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The high pressure of water distribution networks (WDNs) increases leakage, bursts, and water consumption. Pressure-reducing valves (PRVs) are widely used in WDNs because of their flexibility and effectiveness in pressure management. This paper studies pressure management by locating and adjusting PRVs in WDNs, considering the proper objective function and the suitable optimization algorithm. The single-objective algorithms and the EPANET hydraulic simulator in MATLAB programming are combined to manage the pressure. Initially, the proposed method improved by selecting the optimal optimization algorithm and objective function. Both fixed outlets and time-modulated modes of PRVs for two ZJ and Bellingham WDNs as case studies were used. Considering the cost, reliability, hydraulic performance, and leakage, the results were then analyzed and compared by changing the number, location, and adjustment of each PRV. The outcomes show the effect of choosing the best algorithms and cost functions on the results. The results also show that this method increases the reliability and controls the nodal pressure to a desired level in WDNs. Practical Applications: Leakages in water distribution networks (WDNs) are problematic for utilities and other governmental agencies. Pressure management in WDNs is inevitable to reduce the rate of bursts and leaks. Using fixed- and time-modulated pressure-reducing valves (PRVs) is essential for smart pressure management in WDNs. This study presented a method for positioning and adjusting PRVs in WDNs. The proposed method was applied to ZJ and Bellingham WDNs by choosing the best optimization algorithm and objective functions. The grey wolf optimizer (GWO) algorithm is proposed as one of the best algorithms for this subject. The presented method tries to provide the best plan for pressure management by examining the cost, leakage, and reliability. The results show that the presented method effectively increases reliability and reduces leakage in WDNs. [ABSTRACT FROM AUTHOR]

This study was carried out to rank and prioritize the aspects that have been shown to have an impact on the improvement of construction project management (CPM) performance based on value engineering. This analysis was carried out with the Iranian construction industry's current situation in mind. The respondents and the Delphi panel were chosen from among Iranian managers and project management professionals with a focus on building projects. These professionals had more than 20 years of experience working on international projects, and in addition to their expertise in project management, they also understood the principles of earned value analysis and value engineering. Thus, the components extracted from the literature review were used as the basis for designing a structured interview based on 39 important effective components previously determined as identified factors. The questionnaires were distributed among the experts, and the returned questionnaires were analysed using the SWARA technique to rank the weight and importance of the factors. Using the SWARA method, the opinions of the expert panel members consisting of 20 engineers and a semi-structured questionnaire was used to gather expertise in project management and managers, with a focus on Iranian CPM. As shown by the results, stakeholder management, time value of money, and worth, allocated the first to the third rank to themselves with respective weights of 0.104, 0.103, and 0.087. The sub-criteria of cost objective, function objective, and value objective were in the 37th to 39th ranks with respective weights of 0.00050, 0.00033, and 0.00021. [ABSTRACT FROM AUTHOR]

The management and operation of water distribution networks (WDNs) by establishing district metered areas (DMAs), especially in existing and old WDNs, has many advantages, including water leakage control, ease of operation, and network management in emergencies. Using DMAs in existing WDNs designed and developed traditionally is a challenging issue because of the need to cover several criteria. In the present study, a method for creating DMAs is suggested to minimize the cost as well as to reduce the average pressure in high-pressure WDNs. The proposed method uses the Girvan–Newman clustering and nondominated sorting genetic algorithm (NSGAII) optimization algorithms. This method was implemented on Modena's and Wolf–Cordera Ranch's WDNs. The proposed method can generate several solutions based on performance indicators, including cost, hydraulics, and quality. The results show that by applying the proposed method in the Modena and Wolf–Cordera Ranch WDNs, the average pressure of the networks was reduced by 17% and 31%, respectively, in comparison with the primary WDNs in the base demand and peak demand conditions. This method can be used by water utilities for partitioning WDNs, especially when the pressure is high. [ABSTRACT FROM AUTHOR]

