scholarly journals Mathematical model for predicting oxygen concentration in tilapia fish farms

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
El-Sayed Khater ◽  
Adel Bahnasawy ◽  
Hossam El-Ghobashy ◽  
Yousry Shaban ◽  
Faisal Elsheikh ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Oxygen Consumption ◽  
Dissolved Oxygen ◽  
Growth Period ◽  
Fish Growth ◽  
Fish Farms ◽  
Recirculating Aquaculture ◽  
Oxygen Generator ◽  
Oxygen Addition ◽  
The Individual

AbstractThe main aim of this research is to develop a mathematical model to predict the dissolved oxygen in recirculating aquaculture system. The oxygen consumption of the model through the fish respiration and nitrification and the oxygen addition of the model through oxygen generator and water pumping. The effect of different water temperatures (24, 26, 28, 30 and 32 °C) on the dissolved oxygen consumption through fish respiration, biofilter and nitrification and fish growth were studied. An experiment to measure oxygen consumed by fish respiration and biofilteration and fish growth with the growth period and to validate the model results was carried out. The oxygen consumption predicted by the model was in a good agreement with those measured by the system. The oxygen consumption by fish respiration ranged 12.04 to 47.53 g O2 m−3 h−1 experimentally, while it was from 12.01 to 46.06 g O2 m−3 h−1 theoretically. The predicted and measured oxygen consumption through biofilteration values ranged from 0.43 to 21.91 and 0.45 to 23.09 g O2 m−3 h−1, respectively. The individual fish weight from the system ranged from 3.00 to 209.52 g experimentally while it was from 3.00 to 226.25 g theoretically during the whole period.

A Mathematical Model of Some Aspects of Fish Growth, Respiration, and Mortality

1967 ◽  
Vol 24 (11) ◽  
pp. 2355-2453 ◽  
Author(s):  
Erik Ursin
Keyword(s):  
Mathematical Model ◽  
Weight Loss ◽  
Oxygen Consumption ◽  
Metabolic Model ◽  
The Body ◽  
Fish Growth ◽  
Natural Mortality ◽  
Gill Area ◽  
Growth Respiration ◽  
The Difference

A simple metabolic model describing growth as the difference between what enters the body and what leaves it, is elaborated assuming that synthetic processes (the building-up, the anabolism) are consuming energy supplied by processes of decomposition (the break-down, the catabolism). This leads to partitioning total catabolism into two components, one being a function of the rate of synthesis, another keeping the body functioning independently of synthesis. The rate of synthesis is described as a function of food taken, of the efficiencies of digestion and energy conversion, and of the absorbing surface of the intestine. Catabolic processes are supposed to be functions of the oxygen concentration in the water, the absorbing surface of the gills, and the rate of oxygen transport. Both kinds of processes are made functions of temperature in the way enzymatic processes usually are. Assuming that molecular interactions accidentally go wrong makes natural mortality, like growth, a function of the rates of anabolic and catabolic processes and body size.Application of the model to data of length-at-age, food and oxygen consumption, weight loss, gill area, and natural mortality indicates that at least some of the main hypotheses cannot be rejected on available evidence.

scholarly journals Automatic Dissolved Oxygen Control to Oreochromis Fish’s Crop into Geomembrane Tank

2020 ◽  
Vol 25 (1) ◽  
pp. 97-103
Author(s):  
Gustavo Adolfo Perdomo-Gómez ◽  
Karina Corredor-Galvis ◽  
Santiago Duarte-Rivera ◽  
Kelyn Rosely Botina-Trujillo ◽  
Diego Andres Mendez-Pastrana
Keyword(s):  
Dissolved Oxygen ◽  
Oxygen Sensor ◽  
Fish Growth ◽  
Raspberry Pi ◽  
Oxygen Control ◽  
Recirculation Flow ◽  
Oxygen Generator ◽  
Dissolved Oxygen Control ◽  
Water Recirculation ◽  
National Production

Huila is a Colombian state with a high production of Oreochromis fish, its contribution to national production is of 53%, that is distributed in 338 hectares of ponds on land and floating cages. The environmental and climatic characteristics of the region allow having dissolved oxygen production in the ponds between 4ppm and 12ppm during the day, but at night the situation is unfavorable, since the amount of dissolved oxygen can decrease up to 1ppm while carbon dioxide increases. Therefore, it is necessary to have adequate oxygenation equipment and systems to prevent delayed in fish growth and to decrease death rates. This article presents the design and implementation of an automatic dissolved oxygen control system by manipulation of a water recirculation flow that operates in parallel with an industrial oxygen generator. The implemented system tracks and records the temperature and oxygen variables present in the geomembrane tank to evaluate the process evolution for different periods of the fish development cycle. The data was acquired using an Atlas Scientific dissolved oxygen sensor kit and a DS18B20 temperature probe they send the data directly to a Raspberry Pi that transmits by wireless the information collected from the process to the SISCEFA web server and a mobile application through which users can observe the data traceability. The dissolved oxygen concentration was maintained within the threshold established and the fish rate death decrease.

scholarly journals Effects of face masks on performance and cardiorespiratory response in well-trained athletes

2021 ◽  
Author(s):  
Florian Egger ◽  
Dominic Blumenauer ◽  
Patrick Fischer ◽  
Andreas Venhorst ◽  
Saarraaken Kulenthiran ◽  
...  
Keyword(s):  
Oxygen Consumption ◽  
Minute Ventilation ◽  
Anaerobic Exercise ◽  
Peak Oxygen Consumption ◽  
Exercise Tests ◽  
Maximum Performance ◽  
Outdoor Sports ◽  
Cardiorespiratory Response ◽  
Individual Anaerobic Threshold ◽  
The Individual

