Showing 61 results for لا
Volume 10, Issue 2 (2-2010)
Abstract
The Muteh gold deposit located in the center of Sanandaj-Sirjan Zone (SSZ) in western Iran. Gold mineralization is related to series of quartz and quartz-sulfide veins, lenses and veinlets, cutting the Neoprotrozoic crystalline basement rocks, along a NW-SE trending shear zone. Gold mineralization is closely associated with hydrothermal alteration along the ductile shear zones, with a typical greenschist facies assemblage of quartz+sericite+chlorite+albite, plus sulfidation and silicification alteration zones adjacent to ore body. Ore minerals include pyrite, chalcopyrite, emplectite (Cu-Bi sulfide), arsenopyrite, pyrrhotite, bismuth, gold and subordinate galena and sphalerite. Native gold occurs in the quartz veins and adjacent to wall rocks as inclusions in the second generation of pyrite and chalcopyrite in form of fracture fillings within rim or around euhedral to subhedral coarse pyrite. Fluid inclusions in quartz veins contain carbonic, aqueous-carbonic and aqueous types in the Chah-Khatoon and Senjedeh gold mines. Homogenization temperature of CO2 (ThCO2) in carbonic inclusion is between 12.6 to 27.3 ̊C. Aqueous-carbonic fluid inclusions show salinities of 2.3 to 12.5 NaCl eq. wt% and total homogenization of 145.6 to 304.2 ̊C. The aqueous fluid inclusions, based on association with auriferous and barren veins categorized as 1) salinity of 2.1 to 15.2 NaCl eq. wt% and total homogenization of 212.2 to 297.6◦C in auriferous quartz-sulfide veins, and 2) salinity of 16.2 to 28.2 NaCl eq. wt% and total homogenization of 147.4.2 to 245.6◦C in barren quartz veins. While most of aforementioned characteristics of the Muteh deposit are consistent with orogenic (mesothermal) gold deposit, but features such as genetic linkage with tectonic evolution of lithospheric mantle through upper crust with the tectono-magmatic history of SSZ accompanied with extensional structure setting, ore geology style, alteration assemblages, mineral chemistry, vertical elemental zonation and fluid inclusions characteristics presented in this research, it may inferred that gold mineralization in the Muteh deposit can be favored as an reduced intrusion related gold system (IRGS).
Volume 11, Issue 1 (10-2011)
Abstract
The taxonomy and morphology of 24 Salvia atropatana Bunge (Lamiaceae) accessions were studied in Iran. The morphological variations are mostly related to the indumentum and trichome frequency in surface and base of stem, leaf length, form of leaf margin, indumentum of leaf surface, form of bract margin, indumentum of bracteole surface, indumentum of calyx surface, corolla length, indumentum of corolla surface and style length. The cluster analysis based on Euclidian Distance Coefficient and SPSS V.11.5 software was used to determine the infra-specific relationships. The results of cluster analysis show diversity among the accessions of this species. Based on the findings, it can be concluded that the morphological variability of S. atropatana accessions is due to the polymorphism, and infra-specific hybridization.
Volume 11, Issue 1 (10-2011)
Abstract
Aluminum toxicity is one of the most important limiting factors for plant growth and development in acidic soil (pH <5.5). Soil acidity and consequently availability of Al in the soil can be accelerated by some farming practices and acid rain. The mechanisms of Aluminum toxicity have not been elucidated yet. The first response of the plant to aluminium toxicity is the inhibition of root elongation, that is apparently resulted from increasing of cell wall cross links. Therefore, the effect of aluminium on activity and gene expression of enzymes involved in phenolic compounds biosynthesis such as phenylalanine ammonialyase and peroxidase was investigated in this research.To this end, the flax seeds grown in Hoagland’s solution were treated with 0, 50 and 100 &muM aluminium (as AlCl3. 6H2O). The results showed that aluminium decreased root growth but increased wall bound phenolics content, compared with those of the control plants. Increase of the activity of peroxidase especially in ionically and covalently fractions in Al-treated roots was consisted with reducing root growth. Increased activity, PAL expression and lignin contents were observed in higher concentrations of aluminum. The investigation of the expression of peroxidase isozymes, Flxper1 and Flxper3 suggested that Flxper3 is the isozyme which is more involved in aluminium toxicity in flax roots.
