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    Comparative study of partial least squares and multivariate curve resolution for simultaneous spectrophotometric determination of pharmaceuticals in environmental samples

    , Article RSC Advances ; Volume 5, Issue 86 , Aug , 2015 , Pages 70017-70024 ; 20462069 (ISSN) Parastar, H ; Shaye, H ; Sharif University of Technology
    Royal Society of Chemistry  2015
    Abstract
    The potentials of partial least squares regression (PLSR) and multivariate curve resolution alternating least squares (MCR-ALS) are evaluated for the simultaneous determination of diclofenac (DCF), naproxen (NAP), mefenamic acid (MEF) and carbamazepine (CBZ) as target analytes and gemfibrozil (GEM) as an interference in synthetic and real environmental samples. The analysis of first-order UV-Vis spectra is performed using PLSR with different variable selection methods, which include variable importance in projection (VIP), recursive weighted partial least squares (rPLS), regression coefficient (RV) and uninformative variable elimination (UVE), and using MCR-ALS with correlation constraint... 

    Application of the WEPP model to determine sources of run-off and sediment in a forested watershed

    , Article Hydrological Processes ; Volume 29, Issue 4 , 2015 , Pages 481-497 ; 08856087 (ISSN) Saghafian, B ; Meghdadi, A. R ; Sima, S ; Sharif University of Technology
    John Wiley and Sons Ltd  2015
    Abstract
    This study investigates critical run-off and sediment production sources in a forested Kasilian watershed located in northern Iran. The Water Erosion Prediction Project (WEPP) watershed model was set up to simulate the run-off and sediment yields. WEPP was calibrated and validated against measured rainfall-run-off-sediment data. Results showed that simulated run-off and sediment yields of the watershed were in agreement with the measured data for the calibration and validation periods. While low and medium values of run-off and sediment yields were adequately simulated by the WEPP model, high run-off and sediment yield values were underestimated. Performance of the model was evaluated as... 

    Downscaling of the flood discharge in a probabilistic framework

    , Article Journal of Hydro-Environment Research ; Volume 43 , 2022 , Pages 10-21 ; 15706443 (ISSN) Moghim, S ; Gharehtoragh, M. A ; Sharif University of Technology
    Elsevier B.V  2022
    Abstract
    Many modeled and observed data are in coarse resolution, which are required to be downscaled. This study develops a probabilistic method to downscale 3-hourly runoff to hourly resolution. Hourly data recorded at the Poldokhtar Stream gauge (Karkheh River basin, Iran) during flood events (2009–2019) are divided into two groups including calibration and validation. Statistical tests including Chi-Square and Kolmogorov–Smirnov test indicate that the Burr distribution is proper distribution functions for rising and falling limbs of the floods’ hydrograph in calibration (2009–2013). A conditional ascending/descending random sampling from the constructed distributions on rising/falling limb is... 

    Spring hydrograph simulation of karstic aquifers: impacts of variable recharge area, intermediate storage and memory effects

    , Article Journal of Hydrology ; Volume 552 , 2017 , Pages 225-240 ; 00221694 (ISSN) Hosseini, S. M ; Ataie Ashtiani, B ; Simmons, C. T ; Sharif University of Technology
    Abstract
    A simple conceptual rainfall–runoff model is proposed for the estimation of groundwater balance components in complex karst aquifers. In the proposed model the effects of memory length of different karst flow systems of base-flow, intermediate-flow, and quick-flow and also time variation of recharge area (RA) during a hydrological year were investigated. The model consists of three sub-models: soil moisture balance (SMB), epikarst balance (EPB), and groundwater balance (GWB) to simulate the daily spring discharge. The SMB and EPB sub-models utilize the mass conservation equation to compute the variation of moisture storages in the soil cover and epikarst, respectively. The GWB sub-model... 

    Mapping the spatiotemporal variability of salinity in the hypersaline Lake Urmia using Sentinel-2 and Landsat-8 imagery

    , Article Journal of Hydrology ; Volume 595 , 2021 ; 00221694 (ISSN) Bayati, M ; Danesh Yazdi, M ; Sharif University of Technology
    Elsevier B.V  2021
    Abstract
    The spatiotemporal dynamic of salinity concentration (SC) in saline lakes is strongly dependent on the rate of water flow into the lake, water circulation, wind speed, evaporation rate, and the phenomenon of salt precipitation and dissolution. Although in-situ observations most reliably quantify water quality metrics, the spatiotemporal distribution of such data are typically limited and cannot be readily extrapolated for either long-term projections or extensive areas. Alternatively, remotely sensed imagery has facilitated less expensive and a stronger ability to estimate water quality over a wide range of spatiotemporal resolutions. This study introduces an adaptive learning model that...