karimzadeh

In this study, joining of Ni3Al intermetallic compounds using the transient liquid phase (TLP) process with Cu interlayer was investigated. The binding process was carried out in a vacuum furnace at a temperature of 1050 °C for different times of 30, 60, 90 and 120 minutes. The effect of time variation on microstructure and mechanical properties of the joint zone was investigated. The EDS analysis results of the joints proved formation of the athermally solidified zone (ASZ), isothermally solidified zone (ISZ) and diffusion affected zone (DAZ) at different times. After 90 minutes, brittle eutectic phases still exist in the joint line. However, by increasing the process time to 120 minutes, a copper-rich solid solution was formed in the joint line. Maximum hardness was attained in DAZ region and due to formation of more brittle compounds. By increasing the process time to 90 min, the hardness in the joint center-line increased. After 120 min, the hardness in the joint center-line decreased to about 224 HV. Maximum shear strength was achieved to be about 60 MPa at a process time of 30 minutes and due to formation of Ni-rich matrix at the joint. With increasing time to 90 min, the shear strength decreased to about 34 MPa. After 120 minutes and due to formation of copper-rich solid solution as well as disappearance of eutectic compounds, shear strength again increased to about 44 MPa. Investigation of fracture surfaces showed that until 90 minutes, fracture mode was mainly brittle whereas by increasing time to 120 minutes, a more ductile fracture occurred.

In the present study, the effect of time and base metal microstructure on the Transient Liquid Phase (TLP) bonding of 304L stainless steel was studied. TLP was performed at 1050 0C for 5 and 60 minutes on the coarse grain austenitic and martensitic microstructure using BNi-2 interlayer. To prepare martensitic microstructure, as-received 304L was rolled at -15 0C up to 80% rolling reduction. TEM analysis was proved that the microstructure of 80% rolled samples consisted of two different morphologies of martensite namely as lath-type and dislocation cell type martensite.  It was observed that the structure of bonded zone after 5 min has consisted of isothermally solidified zone (ISZ) containing γ solid solution and athermally solidified zone (ASZ) containing complex boride phases. Meanwhile, after 60 min of  heating, the structure of bonded zone completely solidifies isothermally. The obtained results also showed that the martensitic microstructure considerably effect on the width of diffusion affected zone (DAZ) which was related to the reversion of martensite to ultrafine grain austenite during heating.

The genus Arnica L. comprises of 32 species predominantly confined to the boreal and montane region of the northern hemisphere. Arnica species are rhizomatous perennial herbs belonging to the daisy family, with simple or branched stems bearing opposite leaves, and large, single or cymose heads of yellow flowers. A. chamissonis is distributed over North America from Alaska to New Mexico, and due to its low ecological demand it is easier to cultivate than A. montana. Arnica is a source of sesquiterpene lactones, flavonoids, essential oils, terpenoids, and phenolic acids and exhibits antiseptic, anti-inflammatory, antiradical, antibacterial, anti-sclerotic, antifungal, and antioxidant activities. The flower heads and other parts of the plant of two of the species have been used therapeutically: A. montana and A. chamissonis, both of them containing sesquiterpene lactones as pharmacologically active compounds. Arnica species are used in as many as 300 drug preparations in Europe and about 20 products in Canada. Moreover, A. chamissonisis a good source of bioactive compounds a valuable source of herbal raw material and a pharmaceutical substitute for the endangered mountain arnica. A. chamissonis extracts exhibit potent anti-inflammatory and anti-radical activity and possesses high antioxidant abilities that might be helpful in preventing or slowing the progress of free radicaldependent diseases. Low pH soil is one of the principal ecological requirements of Arnica. Good plant growth and flower yield was achieved on acid soils with a pH of 6.8 and below. After nitrogen, phosphorus and potassium, sulfur is considered as fourth major element in most crops. Rate of sulfur oxidation in soils vary and depend on population Thiobacillus bacteria in soil, particle size and environmental conditions.

