Erratum to: Investigation of the atmospheric mesoscale circulation patterns and their simulation with WRF-CHEM model of the dust storm occurrence over the southern coast of the Caspian Sea     

Sammaneh Negah  Amir Hussain Meshkatee  Sohrab Hajjam  Ali Kamali 《Arabian Journal of Geosciences》2016,9(17):693

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Role of construction of large dams on river morphology (case study: the Karkheh dam in Iran)     

Arash Adib  Hesam Foladfar  Amir Roozy 《Arabian Journal of Geosciences》2016,9(15):661

Unfortunately in developing countries, human activities without attention to the environmental aspects damage to nature. For example, construction of large dams dries wetlands in southwest of Iran. Also, construction of dams is a very important factor for morphological changes. The case study of this research is downstream of the Karkheh dam. This dam is the largest Earth dam in Iran and locates in southwest of Iran. It was constructed in 1999. Small sinuosity coefficient of zone near to dam has been illustrated by satellite images in 2002 and 2014. This subject shows instability of this part of reach; also, the results of Shulits equation illustrate that this part is instable. But, increasing of morphological characteristics (sinuosity coefficient, central angle, and relative radius) show that stability of this reach is increasing. Surveying confirm this matter and shows that severe erosion in upstream and sedimentation in downstream of reach is finishing. Also, it is observed that flow discharge reduced (?56 %) after construction of dam and average width of river reduced (?21 %) from 2002 to 2014. In the early years after the construction of the dam, sediment discharge reduced considerably (?14 %) from Pay-e-Pol to Abdol Khan hydrometric stations. Increasing of morphological characteristics (especially at zones near to dam) and decreasing changes of bed level (sedimentation and erosion) prove that effects of dam are overcoming on effects of other factors, and these effects are permanent in long term.  相似文献   

Temperature-based estimation of global solar radiation using soft computing methodologies     

Kasra Mohammadi  Shahaboddin Shamshirband  Amir Seyed Danesh  Mohd Shahidan Abdullah  Mazdak Zamani 《Theoretical and Applied Climatology》2016,125(1-2):101-112

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Erratum to: The interannual precipitation variability in the southern part of Iran as linked to large-scale climate modes     

Farnaz Pourasghar  Tomoki Tozuka  Saeed Jahanbakhsh  Behrooz Sari Sarraf  Hooshang Ghaemi  Toshio Yamagata 《Climate Dynamics》2012,39(12):3121-3121

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Theory-guided machine learning to predict density evolution of sand dynamically compacted under Ko condition     

Tophel  Amir  Walker  Jeffrey P.  Dutta  Troyee Tanu  Kodikara  Jayantha 《Acta Geotechnica》2022,17(8):3479-3497

Acta Geotechnica - This paper introduces a theory-guided machine learning (TGML) framework, which combines a theoretical model (TM) and a machine learning (ML) algorithm to predict compaction...  相似文献   

Compounding effects of human activities and climatic changes on surface water availability in Iran     

Ashraf  Samaneh  AghaKouchak  Amir  Nazemi  Ali  Mirchi  Ali  Sadegh  Mojtaba  Moftakhari  Hamed R.  Hassanzadeh  Elmira  Miao  Chi-Yuan  Madani  Kaveh  Mousavi Baygi  Mohammad  Anjileli  Hassan  Arab  Davood Reza  Norouzi  Hamid  Mazdiyasni  Omid  Azarderakhsh  Marzi  Alborzi  Aneseh  Tourian  Mohammad J.  Mehran  Ali  Farahmand  Alireza  Mallakpour  Iman 《Climatic change》2019,152(3-4):379-391

Climatic Change - By combining long-term ground-based data on water withdrawal with climate model projections, this study quantifies the compounding effects of human activities and climate change...  相似文献   

A laboratory investigation of bed-load transport of gravel sediments under dam break flow     

Khabat Khosravi  Amir Hooshang Nezamivand Chegini  James Cooper  Luca Mao  Mahmood Habibnejad  Kaka Shahedi  Andrew Binns 《国际泥沙研究》2021,36(2):229-234

