An innovative method to calculate oxygen consumption rate

Based on heat and mass transfer characteristics of spontaneous combustion of coal,Arrhenius equation and the Ranz-Marshall correlation,a novel approach was proposed in this paper to estimate oxygen consumption rate of self-ignition of coal at high temperature.Compared with the conventional methods,this approach involves not only kinetic properties of self-ignition of coal and temperature,but also the ambient air flow characteristics and diameter of coal particle.To testify the proposed approach,oxygen consumption rates at high temperature were measured by the programmable isothermal oven experiments.Comparisons between experimental and theoretical results indicate that the rates of oxygen depletion calculated by the proposed approach agree well with those measured from laboratory-scale experiments,which further validates the proposed approach.

Determining oxygen consumption rate and asphyxiation point in Chanodichthys mongolicus using an improved respirometer chamber

Knowledge of oxygen consumption rates and asphyxiation points in fish is important to determine appropriate stocking and water quality management in aquaculture. The oxygen consumption rate and asphyxiation point in Chanodichthys mongolicus were detected under laboratory conditions using an improved respirometer chamber. The results revealed that more accurate estimates can be obtained by adjusting the volume of the respirometer chamber, which may avoid system errors caused by either repeatedly adjusting fish density or selecting different equipment specifications. The oxygen consumption rate and asphyxiation point of C. mongolicus increased with increasing water temperature and decreasing fish size. Changes in the C. mongolicus oxygen consumption rate were divided into three stages at water temperatures of 11-33~C： （I） a low temperature oxygen consumption rate stage when water temperature was 11-19~C, （2） the optimum temperature oxygen consumption rate stage when water temperature was 19-23~C, and （3） a high temperature oxygen consumption rate stage when water temperature was 〉27~C. The temperature quotients （Q10） obtained suggested that C. mongolicus preferred a temperature range of 19-23~C. At 19~C, C. mongolicus exhibited higher oxygen consumption rates during the day when the maximum values were observed at 10：00 and 14：00 than at night when the minimum occurred at 02：00.

Rates of oxygen consumption and tolerance of hypoxia and desiccation in Chinese black sleeper(Bostrichthys sinensis)and mudskipper(Boleophthalmus pectinirostris)embryos

The rates of oxygen consumption, tolerance of hypoxia and desiccation of the Chinese black sleeper （ Bostrichthys sinensis） and mudskipper （Boleophthalmus pectinirostris） embryos were investigated. The pattern of oxygen consumption of the Chinese black sleeper embryos was similar to that of the mudskipper ones. The lowest rates of oxygen consumption [ （ 1.65 ±0. 66） nmol/ （ind. ·h） ] of the Chinese black sleeper embryos 16 h after fertilization and the lowest rates of oxygen consumption [ （0.79± 0.08 ）nmolf（ ind. · h） ] of the mudskipper embryos 6 h after fertilization were recorded, respectively. Then the rates of oxygen consumption of these two species embryos increased gradually until hatching [ （8.26 ± 1.70 ） nmolf（ ind.· h） in the Chinese black sleeper, （2.69 ± 0.23 ）nmolf（ ind. · h） in mudskipper]. After exposure to hypoxia water （0.16 mg/dm^3）, bradycardia of the embryos occurred in both the Chinese black sleeper and the mudskipper. However, the Chinese black sleeper embryos survived approximately 45 min longer than the mudskipper ones. After exposure to desiccation at a relative humidity of 58%, bradycardia of the embryos was observed in both the Chinese black sleeper and the mudskipper, and the Chinese black sleeper embryos lived approximately 9 min longer than the mudskipper ones.

Effect of Fouling on Feeding, Oxygen Consumption and Waste Excretion of Pearl Oyster Pinctada martensii in Daya Bay Cultivation

Biofouling is a particular problem in the pearl oyster culture. It may reduce the growth and survival rates of the cultured species. Foulers are often themselves filter feeders, and are therefore potential competitors for food resource with the cultured species. Fouling organisms may also reduce the oxygen supply. A study was conducted to measure the impact of foulers on feeding oxygen consumption, and waste excretion. POM, ammonia, phosphate and oxygen concentration were measured in various treatments （cultured species, foulers）. This study showed that fouling organisms had significant effect on food uptake, oxygen consumption and waste excretion. The clearance rate, ammonia and phosphate release rate, oxygen consumption rate of the fouled pearl oyster were greater than those of the clean pearl oysters. Other foulers that settled on cages or buoys also contributed much to phytoplankton depletion, oxygen consumption and concentration increase of ammonia and phosphate in water. Therefore, this study showed us that foulers were important competitors in the pearl oyster cultivation of Daya Bay in November 2005.

