• 대한인간공학회지
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• 제18권1호
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• pp.1-12
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• 1999

The objective of this study was to investigate the metabolic energy consumption rate of the psychophysical Maximum Acceptable Weight of Loads (MAWLs) for different manual materials handling tasks. Lifting activities with four different lifting frequencies (2, 5, 8, 11 lifts/min) for a lifting range (from floor to 76cm height) were studied. The oxygen consumption rate and heart rate were measured or recorded while subjects were lifting their MAWLs. It was found that the relationship between MAWL and frequency can be described best by the exponential function with the R-sq value 0.9865 for this study. Psychophysical MAWL decreased from 22.38 to 7.48 kg, while the oxygen consumption rate with the MAWL increased from 717.8 to $1114.7m{\ell}-O_2/min$ as the frequency increased from 2 to 11 lifts/min. Heart rate also increased from 104.5 to 120.7 bpm. The ratio of oxygen consumption for the MAWL to the Physical Work Capacity (PWC) ranged from 28 to 43%. The MAWLs were greater than or equal to the Maximum Permissible Limits (MPLs) when the frequencies were higher than 8 lifts/min. It seems that the MAWLs by psychophysical approach when the frequencies were higher than 8 lifts/min tend to be overestimated from the viewpoint of the physiological criterion of the oxygen consumption rates. From these findings it is suggested that the NIOSH Guideline should not be directly applied to Korean without reasonable modifications.

• 한국패류학회지
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• 제15권2호
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• pp.127-131
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• 1999

전북 곰소만에 서식하는 바지락의 생리적 리듬을 알아보기 위하여 24시간 동안 1시간 간격으로 산소소비율 및 여수율의 변화를 측정하였다. 바지락의 호흡율 및 여수율에 의한 생리적 리듬은 15$^{\circ}C$와 $25^{\circ}C$에서 두 가지 모두 24시간 동안 2번의 peak를 보이는데, 밤-만조시에 최대를 나타내었으며, 낮-간조시에 최소를 나타내어 조석에 의한 일주리듬 현상을 보였다. 24시간 동안 산소소비율 및 여수율의 변화는 수온별로 급격한 특수한 변화를 보이지 않았다.

• 한국양식학회지
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• 제12권3호
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• pp.247-254
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• 1999

Changes of oxygen consumption of Nile tilapia in relation to different body sizes(average body weight 4 g, 40 g, 120 g and 400 g) and water temperatures ($20^{\circ}C$, $25^{\circ}C$ and $30^{\circ}C$) were investigated by a continuous oxygen monitoring system. Mean oxygen consumption of 4 g, 40 g, 120 g and 400 g Nile tilapia at $20^{\circ}C$ were 318.8, 214.9, 84.1 and 69.4 mg $O_2$/kg fish/hr and that at $25^{\circ}C$ were 435.2, 345.9, 151.5 and 115.9 mg $O_2$/kg fish/hr, and that at $30^{\circ}C$ were 611.1, 538.4, 320.8, and 236.0 mg $O_2$/kg fish/hr, respectively. Oxygen consumption per unit body weight tended to decrease exponentially at all temperatures (P<0.05) as body weigth of the fish increased. Oxygen consumption of this fish at $25^{\circ}C$ was $1.61\pm0.18$ times higher than that at $20^{\circ}C$ and oxygen consumption at $30^{\circ}C$ was $1.53\pm0.27$ times higher than that at $25^{\circ}C$. Oxygen consumption per unit body weight linearly increased with the water temperature increased. Also, oxygen consumption of this fish during day time was higher than that during night time at 12L:12D day light condition. The differences between maximum and minimum daily oxygen consumption of this fish increased with the water temperature increased.

