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Open Access Article
1 - Modifying empirical equations of seepage estimation using dimensional analysis (Boldaji earth canal, Chaharmahal and Bakhtiari province)
Ehsan Tavakoli بهزاد قربانی مهدی رادفر حسین صمدی بروجنی بیژن قهرمانThe high amounts of losses from irrigation canals have resulted in lining the conveyance canals being as an important measure in order to increase water conveyance efficiency. The economical justification of earthen canals lining requires investigating the amount of see MoreThe high amounts of losses from irrigation canals have resulted in lining the conveyance canals being as an important measure in order to increase water conveyance efficiency. The economical justification of earthen canals lining requires investigating the amount of seepage and infiltration in such canals. In this study, using a physical model and dimensional analysis, the water seepage loss from Boldaji earthen canal, Borujen city, Chaharmahal and Bakhtiari province, with loamy soil, was determined in the range of 40 to 100 liters per second flow rates. The empirical equations such as Moritz, Ingham, Molesworth and Yennidumia, Offengenden, Davis-Wilson and Indian equations were chosen for seepage estimation. Results showed that before modifying the coefficients of equations, the results of the modified Ingham have the highest correlation coefficient (0.917) with measured values. Independent variables of this method are water depth, canal length and wetted perimeter. Allocating the highest value of R2 (> 0.90) besides the lowest value of RMSE (< 3.2 liters) in comparison with measured values, after the calibration of the empirical equations for the study region and modifying their coefficients, the modified Moritz and Ingham selected as the best methods. All equations estimated the seepage loss much smaller than the measured values, which was rectified after modifying the coefficients. Utilizing dimensional analysis and transferring canal conditions to laboratory was resulted in lowering costs and less time, that according to acceptable and similar to previous studies results, it could be suggested to apply in controlled conditions of laboratory for other regions. Manuscript profile -
Open Access Article
2 - Studying the effects of two different biochars on soil water repellency
Ali Yazdanpanahi Khaled Ahmadaali salman zare Mohammad JafariWater repellency is one of the important physical properties of soil that affects the soil moisture curve, hydraulic conductivity, and so on. The aim of present study is to investigate the effects of adding natural and artificial biochars on water repellency and some ot MoreWater repellency is one of the important physical properties of soil that affects the soil moisture curve, hydraulic conductivity, and so on. The aim of present study is to investigate the effects of adding natural and artificial biochars on water repellency and some other physical and chemical properties of soil. This study was conducted in factorial design with various levels of additives (natural and waste compost biochars) in a randomized complete block design in three repetitions. The considered factors are natural biochar in four levels (0, 1, 3 and 5%) and municipal waste compost biochar in four levels (0, 1, 3 and 5%) with the total of 16 treatments. The water repellency of natural and municipal waste compost biochar was measured by means of the water drop penetration time (WDPT) test and the actual time required for infiltration ( ) was recorded for each 16 treatments. The results showed that increasing the percentage of applied biochars increased . The highest amount of belongs to treatments No. 5 and 16 were 156 and 170 s, respectively, which increased by 98 and 99 times in comparison with the control treatment. 12 of 16 treatments were classified as wet table or non-water-repellent soil, one treatment in slightly and three treatment as strongly water repellent soil. In general, it can be said that application of biochars, especially the natural biochar, in terms of water repellency does not cause any infiltration problem. Also, it can be concluded that bulk density had an average decrease rate of 4.3% and organic matter and pH had an average increase of 2.2 and 1.8 percentage respectively. Manuscript profile -
Open Access Article
3 - Verification of Water Infiltration in the Soil in the Flood Occurrence Model Using SCS Probability Distribution Equations and HEC-HMS Model