The Effect of Toxic Sulfide Exposure on Oxygen Consumption and Oxidation Products in Urechis unicinctus(Echiura:Urechidae)

To investigate sulfide detoxification in Urech＆ unicinctus, oxygen consumption rate and sulfide detoxification products were analyzed during sulfide exposure under controlled laboratory conditions. The results showed that oxygen consumption rates were elevated significantly during 3 h sulfide exposure compared to the control （P〈0.05）. The concentration of sulfite in body wall and hindgut of experimental worms increased significantly （P〈0.05） when exposed to 50 μmolL^-1 sulfide, reached a maximum at 24 h and then decreased. Similar result was observed in worms exposed to 150 μmolL^-1 sulfide except that sulfite concentration reached a maximum at 12 h. Contents of thiosulfate in body wall and hindgut of U. unicinctus exposed to sulfide were also significantly higher than that of the control without sulfide exposure. In conclusion, during short-time sulfide exposure U. unicinctus may raise oxygen consumption to detoxify toxic sulfide into sulfite and thiosulfate. Sulfide detoxification was restrained when the exposure time was prolonged or sulfide concentration was increased, which was indicated by decrease of sulfite, the intermediate product of sulfide detoxification.

Oxygen consumption and ammonia-N excretion of Meretrix meretrix in different temperature and salinity

Effects of temperatures and salinities on oxygen consumption and ammonia-N excretion rate of clam Meretrix meretrix were studied in laboratory from Oct. 2003 to Jan. 2004. Two schemes were designed in incremented temperature at 10, 15, 20, 25℃ at 31.5 salinity and in incremented salinity at16.0, 21.0, 26.0, 31.5, 36.0, and 41.0 at 20℃, all for 8-10 days. From 10 to 25℃, both respiration and excretion rate were increased. One-way ANOVA analysis demonstrated significant difference （P〈0.01） in physiological parameters in this temperature range except between 15 and 20℃. The highest Q10 thermal coefficient value （12.27） was acquired between 10 and 15℃, and about 1 between 15 and 20℃, indicating M. meretrix could well acclimate to temperature changes in this range. Salinity also had significant effects on respiration and excretion rate （P〈0.05）. The highest values of respiration and excretion rate of M. meretrix were recorded at 16.0 salinity （20℃）. These two physiological parameters decreased as salinity increased until reached the minimum Q10 value at 31.5 （20℃）, then again, these parameters increased with increasing salinity from 31.5 to 41.0. M. meretrix can catabolize body protein to cope with osmotic pressure stress when environmental salinity is away from its optimal range. No significant difference was observed between 26.0 and 36.0 in salinity （P〉0.05）, suggesting that a best metabolic salinity range for this species is between 26.0 and 36.0.

Study on Oxygen Consumption of Erinaceus europaeus under Laboratory Conditions

[Objective]The study aimed to determine oxygen consumption of Erinaceus europaeus at different temperatures to accumulate basic da- ta for the protection and deep discuss of Erinaceus europaeus. [Method]By using the improved close respiration apparatus,the time spent by ani- mals consuming a unit volume of oxygen was recorded by the improved close respiration apparatus to estimate oxygen consumption of Erinaceus europaeus at 20,25 and 30 °C respectively. [Result]When the temperature varied from 20 to 30 °C,the oxygen consumption and oxygen con- sumption rate of Erinaceus europaeus reduced with the increase of external temperature on the whole. The weight of Erinaceus europaeus had no obvious relation with its oxygen consumption and oxygen consumption rate. In addition,the temperature had linear regression relationships with the oxygen consumption and oxygen consumption rate of Erinaceus europaeus,that is,the linear regression equation between oxygen consumption （ x 0 ） （ ml/h） and temperature （ t） was x 0 =658. 81 -14. 98t,and the equation between oxygen consumption rate （ Q 0 ） [L/（ kg·h） ]and tempera- ture （ t） was Q 0 =827. 94 -19. 52t. [Conclusion]The metabolic rate of Erinaceus europaeus changed with environmental temperature,and 20 °C was more suitable for its growth,conforming with the fact that it is active just at night.

