• 한국화재소방학회논문지
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• 제19권3호
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• pp.58-63
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• 2005

등유 풀화재의 화염과 연소에 의해 생성되는 연기의 특성에 대해서 조사하였다. 다양한 발열량을 위해 직경을 변하게 할 수 있는 팬버너를 제작하였다. 풀화재를 조사하기 위해 화염 높이와 떨림 주파수를 분석하였다. 실험적으로 풀화염 높이는 이론적 상관관계 증가율과 잘 일치하지만, 정량적으로는 등유의 연소율에 기인하여 과대 평가된 값을 보인다. 연기의 특성을 조사하기 위해 세 가지의 실험방법을 사용하였다. 먼저 가스분석기를 이용하여 연소시 발생되는 주요 가스 농도를 측정하였는데 이산화탄소의 생성과 산소의 소모율은 풀화염의 열방출율에 비례하지만, 일산화탄소의 발생에 대한 경향성은 발견할 수 없었다. 연기의 매연입자를 광감쇄법과 TEM 이미지를 이용하여 특성을 조사하였다 연기밀도는 발열량의 증가에 따라 매우 급격히 증가하였고, 등유 풀화염에서 발생한 매연입자들은 자연적인 연소조건임에도 불구하고 역확산 제트화염에서 생성된 매연과 유사한 형태와 탄화정도를 보임이 관찰되었다.

• 대한가정학회지
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• 제38권3호
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• pp.149-161
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• 2000

The purpose of the study was to examine the effect of Tencel fabrics on physiological reactions of a human body and thermal comfort under the hot environment. The 3 females subjects in their twenties were selected and a wear sensation test of the subjects was performed with four experimental ensembles made of cotton and Tencel fabrics for the study in the hot environment(3$0^{\circ}C$, 70%RH). The resets of the test were summarized as follows: For the mean skin temperature, Tencel garments showed about 0.2$^{\circ}C$-0.4$^{\circ}C$ lower than that of the cotton garment. The temperature of the rectal was 0.2$^{\circ}C$-0.4$^{\circ}C$ lower for Tencel garments than that for the colon garment. In the form of ensembles, the order of rectal temperature of the subjects for both Tencel and cotton ensembles was 1>IV>III>II. In the body weight loss according to garment materials, Tencel had a lower and more uniform than the cotton Thus, it could concluded that if the perspiration took into account, garments made of Tencel can be more ideal than that of the cotton. The heart rate and oxygen consumption appeared to be proportional to each other. For the heart rate, ensemble TI and TII of Tencel were much lower than ensemble CI and CII. For whole enembles except for TIV, Tencel ensembles showed relatively better thermal sensation and comfort sensation than the cotton ensembles. In the fatigue sensation, the reactions of the subjects were “slightly fatigue” and “fatigue” for the cotton, but “neutral” and “slightly fatigue” for Tencel.

• 한국동물위생학회지
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• 제30권3호
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• pp.291-304
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• 2007

Mutants of an obligate aerobic bacterium, Vitreoscilla, that have deficiency in heat-labile catalase-peroxidase hydroperoxidase I (HPI) were created by EMS treatment. The catalase-peroxidase HPI-deficient mutant showed substantially lower peroxidase activity in exponential and mid-stationary phase compared with the wild type strain. In late stationary phase, the mutant exhibited no peroxidase activity. Peroxidase deficiency in the mutant was revealed by polyacrylamide gels stained for peroxidase activity. Characteristically, catalase levels in the mutant increased about 14- and 8-fold during growth in the exponential and stationary phases, respectively, compared to those in the wild type, suggesting a compensatory effect for protection from $H_2O_2$ toxicity. The mutant showed differences in physiology from the wild type: retardation in growth rate and decrease in oxygen consumption. Both the wild type and the catalase-peroxidase HPI-deficient mutant of Vitreoscilla had lower growth rates in media containing increasing $H_2O_2$ concentrations. However, the mutant exhibited an additionally decreased growth rate after 6 to 8 h of growth compared to the wild type. The wild type was resistent up to 20 mM $H_2O_2$, whereas the mutant was very sensitive to high concentrations of exogenous $H_2O_2$. Although elevated catalase levels would provide protection of the bacteria from the deleterious effect of $H_2O_2$, it did not appear to be complete. Cell-free extracts of the mutant showed decreased NADH oxidation rates and higher accumulation of $H_2O_2$ during this oxidation. These results may account for the impaired growth and earlier onset of death phase by the catalase-peroxidase HPI-deficient mutant of Vitreoscilla.

