Islamic Azad University at Estahban

www.iauest.ac.ir
Parsabad, Iran

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Sabzevari T.,Islamic Azad University at Estahban
Arabian Journal of Geosciences | Year: 2017

Time-area (TA), which constitutes the basis for rainfall-runoff transformation in the Clark model, is conventionally derived from the tedious procedure of delineating isochrones. In the present study, by combining the Nash instantaneous unit hydrograph (IUH), in terms of the gamma function, and the Clark model, a new TA relationship (TAR) is introduced. This equation involves the Nash models’ parameters (i.e., the number of reservoirs, n, and the storage coefficient, k). Considering that n = 5 for ungauged catchments, the following equation for estimating k was obtained: k = tc/4.24, with tc being the time of concentration of the catchment. Finally, a gamma time-area (GTA) function was derived for estimating the time-area diagram (TAD) of catchments. The TADs derived from the GTA function were compared to the GIS-based TADs and those derived from the US Army Corps of Engineers (USACE) method and the kinematic wave (KW) model in four catchments, namely, Kasilian, Ajay, Jafarabad, and Shourandika. In the Kasilian catchment, the direct runoff hydrograph (DRH) was simulated using the Clark model based on the GTA and USACE methods and compared with the observed hydrographs. Results indicate that the coefficient of efficiency (CE) in the Kasilian catchment for the two methods is approximately 0.8, while the errors in the peak discharge prediction are 9 and 11.2% in the GTA and USACE methods, respectively. © 2017, Saudi Society for Geosciences.


Pourmand S.E.,Islamic Azad University at Estahban | Rezaei G.,Yasouj University
Journal of Computational and Theoretical Nanoscience | Year: 2010

Spin-orbit interaction effects on the optical absorption coefficients and refractive index changes associated with intersubband transition in a spherical quantum dot are theoretically investigated. In this regard, the electronic structure of the dot is studied using the effective one-band Hamiltonian with the spin dependent Ben Daniel-Duke boundary conditions, and by means of the compactdensity matrix approach the linear and nonlinear optical absorption coefficients and refractive index changes are calculated. Numerical results indicate that, the magnitudes of these quantities are enhanced and the peaks are shifted to the lower energies as the influence of the spin orbit interaction is considered. Copyright © 2010 American Scientific Publishers All rights reserved.


Kazemian S.,Islamic Azad University | Huat B.B.K.,University Putra Malaysia | Moayedi H.,Islamic Azad University at Estahban
Geotechnical and Geological Engineering | Year: 2012

Peat commonly occurs as extremely soft, wet, unconsolidated surface deposits that are integral parts of wetland systems. Cement is widely used for the stabilization of peat by deep mixing method. This paper presents the results of the shear strength parameters of study models (fibrous, hemic and sapric peats stabilized with columns formed by dry mixing method). The columns were formed of peat treated with cement in different proportions. Triaxial test was performed after curing the samples for 28 days to evaluate the shear strength parameters. The results showed that the shear strength of peats can be improved significantly by the installation of cement stabilized soil columns. The amount of cement used to form the column and its diameter were observed to influence the strain-stress graph of peat reinforced. Furthermore, the result showed that the effect of cement was the highest on sapric peat due to its physico-chemical properties. © 2012 Springer Science+Business Media B.V.


Alizadeh A.,Islamic Azad University at Estahban | Shaabani M.,Islamic Azad University at Estahban
Advances in Environmental Biology | Year: 2012

The essential oil was obtained by hydro-distillation of the aerial part of Salvia officinalis L. cultivated in Iran. The chemical composition of essential oil was determined using Gas Chromatography and Gas Chromatography/Mass Spectrometry. Forty two components were identified in S. officinalis oil. That, α-thujone (41.48%), borneol (8.33%), 1,8 cineole (7.94%), β-thujone (6.75%) virdiflorol (5.85%), camphene (3.46%), α-pinene (3.24%), α-humulene (2.64%) and β-pinene (2.25%) determined as the major components. The total phenolic contents and the antioxidant activity of plant extract were determined, by Folin-Ciocalteau and the 2, 2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging assays respectively. Plant extract of S. officinalis had more phenolic content (25.13 mg GAE/g DW) and antioxidant (17.45μg/ml) activity. Antimicrobial activity of the essential oil was evaluated using the disc diffusion method. The oil showed high antimicrobial activity against Staphylococcus aureus and Candida albicans, two medically important pathogens compare with standard antibiotics.