Sohrab Alizadeh Alireza Zamani Nouri Babak AminnejadBackground and Aim: One of the biggest challenges of the rainfall-runoff model is to accurately determine the rate of water infiltration into the soil as one of the parameters that determine the size and shape of the hydrographs of historical floods. The studies conduct MoreBackground and Aim: One of the biggest challenges of the rainfall-runoff model is to accurately determine the rate of water infiltration into the soil as one of the parameters that determine the size and shape of the hydrographs of historical floods. The studies conducted in different climates that show different morphometry of the earth indicate the weakness of widely used methods such as SCS-CN in determining the rate of water infiltration into the soil. For the SCS-CN method, as the soil storage index approaches infinity, the soil moisture ratio approaches 1, and this is due to the limitation of the SCS-CN method. In this research, focusing on this weakness in the basic relationships of loss calculations, and an integrated approach in determining the infiltration of water into the soil, the magnitude of the historical floods in the watershed was analyzed. The importance of this analysis can be in verifying the magnitude of floods, which is the criterion for determining structures or crisis control programs.Method: Considering that in order to solve the problem of infiltration calculations at the basin scale, and based on the new equations to determine flow losses, a homogeneous but raster criterion is needed, in this research, based on the sensitivity of the produced flow to the amount of losses in the probabilistic investigation of the index humidity and flow ratio, a depth-infiltration model was prepared from the two-dimensional comprehensive model in the range. In this study, based on the new relationships of losses determination, numerical calculations were done in the software and script environment sequentially and based on the outputs of the hydrological model. First, the HEC-HMS rainfall-runoff model structure was generated with Arc Hydro and HEC_GeoHMS extensions in Shadegan catchment. Then, infiltration parameters were determined by SMA method in the analysis of remote sensing images from the basin. In the next stage, the development of the primary continuous model, calibration and validation was done focusing on soil moisture information. After determining the soil moisture relationship based on the results of the soil wetting model, the artificial unit occurrence hydrograph was determined by determining the flood volume based on the SCS-CN and VIC combined method. Results: The general results of the implementation of the hydraulic model of the flood plain showed that the maximum inflow was equal to 3023 cubic meters per second at the 90th hour of the event, and the maximum outflow flood was at the 93rd hour with a figure of 2137 cubic meters per second. The discharge value is assumed to be 0 at the beginning of the calculations. The flow volume at the end of the calculations was equal to 141.03 million cubic meters, which is the remaining volume of 918.36 million cubic meters in the whole event. The difference between the inlet and outlet discharge was calculated as a deficiency of about 6.14%. Also, the layer of flow depth changes shows that the water level in the plain is trying to be at a possible and reasonable level by filling the lower points. So that a large part of the volume of water from the southern strip of the borders of Trava for the active area of modeling will eventually flow into the sea. However, the direction of water movement has even been estimated to be perpendicular to the direct path towards the sea in some cases. These results indicate a maximum depth of 16.4 units in some areas, with a minimum depth of 5.3 units. The important point is that in the plains, according to the cell size, definitely in some cases much lower depths can be calculated. The average depth in active cells is 11.9 meter calculated locally. These figures can change according to different rainfall events.Conclusions: The results showed that it is possible to verify the infiltration based on the new base distribution equations with a probabilistic condition in the estimation of the basin shape parameter. The amount of hydrograph calibration in response to water infiltration in soil is dependent on the correct estimation of initial soil moisture. Flow losses in large-scale watersheds are obtained more suitably based on SCS-based distribution equations. Numerical and hydrological models such as HEC-HMS or modelers such as HEC_GeoHMS are completely dependent on the DEM raw layer introduced for the purpose of upstream demarcation. Changes in land cover in flat areas can actually produce a closed border of the watershed compared to the reality of the land in different simulation models. According to the basic assumptions such as calibration coefficients, the single hydrograph method can be a good substitute for areas without rainfall-runoff statistics. The TUFLOW software model gave the best response to one-dimensional to two-dimensional flow for Shadgan plain according to the type of boundary conditions. Manuscript profile -