Abstract Background During the COVID-19 pandemic, compulsory masks became an integral part of outdoor sports such as jogging in crowded areas (e.g. city parks) as well as indoor sports in gyms and sports centers. This study, therefore, aimed to investigate the effects of medical face masks on performance and cardiorespiratory parameters in athletes. Methods In a randomized, cross-over design, 16 well-trained athletes (age 27 ± 7 years, peak oxygen consumption 56.2 ± 5.6 ml kg−1 min−1, maximum performance 5.1 ± 0.5 Watt kg−1) underwent three stepwise incremental exercise tests to exhaustion without mask (NM), with surgical mask (SM) and FFP2 mask (FFP2). Cardiorespiratory and metabolic responses were monitored by spiroergometry and blood lactate (BLa) testing throughout the tests. Results There was a large effect of masks on performance with a significant reduction of maximum performance with SM (355 ± 41 Watt) and FFP2 (364 ± 43 Watt) compared to NM (377 ± 40 Watt), respectively (p < 0.001; ηp2 = 0.50). A large interaction effect with a reduction of both oxygen consumption (p < 0.001; ηp2 = 0.34) and minute ventilation (p < 0.001; ηp2 = 0.39) was observed. At the termination of the test with SM 11 of 16 subjects reported acute dyspnea from the suction of the wet and deformed mask. No difference in performance was observed at the individual anaerobic threshold (p = 0.90). Conclusion Both SM and to a lesser extent FFP2 were associated with reduced maximum performance, minute ventilation, and oxygen consumption. For strenuous anaerobic exercise, an FFP2 mask may be preferred over an SM.

Factors influencing the individual effects of blood transfusions on oxygen delivery and oxygen consumption*

2001 ◽  
Vol 29 (Supplement) ◽  
pp. S173-S179 ◽  
Author(s):  
Mattias Casutt ◽  
Burkhardt Seifert ◽  
Thomas Pasch ◽  
Edith R. Schmid ◽  
Marko I. Turina ◽  
...  
Keyword(s):  
Oxygen Consumption ◽  
Oxygen Delivery ◽  
Blood Transfusions ◽  
Factors Influencing ◽  
Individual Effects ◽  
The Individual

Positioning changes of mayfly nymphs due to behavioral regulation of oxygen consumption

1980 ◽  
Vol 58 (4) ◽  
pp. 618-622 ◽  
Author(s):  
Michael J. Wiley ◽  
Steven L. Kohler
Keyword(s):  
Oxygen Consumption ◽  
Dissolved Oxygen ◽  
Oxygen Concentration ◽  
Field Conditions ◽  
Experimental Investigations ◽  
Behavioral Patterns ◽  
Behavioral Regulation ◽  
Dissolved Oxygen Concentration ◽  
Habitat Distribution ◽  
Renewal Rate

Experimental investigations in a small artificial stream showed that the positioning of mayfly nymphs (Ephemeroptera) on stones varied with dissolved oxygen concentration (DO). At low DO levels nymphs moved to current-exposed positions, presumably to increase the renewal rate of oxygen at respiratory exchange surfaces. The expected magnitude of positioning changes under field conditions was determined and suggests that behavioral regulation of oxygen consumption may commonly influence both habitat distribution and diel behavioral patterns. The implications of these results to drift studies are also discussed.

scholarly journals Oxygen uptake during mineralization of photosynthesized carbon from phytoplankton of the Barra Bonita Reservoir: a mesocosm study

2008 ◽  
Vol 68 (1) ◽  
pp. 115-122 ◽  
Author(s):  
MB. Cunha-Santino ◽  
SP. Gouvêa ◽  
I. Bianchini Jr ◽  
AAH. Vieira
Keyword(s):  
Electrical Conductivity ◽  
Oxygen Consumption ◽  
Oxygen Uptake ◽  
Dissolved Oxygen ◽  
Water Samples ◽  
Microbial Respiration ◽  
Co2 Concentration ◽  
Ph Values ◽  
Organic Products ◽  
Aulacoseira Granulata

This study aimed to discuss and describe the oxygen consumption during aerobic mineralization of organic products (cells and excretion products) from five unialgal cultures: Cryptomonas sp., Microcystis aeruginosa, Anabaena spiroides, Thalassiosira sp. and Aulacoseira granulata. These species were isolated from Barra Bonita reservoir (22º 29’ S and 48º 34’ W) and cultivated in the laboratory. From each culture, two decomposition chambers were prepared; each chamber contained about 130 mg.L-1 of carbon from water samples of the reservoir. The chambers were aerated and incubated in the dark at 20.0 ºC. The concentration of dissolved oxygen, pH values and electrical conductivity of the solutions were determined during a period of 10 days. The results indicated increases in oxygen consumption for all the solutions studied and also for electrical conductivity. The pH values presented a decreasing tendency throughout the experiment. Oxygen consumption varied from 43 (Aulacoseira granulata chamber) to 345 mg O2 g-1 C (Anabaena spiroides chamber). Decrease in pH values was probably due to increase in CO2 concentration from microbial respiration. Increase in electrical conductivity might be due to the liberation of ions during decomposition. The results demonstrate the potentiality of the studied genera in influencing oxygen availability followed by a die-off event. It also indicates the possibility of changing of the electrical conductivity and pH values in the water column due the aerobic algae mineralization.

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