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- Rahimi, Fariba, et al.
(författare)
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Concurrent and Optimal Structure, Control and Implementation Design
- 2020
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Ingår i: Proceedings of 2020 IEEE 11th International Conference on Mechanical and Intelligent Manufacturing Technologies, ICMIMT 2020. - : Institute of Electrical and Electronics Engineers (IEEE).
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Konferensbidrag (refereegranskat)abstract
- Mechatronic system design includes a combination of different engineering disciplines. A common approach in design of mechatronic systems is based on a sequential method, where different disciplines are treated and designed separately. This paper extends earlier work on integrated physical and control design optimization with integrating an additional aspect of the corresponding embedded control system implementation. Our previous publications describe integrated design optimization through a few specific use cases but the impact of embedded control implementation on the structural design of the systems is neglected. In this paper, the approach is extended to cover discussions on control implementation and its effect on the physical dimensioning and vice versa. A multi-objective optimization approach is implemented and tested on a mechatronic system case study consisting of a DC-motor, a planetary gear, a flexible shaft, an embedded controller and a load. The couplings between the properties of different engineering domains are studied and highlighted. The presented approach which is aimed for early phases of design, considers the integration of three engineering disciplines in one design framework which so far has been missing.
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| 2. |
- Rahimi, Fariba
(författare)
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Multi-Criteria Co-Design optimization of Mechatronic Systems
- 2020
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Ingår i: 2020 IEEE International Conference on Mechatronics and Automation, ICMA 2020. - : Institute of Electrical and Electronics Engineers (IEEE). ; , s. 756-766
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Konferensbidrag (refereegranskat)abstract
- Integrated design optimization of mechatronic systems necessitates a concrete definition of requirements, design parameters and variables, optimization objectives and constraints. A multidisciplinary mechatronic design requires engineers from different domains to work together on the design approach. Different engineering disciplines impose different constraints on the system. To consider the impact of these disciplines and the interactions and coupling between different parameters, there is a need for integrated design method. In this paper, an integrated design optimization approach is presented that takes into account three engineering domains, physical dimensioning, control design and embedded control implementation impact, simultaneously. The optimization problem is a multi-objective method that considers the size of system, sampling frequency and sensor resolution as main objectives. Regarding each objective, there are a few constraints to be satisfied by the final optimum system. The approach is applied to a non-linear mechatronic case including a DC-motor, a timing belt drive and a load. Non-linear dynamics of a timing belt are considered as a new physical component in the method and the system is linearized, controlled and optimized at defined operational points. Sensor resolution and location impact on the optimal system are analysed using a quantization model. It is shown that the approach allows engineering designers to integrate multidisciplinary optimization method to achieve a logical optimal system without degrading the system performance in each domain.
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| 3. |
- Rahimi, Shadi, 1982, et al.
(författare)
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Co-culturing Bacillus subtilis and wastewater microbial community in a bio-electrochemical system enhances denitrification and butyrate formation
- 2020
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Ingår i: Chemical Engineering Journal. - : Elsevier BV. - 1385-8947. ; 397
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Tidskriftsartikel (refereegranskat)abstract
- Bio-augmentation could be a promising strategy to improve processes for treatment and resource recovery from wastewater. In this study, the Gram-positive bacterium Bacillus subtilis was co-cultured with the microbial communities present in wastewater samples with high concentrations of nitrate or ammonium. Glucose supplementation (1%) was used to boost biomass growth in all wastewater samples. In anaerobic conditions, the indigenous microbial community bio-augmented with B. subtilis was able to rapidly remove nitrate from wastewater. In these conditions, B. subtilis overexpressed nitrogen assimilatory and respiratory genes including nasD, nasE, narG, narH, and narI, which arguably accounted for the observed boost in denitrification. Next, we attempted to use the ammonium- and nitrate-enriched wastewater samples bio-augmented with B. subtilis in the cathodic compartment of bioelectrochemical systems (BES) operated in anaerobic condition. B. subtilis only had low relative abundance in the microbial community, but bio-augmentation promoted the growth of Clostridium butyricum and C. beijerinckii, which became the dominant species. Both bio-augmentation with B. subtilis and electrical current from the cathode in the BES promoted butyrate production during fermentation of glucose. A concentration of 3.4 g/L butyrate was reached with a combination of cathodic current and bio-augmentation in ammonium-enriched wastewater. With nitrate-enriched wastewater, the BES effectively removed nitrate reaching 3.2 mg/L after 48 h. In addition, 3.9 g/L butyrate was produced. We propose that bio-augmentation of wastewater with B. subtilis in combination with bioelectrochemical processes could both boost denitrification in nitrate-containing wastewater and enable commercial production of butyrate from carbohydrate- containing wastewater, e.g. dairy industry discharges. These results suggest that B. subtilis bio-augmentation in our BES promotes simultaneous wastewater treatment and butyrate production. © 2020 The Authors
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