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Groundwater travel time computation for two-layer islands
, Article Hydrogeology Journal ; Volume 24, Issue 4 , 2016 , Pages 1045-1055 ; 14312174 (ISSN) ; Mahmoodzadeh, D ; Ataie Ashtiani, B ; Sharif University of Technology
Springer Verlag
2016
Abstract
A closed-form analytical computation of groundwater travel time (GWTT) for two-layer oceanic small island aquifers is developed assuming steady-state and sharp-interface conditions. The two-layer geology impacts on the GWTT are investigated using the developed analytical solution to achieve a greater transparency of such conceptualizations. The results demonstrate that the inclusion of geologic layering leads to large changes in the GWTT. Sensitivity analyses, using specified dimensionless parameters, are employed to assess the influences of hydraulic conductivity, recharge rate, upper layer thickness, and seawater/freshwater density difference parameters, which influence the GWTT. These...
Estimation of current-induced pile groups scour using a rule-based method
, Article Journal of Hydroinformatics ; Volume 15, Issue 2 , September , 2013 , Pages 516-528 ; 14647141 (ISSN) ; Etemad-Shahidi, A ; Ataie-Ashtiani, B ; Sharif University of Technology
2013
Abstract
Scour phenomenon around piles could endanger the stability of the structures placed on them. Therefore, an accurate estimation of the scour depth around piles is very important for engineers. Due to the complexity of the interaction between the current, seabed and pile group; prediction of the scour depth is a difficult task and the available empirical formulas have limited accuracy. Recently, soft computing methods such as artificial neural networks (ANN) and adaptive neuro-fuzzy inference system (ANFIS) have been used for the prediction of the scour depth. However, these methods do not give enough insight into the generated models and are not as easy to use as the empirical formulas. In...
Influence of river cross-section data resolution on flood inundation modeling: Case study of Kashkan river basin in western Iran
, Article Journal of Hydrology ; Volume 584 , 2020 ; Hosseini, S. M ; Ataie Ashtiani, B ; Sharif University of Technology
Elsevier B.V
2020
Abstract
In this study, a coupling of a hydrologic and hydraulic model was utilized to assess the impacts of river geometry data resolution on the flood inundation characteristics in a data-scarce environment. Hydrological modeling incorporates soil conservation service curve-number (SCS-CN) and the geomorphologic based instantaneous unit hydrograph model (GIUH) to compute the direct runoff hydrograph in Kashkan river basin located in western Iran. 1D HEC-Geo-RAS model was used and performed to simulate inundation extent of 100-yr floods (~1800 m3/s) along 40 km reach of Kashkan river with a ground survey of river cross-section (2000 cross-sections, each including 500 data-points). The effect of...
Synchronous measurements of the velocity and concentration in low density turbidity currents using an Acoustic Doppler Velocimeter
, Article Flow Measurement and Instrumentation ; Volume 17, Issue 1 , 2006 , Pages 59-68 ; 09555986 (ISSN) ; Shamsai, A ; Ataie Ashtiani, B ; Sharif University of Technology
2006
Abstract
Low density turbidity currents have been investigated in a laboratory flume. An Acoustic Doppler Velocimeter (ADV) was used to measure the velocity. The dimensionless velocity profiles were compared with previous studies to check the accuracy of acoustic measuring techniques for turbidity currents. Successful use of the ADV to measure the current velocity has led to interest in the technique of using acoustic sensors to estimate concentrations. Acoustic backscattering analyses are used for estimating the sediment concentration in turbidity currents. With this approach, concentration measurements can be reasonably well represented by a similarity profile. Using this technique, an accurate...
Efficiency of mechanochemical ball milling technique in the preparation of fe/tio2 photocatalysts
, Article ChemEngineering ; Volume 6, Issue 5 , 2022 ; 23057084 (ISSN) ; Yeung, K. L ; Ataie Ashtiani, B ; Sharif University of Technology
MDPI
2022
Abstract
Rapid population growth and widespread industrialization are the main contributing factors to the increasing contamination of the world’s diminishing freshwater resources. This work investigates Fe/TiO2 as an efficient and sustainable photocatalyst for treating organic micropollutants in water. The photocatalysts prepared by these mechanochemical methods used a high-energy ball milling technique to manipulate Fe/TiO2’s structural, optical, and catalytic properties for the photo-oxidation of 2,4-Dichlorophenol (2,4-DCP). Doping with iron effectively reduced the band gap of rutile TiO2 from 3 to 2.22 eV. By reducing the ball/powder ratio from 34 to 7, the removal efficiency of 2,4-DCP...
Declaration of Conflicts of Interest in Networking Era: Raising the Bar
, Article Science and Engineering Ethics ; 2015 , Pages 1-3 ; 13533452 (ISSN) ; Sharif University of Technology
Springer Netherlands
2015
Preface: Thematic issue “Landslide-generated tsunamis waves”
, Article Landslides ; 2016 , Pages 1- ; 1612510X (ISSN) ; Sharif University of Technology
Springer Verlag
2016
Erratum to: Preface: Thematic issue “Landslide-generated tsunami waves”
, Article Landslides ; Volume 13, Issue 6 , 2016 , Pages 1593- ; 1612510X (ISSN) ; Sharif University of Technology
Springer Verlag
2016
Abstract
The original version of this article, unfortunately, contained error. In the article title, “tsunamis” should be “tsunami“. Given in this article is the correct title
Declaration of conflicts of interest in networking era: Raising the bar
, Article Science and Engineering Ethics ; Volume 22, Issue 6 , 2016 , Pages 1855-1857 ; 13533452 (ISSN) ; Sharif University of Technology
Springer Netherlands
2016
Recruitment processes in academia: does the emperor have any clothes?