This study was conducted as a complete randomized block design with three replications and four treatments including different levels of bentonite sulfur (0, 250, 500 and 750 kg/ha) combined with the bacterium Thibacillus thiooxidans. Traits such as height and width of plants, number of flowers on each plant, inflorescence diameter, fresh and dry yield of flowers in each plant per square meter and total phenols, total flavonoids, rutin, luteolin and apigenin content in flowers were measured. High-Performance Liquid Chromatography method (HPLC) was used to separate rutin, luteolin and apigenin. HPLC grade methanol and distilled water, each with 0.02% added TFT were used as solvents.

The results showed that A. chamissonis is compatible with Tehran’s climate and it can be cultivated in regions with a similar climate. The use of elemental sulfur has a significant role in reducing soil pH and soil pH decreased more rapidly with increasing sulfur. Thiobacillus bacteria by oxidation of sulfur produced some to sulfuric acid and at low buffered properties can considerably reduce pH. Different levels of sulfur fertilizer had a significant effect (P ≤0.01) on soil acidity (pH), electrical conductivity, and sulfur, iron, zinc and manganese levels. The use of 750 kg sulfur bentonite with Thiobacillus caused to reduce soil acidity by about 0.9 units, and it increased the electrical conductivity of the soil to 7.33 dS/m. The amount of soil sulfate as a result of oxidation of sulfur fertilizers increased linearly. The highest amounts of iron, zinc and manganese were measured in the treatment of 750 kg sulfur as 3.38, 3.84 and 27.94 mg /kg, respectively. In this study, supplying 250 kg of sulfur plus bio-sulfur caused to improve the morphological traits and the highest flower yield (20.67 g / plant) compared to control (3.66 g / plant). Also, it increased the amount of sulfur and microelements in the soil, but in the treatment of 500 and 750 kg sulfur per hectare due to increased electrical conductivity and soil salinity, the growth of Chamisso Arnica decreased. Therefore, these levels of sulfur are not suitable for this plant. Sulfur Bentonite is oxidized by Thiobacillus bacteria and other microorganisms and sulfuric acid is produced. Reducing acidity and, as a result, the release of stabilized and insoluble nutrients can increase their uptake capacity and improve plant growth and development. Due to the increased salinity and osmotic imbalance in the soil by the treatments of 500 and 750 g /kg sulfur, vegetation growth will be incomplete and plants quickly enter to the reproductive phase and produce fewer and smaller flowers. The highest content of rutin was measured in plants grown in soil treated with 750 Kg/ha sulfur while soil treatment with 500 Kg/ha sulfur resulted in highest content of luteolin and apigenin, both showing significant difference to the control.

Results of this study indicated that the Chamisso Arnica showed adaptability to the planting location and it can be mass-cultivated under similar conditions.

In order to study the effect of plant density on some quantitative and qualitative characteristics of Thymus pubescens Boiss. & Kotschy ex Celak under rainfed conditions, a field experiment was conducted in a randomized complete block design with three replications in three different dry farming regions of the country during two years. Experimental treatments consisted of plant density (25, 35 and 50 cm between plants on rows equal to 8, 6 and 4 plant/m2, respectively), time (first and second year after planting) and location (East Azarbayjan, Kordestan, and Tehran). The traits including plant height, canopy diameter, dry matter yield of aerial parts, essential oil yield and content were measured at full flowering stage. The results of ANOVA indicated the significant effect of density, location and time and their interaction on all traits studied. The highest dry matter yield (1147 kg ha-1) was obtained in both two years in Tehran at 8 plant/m2. Kordestan with 2.25% and East Azarbayjan with 0.43% had the highest and lowest essential oil percentage, respectively. In density × location interaction, the highest amount of essential oil yield was obtained in Kordestan (21.73 kg ha-1) and Tehran (17.88 kg ha-1) at a density of 8 plant/m2. Thymus pubescens showed higher dry matter and essential oil yield under high plant density, indicating the establishment and adaptation of the species to different rainfed regions of the country especially Damavand and Kordestan.