EFFECTS OF TEMPERATURE ON OXYGEN CONSUMPTION AND AMMONIA EXCRETION BY SOLENAIA OLEIVORA

The effects of water temperature on oxygen consumption rate and ammonia excretion rate of Solenaia oleivora were studied in the laboratory. The results showed that, under controlled conditions and ambient temperatures 15—30℃, the relationship between oxygen consumption rate (O) [mg/h] and dry weight of soft tissue (W) [g] can be represented by an allometric equation O=aW b, while the relationship between ammonia excretion rate (N) [μg/h] and dry weight of soft tissue (W) [g] follows also an allometric equation N=cW b. It is indicated that both metabolic rates are correlated positively with water temperature. High temperature can reduce the level of protein metabolism. The linear regression among oxygen consumption rate (O), temperature (T) and dry weight of soft tissue (W) can be described by the equation O=-0.6513+0.0532T+0.1073W, and for ammonia this relation is N=32.1626-1.0566T+1.3222W, the multiple relation coefficient was 0.9642 and 0.8921, respectively.

Metabolic rates and biochemical compositions of Apostichopus japonicus (Selenka) tissue during periods of inactivity

Estivation, hibernation, and starvation are indispensable inactive states of sea cucumbers Apostichopusjaponicus in nature and in culture ponds. Generally, temperature is the principal factor that induces estivation or hibernation in the sea cucumber. The present study provided insight into the physiological adaptations ofA. japonicus during the three types of inactivity （hibernation, estivation, and starvation） by measuring the oxygen consumption rates （Vo2） and biochemical compositions under laboratory conditions of low （3℃）, normal （17℃） and high （24℃） temperature. The results show that the characteristics of A. japonicus in dormancy （hibernation and estivation） states were quite different from higher animals, such as fishes, amphibians, reptiles, and mammals, but more closely resembled a semi-dormant state. It was observed that the shift in the A. japonicus physiological state from normal to dormancy was a chronic rather than acute process, indicated by the gradual depression of metabolic rate. While metabolic rates declined 44.9% for the estivation group and 71.7% for the hibernation group, relative to initial rates, during the 36 d culture period, metabolic rates were not maintained at constant levels during these states. The metabolic depression processes for sea cucumbers in hibernation and estivation appeared to be a passive and an active metabolic suppression, respectively. In contrast, the metabolic rates （128.904-11.70 μg/g h） of estivating sea cucumbers were notably higher （107.85±6.31 μg/gh） than in starving sea cucumbers at 17℃, which indicated that the dormancy mechanism here, as a physiological inhibition, was not as efficient as in higher animals. Finally, the principle metabolic substrate or energy source of sea cucumbers in hibernation was lipid, whereas in estivation they mainly consumed protein in the early times and both protein and lipid thereafter.

Effect of temperature on the standard metabolic rates of juvenile and adult Exopalaemon carinicauda

Ridgetail white prawn （Exopalaemon carinicauda） are of significant economic importance in China where they are widely cultured. However, there is little information on the basic biology of this species. We evaluated the effect of temperature （16, 19, 22, 25, 28, 31, and 34℃） on the standard metabolic rates （SMRs） of juvenile and adult E. carinicauda in the laboratory under static conditions. The oxygen consumption rate （OCR）, ammonia-N excretion rate （AER）, and atornic ratio of oxygen consumed to nitrogen consumed （O：N ratio） of juvenile and adult E. carinicauda were significantly influenced by temperature （P〈0.05）. Both the OCR and AER of juveniles increased significantly with increasing temperature from 16 to 34℃, but the maximum OCR for adults was at 31℃. Juvenile shrimp exhibited a higher OCR than the adults from 19 to 34℃. There was no significant difference between the AERs of the two life-stages from 16 to 31 ℃ （P〉0.05）. The O：N ratio in juveniles was significantly higher than that in the adults over the entire temperature range （P〈0.05）. The temperature coefficient （Q_10） of OCR and AER ranged from 5.03 to 0.86 and 6,30 to 0.85 for the adults, respectively, and from 6,09-1.03 and 3.66-1.80 for the juveniles, respectively. The optimal temperature range for growth of the juvenile and adult shrimp was from 28 to 31℃, based on Q_10 and SMR values. Results from the present study may be used to guide pond culture production ofE. carinicauda.

