Assessment of the effectiveness of a field-scale combined ecological treatment system at removing water pollutants, after optimization using a system dynamic model: a case study of rural inland ponds in China

Author(s):  
Mei Liu ◽  
Julin Yuan ◽  
Meng Ni ◽  
Qingping Lian
2015 ◽  
Vol 16 (1) ◽  
pp. 54-68 ◽  
Author(s):  
Andra Blumberga ◽  
Lelde Timma ◽  
Dagnija Blumberga

Abstract When the renewable energy is used, the challenge is match the supply of intermittent energy with the demand for energy therefore the energy storage solutions should be used. This paper is dedicated to hydrogen accumulation from wind sources. The case study investigates the conceptual system that uses intermitted renewable energy resources to produce hydrogen (power-to-gas concept) and fuel (power-to-liquid concept). For this specific case study hydrogen is produced from surplus electricity generated by wind power plant trough electrolysis process and fuel is obtained by upgrading biogas to biomethane using hydrogen. System dynamic model is created for this conceptual system. The developed system dynamics model has been used to simulate 2 different scenarios. The results show that in both scenarios the point at which the all electricity needs of Latvia are covered is obtained. Moreover, the methodology of system dynamics used in this paper is white-box model that allows to apply the developed model to other case studies and/or to modify model based on the newest data. The developed model can be used for both scientific research and policy makers to better understand the dynamic relation within the system and the response of system to changes in both internal and external factors.


10.29007/w5vl ◽  
2018 ◽  
Author(s):  
Barry Evans ◽  
Lydia Vamvakeridou-Lyroudia ◽  
Janez Susnik ◽  
Antonio Trabucco ◽  
Simone Mereu ◽  
...  

Water, land, food, energy, and climate are all interconnected, comprising a coherent system (the ‘Nexus’), dominated by complexity and feedback. The interactions between these different nexus components and their responses to climate change conditions are complicated as each feedback into the other. Consequently future policies should take into account the whole Nexus, when it comes to ascertain their long term impact on the system. This paper presents the conception of a System Dynamic Model (SDM) representing the Nexus, populating it with data from various sources (including output from specific thematic models covering different Nexus components), under different climate change and socioeconomic pathway scenarios. The SDM is then converted into R scripting to be included in the Knowledge Elicitation Engine (KEE) communicating with a Serious Game (SG). Models and games are built specifically for ten Case Studies, at regional, national, continental and global level. The SG is being developed for decision making for local stakeholders to study and get acquainted to long term impacts of different policies on the Nexus. In this paper the regional Case Study of Sardinia is presented as proof of concept.


2016 ◽  
Vol 83 ◽  
pp. 179-192 ◽  
Author(s):  
Duanyang Xu ◽  
Alin Song ◽  
Hefeng Tong ◽  
Hongyan Ren ◽  
Yunfeng Hu ◽  
...  

2021 ◽  
Vol 301 ◽  
pp. 126901
Author(s):  
Tsai-Chi Kuo ◽  
Ni-Ying Hsu ◽  
Reza Wattimena ◽  
I-Hsuan Hong ◽  
Chin-Jung Chao ◽  
...  

Author(s):  
Qiangang Zheng ◽  
Yong Wang ◽  
Chongwen Jin ◽  
Haibo Zhang

The modern advanced aero-engine control methods are onboard dynamic model–based algorithms. In this article, a novel aero-engine dynamic modeling method based on improved compact propulsion system dynamic model is proposed. The aero-engine model is divided into inlet, core engine, surge margin and nozzle models for establishing sub-model in the compact propulsion system dynamic model. The model of core engine is state variable model. The models of inlet, surge margin and nozzle are nonlinear models which are similar to the component level model. A new scheduling scheme for basepoint control vector, basepoint state vector and basepoint output vector which considers the change of engine total inlet temperature is proposed to improve engine model accuracy especially the steady. The online feedback correction of measurable parameters is adopted to improve the steady and dynamic accuracy of model. The modeling errors of improved compact propulsion system dynamic model remain unchanged when engine total inlet temperature of different conditions are the same or changes small. The model accuracy of compact propulsion system dynamic model, especially the measurable parameters, is improved by online feedback correction. Moreover, the real-time performance of compact propulsion system dynamic model and improved compact propulsion system dynamic model are much better than component level model.


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