Volume 11, Issue 1 (10-2011)
Abstract
Manesht and Ghalarang protected region with an area of 29146 hectares (ha) is located in the north part of Ilam province, between 33°34'27" and 33°48'32" northern latitudes and 46°20'31" and 46°38'45" eastern longitudes. The altitude of the area ranges from 1105 to 2650 m. The total annual rain is 536.2 mm and the median annual temperature is 17.43 °C. Manesht and Ghalarang protected area is a mountainous area of Zagros Range Mountains. According to the studies done, Manesht and Ghalarang protected area comprise of seven watersheds. In this study, the flora of Shalam watershed with an area of 4467 ha, has been studied. Totally, 221 taxa (species, subspecies and variety) were collected that belong to 219 species, 150 genera and 46 families. Results showed that from 219 species are known in this area 29 monocotyledones and 190 dicotyledones were determined. Asteraceae with 35, Fabaceae and Lamiaceae with 19, and Brassicaceae and Poaceae with 17 species were the families with the highest number of species. Throphyta 44.80%, Hemicryptophyta 32.58%, Geophyta 11.76%, Phanerophyta 6.33% and Chamaephyta 3.17% are the life forms in the area. The most extended chorotype with 141 taxa (63.80%) is related to Irano-Turanian region
S Bazm, Esmaeil Babolian,
Volume 11, Issue 2 (2-2011)
Abstract
In this paper, we use operational matrices of piecewise constant orthog-
onal functions on the interval [0,1] to solve fractional differential , integral
and integro-differential equations without solving any system. We first ob-
tain Laplace transform of the problem and then we find numerical inversion
of Laplace transform by operational matrices. Numerical examples show
that the approximate solutions have a good degree of accuracy.
Mohammad Jahanshahi, Mojtaba Sajjadmanesh,
Volume 12, Issue 1 (11-2012)
Abstract
Boundary value problems (BVPs) are one of the most important fields in engineering and mathematical physics. In self-adjoint case of these problems, there are some facilities to solve them, such as
eigenvalues of adjoint equations are real numbers and associated eigenfunctions make an orthogonal
basis system.
In this paper a new method for investigation of self-adjoint B.V.Ps including ordinary differential
equations (O.D.Es) is introduced. Based on this method, at first, some necessary conditions
are obtained by making use of fundamental solutions of adjoint equations. Then an algebraic system is made by this necessary conditions and boundary conditions of given boundary value problem.
Finally, by making use of Lagrangian identity and boundary values of unknown function, sufficient conditions for having a self-adjoint problem are presented.
Mansour Mohammadian, Behroz Goleen, Z Khosravi Lorgani,
Volume 12, Issue 3 (11-2012)
Abstract
Citrus fruits are tropical and sub-tropical crops. The main problem in sub-tropical area is chilling and frost damage. Regarding the sensitivity of citrus fruit to low temperature and the conjunction of the fruit harvest season with low temperature, the investigation of the physiological impacts of low temperature treatments are very important. In this study, flavedo tissue of five cultivars of citrus fruit was examined to compare some enzymatic antioxidants activities including Superoxide dismutase (SOD), Ascorbate peroxidase (APX), peroxidase (POD) and Catalase (CAT) under various cold treatments, i.e. control (~15), 3, 0, -3 and -6 °C in two stages of before and after ripening of the fruits. The high activity of SOD enzyme in the flavedo tissue of the examined cultivars indicated that this tissue is the first defensive line of the fruits facing low temperatures treatments. The activity of CAT enzyme in the flavedo tissue of Sanguinello before and after ripening stages was higher in all low temperature treatments compared with other cultivars. Unshiu and Local Orange had maximum and minimum activity of APX enzyme, respectively in both stages. Also, Unshiu, Sanguinello and Local lemon showed increasing activity of POD enzyme by decreasing temperature
Ebrahim Najdegerami, Mehran Javaheri,
Volume 12, Issue 3 (11-2012)
Abstract
Light is one of the most important environmental factors in fish life. The effect of photoperiod on the growth performances and survival of rainbow trout (Oncorhynchus mykiss) larvae and fingerlings was investigated in two consecutive experiments. In both experiments fishes were exposed to four treatments (24L/0D, 16L/8D, 8L/16D, 0L/24D) (light: dark, L: D) in three replicates. The results of first experiment indicated that photoperiod affected on the growth performances in larval stage of rainbow trout. The best weight gain and specific growth rate was observed in 24L: 0D and 16L: 8D without significant differences between them and the lowest rates was achieved in 0L: 24D. Also in second experiment, the effect of photoperiod on the growth performances was significant difference and the highest growth rate and specific growth rate was observed in 8L: 16D and the lowest in 24L: 0D and 0L: 24D. Our results showed that the effect of photoperiod in rainbow trout depends to developmental stage and larvae unlike fingerlings have better growth in long light phases.