Open Access Article
4 - Quantitative simulation of surface and groundwater resources in Behshahr - Bandar-e-Gaz Plain Using SWAT model
behrouz mohseni kaka shahedi mahmoud habibnejhad Abdullah Darzi-NaftchaliOptimal management of water resources in a plain with land uses requires proper prediction of water resources response using efficient models. In this research, Soil and Water Assessment Tools (SWAT) model was used to simulate surface and groundwater resources in Behsha MoreOptimal management of water resources in a plain with land uses requires proper prediction of water resources response using efficient models. In this research, Soil and Water Assessment Tools (SWAT) model was used to simulate surface and groundwater resources in Behshahr - Bandar-e-Gaz Plain. After analysis the sensitivity, calibration and validation of the model was performed based on river flow data of 2007- 2013 and 2014- 2017, respectively. Groundwater table simulation was done by simulating the recharge rate per hydrological response unit (HRU). The results of sensitivity analysis showed that the parameters GW_REVAP, GW_DELAY, SHALLST, DEEPST, RCHRG_ DP, ALPHA_BF, SOL_AWC, CN, HRU_SLP, ESCO, USLE_P, OV_N, FILTERW and EPCO were the most sensitive parameters. In order to evaluate of the model, the performance criteria of Nash- Sutcliffe (NS) and Correlation coefficient (R2) were used. In the calibration stage, these coefficients ranged from 0.56 to 0.93 and 0.74 to 1.00, respectively, and in the validation process were in the range of 0.56 to 0.84 and 0.66 to 0.92, respectively, indicating the acceptable accuracy of the model in river flow simulation. Comparing the observed and simulated water table depths, NS (0.81) and R2 (0.91) coefficients indicated the capability of the model to simulate groundwater level. According to the results of the water balance analysis, the most of the total water input to the plain, it’s 60% was used for evapotranspiration and it’s small parts as 18% and 22% allocetaed to surface runoff and infiltration, respectively. Manuscript profile -
Open Access Article
5 - Analysis and assessing effectability of runoff components from different levels of polyacrylamide
Zeinab Hazbavi Seyed Hamid Reza Sadeghi Habibollah YounesiThis study was performed to investigate the effect of Polyacrylamide (PAM) on pattern of variation of runoff components consist of the amount of runoff during rainfall, cumulative runoff, the runoff commencement and cessation time and runoff amount at different time ste MoreThis study was performed to investigate the effect of Polyacrylamide (PAM) on pattern of variation of runoff components consist of the amount of runoff during rainfall, cumulative runoff, the runoff commencement and cessation time and runoff amount at different time steps. The experiments were taken place in Soil Erosion and Rainfall Simulation Laboratory. In this study, three small cubic plots with dimensions of 0.5 m, total volume of 0.125 m3 and having 20% slope were used. The conducted experimental treatments were consisted of 0 (control), 0.4, 0.6, 1, 2, 3, 4 and 6 g PAM/m2. The results indicated that the PAM-treated plots had no significant reducing influence on runoff amounts (P=0.49). The reduction of runoff amount at different levels of PAM had also no specific trends. In addition, the maximum reduction in total runoff occurred in treatments 2, 6 and 1 g PAM/m2, respectively. The runoff commencement time was increased by increasing the amount of PAM to 2 g/m2 and runoff cessation time was decreased due to increasing amount of PAM level to 1 g m-2, respectively. The assessment of runoff amount in common time steps of different treatments also revealed that the different amount of PAMs had no significant effect (P > 0.12) on runoff control in all steps except the first and third time steps. Manuscript profile -
Open Access Article
6 - Evaluation and determination of filtration models parameters in Oshtorinan plain