• Advances in Traditional Medicine
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• 제4권1호
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• pp.18-21
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• 2004

Six volunteers (mean $age=25.7{\pm}1.7$, $height=173{\pm}1.9$ and $weight=63.4{\pm}2.3{\;}kg$) participated in a graded exercise test and one hour of basic form of ChunDoSunBup (CDSB) Qi-training to investigate the cardiorespiratory responses and exercise intensity of Qi-training, a Korean traditional psychosomatic training. In the maximal exercise, the trainee showed $96.2{\pm}8.89{\;}l/min$ in ventilation (VE), $46.0{\pm}4.4$ in breath frequency (BF), $1.31{\pm}0.05$ in respiratory exchange ratio (RER), $180.7{\pm}3.0$ in heart rate (HR), and $2.6{\pm}1.1{\;}l/min$ or $40.7{\pm}2.3{\;}ml/kg/ml$ in oxygen consumption $(VO_2)$. Qi-training induced significant changes in BF, RER, HR, and $VO_2$. The exercise intensity of Qi-training were 42.3%, 46.9% and 38.7% of $HR_{max}$ during the sound exercise, slow motion (haeng-gong) and meditation respectively and the average was 46.2% of $HR_{max}$. We conclude that Qi-training is an aerobic exercise of a light (mild) intensity exercise, and it leads to decrease the metabolic rate in the trainee by breathing efficiently and relaxing them. In addition, Qi-training may affect cardiorespiratory function of BF, RER, HR and $VO_{2max}$ in trainees.

• 한국분무공학회지
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• 제16권3호
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• pp.119-125
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• 2011

Due to the oxygen contents in biodiesel, application of the fuel to compression ignition engines has significant advantages in terms of lowering PM formation in the combustion chamber. In recent days, considerable studies have been performed to extend the low temperature combustion regime in diesel engines by applying biodiesel fuel. In this work, low temperature combustion characteristics of biodiesel blends in dilution controlled regime were investigated at a fixed engine operating condition in a single cylinder diesel engine, and the comparisons of engine performances and emission characteristics between biodiesel and conventional diesel fuel were carried out. Results show that low temperature combustion can be achieved at $O_2$ concentration of around 7~8% for both biodiesel and diesel fuels. Especially, by use of biodiesel, noticeable reduction (maximum 50% of smoke was observed at low and middle loads compared to conventional diesel fuel. In addition, THC(total hydrocarbon) and CO(Carbon monoxide) emissions decreased by substantial amounts for biodiesel fuel. Results also indicate that even though about 10% loss of engine power as well as 14% increase of fuel consumption rate was observed due to lower LHV(lower heating value) of biodiesel, thermal efficiencies for biodiesel fuel were slightly elevated because of power recovery phenomenon.

• 원예과학기술지
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• 제33권1호
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• pp.133-142
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• 2015

This study aimed to identify the exercise intensity associated with four common physical activities for adults (running, skipping rope, walking, and muscle strength exercises) and two horticultural activities (creating a vegetable bed and garden maintenance). For this experiment, 19 males (mean age: $25.8{\pm}2.3$ years) randomly participated in the activities at a glasshouse at Konkuk University. Each of the six activities lasted for 5 minutes; the subjects rested for 5 minutes during intervals between the activities. A portable metabolic analyzer was used to store the oxygen and energy consumption values obtained upon measurement of each activity. In addition, a wireless heart rate monitor was used to measure the subjects' heart rate. According to the results, the four types of physical activities and two horticultural activities carried out by the subjects are moderate- to high-intensity activities [i.e., $3.8{\pm}0.9$ to $9.9{\pm}2.1$ metabolic equivalents (METs)]. Running ($9.9{\pm}2.1$ METs) and skipping rope ($8.8{\pm}2.2$ METs) were categorized as high-intensity physical activities, whereas creating a vegetable bed ($5.0{\pm}1.2$ METs), walking ($4.9{\pm}0.8$ METs), muscle strength exercises ($4.5{\pm}1.3$ METs), and garden maintenance ($3.8{\pm}0.9$ METs) were classified as moderate-intensity physical activities. The exercise intensities of horticultural activities in this study were similar to those of walking and muscle strength exercises. Therefore, participating in these horticultural activities is expected to garner health benefits similar to those reaped from the physical activities described in the current study.