Roya Karamian, M Asadbigi, M Ranjbar,
Volume 12, Issue 3 (11-2012)
Abstract
Salvia L. is one of the important genera of the Lamiaceae family, that most of its species have nutritious and medicinal values. This study aimed to examine the total phenol and flavonoid contents and the antioxidant activities of S. aethiopis using spectrophotometric method. The essential oil of this species was analyzed using GC and GC/MS methods. In addition, antibacterial activities of the essential oil and methanolic extract were evaluated against six gram positive and negative bacteria, respectively. Results showed that the extract has high content of phenolic compounds with high antioxidant activity. From GC analysis, 11 different compounds were indentified in which &alpha-copaene was the most abundant compound with 33.48%. The extract of the species showed a high antibacterial activity against Proteus vulgaris. However, the essential oil of S. aethiopis had no effect on examined bacteria.
, ,
Volume 12, Issue 3 (11-2012)
Abstract
Umbilical cord (UC) is an important source of multipotential mesenchymal stem cells (MSCs). MSCs can be differentiated into different types of cells if they cultured under specific conditions. It has been proved that vitamin D3 can cause differentiation of stem cells in to osteoblast. Also, it has been observed that bee venom (BV) is effective in differentiation of cancerous cells. In this study differentiating potential of BV and vitamin D3 on MSCs to osteoblast was examined. Furthermore, our hypothesis was that BV could increase differentiating potential of vitamin D3. The cells obtained from UC tissues of 10-12 mouse embryos which were digested enzymatically and suspended in DMEM medium. For approving of stem cells, embryonic Oct4 marker was checked and the mesenchymal character of these cells was proven by surface markers including CD73, CD29, CD44. The flowcytometric analysis revealed high levels of these markers. After the second passage, in order to induce osteogenic differentiation, cells were cultured for 21days in DMEM medium containing different concentrations of BV, vitamin D3 separately and BV/vitamin D3 together. At first, cytotoxic effects of BV on MSCs were tested by MTT assay, which were shown that BV inhibited MSCs growth at higher concentrations than 6&mug/ml. Following the treatment, calcium’s level in the cells was determined by Alizarin red staining. Also, as an osteogenic marker, alkalin phosphatase level was measured in treated and non-treated cells. By Alizarin red staining and alkalin phosphatase assay, we found that BV With non-toxic concentrations (2µgr/ml, 4µgr/ml and 6µgr/ml) can cause a few osteogenic differentiation of MSCs. Whereas, usage of BV/vitamin D3 together, caused increasing the differential effects of vitamin D3. In conclusion we suggest that if MSCs were treated with bee venom and vitamin 3 at the same time, these components able to differentiate MSCs to osteoblast, therefore, they could be useful in cell therapy.
Mohammad Ghazi, Mehdi Hasanshah, , ,
Volume 12, Issue 4 (11-2013)
Abstract
Nickelate with general formula La2-xSrxNiO4 (x≈0.33) were synthesized by the sol–gel method. Then by changing the sintering temperature and growth parameters, particles with various sizes were produced. The crystal structure and physical properties of the prepared samples were investigated by X-ray diffraction (XRD), Fourier transform IR spectroscopy (FTIR), Energy dispersive X-ray spectroscopy (EDX) and field emission scanning electron microscopy (FE-SEM) and resistivity measurements from room temperature to low temperatures. The XRD results and investigation of the surface morphology show the lowest temperature to get a single phase tetragonal structure is 920°C. These data confirm the formation of single phase structure in samples sintered at higher temperatures. The particle size increases with increase in sintering temperature. The FE-SEM results show that the particles sizes are in range of 50nm to 2mm. The results of resistivity measurements versus temperature by fourprobe method indicate that the charge ordering transition temperature move to lower temperature with decrease in particle size.
