• Korean Journal of Ecology and Environment
• /
• v.56 no.3
• /
• pp.187-195
• /
• 2023

Almost all of the water from agricultural dams located to the upper of the Yeongsan river is supplied as irrigation water for farmland and thus is not discharged to the main stream of the river. Also, most of the irrigation water does not return to the river after use, adding to the lack of flow in the main stream. As a result, the water quality and aquatic health of the river have become the poorest among the four major rivers in Korea. Therefore, in this study, several strategies for water quality improvement of the river were developed considering pollution reduction and flow rate increase, and their effect analysis was performed using a water quality model. The results of this study showed that the target water quality of the Yeongsan river could be achieved if flow increase strategies (FISs) are intensively pursued in parallel with pollution reduction. The reason is because the water quality of the river has been steadily improved through pollution reduction but this method is now nearing the limit. In addition, rainfall-related FISs such as dam construction and water distribution adjustment may be less effective or lost if a megadrought continues due to climate change and then rainfall does not occur for a long time. Therefore, in the future, if the application conditions for the FISs are similar, the seawater desalination facility, which is independent of rainfall, should be considered as the priority installation target among the FISs. The reason is that seawater desalination facilities can replace the water supply function of dams, which are difficult to newly build in Korea, and can be useful as a climate change adaptation facility by preventing water-related disasters in the event of a long-term megadrought.

• Korean Journal of Culture and Social Issue
• /
• v.25 no.4
• /
• pp.249-277
• /
• 2019

This study examined the involuntary retirement of executives in conglomerates based on Williams' need-threat temporal model of ostracism(2009), which explains the psychology of individuals facing social exclusion in the stages of reflexive, reflective and resignation. In-depth interviews were conducted on 15 retirees from conglomerates, and their contents were used for phenomenological method of analysis. As a result, in the reflexive stage of need-threat temporal model of ostracism, they experienced cognitive panic and emotional panic immediately following retirement. Due to an unexpected shocking experience of retirement notice, they experienced cognitive numbness first, and repressed the following negative feelings cognitively to hide them. In the reflective stage, retirees dream of 'a complete restoration to their best performance in the past', but as such expectation fails, they don't adjust to the reality more due to 'unrealistic thought', 'self-deception', and 'shift responsibility'. In resignation stage, a long-term failure to satisfy the desire led them to experience a sense of defeat and helplessness. Such results were reviewed and compared to Williams' need-threat temporal model of ostracism, and the implications of such result on the nation, companies and retirees in terms of the response to retirement.

• KSBB Journal
• /
• v.21 no.4
• /
• pp.248-254
• /
• 2006

Animal cell culture industry has a large market and an exponential growth rate among biological industry field. Chines hamster ovary(CHO) cells are the most widely used cell lines for recombinant protein production. They can avoid infection from polio, herpes, hepatitis B, HIV, measles, adenovirus and etc. Moreover it is easy to transfection recombinant genes and possible to suspension culture. Serum free media is one of the most important factor of protein production. Because serum has problems. Serum is not defined the contents until now, it has a number of proteins, lipids, carbohydrates and unknown molecules that cause of risk involve in infection and high cost of product purification. CHO cell line cultured using serum free media were the basis of a very successful method to produce(glyco-)protein in mammalian cells, which are then used as pharmaceutical products. Also, the low protein content of the developed medium facilitates downstream processing and product purification. But non-adapted CHO cells have a limit of proliferation cultured using serum free media and it takes very long time to adapt non-adapted cells to serum free media. There are a number of causes of a limit of proliferation using serum free media. Absence of growth factors and growth stimulating molecules is a major factor of the reasons. It makes growth signals and moves cell cycle. And increase of cellular stress is another reason. It induces increase of intraceullar ROS concentration. The purpose of this study is about improvement of proliferation capacity of non-adapted CHO cells cultured using serum free media without adaptation process.

• KSBB Journal
• /
• v.17 no.1
• /
• pp.73-79
• /
• 2002

The method to optimize the microbial production of ethanol from CO using Clostridium ljungdahlii was developed. The kinetic parameter study on CO conversion with Clostridium ljungdahlii was carried out and maximum CO conversion rate of 37.14 mmol/L-hr-O.D. and $K_{m}$ / of 0.9516 atm were obtained. It was observed that method of two stage fermentation, which consists of cell growth stage and ethanol production stage, was effective to produce ethanol. When pH was shifted from 5.5 to 4.5 and ammonium solution was supplied to culture media as nitrogen source at ethanol production stage, the concentration of ethanol produced was increased 20 times higher than that without shift. Ethanol production from CO in a fermenter with Clostridium ljungdahlii was optimized and the concentration of ethanol produced was 45 g/L and maximun ethanol productivity was 0.75 g ethanol/L-hr.

• Journal of Nutrition and Health
• /
• v.49 no.5
• /
• pp.358-366
• /
• 2016

Purpose: This study was conducted to assess the nutritional status of female marriage immigrants attending Korean language class in Gwangju, Korea by analyzing daily food and nutrient intake. Methods: Eighty-three female immigrants completed a survey. Anthropometric measurements were obtained, and dietary food intake was assessed using a 1-day 24 hour recall method. Results: The average length of residence in Korea was 5.3 years, and mean age of subjects was 31.0 years old. The home countries of subjects were Vietnam (50.6%), China (24.1%), Philippines (13.3%), and others (12%). Due to the length of residence, there were significant differences in body weight (p < 0.05), BMI (p < 0.05), percent body fat (p < 0.05), and diastolic blood pressure (p < 0.05). The subjects who were 30~49 years old consumed more vegetables and less seaweed than the subjects who were 20~29 years old. The other kinds of consumed foods were similar among groups in different age groups or lengths of residence in Korea. Average energy intake of subjects was 1,641.0 Kcal. The group with less than 5 years of residence showed higher cholesterol intake than the group with 5 or more years of residence in Korea (p < 0.05). There was no significant difference in nutrient intake between the groups of different age or length of residence. There was a positive association among dietary cholesterol intake and consumption of eggs, milk. and dairy products, and blood pressure. Conclusion: The study shows that length of residence affects rate of obesity and nutritional status. Further extensive research is needed to understand the effect of dietary changes and nutritional status of female marriage immigrants as well as for their successful adaptation to develop a more active and long-term nutrition education program.