Satureja bachtiarica Bunge. belonging to the family Lamiaceae is an important folkloric medicinal plant in Fars province, South western Iran. In this study, essential oil constituents, phenolic content, antioxidant and antibacterial activities from the aerial parts of S. bachtiarica collected from different natural habitats of Fars province were investigated. The essential oil of all samples was extracted by hydro-distillation using Clevenger type apparatus and analyzed using GC and GC-MS. The main chemical constituents were carvacrol (54.95-65.48 %), thymol (12-15.70 %), γ-terpinene (4.55-13.55 %), p-cymene (1.39-5 %), E-caryophyllene (2.22-4.82 %), linalool (2.34-4.09 %) and borneol (1.25-3.64 %). The total phenolic content and the antioxidant activity of methanolic extracts were determined with the Folin-Ciocalteau reagent and by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging and ferric reducing antioxidant power (FRAP) assay, respectively. Total phenols varied from 38.38 to 44.55 mg gallic acid equivalents/g dry weight (dw), and IC50 values in the radical scavenging assay ranged from 30.24 to 37.24 mg/mL, while those in the FRAP assay were between 36.45 and 43.24 μM quercetin equivalents/g dw. Results of this study indicated that methanolic extract of S. bachtiarica have high phenolic content and antioxidant activity. The antimicrobial activity of the essential oils was individually evaluated against Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli and Candida albicans using disc diffusion and serial dilution methods. The oils of various geographical and cultivation methods, showed high activity against four medically important pathogens. The results support the traditional usage and also possible use of S. bachtiarica essential oil and extracts in the food, pharmaceutical and cosmetic industries. © 2016 Har Krishan Bhalla & Sons


Mazloomi K.,University Putra Malaysia | Sulaiman N.B.,University Putra Malaysia | Moayedi H.,Islamic Azad University at Estahban
International Journal of Electrochemical Science | Year: 2012

Common industrial electrolyzers have a nominal hydrogen production efficiency of around 70%. High power dissipation value is the most important drawback of such systems since electric power expense has the largest share in the price of electrolytic hydrogen. The electrical impedance of an electrolysis cell causes a fraction of the applied energy to be wasted as heat while the electric current passes through it. As the prior publications show, many efforts are made to reduce this effect. According to the available literature, several internal and external variables are pointed out to have an influence on the electrical behavior of such cells. This paper provides an insight to these factors in regards to minimize the energy loss of the process of water electrolysis. © 2012 by ESG.


Alizadeh A.,Islamic Azad University at Estahban
Zeitschrift fur Naturforschung - Section C Journal of Biosciences | Year: 2015

Satureja rechingeri is a rare endemic and endangered species found in Iran. Its propagation, variations in essential oil and phenolic content, as well as antioxidant and antimicrobial activities at different phenological stages are reported in this study. The chemical composition of essential oils obtained by hydro-distillation from the aerial parts were determined by GC and GC-MS. A total of 47 compounds were identified in the essential oils of S. rechingeri at different phenological stages. The major components of all oils were carvacrol (83.6%-90.4%), p-cymene (0.8%-2.9%) and γ-terpinene (0.6%-2.4%). The total phenolic content and the antioxidant activity of methanolic extracts were determined with the Folin-Ciocalteau reagent and by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging and ferric reducing antioxidant power (FRAP) assay, respectively. Total phenols varied from 35.5 to 37.5 mg gallic acid equivalents/g dry weight (dw), and IC50 values in the radical scavenging assay ranged from 46.2 to 50.2 mg/mL, while those in the FRAP assay were between 49.6 and 52.5 μM quercetin equivalents/g dw. By the disc diffusion method and by determination of the minimum inhibitory concentrations (MIC), the essentials oils of the various phenological stages were found to have high activities against four medically important pathogens.


