• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.33 no.2
• /
• pp.110-114
• /
• 2000

Effects of the combinations of six oxygen concentrations ($control, 0.6, 1.0, 2.0, 3.4 and 7.4 mg DO/l$) and two salinity levels ($20{\%_{\circ}} and 32{\%_{\circ}}$) on the rates of oxygen consumption, ammonia excretion and mortality of the mysid, Neomysis awatschensis were tested at $20{\circ}C$. The lethal level ($96 hr-LC-(50)$) of dissolved oxygen for mysid at $20{\%_{\circ}} and 32{\%_{\circ}} were 2,20 mg DO/l and 1.60 mg DO/l$ respectively, and all mysids died within $24hr at 0.6 mg DO/l$. Oxygen consumption rate of mysid was increased with dissolved oxygen increase at $20{\%_{\circ}} and 32{\%_{\circ}}$, but ammonia excretion rate was high af $1.0 mg DO/l$ during 96h exposure to DO concentration, and significantly greater in $20{\%_{\circ}} than 32{\%_{\circ}}$. $O:N$ ratio of mysid exposed during 96hr with salinity anil dissolved oxygen was below $10 at 20{\%_{\circ}} and 1,0{\~}2.0 mg DO/l, and was 4.4 at 32{\%_{\circ}} and 1.0 mg DO/l$. These results indicated that mysids were capable of changing their energy substrate in response to salinity and DO changes, and obtaining energy from proteins.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.48 no.5
• /
• pp.712-718
• /
• 2015

The effects of salinity on survival, oxygen consumption, and hematological response of greenling Hexagrammos otakii, mean body weight 147.1±3.8 g, were investigated under salinity conditions of 33.4 (control), 33.1, 32.8, 32.2, 31.0, 28.7, 23.9, 14.5, and 3.8 psu, to evaluate physiological effects in relation to changes in salinity. The survival and hematological responses of fish were measured at each salinity after 96- and 24-h exposures. The oxygen consumption rate (OCR) of fish was measured in triplicate under conditions of stepwise salinity exposure (33.4→33.1→32.8→32.2→31.0→28.7→23.9→14.5→3.8 psu) with an interval of 24 h at each salinity, using a continuous flow-through respirometer. No fish mortality was observed in the range of 33.4 to 14.5 psu, but the survival rate was reduced to 53.3% at 3.8 psu after 96 h of exposure. The OCRs did not significantly differ in the range between 33.4 to 28.7 psu (P>0.05), but significantly increased at 23.9 and 14.5 psu, and then dramatically decreased at 3.8 psu compared to the control (P<0.05). Hematological variables, such as glucose, glutamic pyruvic transaminase (GPT), hematocrit, and Na⁺, were affected by reduced salinity. This result may be applicable for habitat and culture management of greenlings.

• Ocean and Polar Research
• /
• v.36 no.2
• /
• pp.135-143
• /
• 2014

The effect of salinity on the survival, oxygen consumption and blood physiology of Korean rockfish Sebastes schlegelii (body weight $97.4{\pm}1.7g$, $mean{\pm}SD$) was investigated at nine different salinities of 33.4 (control), 33.1, 32.8, 32.2, 31.0, 28.7, 23.9, 14.5 and 3.8 psu, respectively. Survival and blood physiology were measured at each salinity in two separate trials of 96 and 24 hr duration, respectively. Oxygen consumption rate (OCR) was determined at stepwise salinity exposure ($33.4{\rightarrow}33.1{\rightarrow}32.8{\rightarrow}32.2{\rightarrow}31.0{\rightarrow}28.7{\rightarrow}23.9{\rightarrow}14.5{\rightarrow}3.8$ psu) with an interval of 24 hr for each salinity. No death of fishes were observed in the range of 33.4 to 14.5 psu, but the survival rate was reduced to 26.7% at 3.8 psu after 96 hr. The OCRs were not significantly different in the range 33.4 to 28.7 psu (p > 0.05), but significantly increased until 14.5 psu and then drastically decreased at 3.8 psu compared to the control (p < 0.05). The concentrations of plasma $Na^+$ and $Cl^-$ were significantly lower in fish exposed at 3.8 psu compared to the control (p < 0.05). The results of this study provide evidence that S. schlegelii exposed to concentrations below 23.9 psu show significant physiological responses to tolerate salinity changes under the experimental conditions we established.

