• Journal of Bio-Environment Control
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• v.27 no.2
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• pp.180-184
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• 2018

This study was conducted to examine the effect OTR film type on the quality of garden cress (Lepidium sativum L.) baby leaf during MA storage. Garden cress harvested at baby leaf size of 10cm plant height packed with 1,300 cc, 10,000 cc, 20,000 cc, 40,000 cc, and $80,000cc{\cdot}m^{-2}{\cdot}day^{-1}{\cdot}atm^{-1}$ OTR (oxygen transmission rate) films and MP (micro-perforated) film, and then stored at $8^{\circ}C$ for 10 days. All of the OTR film treatments showed a decrease of 0.5% fresh weight until the storage end date and a 1.3% decrease in the MP film treatment. The oxygen concentration in the packaging during storage was maintained at 18% or more in 20,000 cc, 40,000 cc, and 80,000 cc OTR film treatments, while the 1,300 cc OTR film treatment decreased to 11% at the storage end date. And the concentration of carbon dioxide was steadily increased in the 1,300 cc and 10,000 cc OTR film treatments to show the levels of 4.5% and 3.4%, respectively, and the other OTR film treatments showed a concentration of less than 1%. Ethylene concentration in the package was maintained at the highest level of $3-5{\mu}L{\cdot}L^{-1}$ in the 1,300 cc treatment during the storage period. The lowest odor and the highest quality of appearance were observed in the 1,300 cc treatment, but the MP film treatment and the other OTR treatments lost marketable quality due to yellowing. The color of garden cress baby leaf was changed the lowest in 1,300 cc treatment that showed the highest chlorophyll content and Hue angle value, lowest $b^*$ value, present of yellowing at end of storage date. Therefore, 1,300 cc treatment which was most effective for yellowing and odor suppression during storage is considered to be suitable for packaging of garden cress baby leaf.

• Journal of Bio-Environment Control
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• v.25 no.2
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• pp.89-94
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• 2016

This study was conducted to determine the optimum nutrient solution, pH, irrigation interval, light intensity and planting density to growth of common ice plant (Mesembryanthemum crystallinum L.) in a closed-type plant production system. Three-band radiation type fluorescent lamps with a 12-h photoperiod were used. Nutrient film technique systems with three layers were used for the plant growth system. Environmental conditions, such as air temperature, relative humidity and $CO_2$ concentration were controlled by an ON/OFF operation. Treatments were comparison of the nutrient solution of Horticultural Experiment Station in Japan (NHES) and the nutrient solution of Jeju National University (NJNU), pH 6.0 and 7.0, irrigation interval 5 min and 10 min, light intensity 90 and $180{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$, and within-row spacing 10 cm, 15 cm, 20 cm and 25 cm with between-row spacing 15 cm. Optimum macronutrients were composed N 7.65, P 0.65, K 4.0, Ca 1.6 and Mg $1.0mM{\cdot}L^{-1}$. There were no significant interactions between pH 6.0 and 7.0 about shoot fresh weight and shoot dry weight of common ice plant. Irrigation interval 5 min and 10 min was also the same result. Shoot fresh weight and shoot dry weight were highest at $180{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$. Shoot fresh weight and shoot dry weight were decreased according to increasing the planting density. From the above results, we concluded that optimum nutrient solution, optimum levels of pH, irrigation interval, light intensity and planting density were 6.0-7.0 and 10 min, $180{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ and $15{\times}15cm$, respectively for growth of common ice plant in a closed-type plant production system.

• Journal of Veterinary Clinics
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• v.26 no.4
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• pp.317-323
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• 2009

This study was performed to evaluate the effect of intravenous administration of glycopyrrolate on cardiovascular and respiratory system in dogs given intravenous medetomidine (20 ${\mu}g$/kg) and intramuscular midazolam (0.3 mg/kg) (MM). Prior to administration of MM, glycopyrrolate was administered intravenously at doses of 5 ${\mu}g$/kg (Gly-5), 10 ${\mu}g$/kg (Gly-10) or 20 ${\mu}g$/kg (Gly-20), respectively. For the control group saline was administered intravenously. In the cardiovascular system, HR, BP, RAP, PAWP, CI, SI, SVR, and PVR were measured. RR, $V_T$, $P_{ETCO2}$, and arterial blood gas analysis were measured for respiratory system. Although rapid and satisfied depth of sedation was obtained by MM, life-threatening bradycardia, the outstanding side-effect on cardiovascular system in dogs were observed. This combination also decreased CO and increased SVR, RAP, and PAWP significantly. The bradycardia could be prevented in all the glycopyrrolate treated groups, but tachycardia was observed in Gly-10 and Gly-20 groups. Significant increases in blood pressure were shown in glycopyrrolate treated groups. Also, tachycardia depends on dose of glycopyrrolate, compensating the CO. However, these were not fully reserved. In conclusion, MM combination could induce rapid and satisfied depth of sedation but was not the suitable method for the deep sedation of dogs with cardiovascular or circulatory problems.