Leila Goodarzi Ali Mohammad Akhond Ali Heidar ZareiUsing infiltration models for modeling surface and subsurface flow as well as designing and evaluation of irrigation systems is necessary. Since the parameters used in these equations are highly dependent onthe soil types and surface conditions, field tests is a ne MoreUsing infiltration models for modeling surface and subsurface flow as well as designing and evaluation of irrigation systems is necessary. Since the parameters used in these equations are highly dependent onthe soil types and surface conditions, field tests is a necessary tool for determination of these parameters. Several infiltration models have been proposed for this purpose that are mostly empirical, semi-empirical or theoretical in nature. In order to select an appropriate model for various field conditions, field tests are required. In this study, several empirical infiltration models were compared with one another and with the Philip exact infiltration equation which was obtained by simplifying the numerical solution of general flow equation in porous media. Required data for selecting appropriate model were taken from Oshtorinan plain, Lorestan, Iran to predict cumulative infiltration values. In this area surface soils are dominantly clay. Infiltration tests were conducted in three locations with clay texture, using double rings infiltrometers. Parameters of four infiltration models (Kostiakov,SCS, Philip, Kostiakov-Lowis) were determined. Model evaluation was performed by comparing relative error. The results of this analysis indicated that the Kostiakov model with a mean relative error of 0.8 was the most appropriate model for estimating cumulative infiltration in the studied area. Manuscript profile -
Open Access Article
7 - Effect of land abandonment on variation of soil water infiltration parameters
Amir Masoud Ghaiumi Mohamadi Shoja Ghorbani Dashtaki Faez Raiesi Pezhman TahmasbiInfiltration parameters are the most important indicators of soil quality. Soil water infiltration is one of the key properties for designing irrigation systems, hydrological studies, water resources management, drainage projects and soil conservation practices in water MoreInfiltration parameters are the most important indicators of soil quality. Soil water infiltration is one of the key properties for designing irrigation systems, hydrological studies, water resources management, drainage projects and soil conservation practices in watershed scale. The objective of this study was to investigate the effect of land abandonment on infiltration parameters in semi-stepped rangelands located in Karsanak, Chahar Mahal va Bakhtiari province, Iran. For this purpose, five types of land uses including pasture, agriculture, 3-5, 10-15 and 25 years-long abandonment were selected and the infiltrated water was measured in six replicates by tension infiltrometer apparatus. The results indicated that land use changing led to reduce soil organic matters, soil aggregate stability, soil pores connectivity and to disarranging soil natural pores. Consequently, the negative and significant effect of land use changing on parameters of water infiltration was deduced. Average saturated hydraulic conductivity in pastures (7.4 mm/h) was almost twice of that for agricultural land use (4.4 mm/h). In addition, the sorptivity experienced 30 percent reductions in agricultural lands compared to pastures. However, because of the land abandonment i.e. restoration of vegetation and macro aggregate formation and increasing aggregates stability, the infiltration process was improved such that saturated hydraulic conductivity of the 25 years-long abandonment improved from 4.38 to 6.09 mm/h. Manuscript profile -
Open Access Article
8 - The Effect of Sowbug (Hemilepistus shirazi Schuttz) on Soil Infiltrability in a Floodwater Spreading Systems of Gareh Baygone Plain
Gholamreza Rahbar Ataollah Kavian Ahang Kowsar Mahmood Habibnejad Rooshan Kaka ShahediBackground and Objective: Artificial recharge of groundwaterthrough floodwater spreading is an approved method for improvement of groundwater resources. The appearance of sowbug to floodwater spreading system of Gareh Baygon Plain has been changed physic-chemical proper MoreBackground and Objective: Artificial recharge of groundwaterthrough floodwater spreading is an approved method for improvement of groundwater resources. The appearance of sowbug to floodwater spreading system of Gareh Baygon Plain has been changed physic-chemical properties of soil. The main objective of this research is to evaluate soil infiltration rate with activity of sowbugs. Method:This study has been conducted in Kowsar aquifer management of Gareh Bygone plain. One of the floodwater spreading systems named Bisheh Zard1 was selected. This system has 6 sedimentation basins. The