scholarly journals Impact of New Water Sources on the Overall Water Network: An Optimisation Approach

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Godfrey Chagwiza ◽  
Brian C. Jones ◽  
Senelani D. Hove-Musekwa

A mathematical programming problem is formulated for a water network with new water sources included. Salinity and water hardness are considered in the model, which is later solved using the Max-Min Ant System (MMAS) to assess the impact of new water sources on the total cost of the existing network. It is efficient to include new water sources if the distances to them are short or if there is a high penalty associated with failure to meet demand. Desalination unit costs also significantly affect the decision whether to install new water sources into the existing network while softening costs are generally negligible in making such decisions. Experimental results show that, in the example considered, it is efficient to reduce number of desalination plants to remain with one central plant. The Max-Min Ant System algorithm seems to be an effective method as shown by least computational time as compared to the commercial solver Cplex.

Energies ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 1107
Author(s):  
Stefano d’Ambrosio ◽  
Roberto Finesso ◽  
Gilles Hardy ◽  
Andrea Manelli ◽  
Alessandro Mancarella ◽  
...  

In the present paper, a model-based controller of engine torque and engine-out Nitrogen oxide (NOx) emissions, which was previously developed and tested by means of offline simulations, has been validated on a FPT F1C 3.0 L diesel engine by means of rapid prototyping. With reference to the previous version, a new NOx model has been implemented to improve robustness in terms of NOx prediction. The experimental tests have confirmed the basic functionality of the controller in transient conditions, over different load ramps at fixed engine speeds, over which the average RMSE (Root Mean Square Error) values for the control of NOx emissions were of the order of 55–90 ppm, while the average RMSE values for the control of brake mean effective pressure (BMEP) were of the order of 0.25–0.39 bar. However, the test results also highlighted the need for further improvements, especially concerning the effect of the engine thermal state on the NOx emissions in transient operation. Moreover, several aspects, such as the check of the computational time, the impact of the controller on other pollutant emissions, or on the long-term engine operations, will have to be evaluated in future studies in view of the controller implementation on the engine control unit.


2021 ◽  
Vol 11 (5) ◽  
pp. 2307
Author(s):  
João Lincho ◽  
Rui C. Martins ◽  
João Gomes

Parabens are widely used in different industries as preservatives and antimicrobial compounds. The evolution of analytical techniques allowed the detection of these compounds in different sources at µg/L and ng/L. Until today, parabens were already found in water sources, air, soil and even in human tissues. The impact of parabens in humans, animals and in ecosystems are a matter of discussion within the scientific community, but it is proven that parabens can act as endocrine disruptors, and some reports suggest that they are carcinogenic compounds. The presence of parabens in ecosystems is mainly related to wastewater discharges. This work gives an overview about the paraben problem, starting with their characteristics and applications. Moreover, the dangers related to their usage were addressed through the evaluation of toxicological studies over different species as well as of humans. Considering this, paraben detection in different water sources, wastewater treatment plants, humans and animals was analyzed based on literature results. A review of European legislation regarding parabens was also performed, presenting some considerations for the use of parabens.


2018 ◽  
Vol 28 (4) ◽  
pp. 436-444 ◽  
Author(s):  
Raul I. Cabrera ◽  
James E. Altland ◽  
Genhua Niu

Scarcity and competition for good quality and potable water resources are limiting their use for urban landscape irrigation, with several nontraditional sources being potentially available for these activities. Some of these alternative sources include rainwater, stormwater, brackish aquifer water, municipal reclaimed water (MRW), air-conditioning (A/C) condensates, and residential graywater. Knowledge on their inherent chemical profile and properties, and associated regional and temporal variability, is needed to assess their irrigation quality and potential short- and long-term effects on landscape plants and soils and to implement best management practices that successfully deal with their quality issues. The primary challenges with the use of these sources are largely associated with high concentrations of total salts and undesirable specific ions [sodium (Na), chloride (Cl), boron (B), and bicarbonate (HCO3−) alkalinity]. Although the impact of these alternative water sources has been largely devoted to human health, plant growth and aesthetic quality, and soil physicochemical properties, there is emergent interest in evaluating their effects on soil biological properties and in natural ecosystems neighboring the urban areas where they are applied.


2021 ◽  
Vol 4 (S3) ◽  
Author(s):  
Enrico Toniato ◽  
Prakhar Mehta ◽  
Stevan Marinkovic ◽  
Verena Tiefenbeck

AbstractThe transport sector is responsible for 25% of global CO2 emissions. To reduce emissions in the EU, a shift from the currently 745,000 operating public buses to electric buses (EBs) is expected in the coming years. Large-scale deployments of EBs and the electrification of bus depots will have a considerable impact on the local electric grid, potentially creating network congestion problems and spikes in the local energy load. In this work, we implement an exact, offline, modular multi-variable mixed-integer linear optimization algorithm to minimize the daily power load profile peak and optimally plan an electric bus depot. The algorithm accepts a bus depot schedule as input, and depending on the user input on optimization conditions, accounts for varying time granularity, preemption of the charging phase, vehicle-to-grid (V2G) charging capabilities and varying fleet size. The primary objective of this work is the analysis of the impact of each of these input conditions on the resulting minimized peak load. The results show that our optimization algorithm can reduce peak load by 83% on average. Time granularity and V2G have the greatest impact on peak reduction, whereas preemption and fleet splitting have the greatest impact on the computational time but an insignificant impact on peak reduction. The results bear relevance for mobility planners to account for innovative fleet management options. Depot infrastructure costs can be minimized by optimally sizing the infrastructure needs, by relying on split-fleet management or V2G options.