Dam break flows and resulting river bed erosion can have disastrous impacts on human safety,infrastructure,and environmental quality.However,there is a lack of research on the mobility of non-uniform sediment mixtures resulting from dam break flows and how these differ from uniform sized sediment.In this paper,laboratory flume experiments revealed that coarse and fine fractions in non-uniform sediment had a higher and a lower bed-load parameter,respectively,than uniform sediments of the same size.Thus,the finer fractions were more stable and the coarser fractions were more erodible in a nonuniform bed compared to a uniform-grained bed.These differences can be explained by the hiding and protrusion of these fractions,respectively.By investigating changes in mobility of the mixed-size fractions with reservoir water levels,the results revealed that at low water levels,when the coarser fractions were only just mobile,the bed-load parameter of the finer fractions was higher than the coarser fractions.The opposite was observed at a higher water level,when a significant proportion of the coarsest fractions was mobilized.The higher protrusion of these grains had an important effect on their mobility relative to the finer grains.The transported sediment on these mixed-sized beds was coarser than the initial bed sediment,and became coarser with an increase in reservoir water level.  相似文献   

A global method for coupling transport with chemistry in heterogeneous porous media     

Laila Amir  Michel Kern 《Computational Geosciences》2010,14(3):465-481

Modeling reactive transport in porous media, using a local chemical equilibrium assumption, leads to a system of advection–diffusion PDEs coupled with algebraic equations. When solving this coupled system, the algebraic equations have to be solved at each grid point for each chemical species and at each time step. This leads to a coupled non-linear system. In this paper, a global solution approach that enables to keep the software codes for transport and chemistry distinct is proposed. The method applies the Newton–Krylov framework to the formulation for reactive transport used in operator splitting. The method is formulated in terms of total mobile and total fixed concentrations and uses the chemical solver as a black box, as it only requires that one be able to solve chemical equilibrium problems (and compute derivatives) without having to know the solution method. An additional advantage of the Newton–Krylov method is that the Jacobian is only needed as an operator in a Jacobian matrix times vector product. The proposed method is tested on the MoMaS reactive transport benchmark.  相似文献   

Seismic safety of reinforced concrete members and structures     

Hooshang Banon  Daniele Veneziano 《地震工程与结构动力学》1982,10(2):179-193

Based on cyclic load tests of large-scale reinforced concrete elements and assemblages, a probabilistic model of member failure is developed. The model gives the probability of survival at time t as a functional of damage ratio and dissipated energy up to t. After extension to multivariate survival of several members with correlated resistance, the model is used to calculate the safety of reinforced concrete frames subjected to given input motions. Results are in terms of the probability of local failure and of no failure anywhere in the system.  相似文献   

Elasticity of a beryllium silicate (phenacite: Be2SiO4)     

Amir Yeganeh-Haeri  Donald J. Weidner 《Physics and Chemistry of Minerals》1989,16(4):360-364

The adiabatic single-crystal elastic moduli of a beryllium silicate (phenacite: Be₂SiO₄, trigonal, have been determined at atmospheric pressure and 22° C by Brillouin spectroscopy. The elastic stiffness moduli in gigapascals are: C ₁₁=341.9 C ₃₃=391.0 C ₄₄=91.4 C ₆₆= 96.9 C ₁₂=148.0 C ₁₃=136.0 C ₁₄= 0.1 C ₁₅= 3.5Overall, the elastic stiffness moduli for phenacite parallel and perpendicular to the c axis are comparable (i.e., it is almost cubic in its elastic signature). The elastic moduli can be rationalized in terms of division of the structure into two types of coordination polyhedra (1Si+2Be) with slightly different stiffnesses, which are linked to form a three dimensional framework. Values of the isothermal bulk modulus and the linear compressibilities, as determined from hydrostatic compression experiments of Hazen and Au (1986), are in good agreement with those obtained here. Combining the two studies indicates a low pressure derivative of the bulk modulus for phenacite.  相似文献