alireza majidi | Ferdowsi University of Mashhad (original) (raw)

Papers by alireza majidi

Research paper thumbnail of Estimating compaction parameters of marl soils using multi-layer

Journal of the Balkan Tribological Association, Jun 12, 2014

The compaction parameters of fine-grained soils, maximum dry density (MDD) and optimum moisture c... more The compaction parameters of fine-grained soils, maximum dry density (MDD) and optimum moisture content (OMC) are fundamental data required for the design, construction and choosing construction materials. This paper presents two multi-layer perceptron (MLP) artificial neural network (ANN) models to estimate the MDD and OMC of marl soils. Marl soil is a fine-grained soil. The Levenberg-Marquadt learning algorithm was used to train the networks. Existing models estimate soil compaction parameters based on physical and soil index parameters. The present study considers the effects of chemical factors on the behavior and characteristics of fine-grained soils along with the common soil index parameters. The model used test results from 60 marl soil samples taken from marl formations in the Neogene basin in central Iran. The models were designed to use different input data sets and structures to determine which soil properties and ANN structures correlate well with the compaction parameters. Electrical conductivity (EC) of saturated soil was a new input parameter used in addition to the physical and soil index parameters that include the Atterberg limit, and the activity and content of the clay, silt and sand. The results show that inclusion of EC improved the accuracy of the models.

Research paper thumbnail of Exploitation Management of Underground Dams by Using Mathematical Models of Finite Difference in GMS7.1 (The Case Study of Sanganeh Underground Dam-Iran)

Being located in an arid and semi-arid climate, the scarcity of surface water, and the growing po... more Being located in an arid and semi-arid climate, the scarcity of surface water, and the growing population have caused the use of underground dams for storing groundwater to flourish in Iran over the last 10 years. So that at the moment, several underground dams have been built in different areas in Iran. One of the most important issues about underground dams and any hydraulic structure in general that is built for storing water, is exploitation management. Thus in this research, by applying mathematical modeling process, first through basic studies, conceptual model of underground dams in GMS7.1 software was created by the help of vector and raster data produced by GIS software. In the next step, after determining model networks, boundary conditions, and the necessary data input such as hydrodynamic coefficients of underground dam reservoir and recharge and discharge rates, the model was applied by the use of Modflow module in GMS7.1 software. Then, considering the observed well an...

Research paper thumbnail of Estimating sediment yield from a forest road network by using a sediment prediction model and GIS techniques

Building and Environment, 2008

Research paper thumbnail of Exploitation Management of Underground Dams by Using Mathematical Models of Finite Difference in GMS7.1 (The Case Study of Sanganeh Underground Dam-Iran

Textroad, 2012

Being located in an arid and semi-arid climate, the scarcity of surface water, and the growing po... more Being located in an arid and semi-arid climate, the scarcity of surface water, and the growing population have caused the use of underground dams for storing groundwater to flourish in Iran over the last 10 years. So that at the moment, several underground dams have been built in different areas in Iran. One of the most important issues about underground dams and any hydraulic structure in general that is built for storing water, is exploitation management. Thus in this research, by applying mathematical modeling process, first through basic studies, conceptual model of underground dams in GMS7.1 software was created by the help of vector and raster data produced by GIS software. In the next step, after determining model networks, boundary conditions, and the necessary data input such as hydrodynamic coefficients of underground dam reservoir and recharge and discharge rates, the model was applied by the use of Modflow module in GMS7.1 software. Then, considering the observed well and comparison of the conclusions from water level resulting from the model and observed figures, calibration step of the model was done. After preparing the calibrated model, the authenticity of the model's data was assessed and after verifying the accuracy of the model's results, through applying 4 scenarios, groundwater level changes in the underground dam reservoir was investigated for exploitation management. In the 1 to 3 scenarios by assuming the change in the recharge rate due to rainfall at the predicted time, the maximum operational rate, permitted from the existing operational well in the reservoir, was suggested. In the fourth scenario, the appropriate place for building other operational wells whose maximum exploitation rate permitted is more appropriate than other areas of reservoir, was suggested.

Research paper thumbnail of Is there any relationship between food habits in the last two decades and gastric cancer in North-Western Iran?

