• Journal of Radiation Protection and Research
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• 제31권4호
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• pp.197-201
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• 2006

Daily and seasonal variations of the ambient gamma ray exposure rates were measured by using a pressurized ion chamber from January 2003 to December 2005 in the CheongJu Regional Radiation Monitoring Post and the patterns of the distributions were studied. The annual average of the daily variation of the exposure rate was $\sim0.17{\mu}R/h$. The exposure rate was found to be maximum during 8:00 am to 9:00 am and minimum during 8:00 pm to 10:00 pm. For the annual data, the exposure rate was the minimum during the month of February. The exposure rate increased from February to mid-October (except during the period from May to July with no change) and decreased from October to February. The seasonal variation was found to be about $1{\mu}R/h$. Most of the measured values (96%) of the exposure rates fell under the normal distribution with a deviation of less than 4.8% and the remaining 4% had large fluctuations caused mainly by the rainfalls.

• 한국수산과학회지
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• 제49권1호
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• pp.45-52
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• 2016

This experiment investigated changes in metabolic rate (MO₂), critical oxygen saturation (S_crit), and blood chemistry of olive flounder Paralichthys olivaceus exposed to progressive hypoxia and returned to normoxic water at 20°C. The normoxic standard metabolic rate (SMR) and routine metabolic rate (RMR) were 69.5-83.9 and 70.2-156.4 mg O₂ kg^-1h^-1, respectively based on fish weight. S_crit was 31.0% dissolved oxygen (DO) at 20°C. After returning the fish to 70% DO following exposure to hypoxia (20% DO), MO₂ increased two-fold compared to the normoxic SMR and then decreased into the range of the RMR with time. Blood PO₂ and plasma lactate decreased significantly after exposure to hypoxia (20% DO) and then increased as ambient oxygen saturation decreased. Cortisol levels increased as ambient oxygen saturation decreased, but the levels decreased rapidly in the range of the normoxic control when the fish were returned to ambient water with 70% DO. Plasma glucose levels increased when the fish were returned to normoxic water after exposure to a progressively more hypoxic condition.

• 대한방사선방어학회:학술대회논문집
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• 대한방사선방어학회 2009년도 춘계 학술발표
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• pp.272-273
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• 2009

• Journal of Nutrition and Health
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• 제38권2호
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• pp.117-124
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• 2005

We investigated the effects of prolonged exposure in hot environmental condition and ingestion of fluid on various physiological variables including plasma glucose, lactate, the rating of perceived exertion (RPE), and heart rate as well as golf putting performance. Six male professional golfers were voluntarily participated in three different putting trials which were separated by seven days of time interval period. Three different putting trials were conducted at either 20℃ or 32℃, or 32℃ + Fluid ingestion. Performing 32℃ + Fluid ingestion trial, all subject ingested sport drink as much as their body mass was decreased. For each experiment, all subjects were undertaken total 48 putting, which separated by four x 12 putting in four different time points (i.e., Rest, 1 hr, 2 hr, and 3 hr). Plasma glucose concentration was significantly decreased with hot ambient condition but it was almost fully recovered by fluid ingestion. Plasma lactate concentration was significantly higher when subjects were exposed in hot environmental condition, and it did not change with fluid ingestion. There was a no different in putting performance and psychological fatigue level (performed by GRID test) at any environmental conditions. The RPE, commonly used for evaluating of physical fatigue level, was significantly dropped by fluid ingestion which indicates lower physical fatigue level. In addition to this, heart rate (HR) was also significantly decreased after fluid ingestion. Based on these results, it was concluded that the ingestion of fluid during prolonged exposure in hot ambient condition decrease the degree of physical fatigue levels and heart rate, which will possibly improve the golf performance when exposed in extreme weather condition in summer. (Korean J Nutrition 38(2): 117～124, 2005)

• Asian-Australasian Journal of Animal Sciences
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• 제10권5호
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• pp.478-483
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• 1997

Six adult female Murrah buffaloes of about 12 years were exposed to solar radiation during summer when minimum and maximum ambient temperatures were 27.1 and $44.1^{\circ}C$, respectively. The skin surface temperature at forehead, middle pinna, neck, rump, foreleg, hind legs were recorded using non-contact temperature measuring instrument and respiration rate and rectal temperature were measured throughout the 24 hours starting from 6:30 AM. The diurnal fluctuations and temperature gradients have been reported for buffaloes. During summer when ambient temperature and solar radiation was maximum, adult buffaloes were not able to maintain their thermal balance even after increasing the pulmonary frequency 5 - 6 times. The changes in skin temperature at various sites indicate that the temperature of skin surface not only varies in relation to exposure but also due to water diffusion and evaporation.