This paper aims to obtain a relation for estimating the median size of bed sediment, d 50 , at the bends of meandering rivers based on real data. To achieve such a purpose, field data, including topographic, sediment sampling, and flow measurements, were collected from various rivers in Iran at different times of the year. Then, the Buckingham Π-theorem was applied to identify the effective dimensionless numbers such as the Shields function, Reynolds particle number, Froude number, submerged specific gravity of sediment, and aspect and curvature ratios. A correlation analysis was conducted between such factors to eliminate those dependent on others. In the following, three regression techniques, containing the power function approach, the general additive model (GAM), and the multivariate adaptive regression spline (MARS), were chosen to achieve the best relation. The obtained results indicated that the developed MARS model produced a better result than the others and was much more satisfactory, with a coefficient of determination (R2) of 0.96 and 0.95 and root-mean-square error (RMSE) of 140.64 and 140.47 for the training and testing phases, respectively. Furthermore, the MARS outputs were validated with an analytical method, which showed that MARS fitted with the field data much better. Consequently, the distinguished merit of this study is the development of a relation for determining d 50 that shows which geometric and hydraulic parameters have the most effect on sediment size in the river bend. [ABSTRACT FROM AUTHOR]

Near-field earthquakes have been shown to have different effects on structures than far-field events. This study examines the dynamic response of a rectangular concrete liquid storage tank with tapered walls to near-field ground motions, with particular emphasis on the effect of higher sloshing modes. The tank's numerical modeling, calibrated using experimental results, was performed considering the tank's wall flexibility. Seven selected near-field records were applied in each case, and the effects of the first five sloshing modes on the tank response at three different locations, including the corner, middle of the long wall, and middle of the short wall, were investigated. The effect of the earthquake incident angle on the tank's response was also studied by applying major and minor horizontal earthquake components once along the longer and shorter tank walls, respectively, and vice versa. Results show that the tank corner may have a sloshing height up to 50% greater than the middle of the walls and that the maximum sloshing response is substantially influenced by the spectral acceleration value at the first sloshing period. Higher sloshing modes are found to affect the sloshing response, with a maximum R2 score of 0.95, depending on the excitation's incidence angle. [ABSTRACT FROM AUTHOR]

This study proposes a numerical model for depth-averaged Reynolds equations (shallow-water equations) to investigate a dam-break problem, based upon a two-dimensional (2D) second-order upwind cell-centre finite volume method. The transportation terms were modelled using a modified approximate HLLC Riemann solver with the first-order accuracy. The proposed 2D model was assessed and validated through experimental data and analytical solutions for several dam-break cases on a wet and dry bed. The results showed that the error values of the model are lower than those of existing numerical methods at different points. Our findings also revealed that the dimensionless error parameters decrease as the wave propagates downstream. In general, the new model can model the dam-break problem and captures the shock wave superbly. [ABSTRACT FROM AUTHOR]