• Journal of Microbiology and Biotechnology
• /
• v.23 no.4
• /
• pp.560-564
• /
• 2013

${\small{D}}$-Ribose is a value-added five-carbon sugar used for riboflavin production. To investigate the effects of oxygen supply and mixed sugar concentration on microbial production of ${\small{D}}$-ribose, a transketolase-deficient Bacillus subtilis SPK1 was cultured batch-wise using xylose and glucose. A change of agitation speed from 300 rpm to 600 rpm at 1 vvm of air supply increased both the xylose consumption rate and ${\small{D}}$-ribose production rate. Because the sum of the specific consumption rates for xylose and glucose was similar at all agitation speeds, metabolic preferences between xylose and glucose might depend on oxygen supply. Although B. subtilis SPK1 can take up xylose and glucose by the active transport mechanism, a high initial concentration of xylose and glucose was not beneficial for high ${\small{D}}$-ribose production.

• Journal of the Korean Society of Safety
• /
• v.31 no.4
• /
• pp.55-63
• /
• 2016

A dust explosion is a phenomenon of strong blast wave propagation involving destruction which results from dust pyrolysis and rapid oxidation in a confined space. There has been some research done to find individual explosion characteristics and common physical laws for various dust types. However, there has been insufficient number of studies related to the heat of combustion of materials and the oxygen consumption energy about materials in respect of dust explosion characteristics. The present study focuses on the relationship between dust explosion characteristics of wood dust samples and oxygen consumption energy. Since it is difficult to estimate the weight of suspended dust participating in explosions in dust explosion and mixtures are in fuel-rich conditions concentrations with equivalent ratios exceeding 1, methods for estimating explosion overpressure by applying oxygen consumption energy based on unit volume air at standard atmospheric pressure and temperature are proposed. In this study an oxygen consumption energy model for dust explosion is developed, and by applying this model to TNT equivalent model, initial explosion efficiency was calculated by comparing the results of standardized dust explosion experiments.

• Journal of Fisheries and Marine Sciences Education
• /
• v.26 no.1
• /
• pp.214-222
• /
• 2014

Hagfish Eptatretus burgeri is classified as a agnathans and has many different physiological properties compared with vertebrates. In this study, we examined effects of water temperature and salinity on blood properties and oxygen consumption in hagfish. In the experiment of water temperature change, hematocrit (Ht), red blood cell (RBC) and glucose of hagfish blood revealed the lowest values at $15^{\circ}C$. Oxygen consumption of hagfish had significantly increased with rising water temperature, and the increasing rate was twice as much when the temperature was manipulated every $5^{\circ}C$. Also, oxygen consumption during the night time (a short photoperiod) was significantly higher than that of the daytime. Q10 level was 3.50 in the light period and 3.92 in the dark period. No significant change in plasma glucose level was showned in changing salinity from 30 psu to 22 psu, while it had rapidly increased at 20 psu ($13.7{\pm}4.0mg/dL$) and thereafter all hagfish were dead at 18 psu. However, osmolarity, $Na^+$, $K^+$ and $Cl^-$ levels had significantly decreased when salinity decreased. This results are expected to develop the artificial rearing techniques of natural hagfish.

• The Korean Journal of Physiology
• /
• v.6 no.2
• /
• pp.9-17
• /
• 1972

This experiment was carried out to investigate systematically how the aerobic metabolic capacity of renal tissue reduced by the effects of a period of induced ischemia. Aerobic metabolic studies were performed on homogenates of cortex and medulla of rabbits. Ischemia was induced by occluding the renal vein or renal artery of the left kidney for an hour. The right kidney used as a paired control. Aerobic metabolism was asesssed by measuring the oxygen consumption using the Warburg's manometric apparatus. The results are summarized as follows: 1. One hour of occlusive ischemia does not increase in the kidney weight in the renal arterial occlusion but increase in the renal venous occlusion. 2. Occlusion of either the renal vein or renal artery for an hour did not reduce to any significant degree the level of endogenous substrate in cortical homogenates as measured the rates of $0_2$ consumption. 3. A significant reduction in the rate of $C_2$ consumption was noted in the medullary homogenates of renal venous occluded kidneys while renal arterial occlusion had less of an effect. 4. The capaciy of homogenates for aerobic metabolism is not reduced by acute ischemia, because of the higher rate of oxygen consumption induced by exogenous glucose in renal vein occlusion. 5. The oxygen consumption of medullary homogenate more decreased to acute ischemia than cortical homogenates. The results of this investigation suggest that one hour circulatory stasis does not reduce major potential capacity of renal cortical tissue at the subcellular level to produce energy. In contrast, the aerobic metabolism of medullary tissue is reduced by renal ischemia. Further, both cortex and medulla appear to be more sensitive to ischemia induced by renal venous occlusion than by renal arterial occlusion.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.30 no.5
• /
• pp.874-881
• /
• 1997

