Jahrom University

Jahrom, Iran

Jahrom University

Jahrom, Iran
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Faghih S.,Isfahan University of Technology | Ghobadi C.,Isfahan University of Technology | Zarei A.,Jahrom University
Journal of Plant Growth Regulation | Year: 2017

The possible role of salicylic acid (SA) and methyl jasmonate (MJ) treatments on the physiology responses and growth of strawberry (Fragaria × ananassa) cv. ‘Camarosa’ subjected to the different levels of salinity stress were investigated. Root and shoot growth as well as their Na+/K+ ratio, photosynthetic-related factors, and activity of some important antioxidant enzymes were determined in the salt-treated plants. Results indicated that salt stress reduced plant performance especially at higher concentrations. By increasing the levels of salinity stress, fresh and dry weight of shoot and roots, net photosynthetic rate (Pn), and stomatal conductance (Gs) significantly decreased, whereas intercellular CO2 (Ci) increased. Application of exogenous SA and MJ significantly improved the plant physiological characters as well as fresh and dry weight of shoots and roots. Moreover, the ratio of Na+/K+ was elevated in the leaves and roots concomitantly with salinity levels, whereas SA and MJ treatments significantly reduced this ratio. Results of enzymatic assays showed that activity of ascorbate peroxidase, peroxidase, and superoxide dismutase enzymes increased in the salt-stressed plants. In addition, SA and MJ treatments reduced the destructive effects of salinity in strawberry plant. In general, among the tested concentrations, 0.5 mM SA and 0.25 mM MJ best increased the activity of antioxidant enzymes and hence alleviated the detrimental effects of salinity stress. © 2017 Springer Science+Business Media New York

Mahmoodi-Eshkaftaki M.,Jahrom University | Ebrahimi R.,Shahrekord University | Ghanbarian D.,Shahrekord University | Houshyar E.,Jahrom University
Soil and Tillage Research | Year: 2017

Designing a moldboard plow is a complex task. In many cases, moldboard plows are manufactured mostly based on experience and empirical methods The objective of this study is to identify a way to use a mathematical approach for the design. Therefore, both the mathematical surface (multi variable equations, NURBS and Bezier) and the number of control points required for its adjustment (A, B, C, D), are examined to produce optimal modeling of the semi helical moldboard plough geometry. The 3D coordinates of 196 marked points on the plough surface were acquired using image processing techniques. The results obtained indicate that the surface of the moldboard plough can be shaped with R2 = 0.81 and RMSE = 13.35, by the adjustment of a coupled fifth-order polynomial, exponential and sinus functions. Furthermore, the guide curve and angles of generatrix lines can be represented with a coupled first-order polynomial, exponential and sinus functions and fourth-order polynomial function, respectively, by high R2 = 0.9998 and low RMSE = 8.5 × 10−5. Overall the results confirmed that our method is suitable and effective for designing the moldboard plough. © 2017 Elsevier B.V.

Houshyar E.,Jahrom University | Dalgaard T.,University of Aarhus | Tarazkar M.H.,Shiraz University | Jorgensen U.,University of Aarhus
Journal of Cleaner Production | Year: 2015

The central Fars province is the main tomato producer region in Southwest Iran. This study was undertaken to evaluate the energy consumption patterns of tomato production, corresponding GHG emissions, and relationships between inputs and output by a Cobb-Douglass econometric model. The changes in GHG emissions were also investigated to display if the result is in favor of the environment as well as economy. The non-hierarchical cluster analysis determined three groups of tomato farmers with respect to the energy inputs and tomato yield; C1, C2 and C3 including 90, 46 and 20 farmers, respectively. The findings showed that around 40-60 GJ/ha energy is needed to produce 54-70 ton/ha tomato. Although, the C1 farmers consumed around 20 GJ/ha higher energy than C3, they also had a higher output-input energy ratio; 1.15 and 1.12, respectively. The GHG emission index (IGHG) disclosed that energy efficiency indices cannot represent the environmental risks of energy inputs since some higher energy efficient groups also emitted higher carbon. The econometric analysis revealed that some energy inputs significantly correlates with the yields of C1 and C2 farmers. The highest marginal physical productivities (MPPs), however, indicated that tomato yield is most sensitive to machinery and chemicals energy inputs in the C1 and C2, respectively, which should be considered first to increase in order to achieve productivity enhancement. The result displayed that higher energy consumption according to the econometric models and MPPs may lead to much higher CO2 emissions compared to the current average emissions particularly when MPP is low. Hence, it is suggested that production types with the highest MPPs should be considered if change in energy inputs is desired. In addition, it is recommended that "green econometric" models are needed to evaluate balanced energy use consumption together with other agronomical, economical and the environmental sustainability impact assessment criteria. © 2014 Elsevier Ltd. All rights reserved.

Dehghani M.H.,Shiraz University | Dehghani M.H.,Research Institute for Astrophysics and Astronomy of Maragha RIAAM | Bazrafshan A.,Shiraz University | Bazrafshan A.,Jahrom University | And 4 more authors.
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2012

We construct quartic quasitopological gravity, a theory of gravity containing terms quartic in the curvature that yields second-order differential equations in the spherically symmetric case. Up to a term proportional to the quartic term in Lovelock gravity we find a unique solution for this quartic case, valid in any dimensionality larger than 4 except 8. This case is the highest degree of curvature coupling for which explicit black hole solutions can be constructed, and we obtain and analyze the various black hole solutions that emerge from the field equations in (n+1) dimensions. We discuss the thermodynamics of these black holes and compute their entropy as a function of the horizon radius. We then make some general remarks about K-th order quasitopological gravity, and point out that the basic structure of the solutions will be the same in any dimensionality for general K apart from particular cases. © 2012 American Physical Society.