• International Journal of Stem Cells
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• 제17권2호
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• pp.194-203
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• 2024

Evaluating cell metabolism is crucial during pluripotent stem cell (PSC) differentiation and somatic cell reprogramming as it affects cell fate. As cultured stem cells are heterogeneous, a comparative analysis of relative metabolism using existing metabolic analysis methods is difficult, resulting in inaccuracies. In this study, we measured human PSC basal metabolic levels using a Seahorse analyzer. We used fibroblasts, human induced PSCs, and human embryonic stem cells to monitor changes in basal metabolic levels according to cell number and determine the number of cells suitable for analysis. We evaluated normalization methods using glucose and selected the most suitable for the metabolic analysis of heterogeneous PSCs during the reprogramming stage. The response of fibroblasts to glucose increased with starvation time, with oxygen consumption rate and extracellular acidification rate responding most effectively to glucose 4 hours after starvation and declining after 5 hours of starvation. Fibroblasts and PSCs achieved appropriate responses to glucose without damaging their metabolism 2~4 and 2~3 hours after starvation, respectively. We developed a novel method for comparing basal metabolic rates of fibroblasts and PSCs, focusing on quantitative analysis of glycolysis and oxidative phosphorylation using glucose without enzyme inhibitors. This protocol enables efficient comparison of energy metabolism among cell types, including undifferentiated PSCs, differentiated cells, and cells undergoing cellular reprogramming, and addresses critical issues, such as differences in basal metabolic levels and sensitivity to normalization, providing valuable insights into cellular energetics.

• 한국양식학회지
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• 제10권3호
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• pp.261-271
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• 1997

해수 순환여과식 양식 시스템의 여과 재료별 암모니아 제거 능력을 정량적으로 평가하기 위하여 5종류의 침지식 여과 재료인 모래(직경 2-3 mm), 산호사 (직경 30-50 mm), 자갈 (직경 20-40 mm), 폴리에틸렌 망 (네트론) 및 플라스틱 파판(스카이라이트)의 암모니아 제거량과 산소 소비량을 측정하고 그리고 회전원판식 여과 재료의 암모니아 제거량을 측정하여 비교하였다. 실험 기간중 사육조의 암모니아 농도는 0.052-0.904(평균 0.338$\pm$0.219) mg/l였고, 수온은 19.2-21.4 (평균 20.2$\pm0.58) ^{\circ}C$의 범위였으며 사육수의 암모니아 농도 (x : mg/l)에 대한 여과 재료별 단위 용적당 일간 암모니아 제거량 (y : g/m supper(3)/day)의 1/2-order kinetic 식과 1일 평균 암모니아 제거량(g/m supper(3)/day)은 다음과 같다. 모래 : Y=135.5X 상(0.5)-25.1 (r 상(2)=0.8110), 45.1 자갈 Y=43.7X 상(0.5)-5.5 (r 상(2)=0.2596), 17.1 산호사 : Y=125.1X 상(0.5)-33.0 (r 상(2)=0.7307), 31.8 폴리에틸렌 망 : Y=87.4X 상(0.5)-20.1 (r 상(2)=0.6780), 25.2 플라스틱 파판 : Y=71.1X 상(0.5)-17.6 (r 상(2)=0.5206), 19.2 회전원판 : Y=127.6X 상(0.5)-33.4 (r 상(2)=0.7146), 32.8 사육조의 용존산소 농도 범위 3.8-7.5 (평균 5.7$\pm0.98)\;mg/\ell$ 에서의 여과 재료 단위 용적($m^3$/day))당 1일 산소 소비량은 모래, 산호사, 폴리에틸렌망을 이용한 여과조에서 각각 442.1, 291.1, 및 236.9 g/$m^3$/day 로 모래 여과조의 산소 소비량이 가장 많았으며, 자갈과 플라스틱 파판은 각각 135.6 및 134.2 g/$m^3$/day로 가장 적었다. 한편 회전원판 여과조는 물에 노출되는 구조적 특성 때문에 산소 소비량 측정은 불가능하였다.