Asian Pacific journal of cancer prevention : APJCP, 2015

The aims of this case-control study were to assess the correlation between some food habits in th... more The aims of this case-control study were to assess the correlation between some food habits in the last two decades and gastric cancer in East Azerbaijan of Iran. In this hospital based case control study, 616 patients (212 gastric cancer patients, 404 cancer free patients) were recruited. Food habits of patients over the past two decades were assessed with a structured questionnaire. We used conditional logistic regression analysis for estimating crude and adjusted odds ratios (OR) and their respective 95% confidence intervals (95%CI). In this study, over-eating, consumption of high fat milk and yogurt and especial types of cheese increased the risk of gastric cancer (All<0.05). Consumption of such especial cheeses such as Koze and Khiki increased the risk of gastric cancer by 12.6 fold (95% CI:1.99-79.36) and 7.36 fold (95% CI:1.33- 40.54), respectively. In addition, high fat food, moldy food, and pickled vegetables consumption as well as reuse of cooking oil for frying were si...

Research paper thumbnail of Exploitation Management of Underground Dams by Using Mathematical Models of Finite Difference in GMS7.1 (The Case Study of Sanganeh Underground Dam-Iran

Textroad, Jul 10, 2012

Being located in an arid and semi-arid climate, the scarcity of surface water, and the growing po... more Being located in an arid and semi-arid climate, the scarcity of surface water, and the growing population have caused the use of underground dams for storing groundwater to flourish in Iran over the last 10 years. So that at the moment, several underground dams have been built in different areas in Iran. One of the most important issues about underground dams and any hydraulic structure in general that is built for storing water, is exploitation management. Thus in this research, by applying mathematical modeling process, first through basic studies, conceptual model of underground dams in GMS7.1 software was created by the help of vector and raster data produced by GIS software. In the next step, after determining model networks, boundary conditions, and the necessary data input such as hydrodynamic coefficients of underground dam reservoir and recharge and discharge rates, the model was applied by the use of Modflow module in GMS7.1 software. Then, considering the observed well and comparison of the conclusions from water level resulting from the model and observed figures, calibration step of the model was done. After preparing the calibrated model, the authenticity of the model's data was assessed and after verifying the accuracy of the model's results, through applying 4 scenarios, groundwater level changes in the underground dam reservoir was investigated for exploitation management. In the 1 to 3 scenarios by assuming the change in the recharge rate due to rainfall at the predicted time, the maximum operational rate, permitted from the existing operational well in the reservoir, was suggested. In the fourth scenario, the appropriate place for building other operational wells whose maximum exploitation rate permitted is more appropriate than other areas of reservoir, was suggested.

Research paper thumbnail of Estimating compaction parameters of marl soils using multi-layer

Journal of the Balkan Tribological Association, Jun 12, 2014

The compaction parameters of fine-grained soils, maximum dry density (MDD) and optimum moisture c... more The compaction parameters of fine-grained soils, maximum dry density (MDD) and optimum moisture content (OMC) are fundamental data required for the design, construction and choosing construction materials. This paper presents two multi-layer perceptron (MLP) artificial neural network (ANN) models to estimate the MDD and OMC of marl soils. Marl soil is a fine-grained soil. The Levenberg-Marquadt learning algorithm was used to train the networks. Existing models estimate soil compaction parameters based on physical and soil index parameters. The present study considers the effects of chemical factors on the behavior and characteristics of fine-grained soils along with the common soil index parameters. The model used test results from 60 marl soil samples taken from marl formations in the Neogene basin in central Iran. The models were designed to use different input data sets and structures to determine which soil properties and ANN structures correlate well with the compaction parameters. Electrical conductivity (EC) of saturated soil was a new input parameter used in addition to the physical and soil index parameters that include the Atterberg limit, and the activity and content of the clay, silt and sand. The results show that inclusion of EC improved the accuracy of the models.

Research paper thumbnail of Exploitation Management of Underground Dams by Using Mathematical Models of Finite Difference in GMS7.1 (The Case Study of Sanganeh Underground Dam-Iran)

Being located in an arid and semi-arid climate, the scarcity of surface water, and the growing po... more Being located in an arid and semi-arid climate, the scarcity of surface water, and the growing population have caused the use of underground dams for storing groundwater to flourish in Iran over the last 10 years. So that at the moment, several underground dams have been built in different areas in Iran. One of the most important issues about underground dams and any hydraulic structure in general that is built for storing water, is exploitation management. Thus in this research, by applying mathematical modeling process, first through basic studies, conceptual model of underground dams in GMS7.1 software was created by the help of vector and raster data produced by GIS software. In the next step, after determining model networks, boundary conditions, and the necessary data input such as hydrodynamic coefficients of underground dam reservoir and recharge and discharge rates, the model was applied by the use of Modflow module in GMS7.1 software. Then, considering the observed well an...