The purpose of this research is to investigate the antimicrobial activity of the microalgae Scenedesmus sp. and Spirulina platensis cultivated in BG-11 culture medium and the effluent of desalination facilities of Bandar Turkmen unit, Golestan province in inhibiting the growth and proliferation of gram-positive Staphylococcus aureus bacteria. And gram-negative Escherichia coli. Algae were extracted by water-alcohol method in proportion (500 cc of alcohol and 50 cc of distilled water) and determination of minimum inhibitory concentration (MIC) was checked by broth micro dilution method (96 plates) and with The amount of antibacterial activity grown in the water of their usual environment was compared. The results of the two mentioned bacteria in the presence of different concentrations of water-ethanol extract within 24 hours showed that in the extracted extract of the genus Scenedesmus sp. and Spirulina platensis cultivated in BG-11 culture medium and 50 and 100% dilutions of wastewater, against the bacteria There was no minimum inhibitory concentration (MIC) of Staphylococcus aureus and Escherichia coli during (24 hours). The extract of Scenedesmus sp. grown in BG-11 with a concentration of 25 and 50 mg/ml has a higher concentration of Escherichia coli than spirulina platensis in the early hours. As the concentration increases, the amount of bacteria decreases in the early hours. The extract of Spirulina platensis grown in BG-11 showed high control properties to Staphylococcus bacteria in the early hours compared to Scenedesmus sp. extract grown in 50% wastewater compared to spirulina platensis had the highest concentration of Escherichia coli bacteria in the final hours, so that it showed higher controlling properties than spirulina platensis against Escherichia coli. Also, in the extract of Scenedesmus sp. grown in 50% wastewater at concentrations of 25, 100 and 200 mg/ml in the last hours, the concentration of Staphylococcus bacteria is higher than the concentration of 50 mg/ml and in spirulina in the last hours It has had a steady trend. In both extracts grown in 100% wastewater, they showed the highest concentration of bacteria in all concentrations within 4 hours. Therefore, in all concentrations of the two extracts, they showed an increase in the concentration of Staphylococcus bacteria over time (2-4 hours). Therefore, spirulina cultivated in 100% wastewater had a stable trend in the final hours compared to Scenedesmus sp. and showed more controlling properties against staphylococcus. [ABSTRACT FROM AUTHOR]

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This study analyses the impact of climate change on the inflows, sediment loads, and nutrient inputs to the Sabalan dam reservoir, a warm monomictic lake located northwest of Iran. For this purpose, the Soil and Water Assessment Tool (SWAT) was calibrated (2005–2018) and validated (2001–2004). Future climate-based data under the AR5 emission scenarios were obtained from the HadGEM2–ES general circulation model and then downscaled using the LARSWG 6.0. The tuned SWAT model was used to investigate the climate change impact on the hydrological processes and pollution loads to the Sabalan dam reservoir. Our findings based on the Nash–Sutcliffe efficiency coefficient and the coefficient of determination indicated an acceptable performance of the SWAT model in the simulation of inflows, sediment loads, and nutrient inputs to the reservoir. Inflow and sediment load to the reservoir will increase during the period of 2030–2070 compared to the base period (1998–2018). The annual total nitrogen (phosphorus) load to the reservoir will increase by 8.5% (9.4%), 7.3% (8.2%), and 5% (3.4%) under the emission scenarios of RCP2.6, RCP4.5, and RCP8.5, respectively. An increase in sediment loads and nutrient inputs to the Sabalan dam reservoir will significantly exacerbate the reservoir eutrophic condition, leading to water quality deterioration with acute consequences for the positive functions of the dam. [ABSTRACT FROM AUTHOR]

Proper planning and management of construction projects have long been regarded as a necessity. The ability to make sound decisions and solve problems using appropriate performance reports related to the project implementation process are the two most key factors in controlling the performance of construction project management. Even though these factors considerably contribute to controlling precise project performance, previous research has failed to investigate them to their fullest potential. Therefore, this research seeks to fill the existing gap by determining the influential factors on construction project management performance through earned value-based value engineering strategy. In this line, a comprehensive literature analysis was undertaken to extract the influential factors on construction project management performance. Then, three rounds of a Delphi survey were conducted to consolidate the influential factors. There were a total of 39 factors that were grouped into four categories. The identified influential factors were then evaluated through the analysis of quantitative data. The findings showed that the dimension of "Engineering economics" was ranked first in terms of importance, followed by "Project management performance", "Value engineering approach", and "Earned value management" at the second to fourth ranks, respectively. The overall ranking of the factors placed "Project Stakeholder Management" in the first position and "Project Management Software" in the bottom place. It is anticipated that the key findings and effective recommendations of this study will considerably contribute to the improvement of decisions on project planning and improve the performance of construction project management while enhancing different stakeholders' understanding of the most influential factors on the performance of construction project management. [ABSTRACT FROM AUTHOR]