Engineering Aspects of Recirculating Aquaculture Systems

2000 ◽  
Vol 34 (1) ◽  
pp. 68-78 ◽  
Author(s):  
James M. Ebeling
Keyword(s):  
System Integration ◽  
Pure Oxygen ◽  
Monitoring Systems ◽  
Oxygen Injection ◽  
Recirculating Aquaculture ◽  
Individual Unit ◽  
Recirculating Aquaculture Systems ◽  
Water Recirculation ◽  
The Individual ◽  
And Control

Intensive recirculating aquaculture systems utilizing water recirculation and pure oxygen injection are examined in terms of the individual unit processes that are required to handle the wastes generated by fish at stocking densities as high as 120‐150 kg/m3. These unit processes include solid waste removal, nitrification of ammonia and nitrite, aeration or oxygenation, carbon dioxide removal, and control and monitoring systems. Overall system integration is reviewed and an example of a research/commercial intensive recirculating system is presented.

scholarly journals Tracking and Analysis of the Movement Behavior of European Seabass (Dicentrarchus labrax) in Aquaculture Systems

2021 ◽  
Vol 2 ◽  
Author(s):  
Dimitra G. Georgopoulou ◽  
Orestis Stavrakidis-Zachou ◽  
Nikos Mitrizakis ◽  
Nikos Papandroulakis
Keyword(s):  
Computer Vision ◽  
Dicentrarchus Labrax ◽  
Movement Behavior ◽  
Monitoring And Control ◽  
Fish Welfare ◽  
Recirculating Aquaculture ◽  
European Seabass ◽  
Recirculating Aquaculture Systems ◽  
Acoustic Methods ◽  
And Control

Monitoring and understanding fish behavior is crucial for achieving precision in everyday husbandry practices (i.e. for optimizing farm performance), and for improving fish welfare in aquaculture. Various intelligent monitoring and control methods, using mathematical models, acoustic methods and computer vision, have been recently developed for this reason. Here, a tracking algorithm based on computer vision that extracts short trajectories of individual European seabass in both recirculating aquaculture systems and sea cages was developed using videos from network cameras. Using this methodology, parameters such as instantaneous normalized speed, travel direction and preference for the tank surface by European seabass could be quantified. When testing the sensitivity of this algorithm for detecting fish swimming variations under different husbandry scenarios, we found that the algorithm could detect variations in all of the abovementioned parameters and could potentially be a useful tool for monitoring the behavioral state of European seabass.

scholarly journals Interactive effects between travel behaviour and COVID-19: a questionnaire study

2021 ◽  
Author(s):  
Jinbao Zhang ◽  
Jaeyoung Lee
Keyword(s):  
Early Stage ◽  
Travel Behaviour ◽  
Interactive Effects ◽  
Factors Affecting ◽  
Individual Level ◽  
Passenger Volume ◽  
Spatial Autoregressive ◽  
Railway Passenger ◽  
The Individual ◽  
And Control

Abstract This study has two main objectives: (i) to analyse the effect of travel characteristics on the spreading of disease, and (ii) to determine the effect of COVID-19 on travel behaviour at the individual level. First, the study analyses the effect of passenger volume and the proportions of different modes of travel on the spread of COVID-19 in the early stage. The developed spatial autoregressive model shows that total passenger volume and proportions of air and railway passenger volumes are positively associated with the cumulative confirmed cases. Second, a questionnaire is analysed to determine changes in travel behaviour after COVID-19. The results indicate that the number of total trips considerably decreased. Public transport usage decreased by 20.5%, while private car usage increased by 6.4%. Then the factors affecting the changes in travel behaviour are analysed by logit models. The findings reveal significant factors, including gender, occupation and travel restriction. It is expected that the findings from this study would be helpful for management and control of traffic during a pandemic.

scholarly journals Medicolegal Causation Investigation of Bacterial Endocarditis Associated with an Oral Surgery Practice Using the INFERENCE Approach

2021 ◽  
Vol 18 (14) ◽  
pp. 7530
Author(s):  
Putri Dianita Ika Meilia ◽  
Maurice P. Zeegers ◽  
Herkutanto ◽  
Michael D. Freeman
Keyword(s):  
Oral Surgery ◽  
Invasive Procedure ◽  
Bacterial Endocarditis ◽  
Infection Prevention And Control ◽  
Healthcare Associated Infection ◽  
Department Of Health ◽  
The Individual ◽  
Healthcare Associated ◽  
And Control ◽  
Causation Analysis

Investigating causation is a primary goal in forensic/legal medicine, aiming to establish the connection between an unlawful/negligent act and an adverse outcome. In malpractice litigation involving a healthcare-associated infection due to a failure of infection prevention and control practices, the medicolegal causal analysis needs to quantify the individual causal probabilities to meet the evidentiary requirements of the court. In this paper, we present the investigation of the most probable cause of bacterial endocarditis in a patient who underwent an invasive procedure at a dental/oral surgical practice where an outbreak of bacterial endocarditis had already been identified by the state Department of Health. We assessed the probability that the patient’s endocarditis was part of the outbreak versus that it was an unrelated sporadic infection using the INFERENCE (Integration of Forensic Epidemiology and the Rigorous Evaluation of Causation Elements) approach to medicolegal causation analysis. This paper describes the step-by-step application of the INFERENCE approach to demonstrate its utility in quantifying the probability of causation. The use of INFERENCE provides the court with an evidence-based, transparent, and reliable guide to determine liability, causation, and damages.

scholarly journals Anaerobic Mineralization of Recirculating Aquaculture Drum Screen Effluent for Use as a Naturally-Derived Nutrient Solution in Hydroponic Cropping Systems

Conservation ◽  
2021 ◽  
Vol 1 (3) ◽  
pp. 151-167
Author(s):  
Joseph Tetreault ◽  
Rachel Fogle ◽  
Todd Guerdat
Keyword(s):  
Nutrient Solution ◽  
Agricultural Waste ◽  
The United States ◽  
Anaerobic Treatment ◽  
Production Costs ◽  
Effluent Treatment ◽  
Limiting Factors ◽  
Fertilizer Treatment ◽  
Recirculating Aquaculture ◽  
Recirculating Aquaculture Systems

Operation and effluent treatment costs are limiting factors for the success of recirculating aquaculture systems (RAS) in meeting seafood demand in the United States. Adopting a capture-and-reuse waste management model similar to terrestrial agriculture farmers would allow RAS farmers to monetize effluent and offset production costs. The moisture content and nutrient profile of RAS effluent makes it a potential option for use as a hydroponic fertilizer. Treatment of RAS waste is needed to mineralize particulate-bound nutrients before becoming a viable hydroponic nutrient solution. Anaerobic treatment (AT), a method used by municipal and agricultural waste treatment facilities to reduce total solids, has been shown to successfully mineralize particulate-bound nutrients from RAS effluent. Continuously mixed anaerobic batch bioreactors were used to evaluate the degree to which AT may mineralize particulate-bound nutrients in solid RAS waste. Concentrations of twelve different macro- and micro-nutrients were analyzed in the waste before and after treatment. Effluent samples were analyzed to determine the fraction of each nutrient in the solid and aqueous forms. This study showed that AT is an effective method to mineralize particulate-bound nutrients in RAS effluent and the mineralization rate data may be used to design a pilot-scaled flow-through RAS effluent treatment system.

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