The present research aimed to study some biological parameters of  Alosa caspia Caspian Sea in the southeast Mazandaran Province in 2014-2015. A total of 600 samples were examined during this period and data were analyzed using SPSS software. The results showed that the mean fork length and total weight of A. caspia was 24.22 ± 54.2 cm and 167.63 ± 63.59 g, respectively, and the length and weight relationship were as W = 0.0558 FL 2.68 R2 = 0.825 for females and W = 0.0553FL 2.65 R2 = 0.825 for males. The results also showed that the age structure of the fish was about 1-5 years old, with the age group of 2 years (with a mean length of 25 cm and an average weight of 190 g), the most frequent (47%). The female sex ratio of male to female was 1:2. Also, the stage 3 of sexual maturity with the frequency of 45% was the highest in the sample population. According to the results, the average length and weight of the Caspian Sea has increased in recent years, but, on the contrary, the frequency of fish with lower ages has also increased. Therefore, given the important role and importance of these fish in the food resource chain of the Caspian Sea, the conservation has a great importance.

This study aimed at investigating the rural entrepreneurship capacities in the villages of Bonab County of Iran. It was a descriptive-analytic research using documents and field studies to collect data through a questionnaire. The statistical population of the study included 12369 rural households living in villages of Bonab. Using the Cochran formula and random sampling, 372 households were selected as the sample. Data analysis was performed using inferential statistics and multi-attribute decision-making models. The study results showed that institutional-structural variables with an effect of 0.849, economic 0.833, social 0.813 and environmental 0.805, respectively, had priorities on the rural entrepreneurship development. The results from the use of TOPSIS, VIKOR, ANP and Copland models showed that villages such as Akhond Gheshlagh and Zavosht, densely populated and close to city center, had more local capacities for entrepreneurship development. Finally, according to the research findings, a number of practical recommendations were presented.

Rainfall erosivity is one of the factors determining the amount of water erosion in the soil. Rainfall erosivity is determined by the  total rainstorm energy and the maximum intensity in 30 minutes (I30). Since rainfall erosivity is closely related to the amount and intensity of rainfall, it is expected that the rainfall erosivity would change monthly and seasonally throughout the year. The main objective of this study was the  spatial and temporal variation modeling of rainfall erosivity, erosivity density and their impacts on the soil erosion in Menderjan watershed. In this research, by using rainfall data with 1 minute from the rain gauge in the proximity of the basin during the 11-year statistical period (2005-2015), the rainfall erosivity factor (R) was calculated on a monthly average; then it was mapped using geostatistical technologies. Comparison of the monthly, seasonal and annual rainfall erosivity maps showed the highest rainfall erosivity occur in autumn (about 41 percent), while  the lowest one was recorded in summer (less than 1%), respectively. According to the results obtained the maximum amount of erosivity was observed in November, which was 65 (MJ.mm.ha-1.h-1.month-1), while the lowest amount was observed in August. This study showed that the highest risk of soil erosion was  expected to occur in November, because this month  is not only the time of rainfall erosion, but also involves a high erosion density.

The purpose of the present research is to investigate factors that influence accountants’ intentions of whistle-blowing using components of the extended theory of planned behavior and professional commitment. In doing so, the present research studies the effects of perceived behavioral control, perceived subjective norms, attitude toward whistle-blowing, moral obligation, and professional commitment on whistle-blowing intentions and also examines the moderating role of moral intensity. The research uses surveys completed by 171 accountants of the companies listed in Tehran Stock Exchange and Fara Bourse in 2018. In order to test the hypotheses, we exerted Partial Least Squares Structural Equation Modeling. The results indicate that perceived behavioral control, subjective norms, attitude toward whistle-blowing, moral obligation, and professional commitment posit positive and significant effects on intentions of reporting fraudulent activity, and moral intensity moderates the effects of social norms and professional commitment on whistle-blowing intentions. The results suggest that the extended theory of planned behavior represents a parsimonious theoretical framework for predicting whistleblowing intentions.Contribution: The findings of this research has notable consequences for improving internal control systems of the firms, increasing accountants’ social responsibility, and promotion of accounting profession in the society.