Adaptation strategies of juvenile grass carp(Ctenopharyngodon idella)facing different dissolved oxygen concentrations in a recirculating aquaculture system

Fishes exposed to different dissolved oxygen concentrations over prolonged time periods have different susceptibility and adaptation mechanisms.In this study,healthy grass carp with an average weight of 214.6±18.7 g were selected for long-term culture in recirculating aquaculture systems at three different dissolved oxygen concentrations,i.e.,3.00 mg/L[(2.57±0.33)mg/L,DO_(2.57)),5.00 mg/L[(4.61±0.11)mg/L,DO_(4.61)],which was the control group,and 7.00 mg/L[(6.50±0.48)mg/L,DO_(6.50)].Blood,gill,muscle,and liver samples were collected after 60 days.Using hematoxylin-eosin(HE),alcian blue periodic acid Schiff(AB-PAS)staining,determination of respiratory metabolism enzyme activity,and fluorescent quantitative PCR,the adaptability of juvenile grass carp facing different dissolved oxygen levels were explored.The results showed that the respiration rate increased,and hemoconcentration and hemoglobin(Hb),electrolyte and pH changed at DO2.57.Furthermore,gill lamellae became thinner and longer,the distance between them increased,the mucus on them decreased and the interstitial cell mass decreased.In addition,the relative expression of apoptosis-related genes bcl-2 and bcl-xl in gill tissue decreased,while caspase-3 and bax increased.In muscles and liver tissues,lactate dehydrogenase(LDH)activity and lactic acid content(LA)increased,pyruvate dehydrogenase(PDH)activity decreased,and genes related to the respiratory metabolic enzymes PDH-A4 and PDH-E1α also changed accordingly.The oxygen consumption rate decreased significantly(P<0.05).At DO_(6.50),the distance between gill lamellae,numbers of red blood cells(RBC)and the content of hemoglobin decreased wheras the mucus on gill lamellae increased.The activity of PDH,the expression of PDH-E1a in liver and oxygen consumption rate increased.Different dissolved oxygen concentrations affected the respiratory behavior,gill tissue structure,blood transport capacity and tissue enzyme activity of juvenile grass carp.In summary,juvenile grass carp showed different adaptation strategies when facing different dissolved oxygen concentrations over prolonged periods in recirculating aquaculture systems.

Re-activation characteristics of preserved aerobic granular sludge

In some industrial plants, wastewater was intermittently or seasonally generated. There may be periods during which wastewater treatment facilities have to be set into an idle phase over several weeks. When wastewater was generated again, the activated sludge flocs may have disintegrated. In this experiment, re-activation characteristics of aerobic granular sludge starved for 2 months were investigated. Specific oxygen utilization rate(SOUR) was used as an indicator to evaluate the metabolic activity of the sludge. The results revealed that aerobic granular sludge could be stored up to two months without running the risk of losing the integrity of the granules and metabolic potentials. The apparent color of aerobic granules stored at room temperature gradually turned from brownish-yellowish to gray brown. They appeared brownish-yellowish again 2 weeks after re-activation. The velocity and strength of granules after 2-month idle period could be fully restored about 3 weeks after re-activation. Metabolic activity, however, dropped to 15 8 mg O_2/(g MLVSS·h), i.e. 74 % reduction after 2 months of storage. After restarting the reactor, it took 2 weeks that SOUR of up to 48 5 mg O_2 /(g MLVSS·h) was achieved. A stable effluent COD concentration of less than 150 mg/L was achieved during the re-activation process.

Growth, Metabolism and Physiological Response of the Sea Cucumber, Apostichopus japonicus Selenka During Periods of Inactivity

The growth, metabolism and physiological response of the sea cucumber, Apostichopus japonicus, were investigated during periods of inactivity. The body weight, oxygen consumption rate (OCR), activities of acidic phosphatase (ACP), alkaline phosphatase (AKP), catalase (CAT) and superoxide dismutase (SOD), and content of heat shock protein 70 (Hsp70) in the body wall and coelomic fluid of A. japonicus were measured during starvation, experimental aestivation and aestivation. The results showed that the body weight of sea cucumber in the three treatments decreased significantly during the experimental period (P < 0.05). The OCR of sea cucumber reduced in starvation and experimental aestivation treatments, but increased gradually in natural aestivation treatment. The activities of ACP and AKP of sea cucumber decreased gradually in all treatments, whereas those of SOD and CAT as well as Hsp70 content decreased in the starvation and experimental aestivation treatments and increased in natural aestivation treatment. The sea cucumber entered a state of aestivation at 24℃. To some extent, the animals in experimental aestivation were different from those in natural aestivation in metabolism and physiological response. These findings suggested that the aestivation mechanism of A. japonicus is complex and may not be attributed to the elevated temperature only.

