Showing papers by "University of Tabriz published in 2011"
TL;DR: In this article, a series of corn starch films with varying concentrations of citric acid (CA) and carboxymethyl cellulose (CMC) were produced by casting method, and the effects of CA and CMC on the water vapor permeability, moisture absorption, solubility and tensile properties were investigated.
385 citations
TL;DR: A non-reference objective image fusion metric based on mutual information which calculates the amount of information conducted from the source images to the fused image is proposed which is more consistent with the subjective criteria.
323 citations
TL;DR: In this article, the authors examined the trends in reference crop evapotranspiration (ET0) on monthly and annual time scales in Iran using the globally accepted FAO Penman Monteith method.
322 citations
TL;DR: Two hybrid AI-based models which are reliable in capturing the periodicity features of the process are introduced for watershed rainfall–runoff modeling and show that the second model is relatively more appropriate because it uses the multi-scale time series of rainfall and runoff data in the ANFIS input layer.
279 citations
TL;DR: Curcumin was able to penetrate into the polar medium inside the cells and to protect them against the highly toxic and lethal effects of cumene hydroperoxide and showed good electron-transfer capability, with greater activity than trolox in aqueous solution.
Abstract: Curcumin has many pharmaceutical applications, many of which arise from its potent antioxidant properties. The present research examined the antioxidant activities of curcumin in polar solvents by a comparative study using ESR, reduction of ferric iron in aqueous medium and intracellular ROS/toxicity assays. ESR data indicated that the steric hindrance among adjacent big size groups within a galvinoxyl molecule limited the curcumin to scavenge galvinoxyl radicals effectively, while curcumin showed a powerful capacity for scavenging intracellular smaller oxidative molecules such as H2O2, HO•, ROO•. Cell viability and ROS assays demonstrated that curcumin was able to penetrate into the polar medium inside the cells and to protect them against the highly toxic and lethal effects of cumene hydroperoxide. Curcumin also showed good electron-transfer capability, with greater activity than trolox in aqueous solution. Curcumin can readily transfer electron or easily donate H-atom from two phenolic sites to scavenge free radicals. The excellent electron transfer capability of curcumin is because of its unique structure and different functional groups, including a β-diketone and several π electrons that have the capacity to conjugate between two phenyl rings. Therfore, since curcumin is inherently a lipophilic compound, because of its superb intracellular ROS scavenging activity, it can be used as an effective antioxidant for ROS protection within the polar cytoplasm.
279 citations
TL;DR: In this paper, a new nonsingular terminal sliding surface is introduced and its finite-time convergence to the zero equilibrium is proved, and appropriate adaptive laws are derived to tackle the unknown parameters of the systems.
270 citations
TL;DR: The proposed topology is based on a cascaded connection of single-phase submultilevel converter units and full-bridge converters and is optimized in order to utilize a minimum number of switches and dc voltage sources and produce a high number of output voltage steps.
Abstract: In this paper, a new topology of a cascaded multilevel converter is proposed. The proposed topology is based on a cascaded connection of single-phase submultilevel converter units and full-bridge converters. Compared to the conventional multilevel converter, the number of dc voltage sources, switches, installation area, and converter cost is significantly reduced as the number of voltage steps increases. In order to calculate the magnitudes of the required dc voltage sources, three methods are proposed. Then, the structure of the proposed topology is optimized in order to utilize a minimum number of switches and dc voltage sources, and produce a high number of output voltage steps. The operation and performance of the proposed multilevel converter is verified by simulation results and compared with experimental results of a single-phase 49-level converter, too.
249 citations
TL;DR: In this article, a review of the concepts and findings of spray drying of lactic acid starter cultures, with specific reference to methods suitable for achieving high levels of cell viability is discussed.
Abstract: The preservation of lactic acid cultures by spray drying has been widely studied as an alternate industrial process for the preservation of lactic acid starter cultures because of the high costs and energy consumption of freezing and freeze drying. This article reviews the concepts and findings of spray drying of lactic acid starter cultures, with specific reference to methods suitable for achieving high levels of cell viability. Spray drying features, advantages and disadvantages in the preservation of lactic acid cultures are discussed. Particular attention has been paid to the factors influencing cell viability including intrinsic tolerance of cultures, growth media and conditions, stress induction, cell harvesting conditions, protective agents, rehydration conditions, packaging and storage conditions.
248 citations
TL;DR: An efficient approach for fusion of multi-focus images based on variance calculated in DCT domain is presented and it can be easily used in real-time applications.
221 citations
TL;DR: An in vitro model of human tenocytes is used to demonstrate a potential role for curcumin in treating tendon inflammation through modulation of NF-κB signaling, which involves PI-3K/Akt and the tendon-specific transcription factor scleraxis in tenocytes.
198 citations
TL;DR: By increasing of OA content, the cloudiness of the CMC films was intensified and Hunter value of the films increased (by ca. 35.8%).