Iranian poppy (Papaver bracteatum Lindl.) is one of the medicinal plants belonging to the Papaveraceae family, which is widely used in pharmaceutical industries due to the presence of benzyl isoquinoline alkaloids. The polyploidy induction is one of the most interesting issues in the breeding and biotechnology of medicinal plants. In this study, colchicine treatment was carried out in five concentrations (0, 0.05, 0.1, 0.2 and 0.5) and three duration times (24, 48, 72 hours) with three replications as a factorial in a completely randomized design under greenhouse conditions, which aimed at studying morphological and phytochemical changes in polyploid plants and comparing them with diploid ones. The Microscopic, morphological and chromosomal counts were used to determine ploidy level of plants. The results showed that the concentration of 0.2% of colchicine for 48 hours was the most suitable treatment for polyploidy induction. Polyploidy caused significant changes in the increasing phytochemicals amount such as phenol, flavonoids and total antioxidants (DPPH) and decreasing the stomatal density index in comparison with the diploid plants. The chromosomes number of the diploid and tetraploid plants was obtained 14 (2n=2x=14) and 28 (2n=4x=28), respectively. Therefore, it can be concluded that the increase in ploidy level increases the phytochemical and antioxidant compounds in Iranian poppy herb.

Evaluating the possible relationships between vegetation and environmental characteristics can assist managers to identify effective factors influencing plants establishment and to characterize various vegetation communities. This study was aimed to evaluate the effects of long term grazing exclusion ( more than 33 years) and the controlled grazing system (resting – rotation grazing system) on the vegetation distribution and some soil properties in the Hamzavi research station in Hanna area-Semirom, Isfahan. Six transects (three parallel transects and three transects perpendicular to the general slope of the area) were established in each area and 10 square plots with the size of 2m2 were placed along each transect; then, the cover percentage, production and list of all plant species were recorded. In each area, eighteen plots were collected randomly and in each plot, five soil samples were collected from 0-30 cm of the soil and then the samples were mixed and one sample of the compound was selected as an evidence plot. Soil properties such as pH, EC, CaCO3, organic carbon, absorbable phosphor, total nitrogen, K, Ca, Mg, soil saturated percentage, cation exchange capacity, soil clay, silt, sand and fine sand contents were measured in the soil laboratory. The independent t test was used to compare the vegetation characteristics in two areas. Cation exchange capacity, CaCO3, gravel percentage, soil phosphor content and grazing management were identified as the most discriminative factors in separating vegetation communities based on Canonical correspondence analysis (CCA) and cluster analysis. Controlled grazing management significantly modified some soil characteristics and increased the production (352 versus 184.2 kg/ha) and vegetation cover percentage (25.46 versus 18.37), as compared to the exclusion area (α= 5%). The vegetation density was increased significantly in the exclusion rather than controlled grazing area (3.03 versus 2.02 plant/m2). This study, therefore, revealed that controlled grazing management was more effective on improving some soil quality and vegetation characteristics rather than p long term grazing exclusion in the semi-arid ecosystems. So, avoiding long term grazing exclusion in semi-arid rangelands is suggested.

The properties such as weak wear resistance and low hardness of aluminum alloys have limited their use in various industries. In this research, it has been attempted to improve the mechanical and tribological properties of these materials by deposition of nickel-phosphorous-alumina functionally graded coating. Functionally graded coatings have been produced by a gradual change in the chemical composition and content of the nanoparticle, using continuous change in pulse parameters such as duty cycle and frequency during the coating process. So, the effect of the duty cycle and frequency has been investigated. Two types of coatings have been created with a gradual decrease in the duty cycle of 90% to 30% and a pulse frequency of 50 to 500 Hz. The result shows that the effect of frequency on the amount of phosphorus and nanoparticles is negligible, and it has mainly affected on grain size. However, in nanocomposite coats, the gradual decrease of duty cycle has led to an increase in the amount of phosphorus (5.3% to 15.5 wt. %) and alumina nanoparticles (0.7% to 2.6 wt. %) from the substrate to the top surface. With the gradual changes in chemical and microstructure, the adhesion of the coating to the substrate has improved. The results of micro-hardness have also shown that the creation of functionally graded coatings using duty cycle variation has a higher hardness than the one produced by frequency changing. Also, based on the results of the pin test on a disk against abrasive steel 52100, the wear resistance of functionally graded coatings has improved compared to single-layer coatings.