• Asian-Australasian Journal of Animal Sciences
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• 제10권3호
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• pp.318-323
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• 1997

In order to assess the effect of solar exposure on pulmonary functions and evaporative losses from skin and pulmonary surfaces, in six healthy Sahiwal (S) and six Sahiwal ${\times}$ Holstein ($S{\times}H$) cattle were exposed to direct sun during summer. Breed differences were observed during exposure. Increase in sweating rate was higher in crossbreds (222%) than in Sahiwal (125%). Pre-exposure (ambient temperature, $32.6{\pm}0.85^\circ}C$, solar radiation, $0.9cal\;cm^{-2}min^{-1}$) evaporative loss from skin accounted for about 90% of the losses and remaining losses were contributed by pulmonary surfaces in Sahiwal. The contribution of evaporation through skin increased to 92% (ambient temperature $39.4{\pm}0.68^\circ}C$, solar radiation, $1.35cal\;cm^{-2}min^{-1}$). In crossbreds 80% of the evaporative losses were through skin before exposure which increased to 87% after exposure to solar radiations. Rectal temperature increase was higher in crossbreds ($1.5^{\circ}C$) than in Sahiwal ($0.8^{\circ}C$). With the increase in pulmonary evaporative losses, respiratory frequency increased to 2 fold in Sahiwal and pulmonary ventilation increased 1.6 times the resting value in Sahiwal due to solar exposure. In $S{\times}H$ crossbreds the respiratory frequency increased 3.5 times and pulmonary ventilation increased only to 1.8 times due to decrease in tidal volume. There was about 2 fold increase in alveolar ventilation in both the breeds, the increase in dead space ventilation was more in crossbreds than in Sahiwal. Behavioral symptoms exhibited by animals after exposure were profuse salivation, open mouth panting, tongue protrusion and general restlessness.

• 한국환경보건학회지
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• 제41권4호
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• pp.223-230
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• 2015

Objectives: There is considerable evidence that polluted ambient air contributes to the risk of cardiovascular morbidity and mortality. Heart rate variability (HRV) is defined as the variation in heartbeat intervals and has been reported as a biological marker of cardiovascular disease. This article reviews the existing literature in order to examine the association between air pollution and HRV. Methods: Literature was searched using Web of Science with the key words of "air pollution", "heart rate variability" and other related terms. A total of 156 articles were listed. For review, 21 of those listed publications were chosen after excluding studies regarding chamber studies, occupational environment, secondhand smoke and automobile exhaust. Results: Research methods employed in the publications were classified by type of participants (elderly/adult), air pollution monitoring (ambient/personal) and HRV monitoring (continuous/spot). Among HRV parameters, power in the low frequency range (LF), power in the high frequency range (HF) and standard deviation of all NN intervals (SDNN) were all associated with air pollutants. The chosen studies were mostly based on elderly populations. In studies based on continuous HRV monitoring, LF and SDNN significantly decreased when $PM_{2.5}$ exposure increased. Conclusion: Continuous HRV monitoring combined with personal exposure monitoring has been one of the most common study methods in recent publications. We expect that this review will be useful for the study of the association between air pollution and cardiovascular effects using HRV.

• Asian-Australasian Journal of Animal Sciences
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• 제5권1호
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• pp.81-90
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• 1992

Five buffaloes kept in normal ambient temperature ($30^{\circ}C$) showed no significant changes in the heart rate, respiratory rate, packed cell volume, plasma constituents and renal hemodymics during intravenous infusion of urea for 4 h. The rate of urine flow, fractional urea excretion, urinary potassium excretion and osmolar clearance significantly decreased while the renal urea reabsorption markedly increased during urea infusion. The decrease of fractional potassium excretion was concomitant with the reduction of the rate of urine flow and urine pH. In animals exposed to heat ($40^{\circ}C$) the rectal temperature heart rate and respiratory rate significantly increased while no significant changes in GFR and ERPF were observed. An intravenous infusion of urea in heat exposed animals caused the reduction of the rate of urine flow with no changes in renal urea reabsorption, urine pH and fractional electrolyte excretions. During heat exposure, there were marked increases in concentrations of total plasma protein and plasma creatinine whereas plasma inorganic phosphorus concentration significantly decreased. It is concluded that an increase in renal urea reabsorption during urea infusion in buffaloes kept in normal ambient temperature depends on the rate of urine flow which affect by an osmotic diuretic effect of electrolytes. The limitation of renal urea reabsorption in heat stressed animals would be attributed to an increases in either plasma pool size of nitrogenous substance or body metabolism.

• 한국환경과학회지
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• 제15권10호
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• pp.929-933
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• 2006

Indoor air quality is the dominant contributor to total personal exposure because most people spend a majority of their time Indoors. Especially when indoor environments have sources of contaminants, exposure to in-door air can potentially pose a greater threat than exposure to ambient air. In this study, estimations of volatile organic compounds and formaldehyde omission rate in indoor environments of new apartments were carried out using mass balance model in indoor environment, because indoor air quality can be affected by source generation, outdoor air level, ventilation, decay by reaction, temperature, humidity, mixing condition and so on. Considering the estimated emission rate of volatile organic compounds and formaldehyde, it Is suggested that new apartment should be designed and constructed in the aspect of using construction materials to emit low hazardous air pollutants.

• Asian-Australasian Journal of Animal Sciences
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• 제3권1호
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• pp.47-52
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• 1990

During prolonged exposure to the sun for 8 h each day for 10 days in which the highest ambient temperature around 14:00 h was $39^{\circ}C$, buffaloes exposed to the sun without shade increased the turnover of body water by 35% and 76% on day 5 and day 10 of exposure respectively. The total body water markedly decreased on day five and this amount was maintained thereafter. Plasma and blood volumes did not change significantly on day five but markedly decreased on day 10. Packed cell volume significantly decreased on day five and day 10 of the exposure period. The reduction of packed cell volume on day 10 coincided with the decrease in total plasma water. On day 10 of the exposure, an increase in the rate of liquid flow from the rumen was noted. It is concluded that on the fifth day of exposure, the increase in the evaporative cooling process was attributed to initial mobilization of water from the intracellular compartment. The reduction of both plasma and cell volumes occurring from day five to day 10 indicated a loss of body water from both intracellular and extracellular compartments.