Young Researchers and Elite Club
Young Researchers and Elite Club
Rostami H.,Health Research CenterBaqiyatallah University of Medical SciencesTehran Iran |
Gharibzahedi S.M.T.,Young Researchers and Elite Club
Journal of Food Processing and Preservation | Year: 2017
Six empirical models of Elowich's logarithmic, hyperbolic, parabolic diffusion, power law, unsteady diffusion and Weibull's exponential were applied to describe the extraction kinetic of mucilage from jujube waste hydrolysate (JWH). The microwave-assisted extraction process at 400 W, 75°C, 60 min, using 30 g water/g JWH led to a considerable yield (8.76±0.17%) of mucilage. Parabolic diffusion model with R2 of 0.9871 and the root mean square error (RMSE) of 0.3587 considered as the best kinetic equation to fit the experimental data. However, Weibull's exponential equation among the different mathematical models was not capable of predicting the extraction yield profile (R2=0.318; RMSE=3.577). The current kinetic study can be successfully used for the design, optimal control, and economic analysis of polysaccharide extraction processes. Practical Applications: This is the first report on the kinetic modeling of microwave-assisted extraction of mucilage from acid hydrolysate of jujube waste. The different kinetic models were successfully derived for the mucilage yield. The superior mathematical model might be, thus, exploited to viably apply the technique at the industrial scale because the exact control of contact time is essential in order to obtain good quality of the final product and reduce refining costs. © 2017 Wiley Periodicals, Inc.
Ebadollahi A.,University of Mohaghegh |
Ashrafi Parchin R.,Young Researchers and Elite Club |
Farjaminezhad M.,Islamic Azad University at Ardabil
Toxin Reviews | Year: 2016
Tribolium castaneum considered as an economically worldwide insect pest for agricultural and medicinal aspects. Synthetic chemicals have been used in the management of T. castaneum but their residual problems have been renovated the interest in ecofriendly safe materials such as plant essential oils. In the present study, toxicity and antifeedant effects of an essential oil from Melissa officinalis as well-known medicinal plant investigated against T. castaneum. Chemical analysis indicated γ-terpinene, carvacrol and α-terpinene were the main components of essential oil. The essential oil showed strong toxicity on T. castaneum adults at several concentrations and treatment times. The LC50 values were assessed as 19.418, 18.418 and 16.159 μl/l air after 24, 48 and 72 h exposure time, respectively. Sub-lethal concentrations of essential oil caused significant dose-dependent antifeedant activity. Results indicate M. officinalis essential oil can be suggested as a potential alternative to harmful synthetic chemicals. © 2016 Informa UK Limited, trading as Taylor & Francis Group.
Moradi-Dastjerdi R.,Young Researchers and Elite Club
Polymer Composites | Year: 2017
In this article, free vibration and damping behavior of functionally graded (FG) nanocomposite cylinders reinforced by carbon nano tube (CNT) subjected to magnetic field are investigated by finite element method (FEM). The nanocomposite cylinders are filled by magnetorheological (MR) oil and are assumed combinations single-walled carbon nanotubes (SWCNTs) and isotropic matrix. An extended rule of mixture based on micro mechanical model is used to estimate material properties of the nanocomposite. Uniform and three types of linear functionally graded distributions along the radial direction are assumed and compared. In this simulation, an axisymmetric model is used to investigate the effects of magnetic field, MR oil, cylinder dimension, CNT volume fraction, and CNT distribution are investigated on the vibrational behavior of the MR filled-nanocomposite cylinders. It is shown that the frequency of cylinder is decreased dramatically when the cylinders are filled by MR oil. © 2017 Society of Plastics Engineers.