In this paper vibrational analysis of size dependent micro-ring gyroscope under electrostatic DC voltage is performed. Based on the modified couple stress theory, Hamilton’s principle and in-extensionality approximation governing equations of size dependent micro rings and corresponding finite element formulation of circular micro ring along with eight half circular stiffeners embedded inside the ring is derived. Frequency analysis indicate that the obtained ring gyroscope mode shape is slightly different from the one previously reported in the literature. Size dependent behavior of the gyroscope is studied and findings confirmed the gap between classic and non-classic natural frequencies and pull-in voltage when the ring thickness is in order of material length scale parameter. Two different orientations for the actuation electrodes of the micro-ring gyroscope are implemented and effect of these orientations on the static deflection, pull-in instability and device frequencies in the sense ( direction) and drive ( direction) directions is investigated. Results reveal that the pull-in phenomena take place under lower voltage for & orientation of electrodes in comparison with orientation and frequency split occurs in higher voltages for & orientation. A comparison between finite element numerical natural frequencies of single ring and previously obtained analytical ones shows excellent agreement.

Due to electrical properties (high electron mobility) and electrochemical characteristics (high electron transport rate), graphene-based materials have been widely applied for various scientific fields. However, due to their two-dimensional structures, these materials have low active sites for reaction. Therefore, changing from two-dimensional sheets dimensional to the three-dimensional ones could provide graphene-based materials with high specific surface and electron and mass transport particles. For these purpose, reduced graphene oxide (rGO) and polystyren (PS) aqueous solution were mixed with two different weight ratios kinetic. In this study, the three-dimensional graphene (3DG) was synthesized with graphene oxide using sacrificial PS particles. For this purpose, rGO and the PS aqueous solution were mixed with two different weight ratios of 95:5 and 85:15. Then, the 3DG-PS scaffolds were synthesized by controlling the pH value in the range of 6-8. Subsequently, PS particles were removed by immersing the synthesized scaffolds in toluene. In this research, the effect of filtering through the member filter and centrifuge on the morphology of the scaffolds was investigated. The scaffolds were characterized with X-ray diffraction and scanning electron microscopy. The results showed the formation of 3DG with a uniform distribution of porosities by using the centrifuge procedure. Moreover, the sacrificial PS particles were completely removed when the rGO to PS weight ratio was 95:5. So, 3DG with the uniform distribution of microscopy porosity could be synthesized through the sacrificial mold method and the centrifuge procedure; graphene oxide was also reduced with the PS weight ratio of 95:5. Further, based on the electrochemical evaluation of this optimized sample, as compared to the rGO , it was found that the 3DG had better electrochemical properties than the rGO. Therefore, 3DG with the optimized rGO to PS weight ratio of 95:5 could be an ideal substitute for rGO in electrochemical applications

Detection of power quality disturbances requires some methods to decompose, identify and then classify waveforms. In this paper, a statistical method called Single Channel Independent Component Analysis (SCICA) is used for this means. In this method, source signals are separated from observed signals by using the characteristics of statistical independence as well as the non-Gaussian distribution of disturbance sources. The proposed method for classification of PQ disturbances consists of three stages: a) data generation, b) feature extraction and c) disturbances classification. The advantages of this method are its lower cost (due to the using of only one sensor), high accuracy in extracting independent components of non-Gaussian, non-linear and non-static signals, excellence of estimated signals, classification of multiple power quality disturbances that include more than two disturbances for any combination (ternary and quaternary disturbances) and estimation the starting time, ending time and duration of voltage swell, voltage sag, flicker and oscillatory transients with great accuracy. The results of the simulations on generated and real waveform show capability and high performance of the proposed method.

