Multi-Objective Optimization of Integrated Surface and Groundwater Resources Under the Clean Development Mechanism

Acquiring sustainable water resources for water-based development of countries is the experts? concern in this field, who seek to follow the clean development mechanism (CDM) regulations and overcome water crisis through integrated water resources management (IWRM). The Great Karun River basin is one of the major basins in the Middle East. This basin, containing six of the largest reservoir dams with a cumulative power plant capacity of more than 10,500 MW generates about 93% of hydropower of Iran. The water balance of the aquifer in the study area was simulated using MODFLOW model while water resources and surface water reserves were simulated by the water evaluation and planning (WEAP) model. A separate simulation was performed with each of two models and the results of two models were coupled using a link file. The multi-objective function optimization process including the maximized supply of demands and hydropower and the minimized aquifer drawdown was completed using non-dominated sorting genetic algorithm (NSGA-II). All effective system components, such as inter-basin water transfer, integrated use of water resources, variation of irrigation network efficiencies, and the effect of water shortage were studied and analyzed under the targeted scenarios. Finally, the best scenario, which was capable to supply the future needs until time horizon of 2040 was planned for the basin considering minimization of aquifer drawdown and optimal generation of hydropower resulting in a maximum decrease in emission of greenhouse gases.

     

Polypyrrole‐modified magnetic nanoparticles and high‐performance liquid chromatography for determination of glibenclamide from biological fluids

In this research, the successful application of polypyrrole (PPy)‐modified magnetic nanoparticles (NPs) is described as an efficient adsorbent for the extraction and the preconcentration of glibenclamide (GB). To measure it in biological fluids samples, HPLC‐UV detection was used. First, iron oxide NPs were prepared by coprecipitation procedure and then their surface was modified by PPy monomers. Characteristics of Fe₃ O₄ @PPy NPs were investigated by FTIR technique and NP size studied with scanning electron microscopy. The vibrating sample magnetometer was used to characterise the magnetic properties of the prepared modified NPs. The affecting parameters in extraction including analyte sorption time, analyte desorption time, ionic strength, sample volume, pH, eluent type, eluent amount, and amount of Fe₃ O₄ @PPy NPs were investigated and optimised. The linear range of the proposed method is 0.2–700.0 μg l⁻¹ and the limit of detection is 0.1 μg l ^{− 1}. The relative standard deviation for five replicate analyses was 3.9. Finally, the proposed procedure was successfully employed for preconcentration and determination of GB in biological fluids.Inspec keywords: nanofabrication, pH, nanomagnetics, desorption, iron compounds, chromatography, adsorption, spectrochemical analysis, nanoparticles, magnetic particles, scanning electron microscopy, Fourier transform infrared spectraOther keywords: polypyrrole‐modified magnetic nanoparticles, high‐performance liquid chromatography, glibenclamide, preconcentration, biological fluids samples, HPLC‐UV detection, iron oxide NPs, coprecipitation procedure, PPy monomers, scanning electron microscopy, vibrating sample magnetometer, magnetic properties, analyte desorption time, analyte sorption time, biological fluids     

Enhancing the exergetic performance of a pilot-scale convective dryer by exhaust air recirculation

Abstract

In this study, an air recirculating pilot-scale convective dryer operating at various exhaust air recycle fractions was exergetically investigated in detail. Two drying air temperatures (55–70?°C), two air volume flow rates (360–450?m³/h), and six exhaust air recycle fractions (0–100%) were considered for drying of poplar wood chips. The effects of drying variables were studied on the exergetic efficiencies of drying system and drying chamber. The total exergy of air exhausting from drying chamber was also fractionated into thermophysical and wet exergies for further evaluating the effect of recycle fraction. The universal exergetic efficiency of drying chamber ranged from 41.84% to 98.07%, while the average overall functional exergetic efficiency of drying system varied from 1.32% to 4.01%. Exhaust air recirculation profoundly improved the overall functional exergetic efficiency of drying system as a decision-making parameter up to over two times. Although the recycle fraction of 100% showed the highest improvement in the overall functional exergetic efficiency of drying system, the drying time drastically increased at this condition as expected. Overall, a compromise should be made between drying time and exergetic improvement in order to select a proper recycle fraction for recovering exergy from outflow air.