• Fisheries and Aquatic Sciences
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• 제18권4호
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• pp.373-378
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• 2015

Postprandial ammonia excretion and oxygen consumption in olive flounder Paralichthys olivaceus fed two different feed types, moist pellet (MP) and expanded pellet (EP) diets, to satiation were determined at $12^{\circ}C$, $15^{\circ}C$, $20^{\circ}C$, and $25^{\circ}C$ for 48 h. The ammonia excretion and oxygen consumption rates increased with increasing water temperature. However, the postprandial times for the maximum rates of ammonia excretion and oxygen consumption were shortened from 12 h to 6 h after feeding with increasing water temperature. The ammonia excretion and oxygen consumption rates of the fish fed EP were significantly higher (P < 0.05) than those fed MP at 12 h post-feeding both for $12^{\circ}C$ and $15^{\circ}C$. The highest (P < 0.05) weight-specific ammonia excretion rates at $12^{\circ}C$ were observed in the fish fed EP and MP at $12.1mg\;NH_3-N\;kg^{-1}h^{-1}$ and $8.7mg\;NH_3-N\;kg^{-1}h^{-1}$, respectively, for 12 h and 9 h after feeding. The highest (P < 0.05) weight-specific oxygen consumption rates at $12^{\circ}C$ were observed in fish fed EP and MP at $116.4mg\;kg^{-1}h^{-1}$ and $101.0mg\;kg^{-1}h^{-1}$, respectively, for 12 h after feeding. The highest ammonia excretion rates at $25^{\circ}C$ in the fish fed EP and MP increased to $16.9mg\;NH_3-N\;kg^{-1}h^{-1}$ and $18.3mg\;NH_3-N\;kg^{-1}h^{-1}$, respectively, for 6 h after feeding. The highest (P < 0.05) weight-specific oxygen consumption rates at $25^{\circ}C$ were observed in fish fed EP and MP at $184.3mg\;O_2kg^{-1}h^{-1}$ and $197.3mg\;O_2kg^{-1}h^{-1}$, respectively. These data are valuable for the design of biofilters and development of effluent treatment technologies for the land-based flounder farms.

• 한국수산과학회지
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• 제32권2호
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• pp.144-148
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• 1999

상업적 규모의 순환여과식 탱크에서 사료 공급 횟수에 따른 산소 소비량의 변화를 조사하였다. 실험에 이용된 사육 장치는 순환여과식 시설내의 원형 콘크리트 탱크 (직경 270cm, 높이 80cm)를 이용하여 평균 체중 400g의 나일틸라피아 (Oreochromis niloticus)를 390kg 방양하여 실험에 이용하였다. 우선 3일간 사육 어류를 절식시킨 후 기초대사율을 측정하였고, 사료 공급 횟수를 1회, 2회, 5회 그리고 9회로 나누어 공급한 후 산소 소비량의 일간 변화를 측정하였다. 절식 상태에서 산소 소비량 (기초대사율)은 평균 $39.31{\pm}4.4mg\;O_2/kg$ fish/hr이였고 사료 공급횟수에 따른 1일 평균 산소 소비량은 1회, 2회, 5회 및 9회 공급시 각각 $79.9{\pm}21.5,\;81.3{\pm}14.8,\;84.2{\pm}9.9$ 및 $98.9{\pm}11.0mg\;O_2/kg$ fish/hr을 소비하는 것으로 나타나 사료 공급 횟수가 증가함에 따라 평균 산소 소비량은 증가하였으나, 유의적인 차이는 나타나지 않았다. 사료 공급후 최대 산소 소비량에 도달하는 시간은 사료 공급후 30$\~$50분으로 나타나 사료공급 횟수와는 유의적인 상관 관계가 없는 것으로 나타났다. 사료공급 횟수에 따른 산소 소비량의 최대치는 1회, 2회, 5회 및 9회 공급시에 각각 161.2, 123.4, 111.1 및 111.1 mg $O_2/kg$ fish/hr을 소비하는 것으로 나타나 하루에 1회 공급하였을 때 최대 산소 소비량이 가장 높은 것으로 나타났다.