• Journal of Chest Surgery
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• v.32 no.7
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• pp.637-647
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• 1999

Background: Ischemia-reperfusion injury is one of the major contributing causes of early graft failure in lung transplantation. It has been suggested that triiodothyronine (T3) may ameliorate ischemia-reperfusion injury to various organs in vivo and in vitro. Predicting its beneficial effect for ischemic lung injury, we set out to demonstrate it by administering T3 into the in situ canine ischemia-reperfusion model. Material and Method: Sixteen adult mongrel dogs were randomly allocated into group A and B. T3 $(3.6\mug/kg)$ was administered before the initiation of single lung ischemia in group B, whereas the same amount of saline was administered in group A. Ischemia was induced in the left lung by clamping the left hilum for 100 minutes. After reperfusion, various hemodynamic parameters and blood gases were analyzed for 4 hours while intermittently clamping the right hilum in order to allow observation of the injured left lung function. Result: Arterial oxygen partial pressure $(PaO_2)$ decreased 30 minutes after reperfusion and recovered gradually thereafter in both groups. In group B the decrease of $PaO_2$ was less marked than in group A. The recovery of $PaO_2$ was faster in group B than in group A. The differences between the two groups were statistically significant from 30 minutes after reperfusion $(125\pm34$ mmHg and $252\pm44$ mmHg, p<0.05) until the end of the experiment $(178\pm42$mmHg and $330\pm37$ mmHg, p<0.05). The differences in the arterial carbon dioxide pressure, airway pressure and lung compliance showed no statistical significance. The malondialdehyde (MDA) level, measured from the tissue obtained 240 minutes after reperfusion, was lower in group B $(0.40\pm0.04\mu$M) than in group A $(0.53\pm0.05\mu$M, p<0.05). The ATP level of group B $(0.69\pm0.07\mu$M/g) was significantly higher than that of group A $(0.48\pm0.07\mu$M/g, p<0.05). The microscopic exami nation revealed varying degrees of injury such as perivascular neutrophil infiltration, capillary hemorrhage and interstitial congestion. There were no differences in the microscopic findings between the two groups. CONCLUSION T3 has beneficial effects on the ischemic canine lung injury including preservation of oxygenation capacity, less production of lipid peroxidation products and a higher level of tissue ATP. These results suggest that T3 is effective in pulmonary allograft preservation.

• Journal of the Korea Organic Resources Recycling Association
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• v.25 no.1
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• pp.103-110
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• 2017

In Concentrated Animal Feeding Operations(CAFOs), emission of ammonia from stored manure contributes negatively on the wellness of livestock. In CAFOs facilities, indoor aerial ammonia concentration oftentime surpasses the critical level potentially harmful to livestock's immune system. Understandably, numerous researches to control aerial ammonia have been conducted in countries where CAFOs were practiced for many decades. Some innovative technologies, such as scrubber, bio-filter, and additives emerged, as a result. Among them, microbial additives became popular in Korea, due to an easiness of use and affordability. However, microbial additives still have some weaknesses. Their price is still high enough to discourage farmers who run a small scale farm and their effectiveness are still questioned by many users and researchers. In the present study, we found soluble carbohydrates, such as sugar, glucose, and molasses, when supplemented to pig slurry manure, can mitigate ammonia emission. To be more specific, pig manure slurry(120kg), stored in container(200L), was supplemented with sugar at 0.1%(w/w) and was, subsequently, monitored for pH and aerial ammonia for next 10 days. From this experiment, it was found that the sugar supplementation was effective in mitigating the aerial ammonia concentration (33% in average) when monitored daily. Also, the pH of manure slurry was maintained at relatively low level(8.2) in sugar-supplemented manure slurry while it was elevated to 8.5 in untreated slurry. Conclusively, the obtained data suggest that soluble carbohydrate can mitigate ammonia emission by acidifying manure slurry. Additionally, it can be suggested that soluble carbohydrates, such as sugar, glucose, and molasses, can be reasonable choices for animal farmers who have been looking for an alternative choice to replace expensive microbial additives.