second sedimentation basin was chosen and divided to 11 plots. Infiltrability of 11 paired plots was determined utilizing the double ring method. Findings: Results showed that the appearance of sowbug that make hols with 7 milimeter and average one meter depth improve the soil physical properties and enhance the infiltration rate about 7.2 centimetres per hours and showed a significant difference at the 1 % level. The burrowing macro fauna, including the sowbug, form channels that facilitate accelerated flow of water towards the aquifer. Discussion and Conculation: This study approved that sowbug has a great effect on infiltration water to crusted soil that occurs by floodwater spreading. Sowbugs burrows have a marked effect on surface infiltration of water through the soil. The present research state that sowbug can be as useful agent for controlling of crusted soil from fine clay in sedimentation basinsform channels that facilitate accelerated flow of water towards the aquifer and increase the life time of floodwater spreading systems after 30 years and Gareh Bygone Plain desert has been changed to a evergreen forest. Manuscript profile -
Open Access Article
9 - Evaluation of temporal-spatial variations of soil moisture balance by Thorenthwaite Matter method (Case study: Behesht Abad basin)
Elham Davoodi Hoda Ghasemieh Khodayar Abdollahi Okke BatelaanFor the sustainable management of water resources, it is necessary to determine the water balance and its components for the correct use of water. In this study, to obtain a general overview of the water balance and its components, the soil moisture balance was calculat MoreFor the sustainable management of water resources, it is necessary to determine the water balance and its components for the correct use of water. In this study, to obtain a general overview of the water balance and its components, the soil moisture balance was calculated using the Thorenthwaite Matter model in the Behesht Abad basin during 2003-2015. Distribution maps, including rainfall, temperature, actual and potential evapotranspiration, soil moisture, infiltration, surface runoff and leaf area index were prepared. The results showed that in spatial distribution, in spring and summer, the highest (8.98 mm) and the lowest runoff occurs at the altitudes and in the basin outlet, and in autumn and winter, the highest (46.72 mm) and the lowest runoff occurs at the outlet and in the altitudes, respectively. The correlation coefficient between observed and simulated surface runoff is 53%. The amount of infiltration decreases during dry months, the highest infiltration (range from 16 to 31 mm) has occurred in the range of sandy loam and clay loam textures and in agricultural areas and rangeland with good and medium coverage. In terms of spatial distribution, agriculture land and good and medium rangeland have more actual evapotranspiration, which often consistent with regions have the highest leaf area index. In general, the results of this research can be useful in identifying the soil moisture condition and various aspects of this complex system and also watershed management. Manuscript profile -
Open Access Article
10 - The Effect of Different Ratios Municipal Wastewater Applied in Irrigation Water on Some Physical and Chemical Properties of Soil
Alireza Ameri Najme YazdanpanahThe aim of this study was to investigate the effects of using different combinations of waste water and well water with the approach of using unconventional water on some physical and chemical properties of soil. For this purpose، a factorial experiment was conducted in MoreThe aim of this study was to investigate the effects of using different combinations of waste water and well water with the approach of using unconventional water on some physical and chemical properties of soil. For this purpose، a factorial experiment was conducted in a completely randomized design with three factors. The main factors include irrigation with waste water to well water ratio in 5 levels including I1 (control: irrigation with well water)، I2 (75% well water and 25% waste water)، I3 (50% well water and 50% waste water)، I4 (25% well water and 75% waste water) and I5 (irrigation with 100% waste water)، the second factor includes two soil depths (0-30 and 30-60 cm) and the third factor includes the duration of irrigation in 5 levels (zero، 1، 2، 3 and 4 months). The results showed that soil salinity، pH and organic carbon increased with increasing irrigation time. The highest increase in salinity was observed after 4 months in I5 treatment with about 37% increase compared to the control treatment. The amount of organic carbon in treatments I4 and I5 in the surface layer increased by about 60% compared to the subsurface layer. However، waste water consumption improved hydraulic conductivity compared to well water، so that its amount increased in I5 treatment، at surface and subsurface depth by 76.7% and 80%، respectively، compared to the control treatment. The findings of this study showed that the use of treated wastewater as one of the unconventional water sources، despite increasing soil salinity، can increase organic carbon and improve soil permeability. Manuscript profile -