Nikkhah A.,Young Researchers and Elite Club
Environmental Progress and Sustainable Energy | Year: 2017
The aim of this study was to investigate the non-renewable energy use efficiency, greenhouse gas (GHG) emissions, and carbon efficiency of groundnut sole cropping and groundnut-bean intercropping agro-ecosystems. Data were collected from 136 farmers using face-to-face questionnaires in the Kiashahr region of northern Iran. The results analysis suggested that the non-renewable energy ratio of groundnut-bean intercrop agro-ecosystem (6.03) was greater than that of groundnut sole cropping system (4.59). The highest share of non-renewable energy belonged to diesel fuel, which was followed by the nitrogen fertilizer for both systems. This demonstrates the importance of fossil fuel and N fertilizer use management in both agro-ecosystems. The total GHG emissions from groundnut and groundnut-bean intercrop agro-ecosystems were computed as 636.14 and 657.36 kgCO2eq ha-1, respectively. The highest impact of GHG emissions was from diesel fuel within both farming systems, confirming the prominent role of the fossil fuel input again. The carbon efficiency for groundnut-bean intercrop agro-ecosystem (14.78) was greater than that of the groundnut sole cropping system (11.14). Therefore, groundnut-bean agro-ecosystem can be observed to be more effective for carbon sequestration. The use of greater amounts of biological resources helps to improve the efficiency of energy use and mitigation of GHG emissions in both agro-ecosystems. © 2017 American Institute of Chemical Engineers.
Zamani A.,Young Researchers and Elite Club |
Azargoshasb T.,Young Researchers and Elite Club |
Niknam E.,Young Researchers and Elite Club
Physica B: Condensed Matter | Year: 2017
In current article, the Zeeman effect is considered in the presence of simultaneous Rashba and Dresselhaus spin-orbit interactions (SOI) and under such circumstances the second and third harmonic generations (SHG and THG) of a GaAs quantum ring are investigated at finite temperature. The effective Hamiltonian is derived in cylindrical coordinate while the angular part is eliminated because of axial symmetry and the energy eigenvalues and eigenvectors of two lowest levels are obtained numerically. Eventually, the optical properties of such system are studied hiring compact density matrix approach. The results show that, an increase in the magnetic field, leads to blue shift in resonant peaks of both SHG and THG. Furthermore, by reducing the temperature, all the resonant peaks of both SHG and THG experience a red shift. Finally, the effect of the structure dimension is studied and results illustrate that variation of size leads to both red and blue shifts in resonant peaks. © 2017 Elsevier B.V.
Tahouneh V.,Young Researchers and Elite Club
Polymer Composites | Year: 2016
This article deals with free vibration analysis of thick nanocomposite laminated curved panels with finite length resting on two-parameter elastic foundations, based on the three-dimensional elasticity theory. The main objective of this research paper is to present a 3D elasticity solution for free vibration analysis of thick laminated curved panels with continuously graded carbon nanotube-reinforced (CGCNTR) sheets. The structure is supported by an elastic foundation with Winkler's (normal) and Pasternak's (shear) coefficients. The volume fractions of oriented, straight single-walled carbon nanotubes (SWCNTs) are assumed to be a three-parameter power-law distribution which is graded in the radial direction of the panels. An equivalent continuum model based on the Eshelby-Mori-Tanaka approach is employed to estimate the effective constitutive law of the elastic isotropic medium (matrix) with oriented, straight carbon nanotubes (CNTs). Because of using two-dimensional generalized differential quadrature method, the present approach makes possible vibration analysis of cylindrical panels with two opposite axial edges simply supported and arbitrary boundary conditions including Free, Simply supported and Clamped at the curved edges. The convergence of the method is demonstrated and comparisons are made between the present results and results reported by well-known references and have confirmed accuracy and efficiency of the present approach. This study serves as a benchmark for assessing the validity of numerical methods or two-dimensional theories used to analysis of laminated curved panels. © 2016 Society of Plastics Engineers.