In order to estimate toxicity of copper, radmium and chromium on survival, growth and oxygen consumption of the estuarine mysid, Neomysis awatschensis, adult and juvenile, the experiments were conducted by renewal bioassay method at $20{\pm}1^{\circ}C\;and\;20{\pm}1\%_{\circ}$ salinity. The $96hr-LC_{50}$ of the mysid exposed to cadmium, copper and chromium was 20.2, 11.3 and $670.4\;{\mu}g/\ell$ in adut and 3.4, 1.9 and $49.4\;{\mu}g/\ell$ in juvenile, respectively, and were ranked in order of toxicity : copper >cadmium >chromium. Survival rates of the mysid exposed to the sublethal concentrations of heavy metals for 40 days were significantly affected by cadmium $\geq1.0\;{\mu}g/\ell$ and copper $\geq0.6\;{\mu}g/\ell$ concentrations. The growth rate of the mysid exposed to $cadmium\geq2.0\;{\mu}g\ell$ and copper $\geq1.2\;{\mu}g/\ell$ concentrations were significantly reduced than that exposed to normal condition, but there was no affect on intermoult period. Oxygen consumption rate of the mysid exposed to heavy metals was significantly reduced with increasing heavy metals concentrations. The results of the present study led us to conclude that concentrations levels cadmium$\geq1.0\;{\mu}g\ell$ and copper $\geq0.6\;{\mu}g\ell$ of the estuarine could markedly affect the distribution and population of the mysid by reduced survival, growth and oxygen consumption rate.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.33 no.5
• /
• pp.408-412
• /
• 2000

The juvenile Bobiids, Faronirobius gymnauchen, were reared for 40 days under $0{\~}33.6{\%_{\circ}}$ salinity conditions to examine the effects of various salinity on its survival, growth and oxygen consumption rates, Survival rate was significantly declined below $6.7{\%_{\circ}}$ salinity, and daily growth rate was also reduced below $10.1{\%{\circ}}$. Body length and weight of gobiids reared below $10.1{\%_{\circ}}$ were smaller than those of gobiids reared above $20.2{\%_{\circ}}$. Oxygen consumption rate in the salinity conditions ${\leq}13.4{\%_{\circ}}$ was significantly reduced with decreasing salinity than that in natural seawater ($33.6{\%_{\circ}}$), This study revealed that low salinity reduced survival, growth and oxygen consumption rates of the juvenile gobiids suggesting potential influence on the natural mortality of F gymnauchen in the coastal areas.

• The Korean Journal of Zoology
• /
• v.29 no.3
• /
• pp.201-207
• /
• 1986

The authors attempted to investigate the oxygen consumption rate of sexuals in the water-striders, Gerris paludum insuralis, at four temperature groups of 25, 30, 35 and $40^\\circ C$ in a series of studies on respiration of a heminetabolous insects. THe results are summarised as follows: (1) At $30^\\circ C$, the change of oxygen consumption rate according to the lapse of time was small in comparison with the other three temperature groups which shows a cyclic decreasing pattern. The rate during initial and final 5 minutes was much alike. Thereupon, the optimum temperature was regarded as $30^\\circ C$. (2) The oxygen consumption rate of male was higher than that of female. (3) The oxygen consumption rates at 25, 30, 35 and $40^\\circ C$ were 0.42, 0.49, 0.79 and 1.11 $\\mu$l/mg/h respectively. That is, the rate was increased as the temperature was increased. (4) The $Q_10$ of male showed a high value in the lower temperature interval ($25^\\circ C \\sim 35^\\circ C$), but the female showed a high value in the higher temperature interval ($30^\\circ C \\sim 40^\\circ C$). The mean $Q_10$ was 2.12. (5) The respiratory rate was decreased as the body weight was increased in the above fresh weight of 10mg and dry weight 5 mg. (6) The upper temperature threshold for respiration was $48.31^\\circ C$ and the lower temperature threshold was $17.68^\\circ C$. (7) The ceasing time of breathing at the other three temperature groups except $30^\\circ C$ was infered to be about 110 minutes after the start of experiment.