Research paper thumbnail of Estimating sediment yield from a forest road network by using a sediment prediction model and GIS techniques

Building and Environment, 2008

Research paper thumbnail of Exploitation Management of Underground Dams by Using Mathematical Models of Finite Difference in GMS7.1 (The Case Study of Sanganeh Underground Dam-Iran

Textroad, 2012

Being located in an arid and semi-arid climate, the scarcity of surface water, and the growing po... more Being located in an arid and semi-arid climate, the scarcity of surface water, and the growing population have caused the use of underground dams for storing groundwater to flourish in Iran over the last 10 years. So that at the moment, several underground dams have been built in different areas in Iran. One of the most important issues about underground dams and any hydraulic structure in general that is built for storing water, is exploitation management. Thus in this research, by applying mathematical modeling process, first through basic studies, conceptual model of underground dams in GMS7.1 software was created by the help of vector and raster data produced by GIS software. In the next step, after determining model networks, boundary conditions, and the necessary data input such as hydrodynamic coefficients of underground dam reservoir and recharge and discharge rates, the model was applied by the use of Modflow module in GMS7.1 software. Then, considering the observed well and comparison of the conclusions from water level resulting from the model and observed figures, calibration step of the model was done. After preparing the calibrated model, the authenticity of the model's data was assessed and after verifying the accuracy of the model's results, through applying 4 scenarios, groundwater level changes in the underground dam reservoir was investigated for exploitation management. In the 1 to 3 scenarios by assuming the change in the recharge rate due to rainfall at the predicted time, the maximum operational rate, permitted from the existing operational well in the reservoir, was suggested. In the fourth scenario, the appropriate place for building other operational wells whose maximum exploitation rate permitted is more appropriate than other areas of reservoir, was suggested.

Research paper thumbnail of Is there any relationship between food habits in the last two decades and gastric cancer in North-Western Iran?

Asian Pacific journal of cancer prevention : APJCP, 2015

The aims of this case-control study were to assess the correlation between some food habits in th... more The aims of this case-control study were to assess the correlation between some food habits in the last two decades and gastric cancer in East Azerbaijan of Iran. In this hospital based case control study, 616 patients (212 gastric cancer patients, 404 cancer free patients) were recruited. Food habits of patients over the past two decades were assessed with a structured questionnaire. We used conditional logistic regression analysis for estimating crude and adjusted odds ratios (OR) and their respective 95% confidence intervals (95%CI). In this study, over-eating, consumption of high fat milk and yogurt and especial types of cheese increased the risk of gastric cancer (All<0.05). Consumption of such especial cheeses such as Koze and Khiki increased the risk of gastric cancer by 12.6 fold (95% CI:1.99-79.36) and 7.36 fold (95% CI:1.33- 40.54), respectively. In addition, high fat food, moldy food, and pickled vegetables consumption as well as reuse of cooking oil for frying were si...

Research paper thumbnail of Exploitation Management of Underground Dams by Using Mathematical Models of Finite Difference in GMS7.1 (The Case Study of Sanganeh Underground Dam-Iran

Textroad, Jul 10, 2012

Being located in an arid and semi-arid climate, the scarcity of surface water, and the growing po... more Being located in an arid and semi-arid climate, the scarcity of surface water, and the growing population have caused the use of underground dams for storing groundwater to flourish in Iran over the last 10 years. So that at the moment, several underground dams have been built in different areas in Iran. One of the most important issues about underground dams and any hydraulic structure in general that is built for storing water, is exploitation management. Thus in this research, by applying mathematical modeling process, first through basic studies, conceptual model of underground dams in GMS7.1 software was created by the help of vector and raster data produced by GIS software. In the next step, after determining model networks, boundary conditions, and the necessary data input such as hydrodynamic coefficients of underground dam reservoir and recharge and discharge rates, the model was applied by the use of Modflow module in GMS7.1 software. Then, considering the observed well and comparison of the conclusions from water level resulting from the model and observed figures, calibration step of the model was done. After preparing the calibrated model, the authenticity of the model's data was assessed and after verifying the accuracy of the model's results, through applying 4 scenarios, groundwater level changes in the underground dam reservoir was investigated for exploitation management. In the 1 to 3 scenarios by assuming the change in the recharge rate due to rainfall at the predicted time, the maximum operational rate, permitted from the existing operational well in the reservoir, was suggested. In the fourth scenario, the appropriate place for building other operational wells whose maximum exploitation rate permitted is more appropriate than other areas of reservoir, was suggested.