Mokhtarian M.,Young Researchers and Elite Club
Journal of Food Process Engineering | Year: 2016
The effects of storage temperatures (15, 25, 35, and 40°C) and relative humidity (11, 33, 73 and 87%) on peroxide value, lipid oxidation and shelf life of stored pistachio powder studied in this project. Results showed that the changes in lipid oxidation follow zero-order reaction kinetic. Additionally, the highest inhibition (or activation) energy (Ea) for oxidation of fatty acid molecules and forming hydro-peroxides reached to ∼50 kJ/mol at relative humidity of 33%, which corresponds to monolayer moisture content of pistachio powder. Thermodynamic analysis of these reactions indicated that these reactions are endothermic (ΔH++>0) and nonspontaneous (ΔG++>0) processes. Practical Applications: Pistachio nut (Pistachia vera L.) is one of the most popular nuts in the world with its high nutritional value and unique flavor as a snack and a food ingredient (as powder or kernel). It is also used as a main part of many traditional Persian foods such as Gaz, Baghlava and Ghotab. Fat oxidation is one of the main factors for quality loss in pistachio, i.e., changes in nutritional and organoleptic properties of this product during storage period. The main object of this research is the kinetic effects of different storage temperature and RH on auto-oxidation of pistachio powder's lipid during storage period. Generally, the results are applicable by pistachio powder's workstations and their producing factories during processing and storage for controlling the shelf life. © 2016 Wiley Periodicals, Inc.
Ahmadi M.,Young Researchers and Elite Club |
Sami A.,Shiraz University |
Rahimi H.,Shiraz University |
Yadegari B.,Shiraz University
Computer Fraud and Security | Year: 2013
For many years, malware has been the subject of intensive study by researchers in industry and academia. Malware production, while not being an organised business, has reached a level where automatic malicious code generators/engines are easily found. These tools are able to exploit multiple techniques for countering anti-virus (AV) protections, from aggressive AV killing to passive evasive behaviours in any arbitrary malicious code or executable. Development of such techniques has lead to easier creation of malicious executables. Consequently, an unprecedented prevalence of new and unseen malware is being observed. Reports suggested a global, annual economic loss due to malware exceeding $13bn in 2007.1 Traditional signature-based antivirus methods struggle to cope with polymorphic, metamorphic and unknown malicious executables. And analysing and debugging obfuscated programs is a tricky and cumbersome process. Now Mansour Ahmadi of Young Researchers and Elite Club, Shiraz Branch, Iran and Ashkan Sami, Hossein Rahimi and Babak Yadegari of Shiraz University, Iran have developed a novel framework based on runtime API call auditing and data mining, a method that achieved a malware detection rate of 98.4% in tests. Here, they detail their approach and the benefits it could bring. © 2013 Elsevier Ltd.
Sayyadi S.Y.,Young Researchers and Elite Club |
Ardestani V.E.,University of Tehran
Near Surface Geoscience 2015 - 21st European Meeting of Environmental and Engineering Geophysics | Year: 2015
The most important goal in hydrocarbon explorations is finding undersurface anomalies which have good quality for gas and oil explorations. Gravity data can be useful in fields with salt body structures. In our case study, Charak anticline has some out growing salt bodies. This anticline has arc image, it looks that an undersurface anomaly make this image. In this paper, in this paper To clarify this anomaly we improve the precision of inversion result, with minimum inertia, in Lewi algorithm .the result shows a salt body which have at least 2kilometeres depth that is a good place for exploring gas and oil. © (2015) by the European Association of Geoscientists & Engineers (EAGE).
Sadeghi Ghari H.,Young Researchers and Elite Club |
Shakouri Z.,Young Researchers and Elite Club
Journal of Vinyl and Additive Technology | Year: 2016
The present paper addresses the usefulness of a sorption gravimetric technique to assess of the compatibility and reinforcing effect of nanofiller against hazardous liquid media. The reinforcing capability of organoclay (Cloisite 30B) in chlorosulfonated polyethylene (CSM) was characterized by means of transport properties such as diffusion, sorption and permeation coefficients, activation energy, enthalpy, and entropy. The CSM/organoclay nanocomposites were prepared by melt mixing method. The transport of toluene through CSM vulcanizates were studied with special reference to the effect of organoclay concentration (0-9 parts per hundred parts of rubber) and temperature (25-55°C). The microstructure of the nanocomposites was confirmed by studying of dispersion of organoclay in CSM via transmission and scanning electron microscopy and X-ray diffraction. The results showed that the swelling properties of nano-filled CSMs mainly depend on the presence of organoclay and not its concentration and also the formed microstructure. A good relationship was found between the microstructure and swelling properties of CSM nanocomposites. © 2016 Society of Plastics Engineers.