Open Access Article
11 - Influence of Different Types and Amounts of Organic Manure on Soil Physical Properties, Wheat (Triticum aestivum L.) Yield and Correlation between Traits
Mohiaddin Goosheh Mohammad Khayat -
Open Access Article
12 - مقایسه روشهای یک نقطهای و دو نقطهای در برآورد پارامترهای نفوذ در آبیاری جویچهای
جواد جعفری فرشید تاران رضا دلیر حسن نیا امیر حسین ناظمینفوذ یکی از مهم­ترین پارامترهای هیدرولیکی مؤثر در آبیاری سطحی و از مشکل­ترین پارامترهای قابل تعیین در مزرعه می­باشد. معادلات نفوذ در تشریح هیدرولیک جریان و طراحی سیستم­های آبیاری سطحی به کار می­روند. اما تعیین پارامترهای این معادلات مستلزم وقت و هزین Moreنفوذ یکی از مهم­ترین پارامترهای هیدرولیکی مؤثر در آبیاری سطحی و از مشکل­ترین پارامترهای قابل تعیین در مزرعه می­باشد. معادلات نفوذ در تشریح هیدرولیک جریان و طراحی سیستم­های آبیاری سطحی به کار می­روند. اما تعیین پارامترهای این معادلات مستلزم وقت و هزینه زیادی است و به این منظور معمولاً از روش­های تخمین این پارامترها استفاده می­شود. در این مطالعه برای به دست آوردن پارامترهای معادله نفوذ از سه روش ورودی-خروجی به عنوان مبنا و روش­های یک نقطه­ای شپارد و همکاران و دو نقطه­ای الیوت و واکر استفاده شد و دقت دو روش یک نقطه­ای شپارد و همکاران و دو نقطه ای الیوت و واکر در تخمین حجم آب نفوذ یافته ارزیابی گردید. به این منظور از داده­های مربوط به دو مزرعه­C1201 و E201 کشت و صنعت هفت تپه با سیستم آبیاری جویچه­ای و در شرایط مختلف مزرعه­ای با طول و دبی­های ورودی متفاوت استفاده شد. نتایج نشان داد که روش دو نقطه­ای الیوت و واکر در تخمین نفوذ تجمعی با خطای نسبی 08/8 درصد برای مزرعه C1201 و خطای نسبی 85/12 درصد برای مزرعه E201 دارای دقت بیشتری نسبت به روش یک نقطه­ای شپارد و همکاران بود. همچنین این روش در تعیین مرحله پیشروی با خطای نسبی 03/4 درصد برای مزرعه C1201 و 41/6 درصد برای مزرعه E201 دارای بیشترین دقت بود. Manuscript profile -
Open Access Article
13 - Comparison of the Efficiency of Some Soil Infiltration Models Based on the Data Obtained from Double Rings in Different Land Uses (Case Study: Mikhsaz Watershed) (Case Study: Mikhsaz Watershed)
Raziyeh Kojouri mohammad reza javadiThe process of water infiltration into the soil plays a very important role in the water cycle in nature. The importance of this phenomenon has led many researchers to focus their studies in this regard. So that, they can estimate it by providing a suitable model. Since MoreThe process of water infiltration into the soil plays a very important role in the water cycle in nature. The importance of this phenomenon has led many researchers to focus their studies in this regard. So that, they can estimate it by providing a suitable model. Since, conducting infiltration studies in the field is costly and requires a lot of times, therefore, different models are used to estimate the amount of infiltration, and each of these models shows a good fit with experimental data in certain conditions. In the present research, At first, infiltration was measured using the method of double rings in forest, Rangeland and agricultural, land uses. Then, the data of infiltration values obtained from Kostiakov, Horton, Green-Ampt, American soil conservation service(SCS) and Phillip models were evaluated using Nash-Sutcliff adequacy index, explanation index and average error criterion in order to determine the most suitable infiltration estimation model. The results showed that in agricultural land use; American soil conservation service(SCS) model (with average R2=0.890, ME=1.8 and NSE=0.805), in rangeland use; American soil conservation service(SCS) model (with an average of R2=0.927, ME=0.837 and NSE=0.936) and in forest land use, the Philip model (with an average of R2=0.991, ME=0.946 and NSE =0.893) were introduced as the most suitable model in determining the estimation of Infiltration values. Manuscript profile -
Open Access Article
14 - Studying the Relationship between Environmental Factors, Runoff Characteristics and Infiltration Depth Using Rainfall Simulator in Northwestern Rangelands of Iran
Sedigheh Mohamadi -
Open Access Article
15 - Infilterability Reduction of Artificial Recharge of Groundwater System in a Desert in the Absence of Sowbugs