Today, the excessive use of zinc oxide nanoparticles (ZnO NPs) has led to concerns about the potential environmental hazards caused by the presence of these particles in aquatic ecosystems. Therefore, the aim of this study was to investigate the toxic effects of zinc oxide nanoparticles (0. 02, 0. 05 and 0. 1 mg/L) on the oxidative stress enzymes in brain tissue of roach during a period of 7 days. After homogenization of the brain tissue, the activity of oxidative stress enzymes such as superoxide dismutase (SOD), glutathione-S transferase (GST), catalase (CAT), glutathione (GSH) and malondialdehyde (MDA) was determined using biochemical methods. The SOD, CAT and GST activities were significantly increased by exposure to 0. 1 mg/ml zinc nanoparticles compared with other concentrations in brain tissue of roach (P<0. 05). However, the amount of glutathione decreased with increasing exposure dose. In amount of malondialdehyde dose-dependent manner was observed, since the maximum concentration was recorded at 0. 1 mg/ml of nanoparticles (4. 5 ± 5. 3 nmol/g wet). The subacute toxicity of nanoparticles leads to the induction of free radical and oxidative stress in brain tissue of roach. The increase in the activity of antioxidant enzymes causes antioxidant defense system activation for scavenger in free radicals.

High amound of unsaturated fatty acids in kernel, has made walnut as a strategic crop with high nutritional and medicial values in human nutrition. In the present study, carried out during years 2012 to 2015, morphological (in all years) and biochemical (in two years 2014 and 2015) characteristics of nine walnut genotypes which were selected as superior genotypes in former studied in Fars province, were investigated. Based on the results of morphological evaluations, these genotypes had high nut (13.20-19.36g) and kernel (7.13-9.52g) weight, kernel percentage (56.89-57.92%), lateral breeding (45.62-64.80%) and kernel color (light and extra light). Protein, oil and total phenol contents of kernel of the genotypes ranged from 12.58 to 19.13%, 54.83 to 70.72% and 43.26-56.63 mg GAE.g-1 DW extract, respectively. Palmitic (6.00-7.65%), stearic (1.72-3.41%), oleic (19.28-30.96%), linoleic (47.37-59.05) and linolenic (9.89-16.99%) acids were the predominant fatty acids in the walnut genotypes. Very small amount of arachidonic and erucic acids was also detected in some of the genotypes. Polyunsaturated fatty acids (PUFA) were significantly higher than monounsaturated fatty acids (MUFA). Accordingly, the highest amounts of PUFA and MUFA were observed in genotypes FaEqNs5 and FaEqHm1, respectively, and genotype FaEqDm1 had the highest amount of saturated fatty acids (SFA) and the lowest level of unsaturated fatty acid (UFA).

Aim: In current study, we aimed to reduce Cdc42 gene expression in lung carcinoma related cells, Calu-6, and assayed its effect on cell proliferation.
Material and To reduce the expression of Cdc42 gene shRNA system was used and lentiviral system was selected to deliver Cdc42 specific shRNA to Calu-6 cells. Recombinant lentiviruses produced by co-transfection of pMD2G, psPAX2 and p-GFP-C-shLenti plasmids into 293T cells using lipofectamin. Efficiency of transfection and transduction assessed by florescent microscopy. Viability of cells treated by recombinant lentiviruses assessed by MTT assay.
florescent microscopy showed 80% transfection of 293T cells and high rate of Calu-6 cells transduction. MTT assay results revealed that viability of transduced Calu-6 cells reached to %58 and %40 in compare to control and negative control cells, respectively.
recombinant lentiviruses properly transfer Cdc42-shRNA into Calu-6 cells, leading to reduction of cell proliferation. Silencing of Cdc42 gene expression using lentiviruses is persist and long-term effect which can be under attention for gene therapy of lung cancer.

Roads have an important role in plants dispersal on different scales. Various plant species settle on roadsides, but some of them can enter the natural environments and threaten their biodiversity. Worldwide knowledge of roadside flora is necessary for local and global management of natural areas. Accordingly, the roadside flora of Northern Khorasan rangelands was studied along the 600 km of 12 paved roads. Base on a stratified random sampling design, 38 sites were sampled by 100 m² rectangular quadrats stablished on both roadsides. Totally, 330 plant taxa of 39 spermatophyte families were identified and their life-forms and chorology were determined through botanical resources. The results showed that therophytes and hemicryptothytes were the dominant life-forms of roadside vegetation. The native Irano-Turanian elements were the dominant chorotype of roadside habitats. Number of endemic taxa (3.6%) was notable in comparison with cosmopolitan (1.2%) and alien (0.6%) species. Agropyron desertorum (Fisch. ex Link) Schult. and Agropyron elongatum (Host) P. Beauv. were the only two introduced alien species in the studied roadsides. Some of the cosmopolitan and pluriregional species such as Triticum aestivum L. were cultivated plants, but most of them were common weeds. Native weeds like Hordeum glaucum Steud. and Alhagi persarum Boiss. & Buhse had the highest frequency on the studied roadsides. The present study, therefore, revealed that the roadside flora in natural areas could have a considerable stock of native and endemic species which would be suitable for the revegetation of roadsides and the disturbed natural areas around the roads.