, ,
Volume 13, Issue 1 (5-2013)
Abstract
For this purpose 5 sampling stations namely as Astara, Bandar Anzali, Hashtpar, Chaboksar and Bandar Kiashahr were selected along the shoreline of the southwest Caspian. The maximum density was observed in 3-15 m depth. Catch composition from different sampling sites approve this statement. 0.41%, 2.24%, and 2.59% out of total catch was starry goby that came from Bandar Anzali, Chaboksar and Astara sampling stations respectively. This species did not observe in the Hashtpar and Bandar Kiashahr sampling stations. According to the results mean total length was 61.28±16.14 mm and mean weight was 3.16±0.92 gr.
Yadollah Ordokhani, Haneh Dehestani,
Volume 13, Issue 2 (7-2013)
Abstract
In this paper, a collocation method based on the Bessel polynomials is used for the solution of nonlinear Fredholm-Volterra-Hammerstein integro-differential equations (FVHIDEs) under mixed condition. This method of estimating the solution, transforms the nonlinear (FVHIDEs) to matrix equations with the help of Bessel polynomials of the first kind and collocation points. The matrix equations correspond to a system of nonlinear algebraic equations with the unknown Bessel coefficients. Present results and comparisons demonstrate that our estimate has good degree of accuracy and this method is more valid and useful than other methods.In this paper, a collocation method based on the Bessel polynomials is used for the solution of nonlinear Fredholm-Volterra-Hammerstein integro-differential equations (FVHIDEs) under mixed condition. This method of estimating the solution, transforms the nonlinear (FVHIDEs) to matrix equations with the help of Bessel polynomials of the first kind and collocation points. The matrix equations correspond to a system of nonlinear algebraic equations with the unknown Bessel coefficients. Present results and comparisons demonstrate that our estimate has good degree of accuracy and this method is more valid and useful than other methods.
Azim Aminataei,
Volume 13, Issue 3 (11-2013)
Abstract
In this study, we simulate numerically the process of oxygen mass transport in the human circulatory system incorporating the contribution of axial diffusion. Simulated equation is a time dependent convective-diffusion partial differential equation wherein has applicable application in the bioengineering problems such as boundary layer of fluids, electrical circuits in cables and mass transport problems.
The analytical solution of this kind of equations is complicated. Therefore, the numerical solution for obtaining the approximate solution is important and the convergence and stability in this method of solution, is always a question. In this study, we try to answer the above questions with respect to this special equation and for this we use finite differences.
Alireza Sarakhsi, Mohammad Jahanshahi,
Volume 13, Issue 3 (11-2013)
Abstract
In this papear, we produce the method for formation and recognizing boundary layers in singular perturbation problems. This method involves four step for localization of non-local boundary conditions to local case.For the given problem some sufficient and necessary conditions are given for formation and non formation of boundary layers. Since the existence of boundary layers and their places has a direct relation with the structure of approximate solutions and uniform solutions, therefore the main purpose of this paper is recognition and formation of boundary layers in singular perturbation problems with non-local boundary conditions. This process will be done by using fundamental solution of adjoint given differential equation and necessary conditions.In fact by using these necessary conditions and given boundary conditions, we make an algebraic system.By solving this algebraic system by Cramer rule we obtain boundary values of unknown function.These values of unknown function are local boundary conditions.The mathematical model for this kind of problem usually is in the form
of either ordinary differential equations (O.D.E) or partial differential equations (P.D.E) in which the highest derivative is multiplied by some powers of as a positive small parameter.
Nader Nematollahi, Azadeh Kiapour,
Volume 13, Issue 3 (11-2013)
Abstract
In the Bayesian framework, robust Bayesian methods concern on estimation of unknown parameters, or prediction of future observation, by specifying a class of priors instead of a single prior. Robust Bayesian methods have been used extensively in actuarial sciences for estimation of premium and prediction of future claim size. In this paper we consider robust Bayes estimation of premium and prediction of future claim size under two classes of prior distribution and under the scale invariant squared error loss function. Finally, by a simulation study and using prequential analysis, we compare the obtained robust Bayes estimators of future claim size.