Alizadeh A.,Islamic Azad University at Estahban
Journal of Essential Oil-Bearing Plants | Year: 2013

The chemical composition of essential oil isolated by hydrodistillation from the aerial part of Salvia virgata under different ontogenesis (pre-flowering and full-flowering) conditions were determined using Gas Chromatography (GC) and Gas Chromatography-Mass Spectrometry (GC-MS). Twenty nine constituents were identified in S. virgata essential oils under different ontogenesis conditions that represented 98.36 - 99.18 % of the oils. The main components of the oil were β-caryophyllene (24.58-42.54 %), caryophyllene oxide (10.25-19.88 %), sabinene (8.64-19.58 %), 1-Octen -3-Ol (7.54-8.59 %), terpinene-4-ol (4.25-6.64 %) and α-thujene (3.74-6.46 %). The total phenolic content and the antioxidant activity of plant extract were determined by Folin-Ciocalteau and the 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging assays and ferric reducing antioxidant power (FRAP) assay respectively. Total phenols varied from 21.84 to 24.38 (mg GAE/g dw) and the IC50 in the radical scavenging assay ranged from 22.12 to 24.45 mg/ml and FRAP values ranged form 26.84 to 28.46 μM Quercetin E/g dw. Antimicrobial activity of the essential oil was evaluated using the disc diffusion method. The oils of various ontogenesis conditions showed moderate antimicrobial activity against Staphylococcus aureus and Candida albicans two medically important pathogens. © 2013 Copyright Har Krishan Bhalla & Sons.


Mazloomi K.,University Putra Malaysia | Sulaiman N.B.,University Putra Malaysia | Moayedi H.,Islamic Azad University at Estahban
International Journal of Electrochemical Science | Year: 2012

Our research shows that the amount of power consumed in the production of electrolytic hydrogen can be reduced considerably by targeting the resonant frequency of the water electrolysis cell. We tested this by measuring the cell voltage for the same levels of current in both DC and frequency controlled pulsed voltage applications. In order to reach any given level of electrical current, a noticeable reduction of cell voltage was observed when the applied voltage was in the pulsed form at a certain frequency. Therefore, less power was applied to the cell in order to maintain its current level at a desirable value. Higher production efficiency was observed since the volume of produced hydrogen is a function of cell current. The amount of power consumption was up to 15% less in the frequency controlled pulsed voltage application mode. Aluminum plates with surface areas of 1.5 cm2 and 10 cm2 and potassium hydroxide aqueous solutions with molarities between 0.1 M and 2 M were used as electrode plates and electrolyte materials respectively. The electrode plates were placed in different distances ranging between 5 mm and 50 mm, and the power sources were sat to reach current densities between 50 mA and 400 mA. Random combinations of the mentioned variables were tested several times in order to study the electrical behavior, frequency response and impedance characteristics of the experimental cell setups. © 2012 by ESG.


Mokhberi M.,Islamic Azad University at Estahban
International Journal of Disaster Risk Reduction | Year: 2015

During the age of cities, buildings were constructed using different techniques, materials, styles and standard codes. Buildings have different responses to earthquake-related effects, depending on their materials and design rules. Soil layer specifications are recognized by different methods, including geotechnical, geophysical and the horizontal-to-vertical spectral ratios (H/V). The spectral ratio of microtremors was first introduced by Nakamura [14]. This method is useful in site characterization studies due to its low budget and easy use. In this paper, it is presented as a method for estimating the degree of vulnerability of structures using spectral ratio H/V. By applying a vulnerability study in the city of Shiraz, the predominant frequencies are derived for different parts of the city. The data is then used to define a coefficient of vulnerability for the earth. For this purpose, 11 different building structures including masonry, steel and concrete were selected. Then, the primary frequency and amplification of the microtremor H/V spectral ratio for buildings are obtained. Furthermore, the resonant frequency and amplification factor of the ground is calculated. The vulnerability index of soil Kg and the vulnerability of building Kb are defined. By comparing these coefficients, the damage factor η of buildings during an earthquake is obtained. These parameters are able to provide an inexpensive method for preparing a disaster program for an urban area. In this paper, the damage rate of different buildings in Shiraz City was obtained. In addition, the damage potential of the entire city area is calculated. © 2015 .

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