The purpose of this study was examination and comparison of the amount of mathematical errors between the students with learning disorders and normal ones at sixth grade in Lordegan City. The study was a kind of applied with descriptive- analytic survey. The statistical population were all students at sixth grade in Lordegan City (2495 normal students and 238 with learning disorders) in 1394-95. Simple random sampling was used and 50 normal students along with 40students with learning disorders were chosen to do the study. The instruments were a couple of researcher made worksheet and mathematic learning disorders questionnaire. Validity of the instruments were confirmed by 5 mental tests and learning disorders specialists. The reliability with Cronbach alpha was 0.82. T test and variance analysis were used to inferential analysis. Findings showed that there is difference between students with learning disorders and normal ones at problem solving scale and distinction of shape, 4 operation, money and time at mathematical errors. There was no significant difference between students with mathematical learning disorder (whole and subscales) with attention to demographic traits(sex, average and parental education).

Savory (Satureja khuzistanica) is one of the nine endemic species which have phenolic compounds such as carvacrole and thymol in its essential oil and rosmarinic and other phenolic acids in its extract, has strong antioxidant and antimicrobial properties and remarkable effects on several diseases. Drought stress was induced by stopping irrigation at flowering stage. Samples were taken five times with three interval days and several physiological traits were measured. For oil extraction, Clevenger apparatus was used. For determination of essential oil’s components and methanolic extract compounds, GC, GC/MS and HPTLC were utilized. Profiling of volatiles using GC/MS, showed an increasing-decreasing trend at major phenolic and terpenes compounds such as thymol, γ- Terpinene, p- Cymene, Rosmarinic acid and Caffeic acid. Drought stress also led to a significant increase in oil yield, soluble sugars and proline as well as a significant reduction in leaf water potential, relative water content and pigments. Metabolite profiling of Satureja khuzistanica represents the strategies employed by savory in generating different biochemical phenotype. Applicable results of this study for increasing product quality is effective application of drought stress before harvesting. The results verified that drought stress affected physiological characteristics and secondary metabolism of savory which were useful for future work by using metabolic engineering focusing on important species to increase main compounds, such as carvacrol and rosmarinic acid and caffeic acid.

In this research the (Fe,Ti)3Al-Al2O3 nanocomposite was synthesized via the reduction of Fe2O3 by Al during mechanical alloying (MA). For this purpose the Al, Ti and Fe2O3 powders were mixed with molar ratio of 3:1:1in a planetary ball mill. The structural and morphology of powder particles during different milling times were characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM). In order to study the thermal behavior of powder particles, Heat treatment and differential thermal analysis (DTA) were done. It was found that, the reaction of nanocomposite formation is occurred in two stages during MA. The first and second reactions were reduction of Fe2O3 by Al and (Fe,Ti)3Al formation, respectively. The crystallite size and internal strain of powder particles for Al2O3 phase after 100 h of MA, were 20 nm and 3%, respectively. Also ball milling for long time led to the reduction of Fe2O3 by Al before Al melting during DTA.