TL;DR: In this paper, a comparative study of hexavalent chromium (Cr(VI)) removal from aqueous solution using Fe0 and Fe3O4 particles in nano and micro-scale was performed.
TL;DR: The results show the new hybrid WGEP models are effective in forecasting daily precipitation, while the new WNF models are unable to learn the non linear process of precipitation very well.
Abstract: Forecasting precipitation as a major component of the hydrological cycle is of primary importance in water resources engineering, planning and management as well as in scheduling irrigation practices. In the present study the abilities of hybrid wavelet-genetic programming [i.e. wavelet-gene-expression programming, WGEP] and wavelet-neuro-fuzzy (WNF) models for daily precipitation forecasting are investigated. In the first step, the single genetic programming (GEP) and neuro-fuzzy (NF) models are applied to forecast daily precipitation amounts based on previously recorded values, but the results are very weak. In the next step the hybrid WGEP and WNF models are used by introducing the wavelet coefficients as GEP and NF inputs, but no satisfactory results are produced, even though the accuracies increased to a great extent. In the third step, the new WGEP and WNF models are built; by merging the best single and hybrid models’ inputs and introducing them as the models inputs. The results show the new hybrid WGEP models are effective in forecasting daily precipitation, while the new WNF models are unable to learn the non linear process of precipitation very well.
TL;DR: In this article, the effect of applied current, supporting electrolyte concentration, air flow rate and pH on the generation of H 2 O 2 was investigated, and it was shown that the optimal conditions for H 2 o 2 generation were applied current of 100 mA (2.5 mA/cm 2 ), air flow ratio of 2.5 l/min, and pH = 3.6%.
TL;DR: A robust adaptive sliding mode controller (RASMC) is proposed to realize chaos synchronization between two different chaotic systems with uncertainties, external disturbances and fully unknown parameters and the robustness and stability of the proposed RASMC is proved using Lyapunov stability theory.
TL;DR: In this article, a stochastic weather generator downscaled the climate change of six synoptic stations in the province by using the HADCM3 model and three emission scenarios, A1B, A2 and B1, with the horizons 2020, 2055 and 2090.
TL;DR: In this paper, an ultra small size 4-channel wavelength division demultiplexer based on 2D photonic crystal modified Y-Branch, suitable for integration, is proposed.
TL;DR: In this article, the causal relationship between energy use and Gross Domestic Product (GDP) in the United States for the period 1960-2005 was examined. And the authors used Markov-switching vector autoregressive (MS-VAR) models to detect changes in the relationship between variables; in addition, the coefficients of the model are time dependent and they depend on the states of the variables.
TL;DR: This paper investigates the ability of genetic programming (GP) and adaptive neuro-fuzzy inference system (ANFIS) techniques for groundwater depth forecasting and found that the GP and ANFIS models could be employed successfully in forecasting water table depth fluctuations.
TL;DR: The SWCNT/CCE displayed excellent electrochemical catalytic activities toward APAP and AA oxidation compared with bare CCE as well as high recovery in pharmaceutical and biological samples.
TL;DR: In this article, four proposed water transfer schemes to Urmia Lake in Iran, which is in danger of completely drying out, are evaluated with respect to different criteria. And the best alternative transfers about 300 million cubic meters per year from another basin in the north of the lake.
Abstract: Limited water resources with uneven distribution and growing demands are the main challenges of water management in Iran. The government has planned several water resources development projects. The complex technical, socio-economical and environmental outcomes of these projects require a comprehensive evaluation. To select more adaptive and accountable projects, suitable group decision support systems are needed. In this research, 4 proposed routes of water transfer schemes to Urmia Lake in Iran, which is in danger of completely drying out, are evaluated with respect to different criteria. The criteria and weights were obtained from an organization responsible for major water infrastructures in the basin. By using an efficient multi-criteria decision making method of compromise programming, the 4 alternatives were ranked, and the most robust water transfer route was selected. This best alternative transfers about 300 million cubic meters per year from another basin in the north of the lake. Resu...
TL;DR: In this paper, a highly sensitive method was investigated for the simultaneous determination of acetaminophen (AC) and dopamine (DA) using single wall carbon nanotubes modified carbon-ceramic electrode (SWCNT/CCE).
TL;DR: Assessment of water samples from various methods indicated that groundwater in study area is chemically unsuitable for drinking and agricultural uses.