, Article Science and Engineering Ethics ; Volume 22, Issue 5 , 2016 , Pages 1565-1568 ; 13533452 (ISSN) ; Sharif University of Technology
Springer Netherlands
2016
Abstract
The final outcome of promotion and recruitment processes in universities should be conventional and plausible by the members of the relevant scientific community, to affirm that the processes have been competitive and fair. The objective of this opinion letter is to make a plea for the importance of the post-auditing and quantitative assessment of the selection criteria. It is shown that for an example case the outcome of the post-audit does not look reasonable from an external point of view, at least regarding the research competency. © 2015, Springer Science+Business Media Dordrecht
Recruitment processes in academia: does the emperor have any clothes?
, Article Science and Engineering Ethics ; 2015 ; 13533452 (ISSN) ; Sharif University of Technology
Kluwer Academic Publishers
2015
Abstract
The final outcome of promotion and recruitment processes in universities should be conventional and plausible by the members of the relevant scientific community, to affirm that the processes have been competitive and fair. The objective of this opinion letter is to make a plea for the importance of the post-auditing and quantitative assessment of the selection criteria. It is shown that for an example case the outcome of the post-audit does not look reasonable from an external point of view, at least regarding the research competency
Comment on "effects of tidal fluctuations on mixing and spreading in coastal aquifers: Homogeneous case" by María Pool et al
, Article Water Resources Research ; Volume 51, Issue 6 , 2015 , Pages 4858- ; 00431397 (ISSN) ; Sharif University of Technology
Blackwell Publishing Ltd
2015
Curbing Iran's academic misconduct
, Article Science ; Volume 351, Issue 6279 , 2016 , Pages 1273-1274 ; 00368075 (ISSN) ; Sharif University of Technology
American Association for the Advancement of Science
2016
World map of scientific misconduct
, Article Science and Engineering Ethics ; 2017 , Pages 1-4 ; 13533452 (ISSN) ; Sharif University of Technology
Springer Netherlands
2017
Abstract
A comparative world map of scientific misconduct reveals that countries with the most rapid growth in scientific publications also have the highest retraction rate. To avoid polluting the scientific record further, these nations must urgently commit to enforcing research integrity among their academic communities. © 2017 Springer Science+Business Media B.V
Erratum to: world map of scientific misconduct
, Article Science and Engineering Ethics ; 2017 , Pages 1- ; 13533452 (ISSN) ; Sharif University of Technology
2017
Erratum to: World map of scientific misconduct
, Article Science and Engineering Ethics ; Volume 24, Issue 5 , 2018 , Pages 1657- ; 13533452 (ISSN) ; Sharif University of Technology
Springer Netherlands
2018
Abstract
The original version of this article was revised: Reference ‘Qiu, J. (2010). China drought highlights future climate threats. Nature, 463(7278), 142–143.’ has been replaced by ‘Qui, J. (2010). Publish or perish in China. Nature, 463(7278), 142–143.’. © Springer Science+Business Media B.V. 2017
World map of scientific misconduct
, Article Science and Engineering Ethics ; Volume 24, Issue 5 , 2018 , Pages 1653-1656 ; 13533452 (ISSN) ; Sharif University of Technology
Springer Netherlands
2018
Abstract
A comparative world map of scientific misconduct reveals that countries with the most rapid growth in scientific publications also have the highest retraction rate. To avoid polluting the scientific record further, these nations must urgently commit to enforcing research integrity among their academic communities. © 2017, Springer Science+Business Media B.V
Chinese and Iranian scientific publications: Fast growth and poor ethics
, Article Science and Engineering Ethics ; Volume 23, Issue 1 , 2017 , Pages 317-319 ; 13533452 (ISSN) ; Sharif University of Technology
Springer Netherlands
2017
MODSharp: Regional-scale numerical model for quantifying groundwater flux and contaminant discharge into the coastal zone
, Article Environmental Modelling and Software ; Volume 22, Issue 9 , 2007 , Pages 1307-1315 ; 13648152 (ISSN) ; Sharif University of Technology
2007
Abstract
In this paper the development of a quasi-three-dimensional numerical model that can be used for quantifying groundwater inputs and associated contaminant discharged from coastal aquifers into the coastal zone at a regional scale is presented. The present model is called MODSharp. In order to handle problems at a regional scale, the sharp interface approach which is used for conceptualising seawater intrusion, is applied to this model. This model can be used for the simulation of groundwater flow and contaminant transport in layered coastal aquifers at a regional scale. The method of characteristics is used to solve the advection-dispersion equation, which governs contaminant transport in...
Scour hole depth prediction around pile groups: review, comparison of existing methods, and proposition of a new approach
, Article Natural Hazards ; Volume 88, Issue 2 , 2017 , Pages 977-1001 ; 0921030X (ISSN) ; Beheshti, A. A ; Ataie Ashtiani, B ; Sharif University of Technology
2017
Abstract
A dataset of 365 laboratory tests for scour hole depth (SHD) around pile groups (PGs) under unidirectional aligned flow is compiled, and the performances of the existing equations are comparatively evaluated on the dataset using several statistical indices. A formulation based on a correction of HEC-18 equation provides the best estimate with a correlation factor of 0.58. The test durations of the considered data ranged between 4 and 389 h. A time factor (Kt) is proposed to take into account the temporal variation of the SHD around different PGs. Among the datasets, 51 long-duration experiments are scrutinized to show the temporal variation of scour depth toward equilibrium state. The time...