA-TiO2 nanocomposite has outstanding potential to protect the AA3004 against corrosion. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3481

Surface coupling effects on the capacitance of thin insulating films

A general form for the surface roughness effects on the capacitance of a capacitor is proposed. We state that a capacitor with two uncoupled rough surfaces could be treated as two capacitors in series which have been divided from the mother capacitor by a slit. This is in contrast to the case where the two rough surfaces are coupled. When the rough surfaces are coupled, the type of coupling decides the modification of the capacitance in comparison to the uncoupled case. It is shown that if the coupling between the two surfaces of the capacitor is positive (negative), the capacitance is less (higher) than the case of two uncoupled rough plates. Also, we state that when the correlation length and the roughness exponent are small, the coupling effect is not negligible

Dynamical mean field theory of optical third harmonic generation

We formulate the third harmonic generation (THG) within the dynamical mean field theory (DMFT) approximation of the Hubbard model. In the limit of large dimensions, where DMFT becomes exact, the vertex corrections to current vertices are identically zero, and hence the calculation of the THG spectrum reduces to a time-ordered convolution, followd by appropriate analytic continuuation. We present the typical THG spectrum of the Hubbard model obtained by this method. Within our DMFT calculation, we observe a nontrivial approximate {\em scaling} function describing the THG spectra in all Mott insulators, independent of the gap magnitude.Comment: 4 eps figure

A 43-level 33 kV 3-phase modular multilevel cascaded converter for direct grid integration of renewable generation systems

This paper proposed a 43-level 3-phase 33 kV modular multilevel cascaded (MMC) converter for direct grid integration of renewable generation systems. A high-frequency magnetic-link is considered to generate isolated and balanced multiple dc sources for all of the H-bridge inverters of the MMC converter. The proposed converter is designed and analyzed taking into account the specified system performance, control complexity, cost and market availability of the semiconductors. The simulation results demonstrate the excellent feature of the proposed medium-voltage converter. It is expected that the proposed new technology will have great potential for future renewable power plants and smart grid applications. © 2014 IEEE

Multilevel Robust Design Optimization of a Superconducting Magnetic Energy Storage Based on a Benchmark Study

© 2016 IEEE. Superconducting magnetic energy storage (SMES) systems with different superconducting materials are attracting great attentions and funding from the governments around the world because they are promising large-scale energy storage devices for future smart grid. Due to the high cost of SMES, its manufacturing quality and operation reliability have to be investigated in the design optimization stage. This paper presents a robust design optimization method to solve this issue based on a benchmark problem, TEAM problem 22. The proposed method is based on a technique called design for Six Sigma. Meanwhile, a three-level optimization framework is employed to reduce the computation cost of a finite-element analysis due to high-dimensional design space and Monte-Carlo analysis. As shown, the manufacturing reliability and quality of the investigated SMES after robust optimization have been increased greatly

Optimization of folic acid nano-emulsification and encapsulation by maltodextrin-whey protein double emulsions

Due to susceptibility of folic acid like many other vitamins to environmental and processing conditions, it is necessary to protect it by highly efficient methods such as micro/nano-encapsulation. Our aim was to prepare and optimize real water in oil nano-emulsions containing folic acid by a low energy (spontaneous) emulsification technique so that the final product could be encapsulated within maltodextrin-whey protein double emulsions. A non ionic surfactant (Span 80) was used for making nano-emulsions at three dispersed phase/surfactant ratios of 0.2, 0.6, and 1.0. Folic acid content was 1.0, 2.0, and 3.0 mg/mL of dispersed phase by a volume fraction of 5.0, 8.5, and 12. The final optimum nano-emulsion formulation with 12 dispersed phase, a water to surfactant ratio of 0.9 and folic acid content of 3 mg/mL in dispersed phase was encapsulated within maltodextrin-whey protein double emulsions. It was found that the emulsification time for preparing nano-emulsions was between 4 to 16 h based on formulation variables. Droplet size decreased at higher surfactant contents and final nano-emulsions had a droplet size. < 100 nm. Shear viscosity was higher for those formulations containing more surfactant. Our results revealed that spontaneous method could be used successfully for preparing stable W/O nano-emulsions containing folic acid. © 2016 Elsevier B.V

DLQI scores in vitiligo: reliability and validity of the Persian version

BACKGROUND: The objective of this study was to translate and to test the reliability and validity of the 10-item Dermatology Life Quality Index (DLQI) questionnaire in Iranian patients with vitiligo. METHODS: Using a standard "forward-backward" translation procedure, the English language version of the questionnaire was translated into Persian (the Iranian official language) by two bilinguals. Seventy patients with vitiligo attending the Department of Dermatology, Saadi Hospital, Shiraz, Iran, were enrolled in this study. The reliability and internal consistency of the questionnaire were assessed by Cronbach's alpha coefficient and Spearman's correlation, respectively. Validity was performed using convergent validity. RESULTS: In all, seventy people entered into the study. The mean age of respondents was 28.3 (SD = 11.09) years. Scores on the DLQI ranged from 0 to 24 (mean ± SD, 7.05 ± 5.13). Reliability analysis showed satisfactory result (Cronbach's α coefficient = 0.77). There were no statistically significant differences between daily activity (DA) and personal relationship (PR) scale mean scores in generalized versus focal-segmental involvement in sufferers (P = 0.056, P = 0.053, respectively). There were also strong differences between the mean scores of the PR (personal relationship) scale with the involvement of covered only and covered/uncovered areas (P= 0.016) that was statistically significant in the second group. CONCLUSIONS: The study findings showed that the Persian version of the DLQI questionnaire has a good structural characteristic and is a reliable and valid instrument that can be used for measuring the effects of vitiligo on quality of life

The escape problem under stochastic volatility: the Heston model

We solve the escape problem for the Heston random diffusion model. We obtain exact expressions for the survival probability (which ammounts to solving the complete escape problem) as well as for the mean exit time. We also average the volatility in order to work out the problem for the return alone regardless volatility. We look over these results in terms of the dimensionless normal level of volatility --a ratio of the three parameters that appear in the Heston model-- and analyze their form in several assymptotic limits. Thus, for instance, we show that the mean exit time grows quadratically with large spans while for small spans the growth is systematically slower depending on the value of the normal level. We compare our results with those of the Wiener process and show that the assumption of stochastic volatility, in an apparent paradoxical way, increases survival and prolongs the escape time.Comment: 29 pages, 12 figure

Electropolymerized Coatings of Poly (o-anisidine) and Poly (o-anisidine)-TiO2 Nanocompsite on Aluminum Alloy 3004 by using the Galvanostatic Method and Their Corrosion Protection Performance

Poly (o-anisidine) (POA) and also poly (o-anisidine)-TiO2 (POA-TiO2) nanocomposite coatings on aluminum alloy 3004 (AA3004) have been investigated by using the galvanostatic method. The electrosynthesized coatings were characterized by FT-IR, SEM- EDX, SEM and AFM. The corrosion protection performances of POA and also POA-TiO2 nanocomposite coatings were investigated in 3.5% NaCl solution by using the potentiodynamic polarization technique and electrochemical impedance spectroscopy (EIS). The corrosion rate of nanocomposite coatings was found ∼900 times lower than bare AA3004. The results of this study clearly ascertain that the POA-TiO2 nanocomposite has outstanding potential to protect the AA3004 against corrosion. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3481