Gholamreza Rahbar Ataollah Kavian Mahmoud Habibnejad Rooshan Ahang Kowsar Kaka Shahedi -
Open Access Article
16 - Changes in Soil Properties by Harvester Ant's Activity (Messor spp.) in Roodshoor Steppe Rangeland of Saveh, Iran
Mahsa Ghobadi Mohammad Mahdavi DONAT AGOSTI -
Open Access Article
17 - Comparison of Ecological Patches' Potentials and Functions in Rangeland Ecosystems (Case Study: Qahavand Rangelands, Hamedan Province, Iran)
Reza Kavandi Habib Gholamali Heshmati Hamid Siroosi -
Open Access Article
18 - Production of porous TiC preform by the gel casting process in order to synthesize Ti3SiC2 MAX phase via infiltration of preform
حمزه فراتی راد hamidreza baharvandi mohamad maragheThe ternary compound Ti3SiC2 is a representative of materials that exhibit both metals and ceramics characteristics. Similar to metals, this compound is electrical and thermal conductive material, not susceptible to thermal shock and shows plastic properties at high tem MoreThe ternary compound Ti3SiC2 is a representative of materials that exhibit both metals and ceramics characteristics. Similar to metals, this compound is electrical and thermal conductive material, not susceptible to thermal shock and shows plastic properties at high temperature. When considering as a ceramic, it is elastically rigid, lightweight, creep and fatigue resistant and maintains their strengths to high temperatures. In this paper, T3SiC2 bulks have been synthesized by infiltrating Si liquid into porous TiC preforms. High-purity TiC and Si powders with molar ratios of 3TiC:(1 + x)Si (where x = 0.30, 0.50, 1.00) were used as starting powders. Silicon pellets were placed at the top of the precursor pellets as a liquid source. The phase formation and microstructure were investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM) equipped with energy dispersive spectroscopy (EDS) system. The results demonstrated that the 50 percent extra silicon results to formation of Ti3SiC2 with 92 wt.% purity. The conditions are favorable for the formation of the SiC secondary phase with increasing the amount of extra silicon to 100 percent. Also, an increase in the amount of extra silicon leads to the formation of Ti3SiC2 with the columnar morphology. Manuscript profile -
Open Access Article
19 - Effect of activated carbon additive on microstructure and phase composition of reaction bonded boron carbide ceramic
Ahmad bayat Omid Mirzaee Hamidreza BaharvandiAbstract Boron carbide is highly regarded because of many properties such as high hardness, high Young’s modulus, low density and etc. however, application of B4C is rather limited due to difficulties in densification and low fracture toughness. In this research, MoreAbstract Boron carbide is highly regarded because of many properties such as high hardness, high Young’s modulus, low density and etc. however, application of B4C is rather limited due to difficulties in densification and low fracture toughness. In this research, uniaxial press at constant pressure of 140 MPa was applied to fabrication of boron carbide porous preforms. B4C powder with size of 43µm, activated carbon with the amount of 0,5,10 Wt.% and phenolic resin powder as a binder and Porosity-causing agent with the amount of 9 Wt.%, were used as raw materials. Infiltration operation with molten silicon had performed in vacuum furnace in temperature 1600 °C. β-SiC phase produced from silicon and carbon that caused the volume density and strength properties of specimens during infiltration process. Residual silicon was decreased from 35%.vol to 18 vol.% with increasing activated carbon contents, on the contrary, secondary silicon carbide had increasing continuously from 10%.vol to 2 vol.%. Decreasing in residual silicon and increasing in β-SiC phase determined by Image analysis software. Manuscript profile -
Open Access Article
20 - The effect of pressure on the Mg alloy-Alumina composite properties fabricated by infiltration casting