Nematollah Rashidnejad Omran, Maryam Nadri, Mehraj Aghazadeh,
Volume 13, Issue 4 (2-2014)
Abstract
The granitoid intrusion trending NW-SE, is expose in the East of Zanjan, structurally located in the Alborz - Azarbaijan zone and Tarom sub-zone. Petrographic composition of the intrusion includes a range of monzogranite, quartz-monzonite, quartz-monzodiorite to monzodiorite and in fact shows monzonite series composition. The major rock forming minerals consist of K-feldspar, plagioclase, pyroxene (augite-diopside) and quartz. They show granular, intergranular, microgranular to porphyrytic-microgranular textures. The intrusion has metaliminus high-K calc-alkaline to shoshonitic and I-type affinity. Enclaves of the intrusion have micro-granular mafic and monzodiorite, quartz monzodiorite composition, which are fine-grained than their host rock and have micro-granular porphyritic texture. According to the petrographical and geochemical studies, the magma has originated from partial melting of metasomitised sub-continental lithospheric mantle due to fluids and/or partial melts that originated from subduction edge. According to Harker Diagrams seems that monzodiorite magmas differentiation Leads to monzonite Formation And finally the Crystallization and differentiation are monzogranite. Therefore Crystallization and differentiation are the most important processes controlling rock types in the monzonite series intrusion. Tectonic diagrams indicate a continental margin magmatic arc and syn-to-post collisional intra-arc extensional environment.
Ali Yasaghi, Azin Imanpur,
Volume 13, Issue 4 (2-2014)
Abstract
Anbaran inlier is located at the NW of Namin city. In the inlier Pre-Paleozoic roks surrounded by young Eosen and Cretaceouse rocks.To interpret the inlier deformation and its evolution model, geometry as well as kinematic characteristic its major structurs analysed for the first time. For the faults kinematic, indicator, such as slickenside, fault associated folds and S-C structure were used. The results of analysis show that the major structurs of inlier are the Anbaran and RF1 fault at its Norht and South margins.The high angle Anbaran and RF1 faults cause thrusting of the Pre-Paleozoic Biandor and Soltanieh formation in the core of inlier over the Eocen volcanic units and Cretaceouce limeston respectively.This resulted in development of a pop-up structure that form the present morphology of the region .The fault high angele dip, and deposition of Cretaceous sediments on its hanging wall provide evidence for the fault inversion.therefor the RF1 fault is considered as the inverted anbaran fault backthrust.
Rajabali Ebrahimi,
Volume 14, Issue 1 (4-2014)
Abstract
The present work was an attempt to investigate the parameters which can affect the process of hydrogel formation in the presence of ultrasound. These parameters were concentration of the reactants (monomers and cross linker), the reaction medium (solvent, ionic strength, and pH), and acoustic parameters (power and pulse). The monomers were acrylic acid and acrylamide, and the cross linker was methylene bis acrylamide. The experiments were performed at a constant temperature of 37 °C. Pulsed power ultrasound was irradiated to the reaction mixture from the tip of a probe system. The results showthatultrasonic irradiation significantly reduces the reaction time and increases efficiency. Additionally, increasing glycerol in the solution changes the viscosity of the reaction for the better and increases the reaction rate. However, ionic strength and pH were not significantly effective in this respect. Results showed that ultrasonic acrylic hydrogel are sensitive to pH and temperature. Therefore, these hydrogels is capable for rapid drug absorption and release according to porosity in their structure. These findings provide a better understanding of hydrogel synthesis and enable us to control the pertinent parameters.
Behzad Mahmoudian, Mohsen Mohammadzadeh Darrodi, ,
Volume 14, Issue 2 (7-2014)
Abstract
In this article a spatial model is presented for extreme values with marginal generalized extreme value (GEV) distribution. The spatial model would be able to capture the multi-scale spatial dependencies. The small scale dependencies in this model is modeled by means of copula function and then in a hierarchical manner a random field is related to location parameters of marginal GEV distributions in order to account for large scale dependencies. Bayesian inference of presented model is accomplished by offered Markov chain Monte Carlo (MCMC) design, which consisted of Gibbs sampler, random walk Metropolis-Hastings and adaptive independence sampler algorithms. In proposed MCMC design the vector of location parameters is updated simultaneously based on devised multivariate proposal distribution. Also, we attain Bayesian spatial prediction by approximation of the predictive distribution. Finally, the estimation of model parameters and possibilities for capturing and separation of multi-scale spatial dependencies are investigated in a simulation example and analysis of wind speed extremes.