In the present study, FeAl/Al2O3 nanocomposite coating was produced on the carbon steel plate using mechanical alloying (MA) technique via a mechanochemical reaction. Stoichiometric ratios of Fe, Al and Fe2O3 as well as a substrate were mixed and milled up to 22h in a vibrating high energy mill with a 4 mm ball. Samples prepared after 18h of MA were subjected to annealing at 773 K for 1-3 h. X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and microhardness measurements were carried out to study mechanochemical reaction and coating formation characterization. The results showed that mechanochemical reactions were started after 10h of MA, which finally caused the slight formation of FeAl/Al2O3 nanocomposite. Increasing the milling time to 18 hours led to the continuous increase of the coating thickness up to 80 μm, while the coating layer fractured and began to peel by further milling. The microhardness of the coating after 18h milling was 1050 vickers. Annealing of the 18h milled powders at 773K for 3h led to the complete formation and synthesis of the FeAl/Al2O3 nanocomposite. The results showed that the annealing treatment had considerable effects on the hardness increase up to 1200 vickers as well as adhesion strength of the composite coating.

In this paper, based on the modi ed couple stress theory, the size-dependent dynamic behavior of circular rings on elastic foundation is investigated. The ring is modeled by Euler-Bernoulli and Timoshenko beam theories, and Hamilton's principle is utilized to derive the equations of motion and boundary conditions. The formulation derived is a general form of the equation of motion of circular rings and can be reduced to the classical form by eliminating the size-dependent terms. On this basis, the size-dependent natural frequencies of a circular ring are calculated based on the non-classical Euler-Bernoulli and Timoshenko beam theories. The ndings are compared with classical beam theories. Response of the micro-ring under application of static and dynamic loads is investigatedand compared with the classical theories. Results show that when the thickness of the ring is in the order of the length scale of the ring material, the natural frequencies evaluated using the modi ed couple stress are considerably more than those predicted based on the classical beam theories, while the defection and natural frequencies of the classical and non-classical beam theories approach one another for the rings with thickness much larger than the material length scale.

In this study, The Al 6061 alloy sheets were produced by Cryorolling process and then were welded by resistance spot welding method. In this regard, the solution treated Al 6061 alloy cryorolled subsequently up to 90% reduction in thickness to produce nanostructure alloy. The cryorolled sheets were then subjected to aging treatment (130˚C-30h) in order to obtain simultaneous strength and ductility. Tensile strength of 370 MPa, hardness of 135 HV, and ductility of 11 % was obtained for the nanostructured Aluminum sheets. The Cryorolled samples were then resistance spot welded with different welding parameters, including welding current 50 to 100 kA, electrode force of 2.8 kN, and welding time of 0.1 s. The most tensile shear peak load of weld spot of nanostructured samples was 5580 N. The results for different welded samples showed that the nanostructured ones, have higher weld strength when compared with 6061-T6 Aluminum alloy samples with common grain size.

Colorado potato beetle is one of the most important insect pests of potato plants. Frequently and prolonged use of chemical pesticides for controlling this pest, has caused environmental pollution, pest resistance to pesticides and destruction of natural enemies. Some herbal extracts are more degradable and relatively safer than most of the synthetic insecticides and can be used as suitable alternatives in integrated management of Colorado potato beetle. In this study, the effects of leaf extracts of Juglans regia, Sambucus ebulus, Artemisia annua, Satureja sahendica and Salvia sahendica were studied on 2nd instar larvae of Colorado potato beetle, Leptinotarsa decemlineata in laboratory conditions at 26 ± 2 °C, 55±5% RH and a photoperiod of 16:8 (L:D). Potato leaves were treated with 0.625, 1.25, 2.5, 5 and 10% concentrations of the plant extracts using leaf- dipping method. Control leaves were dipped in either methanol or distilled water only. Each treatment consisted of 20 up to 24 h old 2nd instar larvae and had three replicates. Mortality of the larvae was recorded 24, 48, 72 and 96 hours after treatment. The results showed that extracts of Juglans regia, Satureja sahendica and Artemisia annua were more toxic to 2nd instar larvae of the Colorado beetle than Salvia sahendica and Sambucus ebulus. Ninety six hours after treatment, 10% concentration of J. regia, S. sahendica and A. annua caused 93.33, 91.67 and 73.33% mortality and 5% concentration of these extracts caused 58.9, 100 and 48.2% mortality in Colorado potato beetle larvae, respectively. As expected, the mortality decreased with decreasing concentrations. According to the high mortality percent, especially in high concentrations, the extracts of these plants, can be used as potential botanicals for integrated management of Colorado potato beetle.