Bazrafshan A.,Jahrom University | Dehghani M.H.,Center for Excellence in Astronomy and Astrophysics | Dehghani M.H.,Shiraz University | Ghanaatian M.,Payame Noor University
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2012

As in the case of Einstein or Lovelock gravity, the action of quartic quasitopological gravity has not a well-defined variational principle. In this paper, we first introduce a surface term which makes the variation of quartic quasitopological gravity well-defined. Second, we present the static charged solutions of quartic quasitopological gravity in the presence of a nonlinear electromagnetic field. One of the branches of these solutions presents a black brane with one or two horizons or a naked singularity depending on the charge and mass of the solution. The thermodynamics of these black branes are investigated through the use of the Gibbs free energy. In order to do this, we calculate the finite action by use of the counterterm method inspired by AdS/CFT correspondence. Introducing a Smarr-type formula, we also show that the conserved and thermodynamics quantities of these solutions satisfy the first law of thermodynamics. Finally, we present the charged rotating black branes in n+1 dimensions with k≤[n/2] rotation parameters and investigate their thermodynamics. © 2012 American Physical Society.

Ghanaatian M.,Payame Noor University | Bazrafshan A.,Jahrom University | Brenna W.G.,University of Waterloo
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2014

In this paper we elucidate some of the effects of the quartic quasitopological term for Lifshitz-symmetric black holes. The field equations of this theory are difficult to solve exactly; here we use numerical solutions both to verify previous exact solutions for quartic quasitopological anti-de Sitter black holes as well as to examine new quasitopological Lifshitz-symmetric black hole solutions, in order to determine the effect of the quartic coupling parameter on the black hole's thermodynamic behavior. We find that the quartic parameter controls solutions very similarly to the cubic parameter, allowing for the construction of a theory with another free parameter which may find meaning in the phase transition behavior of a gauge/gravity context. © 2014 American Physical Society.

Naseri M.G.,University of Malayer | Halimah M.K.,University Putra Malaysia | Dehzangi A.,National University of Malaysia | Kamalianfar A.,Jahrom University | And 2 more authors.
Journal of Physics and Chemistry of Solids | Year: 2014

Abstract This study reports the simple synthesis of MFe2O 4 (where M=Zn, Mn and Co) nanostructures by a thermal treatment method, followed by calcination at various temperatures from 723 to 873 K. Poly(vinyl pyrrolidon) (PVP) was used as a capping agent to stabilize the particles and prevent them from agglomeration. The pyrolytic behaviors of the polymeric precursor were analyzed by use of simultaneous thermo-gravimetry analyses (TGA) and derivative thermo-gravimetry (DTG) analyses. The characterization studies were conducted by X-ray diffraction (XRD) and transmission electron microscopy (TEM). Fourier transform infrared spectroscopy (FT-IR) confirmed the presence of metal oxide bands for all the calcined samples. Magnetic properties were demonstrated by a vibrating sample magnetometer (VSM), which displayed that the calcined samples exhibited different types of magnetic behavior. The present study also substantiated that magnetic properties of ferrite nanoparticles prepared by the thermal treatment method, from viewing microstructures of them, can be explained as the results of the two important factors: cation distribution and impurity phase of α-Fe2O3. These two factors are subcategory of the preparation method which is related to macrostructure of ferrite. Electron paramagnetic resonance (EPR) spectroscopy showed the existence of unpaired electrons ZnFe2O4 and MnFe2O4 nanoparticles while it did not exhibit resonance signal for CoFe 2O4 nanoparticles. © 2013 Elsevier Ltd. All rights reserved.

Rastegar S.F.,Tarbiat Modares University | Peyghan A.A.,Tarbiat Modares University | Ghenaatian H.R.,Jahrom University | Hadipour N.L.,Tarbiat Modares University
Applied Surface Science | Year: 2013

Adsorption of NH3 and NO2 molecules on aluminum nitride (AlN) nanosheets was investigated by using density functional calculations. Equilibrium geometries, stabilities, and electronic properties of NH3 and NO2 adsorptions on the surface of an AlN surface were identified. The adsorption energies were calculated to be about -91.84 and -95.02 kJ/mol for NH3 and NO2 corresponding to the most stable configurations, respectively. It was revealed that the electrical conductivity of the sheet may be increased upon the NO2 adsorption, being insensitive toward NH3 adsorption. Thus, the AlN sheet may selectively detect NO2 molecules in the presence of NH3 molecules. © 2013 Elsevier B.V. All rights reserved.

Shahrouzi M.,Jahrom University
Iranian Journal of Science and Technology, Transaction A: Science | Year: 2015

In this paper we consider a Petrovsky viscoelastic inverse source problem with memory term in the boundary condition. We obtain sufficient conditions on relaxation function and initial data for which the solutions of problem are asymptotically stable when the integral overdetermination tends to zero as time goes to infinity. © 2015, Shiraz University. All rights reserved.

Ghanaatian M.,Payame Noor University | Bazrafshan A.,Jahrom University
International Journal of Modern Physics D | Year: 2013

In this paper, we present the static charged solutions of quartic quasi-topological gravity in the presence of a nonlinear electromagnetic field. Two branches of these solutions present black holes with one or two horizons or a naked singularity depending on the charge and mass of the black hole. The entropy of the charged black holes of fourth-order quasi-topological gravity through the use of Wald formula is computed and the mass, temperature and the charge of these black holes are found as well. We show that black holes with spherical, flat and hyperbolical horizon in quasi-topological gravity are stable for any allowed quasi-topological parameters. We also investigate the stability of nonlinear charged black holes. © 2013 World Scientific Publishing Company.

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