Abstract: The Harzandat plain is part of the East Azerbaijan province, which lies between Marand and Jolfa cities, northwestern of Iran, and its groundwater resources are developed for water supply and irrigation purposes. The main lithologic units consist chiefly of limestone, dolomite, shale, conglomerate, marl, and igneous rocks. In order to evaluate the quality of groundwater in study area, 36 samples were collected and analyzed for various ions. Chemical indexes like sodium adsorption ratio, percentage of sodium, residual sodium carbonate, and permeability index were calculated. Based on the analytical results, groundwater in the area is generally very hard, brackish, high to very high saline and alkaline in nature. The abundance of the major ions is as follows: Cl(-) >HCO3(-)>SO4(2-) and Na(+) >Ca(2+) >Mg(2+) >K(+). The dominant hydrochemical facieses of groundwater is Na(-)Cl type, and alkalis (Na(+), K(+)) and strong acids (Cl(-), SO4(2-) are slightly dominating over alkali earths (Ca(2+), Mg(2+)) and weak acids (HCO3(-), CO3(2-). The chemical quality of groundwater is related to the dissolution of minerals, ion exchange, and the residence time of the groundwater in contact with rock materials. The results of calculation saturation index by computer program PHREEQC shows that nearly all of the water samples were supersaturated with respect to carbonate minerals (calcite, dolomite and aragonite) and undersaturated with respect to sulfate minerals (gypsum and anhydrite). Assessment of water samples from various methods indicated that groundwater in study area is chemically unsuitable for drinking and agricultural uses.
TL;DR: In this paper, the effect of the aqueous medium pH on the two-phase equilibrium behavior of the {1-butyl-3-methylimidazolium bromide ([C 4 mim]Br)+ potassium citrate} system was investigated.
TL;DR: In this article, an efficient method for synthesis of hydrophobically modified starch without using organic solvents is described, where the esterification of starch was performed with long chain fatty acid chlorides (C8, C12, C16), in two steps.
TL;DR: In this paper, the authors used Halloysite nanotubes (HNTs) as nano-adsorbents for removal of the cationic dye, Malachite Green (MG), from aqueous solutions.
TL;DR: In this article, the photocatalytic degradation of an anthraquinone dye, C.I. Acid Green 25 (AG25), under UV light irradiation using TiO2 nanoparticles in a rectangular photoreactor was studied.
TL;DR: In this article, the antimicrobial effects of carboxymethyl cellulose based-edible film containing potassium sorbate as an antimicrobial agent were studied against Aspergillus flavus (PTCC-5004), Aspergerillus parasiticus and A. parasiticus by using agar diffusion assay.
Abstract: Active packaging is a relatively novel concept of packaging that changes the conditions of the packaged food to extend its shelf-life and improve its safety. In this study, antimicrobial effects of carboxymethyl cellulose based-edible film containing potassium sorbate as an antimicrobial agent were studied against Aspergillus flavus (PTCC-5004), Aspergillus parasiticus (PTCC-5286) and A. parasiticus (PTCC-5018) by using agar diffusion assay. Results showed suitable inhibition effects against A. parasiticus (PTCC-5286) and A. flavus (PTCC-5004) in comparison with A. parasiticus (PTCC-5018). Pistachios were coated with this edible antimicrobial film containing three concentrations of sorbate (1, 0.5 and 0.25 g/100 mL film solution); all concentrations showed no growth of molds. Tensile strength values of films with potassium sorbate, decreased when compared to control, and film’s flexibility, was 28.82 percent for 3 g/100 mL sorbate, while higher concentration of sorbate, decreased the flexibility. The water vapor permeability values (WVP) of films were determined to be 1.18 (g mm/m 2 day kPa) for films plasticized with glycerol, without sorbate while WVP values for the films containing 1 and 2 g/100 mL sorbate increased to 3.77 and 15.5 (g mm/m 2 day kPa), respectively. The observed glass transition temperature ( T G ) depression for these polymer blends was related to the plasticizer content (water, polyethylene, and glycerol), especially water.
TL;DR: In this paper, a star-block copolymer with four arms was synthesized by ring-opening polymerization (ROP) from a symmetric pentaerythritol core via the core-first strategy.
TL;DR: Low-energy X-ray fluorescence spectro-microscopy (LEXRF) was used to study localization of Al and other low Z-elements in leaves of the tea plant and suggested that the retention of Al in epidermal leaf apoplast represent the main tolerance mechanism to Al in tea plants.
Abstract: Information on localization of Al in tea leaf tissues is required in order to better understand Al tolerance mechanism in this Al-accumulating plant species. Here, we have used low-energy X-ray fluorescence spectro-microscopy (LEXRF) to study localization of Al and other low Z-elements, namely C, O, Mg, Si and P, in fully developed leaves of the tea plant [Camellia sinensis (L.) O. Kuntze]. Plants were grown from seeds for 3 months in a hydroponic solution, and then exposed to 200 microM AlCl(3) for 2 weeks. Epidermal-mesophyll and xylem phloem regions of 20 microm thick cryo-fixed freeze-dried tea-leaf cross-sections were raster scanned with 1.7 and 2.2 keV excitation energies to reach the Al-K and P-K absorption edges. Al was mainly localized in the cell walls of the leaf epidermal cells, while almost no Al signal was obtained from the leaf symplast. The results suggest that the retention of Al in epidermal leaf apoplast represent the main tolerance mechanism to Al in tea plants. In addition LEXRF proved to be a powerful tool for localization of Al in plant tissues, which can help in our understanding of the processes of Al uptake, transport and tolerance in plants.