2018 ◽  
Vol 50 (2) ◽  
pp. 205
Author(s):  
Koh Liew See ◽  
Nayan Nasir ◽  
Saleh Yazid ◽  
Hashim Mohmadisa ◽  
Mahat Hanifah ◽  
...  

Clean water supply is a major problem among flood victims during flood events. This article aims to determine the sites of well water sources that can be utilised during floods in the District of Kuala Krai, Kelantan. Field methods and Geographic Information Systems (GIS) were applied in the process of selecting flood victim evacuation centres and wells. The data used were spatial data obtained primarily, namely the well data, evacuation centre data and flood area data. The well and evacuation centre data were obtained by field methods conducted to determine the position of wells using global positioning system tools, and the same for the location of the evacuation centres. Information related to evacuation centres was obtained secondarily from multiple agencies and gathered into GIS as an evacuation centre attribute. The flood area data was also obtained via secondary data and was digitised using the ArcGIS software. The data processing was divided into two stages, namely the first stage of determining the flood victim evacuation centres to be used in this research in a structural manner based on two main criteria which were the extent to which an evacuation centre was affected by the flood and the highest capacity of victims for each district with the greatest impact to the flood affected population. The second stage was to determine the location of wells based on three criteria, namely i) not affected by flood, ii) the closest distance to the selected flood victim evacuation centre and iii) located at different locations. Among the main GIS analyses used were locational analysis, overlay analysis, and proximity analysis. The results showed that four (4) flood evacuation centres had been chosen and matched the criteria set, namely SMK Sultan Yahya Petra 2, SMK Manek Urai Lama, SMK Laloh and SK Kuala Gris. While six (6) wells had been selected as water sources that could be consumed by the flood victims at 4 evacuation centres in helping to provide clean water supply, namely Kg. Keroh 16 (T1), Kg. Batu Mengkebang 10 (T2), Lepan Meranti (T3), Kg. Budi (T4), Kg. Jelawang Tengah 2 (T5) and Kg. Durian Hijau 1 (T6). With the presence of the well water sources that can be used during flood events, clean water supply can be distributed to flood victims at the evacuation centres. Indirectly, this research can reduce the impact of floods in the future, especially in terms of clean water supply even during the hit of a major flood.


Author(s):  
G A H Al-Kindi ◽  
R M Baul ◽  
K F Gill

A comparison of a number of commonly used orthogonal transforms, when applied to the recognition and visual inspection of engineering components, has been made. The impact on the performance and computational time for the machine vision process due to varying numbers of transform coefficients is assessed.


2017 ◽  
Vol 17 (5) ◽  
pp. 1490-1498
Author(s):  
L. J. Del Giacco ◽  
R. Drusiani ◽  
L. Lucentini ◽  
S. Murtas

This paper addresses the issue of how water played a role in ancient conflicts, from the poisoning of water sources to flooding, to stop the advance of enemy armies. It deals with military actions quoted by several ancient Greek and Roman authors, who in some cases narrate these experiences first-hand. Although many abhorred such actions, they were considered tactical expedients to resort to, as cited by the war manuals of the time. The analysis starts from the ‘manual’ Strategemata of Sextus Julius Frontinus, in addition to other references left by historians and chroniclers of different periods. It continues with the evaluation of the impact of the intentional actions of water contamination described by the ancient authors, according to present toxicological and health knowledge.


2013 ◽  
Vol 389 ◽  
pp. 849-853
Author(s):  
Fang Song Cui ◽  
Wei Feng ◽  
Da Zhi Pan ◽  
Guo Zhong Cheng ◽  
Shuang Yang

In order to overcome the shortcomings of precocity and stagnation in ant colony optimization algorithm, an improved algorithm is presented. Considering the impact that the distance between cities on volatility coefficient, this study presents an model of adjusting volatility coefficient called Volatility Model based on ant colony optimization (ACO) and Max-Min ant system. There are simulation experiments about TSP cases in TSPLIB, the results show that the improved algorithm effectively overcomes the shortcoming of easily getting an local optimal solution, and the average solutions are superior to ACO and Max-Min ant system.


Author(s):  
Tobias Hoßfeld ◽  
Michael Duelli ◽  
Dirk Staehle ◽  
Phuoc Tran-Gia

The performance of P2P content distribution in cellular networks depends highly on the cooperation and coordination of heterogeneous and often selfish mobile users. The major challenges are the identification of problems arising specifically in cellular mobile networks and the development of new cooperation strategies to overcome these problems. In the coherent previous chapter, the authors focused on the selfishness of users in such heterogeneous environments. This discussion is now extended by emphasizing the impact of mobility and vertical handover between different wireless access technologies. An abstract mobility model is required to allow the performance evaluation in feasible computational time. As a result, the performance in today’s and future cellular networks is predicted and new approaches to master heterogeneity in cellular networks are derived.


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