• Journal of the Korea Organic Resources Recycling Association
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• v.12 no.1
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• pp.49-57
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• 2004

The effect of gas sparging on continuous fermentative $H_2$ production was investigated using external gases ($N_2$, $CO_2$) with various flow rates (100, 200, 300, 400 ml/min). Gas sparging showed a higher $H_2$ yield than no sparging, indicating that the decrease of $H_2$ partial pressure by gas sparging had a good effect on $H_2$ fermentation. Especially, $CO_2$ sparging was more effective in the reactor performance than $N_2$ sparging. The composition of butyrate, the main metabolic product of $H_2$ fermentation by Clostridium sp., was much higher in $CO_2$ sparging. $H_2$ production increased with increasing flow rate only in $CO_2$ sparging. The best performance was obtained by $CO_2$ sparging at 300 ml/min, resulting in the highest $H_2$ yield of 1.65 mol $H_2/mol$ hexoseconsumed and the maximum $H_2$ production of 6.77 L $H_2/g$ VSS/day. Compared to $N_2$ sparging, there could be another beneficial effect in $CO_2$ sparging apart from lowering down the $H_2$ partial pressure. High partial pressure of $CO_2$ had little effect on $H_2$ producing bacteria but inhibitory effect on other microorganisms like lactic acid bacteria and acetogens which were competitive with $H_2$ producing bacteria.

• Journal of Bio-Environment Control
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• v.24 no.3
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• pp.161-166
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• 2015

To determine the adequate levels of light intensity and $CO_2$ concentration for mango grown in greenhouses, quantitative measurements of photosynthetic rates at various leaf positions in the tree are required. The objective of this study was to develop two-variable leaf photosynthetic models of Irwin mango (Mangifera indica L. cv. Irwin) using light intensity and $CO_2$ concentration at different leaf positions. Leaf photosynthetic rates at different positions (top, middle, and bottom) were measured by a leaf photosynthesis analyzer at light intensities (0, 50, 100, 200, 300, 400, 600, and $800{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$) with $CO_2$ concentrations (100, 400, 800, 1200, and $1600{\mu}mol{\cdot}mol^{-1}$). The two-variable model consisted of the two leaf photosynthetic models expressed as negative exponential functions for light intensity and $CO_2$ concentrations, respectively. The photosynthetic rates of top leaves were saturated at a light intensity of $400{\mu}mol{\cdot}^{-2}{\cdot}s^{-1}$, while those of middle and bottom leaves saturated at $200{\mu}mol{\cdot}^{-2}{\cdot}s^{-1}$. The leaf photosynthetic rates did not reach the saturation point at a $CO_2$ concentration of $1600imolmol^{-1}$. In validation of the model, the estimated photosynthetic rates at top and bottom leaves showed better agreements with the measured ones than the middle leaves. It is expected that the optimal conditions of light intensity and $CO_2$ concentration can be determined for maximizing photosynthetic rates of Irwin mango grown in greenhouses by using the two-variable model.

• Journal of Distribution Science
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• v.10 no.1
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• pp.43-52
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• 2012

With the slowdown in environmental issues and the change of environmental consciousness, ecotourism is being discussed in various social fields. Ecotourism is being popularized for environmental protection, and now it is becoming a mainstream product from one of mass tourism. Ecotourism's emphasis on sustainable development in the tourism destination's society, economy, and environment, through ecotourism study and education, enable people to understand the core value of the ecological environment. 2011 was nominated as "the Year of World Forest" by the UN. In the recent years, forests are becoming increasingly important with their own values and functions in environment, economy, society, and culture. In particular, the global environmental issues caused by climate change are becoming an international agenda. Forests are the only effective solution for the carbon dioxide that causes global warming. Moreover, forests constitute a major part of ecotourism, and are now most used by ecotourists. For example, Korea, wherein 60% of the land is forest, attracts ecotourists. With the increasing interests in environment, the number of tourists visiting the ecosystem forest, which is highly valued for its conservation, is increasing significantly every year and is receiving considerable attention from the government. However, poor facilities in the forest ecotourism sites and improper market strategies are the reasons for the poor running of these sites. Furthermore, tourists' environmental awareness affects ecology environmental pollution or the optimization of forest ecotourism. In order to verify the relationships among tourist attractiveness, environmental consciousness, charm degrees of the attractions, and attitudes after tours, we established some scales based on existing research achievement. Then, using these scales, the researcher completed the questionnaire survey. From December 20, 2010 to February 20, 2011, after conducting surveys for 12 weeks, we finally obtained 582 valid questionnaires, from a total of 700 questionnaires, that could be used in statistical analysis. First, for the method of research and analysis, the researcher initially applied the Cronbach's (Alpha) for verifying the reliability, and subsequently applied the Exploratory factor analysis for verifying the validity. Second, in order to analyze the demographics, the researcher makes use of the Frequency analysis for the AMOS, measurement model, structural equation model computing, and also utilizes construct validity, convergent validity, discriminant validity, and nomological validity. Third, for the analysis of the ecotourists' environmental consciousness, impacts on tourist attractiveness, charm degrees of the attractions, and attitudes after the tour, the researcher uses AMOS 19, with the path analysis and equation of structure. After the research, researchers found that high awareness of natural protection lead to high tourist motivation and satisfaction and more positive attitude after the tour. Moreover, this research shows the psychological and behavioral reactions of the ecotourists to the ecotourist development. Accordingly, environmental consciousness does not affect the tourist attractiveness that has been interpreted as significant. Furthermore, people should focus on the change of natural protection consciousness and psychological reaction of ecotourists while ensuring the sustainable development of ecotourists and developing some ecotourist programs.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.3
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• pp.485-494
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• 2000