• 대한인간공학회:학술대회논문집
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• 대한인간공학회 1997년도 춘계학술대회논문집
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• pp.39-49
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• 1997

The objective of this study was to make comparison of the psychophysical MAWLs for different manual materials handling tasks. Lifting activities with four different lifting frequencies (2, 5, 8, 11 lifts/min) for one lifting range from floor to 76cm height were studied. The oxygen consumption rate and heart rate were measured or recorded while subjects were lifting their MAWLs. Psychophysical MAWL decreased from 22.38 kg to 7.48 kg, while th oxygen consumption rate with the MAWL increased from 717.8 ml/min to 1114.7 ml/min as the frequency increased from 2 to 11 Lifts/min. Heart rate also increased from 104.5 to 120.7 bpm. It was found that the relationship between MAWL and frequency can be described best by the exponentaial function with the R-sq value 0.9865 for this study. The percent ratio of oxygen consumption rate with the MAWL and PWC ranged from 28% to 43%.

• 한국생명과학회:학술대회논문집
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• 한국생명과학회 2008년도 제49회 학술심포지움 및 국제학술대회
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• pp.28.2-28.2
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• 2008

• 한국수산과학회지
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• 제32권1호
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• pp.56-61
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• 1999

참메기, Silurus asotus를 대상으로 수온 ($15^{\circ}C,\;20^{\circ}C,\;25^{\circ}C$ 및 $30^{\circ}C$)과 광주기 (24L:0D, 12L:12D 및 0L:24D)에 따른 산소 소비량의 변화를 연속적인 컴퓨터 모니터링 시스템을 이용하여 조사하였다. 평균 무게 280g의 참메기의 산소 소비량은 수온의 증가에 따라 증가하였고, $15^{\circ}C$에서 $35.2\~96.4mg\;O_2/kg$ fish/hr, $20^{\circ}C$에서$78.6\~127.9mg\;O_2/kg$ fish/hr, $25^{\circ}C$에서$120.1\~231.7mg\;O_2/kg$ fish/hr, $30^{\circ}C$에서 $197.5\~352.3mg\;O_2/kg$ fish/hr으로 나타났다(p<0.05). 광주기에 따른 산소 소비량은 암기 조건에서 보다 명기 조건에서 산소소비량이 더 높게 나타났다. 또한, 24L:0D와 12L:12D와 비교하여 0L:24D에서 평균 산소 소비량이 낮게 나타났다(p<0.05). 산소 소비량의 최대값과 최소값의 차이는 수온이 상승함에 따라 증가하였고, 12L:12D에서 가장 큰 것으로 나타났고, 새벽녁과 저녁 무렵에 산소 소비량의 급격한 변화를 나타내었다. 특히, 12L:12D의 조건에 두었을 때 명기와 암기에 대한 뚜렷한 반응을 보였다.

• 한국안전학회지
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• 제31권4호
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• pp.55-63
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• 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.

• Asian-Australasian Journal of Animal Sciences
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• 제29권5호
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• pp.753-758
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• 2016

Moisture content influences physiological characteristics of microbes and physical structure of solid matrices during composting of animal manure. If moisture content is maintained at a proper level, aerobic microorganisms show more active oxygen consumption during composting due to increased microbial activity. In this study, optimum moisture levels for composting of two bedding materials (sawdust, rice hull) and two different mixtures of bedding and beef manure (BS, Beef cattle manure+sawdust; BR, Beef cattle manure+rice hull) were determined based on oxygen uptake rate measured by a pressure sensor method. A broad range of oxygen uptake rates (0.3 to 33.3 mg $O_2/g$ VS d) were monitored as a function of moisture level and composting feedstock type. The maximum oxygen consumption of each material was observed near the saturated condition, which ranged from 75% to 98% of water holding capacity. The optimum moisture content of BS and BR were 70% and 57% on a wet basis, respectively. Although BS's optimum moisture content was near saturated state, its free air space kept a favorable level (above 30%) for aerobic composting due to the sawdust's coarse particle size and bulking effect.