Effects of temperature on the respiratory metabolism,feeding and expression of three heat shock protein genes in Anadara broughtonii

Anadara broughtonii is one of the main commercially important species of shellfish in northern China.A.broughtonii lives in relatively stable subtidal zone where the clam could respond to environmental changes with minimum energy.Therefore,slight fluctuations in water environment may have a great impact on physiological processes such as feeding and metabolism.Large-scale mortality often occurs during the intermediate rearing processes,and high temperatures in summer are considered the leading cause of mortality.To understand the physiological and molecular response patterns of A.broughtonii at high temperatures and to estimate the appropriate metabolism temperature for A.broughtonii,the effects of temperature on the respiratory metabolism and food intake at different growth stages were studied.The response patterns of heat shock protein genes to heat stress and post-stress recovery were also explored.Results show that the temperature and growth stage of A.broughtonii were two important factors affecting metabolism and feeding.The optimum temperature for feeding and physiological activities in each shell-length group was 24℃.The temperature at which the peak metabolic rate occurred in each shell-length group increased with the increase in shell length.With the increase in heat stress,the expression of three heat shock protein genes(Abhsp60,Abhsp70,and Abhsp90)in the tissues of two size groups of A.broughtonii increased significantly when temperature was above 24℃and reached a peak at 30℃.After heat shock at 30℃for 2 h,the expression of the three heat shock protein genes rapidly increased,peaked at 2 h after the heat shock,and then gradually decreased to the level of the control group at 48 h after the heat shock.The three heat shock protein genes respond rapidly to heat stress and can be used as indicators to the cellular stress response in A.broughtonii under an environmental stress.

Experimental simulation and numerical analysis of coal spontaneous combustion process at low temperature

The characteristic of coal spontaneous combustion includes oxidative property and exothermic capacity. It can really simulate the process of coal spontaneous combustion to use the large scale experimental unit loading coal 1 000 kg. According to the field change of gas concentration and coal temperature determined through experiment of coal self ignite at low temperature stage, and on the basis of hydromechanics and heat transfer theory, some parameters can be calculated at different low temperature stage, such as, oxygen consumption rate, heat liberation intensity. It offers a theoretic criterion for quantitatively analyzing characteristic of coal self ignite and forecasting coal spontaneous combustion. According to coal exothermic capability and its thermal storage surroundings, thermal equilibrium is applied to deduce the computational method of limit parameter of coal self ignite. It offers a quantitative theoretic criterion for coal self ignite forecasting and preventing. According to the measurement and test of spontaneous combustion of Haibei coal, some token parameter of Haibei coal spontaneous combustion is quantitatively analyzed, such as, spontaneous combustion period of coal, critical temperature, oxygen consumption rate, heat liberation intensity, and limit parameter of coal self ignite.

The Research Development of Respiratory Metabolism for Living Beings of Fishery Resources

[Objective]To describe the research development of respiratory metabolism for living beings of fishery resources home and abroad so as to provide reference for fishery production and management. [Method]Investigate research methods of respiratory metabolism about fish,shrimp, crab,shells and other living beings and analyze factors affecting their oxygen consumption rates and ammonia excretion rates according to research results of respiratory metabolism for living beings of fishery resources home and abroad. [Result] Respiratory metabolism is one of the important contents of bioenergetics research,an important part of energy balance research. It reflects not only the physiological status of living beings,but al- so the influence of environment condition on their physiological activities. Factors affecting respiratory metabolism are divided into biological factors and non-biological factors. By researching factors such as weight,temperature,activities,circadian rhythm,ingestion,Oxygen partial pressure and so on,we can evaluate respiratory metabolism of living beings of fishery resources. [Conclusion]Investigating from the individual physiology and e- cology to group physiology and ecology,the research provides data support for enhancement and releasing of sea ranch.

Effects of low-oxygen conditions on embryo growth in the painted turtle,Chrysemys picta

Low-oxygen conditions(hypoxia;<21%O_(2))are considered unfavorable for growth;yet,embryos of many vertebrate taxa develop successfully in hypoxic subterranean environments.Although enhanced tolerance to hypoxia has been demonstrated in adult reptiles,such as in the painted turtle(Chrysemys picta),its effects on sensitive embryo life stages warrant attention.We tested the hypothesis that short-term hypoxia negatively affects growth during day 40 of development in C.picta,when O_(2) demands are highest in embryos.A brief,but severe,hypoxic event(5%O_(2) for 0.5 h)moderately affected embryo growth,causing a 13%reduction in mass(relative to a normoxic control).The same condition had no effect during day 27;instead,a nearly anoxic event(1%O_(2) for 72 h)caused a 5%mass reduction.All embryos survived the egg incubation period.Our study supports the assumption that reptilian embryos are resilient to intermittently low O_(2) in subterranean nests.Further work is needed to ascertain responses to suboptimal O_(2) levels while undergoing dynamic changes in developmental physiology.