According to the worldwide interest in controlling $CO_2$ which contributes to green house effect. new techniques of reducing $CO_2$ are under development. We have developed new technique for reducing $CO_2$. In low $CO_2$ concentration. the chemical absorption method is useful. In this study. the kinetics of the reaction between $CO_2$ and the sterically hindered amine solution with piperazine. have been investigated from measurements of the rate of absorption of $CO_2$ in the stirred vessel that has a horizontal liquid-gas interface, in the temperature range $30{\sim}70^{\circ}C$. The experiments were carried out in the range 10.130~20.260 kPa of partial pressure of $CO_2$, and in aqueous $2.0kmol/m^3$ AMP solution with $0{\sim}0.4kmol/m^3$ piperazine The experimental results are as follows: 1) The absorption rate of $CO_2$ into aqueous AMP + piperazine solution is gett ng faster than that of aqueous AMP absorbents with temperature. Because the activation energy of piperazine 57.147 kJ/mol is higher than that of AMP 41.7kJ/mol. therefore the effect of piperazine on absorption rate increases with temperature. 2) Compared with aqueous AMP solution. the absorption rate of $CO_2$ into AMP + piperazine solution increases from 6.33% at $30^{\circ}C$ to 12% at $70^{\circ}C$, so AMP + piperazine solution is thought to be a better than AMP solution, 3) The reaction rate constants of piprazine in aqueous AMP solution with $CO_2$ have been determined as 217.21, 420.46, 707.00 and $3162.167m^3/kmol{\cdot}s$ respectively at 30, 40, 50 and $70^{\circ}C$ but these results are higher than those of Xu which were 186.7. 367.32. 693.01. $2207.65m^3/kmol{\cdot}s$ at 30, 40, 55, $70^{\circ}C$in aqueous MDEA solution. So the regression analysis of the data has led to the following equation In $k_p$ =28.324-6934.7/T.

• Tuberculosis and Respiratory Diseases
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• v.40 no.3
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• pp.250-258
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• 1993

Background: After general anesthesia, decrease of functional residual capacity and lung compliance, ventilation/perfusion imbalance, and transpulmonary shunting can provoke hypoxemia during postoperative periods. Diaphragmatic dysfunction may be the main cause of these physiological abnormalities. Thus, we evaluated the change of pulmonary function after general anesthesia according to the operative sites, which could suggest clinical course and critical period of respiratory care of postoperative patients. Method: Preoperative portable spirometric evaluation and arterial blood gas analysis were performed at sitting or most-sitting position just previous day of surgery. Pulmonary function tests were also as same condition from postoperative day 1 to day 5. Results: 1) For thoracic surgery, FEV1 and FVC were not recovered at day 5, but FEV1/FVC was not decreased. $PaCO_2$ was slightly elevated at postoperative one day. 2) After upper abdominal surgery, postoperative day 5 did not show the recovery of FEV1 and FVC, but mild hypoxemia was developed at postoperative day 1. 3) Pulmonary function was recovered as preoperative value at postoperative day 5 in lower abdominal operation, but mild hypoxemia was also noted at postoperative day 1. 4) Surgery of peripheral areas did not show significant pulmonary function change and hypoxemia and hypercapnia from postoperative day 1. Conclusion: Surgery involving diaphragm provoke significant postoperative pulmonary function change after day 5. For the operation of peripheral sites adequate respiratory care during operation and postoperative period within 24 hours could prevent patients from respiratory complication.