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| 1 | Soil fixation and erosion control by Haloxylon persicum roots in arid lands, Iran显示文摘Vegetation roots contribute to soil fixation and reinforcement, thus improving soil resistance against erosion. Generally, the amount of soil fixation presented by roots mainly depends on root density and tensile strength. In the present study, we conducted the research in order to further understand the biotechnical properties of Haloxylon persicum and also to quantify its role in increasing soil cohesion in arid lands of Iran. Ten H. persicum shrubs were randomly selected for root distribution and strength investigations, in which five samples were set on flat terrain and other five samples on a moderate slope terrain. The profile trench method was used to assess the root area ratio(RAR) as the index of root density and distribution. Two profiles were dug around each sample, up and downslope for sloped treatment and north and south sides for flat treatment. The results showed that RAR increased with increasing soil depth and significantly decreased in 40–50 cm layers of downhill(0.320%) and 50–60 cm for uphill(0.210%). The minimum values for the northward and southward profiles were 0.003% and 0.003%, respectively, while the maximum values were 0.260% and 0.040%, respectively. The relationship between the diameter of root samples and root tensile strength followed a negative power function, but tensile force increased with increasing root diameter following a positive power function. The pattern of increased cohesion changes in soil profile was relatively similar to RAR curves. The maximum increased cohesion due to the presence of roots in uphill and downhill sides were 0.470 and 1.400 kPa, respectively. In the flat treatment, the maximum increased cohesions were 0.570 and 0.610 kPa in northward and southward profiles, respectively. The analysis of variance showed that wind and slope induced stresses did not have any significant effect on the amount of increased cohesion of H. persicum. The findings served to develop knowledge about biotechnical properties of H. persicum root system that can assist in assessing the efficiency of afforestation and restoration measures for erosion control in arid lands. | Ehsan ABDI Hamid R SALEH Baris MAJNONIAN Azade DELJOUEI | 2019 | Journal of Arid Land2019，11，1： | 4 |
| 2 | 伊朗里海森林山坡上生长的欧洲鹅耳根系分布和抗张强度研究显示文摘对生长在伊朗北部丘陵地带的8株欧洲鹅耳的根面积比率和根系拉伸强度进行了测定,评估了欧洲鹅耳根系生物力学特性。应用剖面挖掘法测得土层深度为0.1米的样品根面积比率。共用了123份根样品分析根系拉伸强度。结果表明,根面积比率随土层深度增加而减小,变化规律遵从幂函数;上坡面和下坡面根面积比率无统计差别。根系可达到的最大土层深度为0.75米,但是最大根面积比率存在于土层深度0.1米内。下坡面最小和最大根面积比率分别为0.004%和6.431%;而上坡面的根面积比率分别为0.004%和3.995%。上、下坡面根数无显著差异,而且90%以上的根系深入到50-60厘米的土层中。Spearman双变量相关性分析结果表明,根面积比率与根数无显著关系。平均根拉伸强度为31.51±1.05MPa,且根系直径越粗根拉伸强度越小,遵从幂函数变化。图5表1参38。 | Ehsan Abdi Baris Majnounian Hassan Rahimi Mahmud Zobeiri | 2009 | Journal of Forestry Research2009，20，2： | 4 |
| 3 | Distribution and tensile strength of Hornbeam(Carpinus betulus) roots growing on slopes of Caspian Forests,Iran | Ehsan Abdi Baris Majnounian Hassan Rahimi Mahmud Zobeiri | 2009 | Journal of Forestry Research2009，20，A2： | 2 |
| 4 | Novel Hybrid X GBoost Model to Forecast Soil Shear Strength Based on Some Soil Index Tests显示文摘When building geotechnical constructions like retaining walls and dams is of interest,one of the most important factors to consider is the soil’s shear strength parameters.This study makes an effort to propose a novel predictive model of shear strength.The study implements an extreme gradient boosting(XGBoost)technique coupled with a powerful optimization algorithm,the salp swarm algorithm(SSA),to predict the shear strength of various soils.To do this,a database consisting of 152 sets of data is prepared where the shear strength(τ)of the soil is considered as the model output and some soil index tests(e.g.,dry unit weight,water content,and plasticity index)are set as model inputs.Themodel is designed and tuned using both effective parameters of XGBoost and SSA,and themost accuratemodel is introduced in this study.Thepredictionperformanceof theSSA-XGBoostmodel is assessedbased on the coefficient of determination(R2)and variance account for(VAF).Overall,the obtained values of R^(2) and VAF(0.977 and 0.849)and(97.714%and 84.936%)for training and testing sets,respectively,confirm the workability of the developed model in forecasting the soil shear strength.To investigate the model generalization,the prediction performance of the model is tested for another 30 sets of data(validation data).The validation results(e.g.,R^(2) of 0.805)suggest the workability of the proposed model.Overall,findings suggest that when the shear strength of the soil cannot be determined directly,the proposed hybrid XGBoost-SSA model can be utilized to assess this parameter. | Ehsan Momeni Biao He Yasin Abdi Danial Jahed Armaghani | 2023 | Computer Modeling in Engineering & Sciences2023，，9： | 1 |
| 5 | Stator- flux-oriented vector control for brushless doubly fed induc- tion generator显示文摘 | Shao Shiyi Abdi Ehsan Barati Farhad | 2009 | IEEE Transactions on Industrial Elec- tronics2009，56，10： | 1 |
| 6 | Statorflux-oriented vector control for brushless doubly fed induction generator显示文摘 | SHAO Shiyi ABDI Ehsan BARATI Farhad | 2009 | IEEE Trans on Industrial Electronics2009，56，10： | 1 |