• Environmental Analysis Health and Toxicology
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• 제24권2호
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• pp.119-125
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• 2009

원유의 WSF가 넙치의 수정란 및 자어발생에 미치는 독성영향을 알아보기 위하여 유류의 농도에 따른 부화소요시간, 부화율, 생존율, 호흡, 심장박동수의 변화 및 기형율 등을 조사하였다. 부화소요시간은 대조구와 실험농도구간에 유의한 차이를 보이지 않았다 (p>0.05). 부화율은 대조구와 1.9 ${\mu}g/mL$ WSF에서 80% 이상이었으나, 3.9 ${\mu}g/mL$ WSF 이상에서는 55.7% 이하로 나타나 유의한 차이를 보였다(p<0.05). 한편 부화 후 3일 동안의 생존율은 농도의존적 감소현상을 나타내었다. 산소소비율은 대조구에 비해 낮게 나타났으며, 심장박동수는 대조구의 경우 부화 전에 비해 부화한 후 다소 증가하였으나, WSF 노출구에서는 감소하는 현상을 나타내었다. 기형율은 WSF 농도증가에 따라 증가하였으며, 주로 척추만곡과 척추형성부전의 현상을 보였다

• 한국양식학회지
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• 제12권2호
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• pp.123-135
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• 1999

In order to investigate the effect of salinity on growth and osmoregulation of the sweetfish, Plecoglossus altivelis, the fish (post-larva, juvenile, adult) reared in seawater were directly transferred into the experimental rearing water of the different salinities (post-larva : $0\textperthousand$, $5\textperthousand$, $10\textperthousand$, $15\textperthousand$, $20\textperthousand$, $30\textperthousand$. juvenile : $0\textperthousand$, $\10textperthousand$, $20\textperthousand$, $30\textperthousand$. adult : $0\textperthousand$, $15\textperthousand$, $35\textperthousand$, respectively). Fish samples were taken in time courses after transfer for blood and body fluid collection. The changes of sodium, potassium concentration and osmolality of the body fluid and plasma, muscle water content, gonadosomatic index (GSI) and hepatosomatic index (HSI) in the experimental fish were observed in time courses. Growth rate of the post-larva in $\5~25\textperthousand$ were faster than in $0\textperthousand$ (P<0.05). Survival rate was very low in $0\textperthousand$ (P<0.05). No fish survived more than 50 days after transferred into $0\textperthousand$. The concentration of sodium, potassium and osmolality in body fluid of the juvenile sweetfish were slightly decreased at 0.25 day after the beginning of the maintainable level of sodium, potassium and osmolality were $36.4\pm6.2 mM/\ell, 47.5\pm0.7 mM/\ell, 366.3\pm19.1 mOsm/kg, respectively. Except potassium concetration, fish in $0\textperthousand$ and $10\textperthousand$ displayed the pattern of hypoosmotic regulation. Growth rate and survival rate of juveniles of $30\textperthousand$ are significantly low than other groups (P＜0.05). The concentration of sodium, potassium and osmolality in plasma of adult sweetfish were slightly decreased at 1 day after the beginning of the maintainable level of sodium, potassium and osmolality were $159.0\pm2.5 mM/\ell, 5.8\pm0.9 mM/\ell, 338.1$\pm13.3 mOsm/kg respectively. Compared with these values, fish in $0\textperthousand$ and $15\textperthousand$ displayed hypoosmotic regultion. Growth and survival rate of adult in $35\textperthousand$ are significantly low than other experimental groups. GSI was the highest in $15\textperthousand$ after 60 days. HSI was the lowest in $35\textperthousand$. With decreased salinities, oxygen consumption was found to be decreased in the other experimental groups compared to the more than $30\textperthousand$.