Bahman Eghtedari Mahmoud Meratian Ali Maleki Mohamad KhodaeiOne of the advanced routes for manufacturing the magnesium-matrix composites is infiltration casting into ceramic foams. In this research, magnesium-matrix composite AZ91-Al2O3 production has been investigated. Therefore, AZ91 alloy molten is prepared by usage of torch MoreOne of the advanced routes for manufacturing the magnesium-matrix composites is infiltration casting into ceramic foams. In this research, magnesium-matrix composite AZ91-Al2O3 production has been investigated. Therefore, AZ91 alloy molten is prepared by usage of torch furnace under protection of MAGREX flux, then, poured in preheated mold at 250°C with preheated alumina foam at 800 °C. For investigating the effect of pressure, pressures at 50, 75 and 100 MPa in 1 minute applied until solidification was completed. For comparison, similar experiments were done without applying pressure. The results showed that solidification under pressure reduced porosity noticeably in comparison with gravity casting to 60%. By addition the ceramic reinforcement to the base alloy, mechanical strength reduced due to formation of MgAl2O4 spinel phase at interface and formation of residual compression stresses because of thermal mismatch between matrix and reinforcement. The mechanical strength and ductility of the samples are increased by rising of applied pressure to (0-100 MPa) due to decrease grain size and better strength interface of alumina and alloy. Additionally, wear rate due of composite decreased in comparison to base alloy declined markedly (about 53%). This may be due to higher intrinsic alumina strength. Also, by applying pressure on molten metal during solidification, wear rate is noticeably lesser than similar gravity sample due to decreasing the grain size and markedly declining the porosity. The dominant mechanism for base alloy is adhesive wear and for composite is abrasive wear and delamination. Manuscript profile -
Open Access Article
21 - The Effects of Tillage Methods on Infiltration and Water Application Efficiency
ابوالفضل ناصری منصوره مظفّريInfiltration and water application efficiency are important parameters in the design and evaluation of irrigation systems, which are affected by agronomic management such as tillage practices. Present study was conducted with the main objective of investigation of tilla MoreInfiltration and water application efficiency are important parameters in the design and evaluation of irrigation systems, which are affected by agronomic management such as tillage practices. Present study was conducted with the main objective of investigation of tillage methods effects on cumulative infiltration and water application efficiency in a wheat farm at the E. Azarbaijan Research Center for Agricultural and Natural Resources ( Khosroshahr ). The experiment treatments were no-tillage, tillage by chisel plow and disc, low tillage and tillage with moldboard plow with disc. Soil infiltration was measured by the ring and water application efficiency determined for studying conditions. Results showed that tillage methods produced different cumulative infiltrations. The cumulative infiltration from low tillage, no-tillage and tillage with moldboard plow were 62, 20 and 10% of cumulative infiltration from chisel plow. Water application efficiencies from chisel plow tillage were less than 55% and efficiencies from no-tillage by moldboard plow were 55% and 68% respectively. Manuscript profile -
Open Access Article
22 - Effect of aeration and topdressing on quantitative and qualitative traits of Lolium grass
Mahboubeh Ghazali Mohammad Reza Nouri Abouzar RahmatiTraffic and over irrigation cause to compress soil in lawn area. Soil compaction considered is undesirable because it reduces hydraulic conductivity and water infiltration and increase evaporation in soil surface. The foctorial experiment was conducted to evaluate effec MoreTraffic and over irrigation cause to compress soil in lawn area. Soil compaction considered is undesirable because it reduces hydraulic conductivity and water infiltration and increase evaporation in soil surface. The foctorial experiment was conducted to evaluate effect of aereation (punching 1 cm diameter holles on the surface in a regular grid pattern) and topdressing techniques on lolium grass.We initialed aeration in 3 level (5×5, 10×5 cm spacing and no aeration) and 2 level topdressing (with topdressing and without topdressing) with sand and compost were performed to investigate their influence on grow of luliom lawn in the city of Isfahan in june 2010. Height and weight of grass, rate of leaf color and leaf density were measured in 3 times 10, 70 and 130 days after aeration and topdressing. Results show that weight, height and color of lawn leaf significantly greater with topdressing. The aeration with 10×5 cm spacing with topdressing was highest infiltration, in addition, weight, height and color of the lawn leaves rate increased compared to control treatment. The results can be advised for maintaining acceptable weight, height and color grass leaves is sufficient. lawn Aeration only, recommended in flood area to control runoff and further intake to soil. Manuscript profile
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