| 7 | Stator- flux-oriented vector control for brushless doubly fed induction generator 显示文摘 | Shao Shiyi Abdi Ehsan Barati Farhad | 2009 | IEEE Transactions on Industrial Electronics2009，56，10： | 1 |
| 8 | Low-cost variable speed drive based on a brushless doubly-fed motor and a fractional unidirectional converter显示文摘 | Shao Shiyi Ehsan Abdi McMahon Richard | 2012 | IEEE Transactions on Industrial Electronics2012，59，1： | 1 |
| 9 | Low-cost variable speed drive based on a brushless doubly-fed motor and a fractional unidirectional converter显示文摘 | Shao Shiyi Abdi Ehsan McMahon Richard | 2012 | IEEE Transactions on Industrial Electronics2012，59，1： | 1 |
| 10 | Improving cross drain systems to minimize sediment delivery using GIS显示文摘A well developed network of roads must exist as a necessary infrastructure system in modern forestry to facilitate forest operations. But forest roads have the potential to disrupt the drainage characteristics of watersheds and lead to negative impacts on the environment with increased erosion and sediment yields. Numerous factors affect surface erosion of roads and sediment production potential; determining and ranking them could be a guide for management decisions to erosion control. In this study, the CULSED model (as an extension of ArcGIS) was used to estimate sediment delivery and the distribution of a road network, given the existing culverts. Using the model, some culverts were added to the road network around places with high sediment delivery in order to minimize it. After a correlation analysis and adjustment between sediment production and the factors, i.e., road width, road gradient, age of road and vegetation cover, the trend of changes in sediment delivery with model changes in the input was investigated with a sensitivity analysis of the model. The results show that adding new culverts to the road resulted in a significant reduction of sediment delivery. The most important factor affecting sediment delivery was road width, followed by road gradient, vegetation cover and age of road. Road width and gradient were positively correlated with sediment delivery, while vegetation cover and age of road were negatively correlated. The best model to show the relation between sediment delivery and road width as well as with road gradient was a linear model, for vegetation cover a cubic equation and for road age a power model. The results of sensitivity analysis showed that sediment delivery had the greatest sensitivity to changes of road width and was least sensitive to changes in the age of the road. This model can help to estimate sediment delivery with its spatial distribution, which can be used for optimization of cross drain systems and strategies of sediment control. Application of the model requires field trials to acquire the necessary input data. The reliability of our results is a function of the accuracy of inputs, especially digital elevation model. | Ehsan ABDI Saeed Rahbari SISAKHT Mostafa Moghadami RAD | 2012 | Forestry Studies in China2012，14，4： | 0 |
| 11 | How does organic matter affect the physical and mechanical properties of forest soil?显示文摘Determining the physical and mechanical properties of soil and its behavior for engineering projects is essential for road construction operations. One of the most important principles in forest road construction, which is usually neglected, is to avoid mixing organic matter with road materials during excavation and embankment construction. The current study aimed to assess the influence of organic matter on the physical properties and mechanical behaviors of forest soil and to analyze the relation between the amount of organic matter and the behavior of forest soil as road material. A typical soil sample from the study area was collected beside a newly constructed roadbed. The soil was mixed with different percentages of organic matter(control treatment, 5, 10, and 15% by mass) and different tests including Atterberg limits, standard compaction, and California bearing ratio(CBR) tests were conducted on these different soil mixtures. The results showed that soil plasticity increased linearly with increasing organic matter.Increasing the organic matter from 0%(control) to 15%resulted in an increase of 11.64% of the plastic limit and 15.22% of the liquid limit after drying at 110 ℃. Also,increasing the organic matter content reduced the soil maximum dry density and increased the optimum moisture content. Increasing the organic matter from 0 to 15% resulted in an increase of 11.0% of the optimum moisture content and a decrease of 0.29 g/cm^3 of the maximum dry density. Organic matter decreased the CBR, which is used as the index of road strength. Adding 15% organic matter to the soil resulted in a decrease of the CBR from 15.72 to 4.75%. There was a significant difference between the two drying temperatures(60 and 110 ℃) for the same organic matter mixtures with lower water content values after drying at 60 ℃. The results revealed the adverse influence of organic matter on soil engineering properties and showed the importance of organic matter removal before excavation and fill construction. | Ehsan Abdi Shojaat Babapour Baris Majnounian Ghavamodin Zahedi Amiri Azade Deljouei | 2018 | Journal of Forestry Research2018，29，3： | 0 |
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