• Korean Journal of Ecology and Environment
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• v.50 no.2
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• pp.238-253
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• 2017

The sewage and wastewater (SAW) are a well-known major source of eutrophication and greentide in freshwaters and also a potential source of thermal pollution; however, there were few approaches to thermal effluent of SAW in Korea. This study was performed to understand the behavioral dynamics of the thermal effluents and their effects on the water quality of the connected streams during winter season, considering domestic sewage, industrial wastewater and hot spring wastewater from December 2015 to February 2016. Sampling stations were selected the upstream, the outlet of SAW, and the downstream in each connected stream, and the water temperature change was monitored toward the downstream from the discharging point of SAW. The temperature effect and its range of SAW on the stream were dependent not only on the effluent temperature and quantity but also on the local air temperature, water temperature and stream discharge. The SAW effects on the stream water temperature were observed with temperature increase by $2.1{\sim}5.8^{\circ}C$ in the range of 1.0 to 5.5 km downstream. Temperature effect was the greatest in the hot spring wastewater despite of small amount of effluent. The SAW was not only related to temperature but also to the increase of organic matter and nutrients in the connected stream. The industrial wastewater effluent was discharged with high concentration of nitrogen, while the hot spring wastewater was high in both phosphorus and nitrogen. The difference between these cases was due to with and without chemical T-P treatment in the industrial and the hot spring wastewater, respectively. The chlorophyll-a content of the attached algae was high at the outlet of SAW and the downstream reach, mostly in eutrophic level. These ecological results were presumably due to the high water temperature and phosphorus concentration in the stream brought by the thermal effluents of SAW. These results suggest that high temperature of the SAW needs to be emphasized when evaluating its effects on the stream water quality (water temperature, fertility) through a systematized spatial and temporal investigation.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2009.05a
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• pp.158-163
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• 2009

Titanium alloy sheets have excellent specific strength and corrosion resistance as well as good performance at high temperature. Recently, titanium alloys are widely employed not only aerospace parts but also bio prothesis and motorcycle. However, due to the low formability and large spring back at room temperature, titanium alloy sheets were usually formed by slow forming or hot forming with heating die and specimen. In the sheet metal forming area, FE simulation technique to optimize forming process is widely used. To achieve high accuracy FE simulation results, Identification of material properties and deformation characteristic such as yield function are very important. In this study, uniaxial tensile and biaxial tensile test of Ti-6Al-4V alloy sheet with thickness of 1.0mm were performed at elevated temperature of 873k. Biaxial tensile tests with cruciform specimen were performed until the specimen was breakdown to characterize the yield locus of Ti-6Al-4V alloy sheet. The experimental results for yield locus are compared with the theoretical predictions based on Von Mises, Hill, Logan-Hosford, and Balat's model. Among these Logan-Hosford's yield criterion well predicts the experimental results.

• Journal of Microbiology and Biotechnology
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• v.19 no.10
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• pp.1230-1237
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• 2009

The selective plugging strategy of Microbial Enhanced Oil Recovery (MEOR) involves the use of microbes that grow and produce exopolymeric substances, which block the high permeability zones of an oil reservoir, thus allowing the water to flow through the low permeability zones leading to increase in oil recovery. Bacillus licheniformis TT33, a hot water spring isolate, is facultatively anaerobic, halotolerant, and thermotolerant. It produces EPS as well as biosurfactant and has a biofilm-forming ability. The viscosity of its cell-free supernatant is $120\;mPa{\cdot}s$ at $28^{\circ}C$. Its purified EPS contained 26% carbohydrate and 3% protein. Its biosurfactant reduced the surface tension of water from 72 to 34 mN/m. This strain gave $27.7{\pm}3.5%$ oil recovery in a sand pack column. Environmental scanning electron microscopy analysis showed bacterial growth and biofilm formation in the sand pack. Biochemical tests and Amplified Ribosomal DNA Restriction Analysis confirmed that the oil recovery obtained in the sand pack column was due to Bacillus licheniformis TT33.

• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.2
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• pp.467-478
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• 1994

This paper deals with dynamic behaviors of a free-piston Vuilleumier heat pump system, which are characterized by stroke of each diplacer/stroke ratio, operating frequency and phase angle. Based on the Isothermal Model, basic equations of motion are derived and linearized. In particular, dependence of damping coefficients of the dynamic parameters are taken into account in the formulation, which does not bring additional difficulties in the analysis. In order to investigate effects of design conditions on the dynamic parameters are taken into account in the formulation, which does not bring additional difficulties in the analysis. In order to investigate effects of design conditions on the dynamic characteristics, calculations are performed for the prototype made by Schulz and Thomas and results are qualitatively compared with their data obtained from the analysis as well as the experiment. It appears that they made a mistake in evaluating the hysteresis loss of the gas spring in their analysis. And, the present results show a better agreement with their experimental data than those by their own analysis. Although there are some unresolved aspects such as frequency variations with respect to the mean pressure and the hot space temperature, it is expected that the present analysis may be an effective tool for prediction of dynamics of a free- pistion VM machine at the preliminary design stage.

• Economic and Environmental Geology
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• v.7 no.1
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• pp.1-21
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• 1974

From the point of view of geological history, the land of South Korea is regarded as the subject of processes of the changes in formations of several geological blocks such as Kyonggi massif, Yeongnam massif, Taebaegsan basin, Kyungsang basin and so on. Through the long period of geological chronology, the present topography and geotectonics have been formed by the complicate interactions of epirogenetic movements, magmatism, orogenesis, differential vertical movements, metamorphism and sedimentation. The reason of the crust movements mentioned above, is suppossed that the Pacific and West Pacific plate have subducted directly or indirectly into the East Asia plate. This fact can be endorsed by the results of the studies on the heat flow, gravity anomaly, absolute age dating, tectonic lineation, lithofacies and the temperature of hot spring in South Korea. The formations of metal ore deposits as well as other geological processes can be determined by the mechanical control of the plates and be divided into several systematic patterns. The investigation of about 110 metal mines in South Korea shows the following results. (1) Plate boundary volcanic type is about 28% (2) Plate boundary plutonic type is about 44% (3) Intraplate sedimentary type is about 26% (4) Intraplate magmatic type is about 2%.

• The Korean Journal of Community Living Science
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• v.17 no.4
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• pp.67-80
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• 2006

This study conducted research on the actual state of community-oriented services for elderly rural inhabitants and their desire related to them to develop a local community service network model suitable to the characteristics of rural longevity villages. The research was conducted on 906 elderly people over 65 living in 20 rural longevity villages through questionnaires assessing filming and economy, economic activity, health care, learning and leisure activities as well as asking their wants and needs relative to local community services. As a result, it was found rural elderly people showed a high desire for local community services such as health, transportation and economy activity. In addition, they were mainly cultivating farm products as their economic activity and showed a high demand in the future as well. Most were found to take a walk in the healthcare field and showed a high demand for health examinations, health education, health consulting, hot spring bathing and basking in the woods. Respecting learning, social and leisure activities, they were mostly found to watch TV and do house chores, and showed a high desire for village environment repair, traditional farm music, visiting and tourism. With the above results, it is expected that the desire of rural elderly for such services can be satisfied, and the development of a local community service network model suitable to the characteristic of a local community is recommended.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.27 no.11
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• pp.581-586
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• 2015

In this study, an analysis was performed on the performance of the solar water heating system with geo-thermal heat pump for a detached house. This system has a flat plate solar collector ($8\;m^2$) and a 3 RT heat pump. The heat pump acts as an auxiliary heater of the solar water heating system. These systems were installed at four individual houses with the same area of $100\;m^2$. The monitoring results for one year are as follows. (1) The average daily operating time of the solar system appeared to be 313 minutes in spring (intermediate season), and 135 minutes and 76 minutes in winter and summer respectively. The reason for the short operating time in summer is the high storage temperature due to low water heating load. The high storage temperature is caused by a decrease in collecting efficiency as well as by overheating. (2) The geothermal heat pump as an auxiliary heater mainly operates on days of poor insolation during the winter season. (3) Despite controlling for total house area, hot water consumption varies greatly according to the number of people in the family, hot water usage habits, etc. (4) The yearly solar fraction was 69.8 to 91.5 percent, which exceeds the maximum value of 80% as recommended by ASHRAE. So the solar collector area of $8\;m^2$ appeared to be somewhat greater for the house with an area of $100\;m^2$. (5) The observed annual efficiency of solar systems was relatively low at 13.5 to 23.6%, which was analyzed to be due to the decrease in thermal efficiency and the overheating caused by a high solar fraction.

• Journal of the Korean Association of Geographic Information Studies
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• v.25 no.4
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• pp.81-93
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• 2022

There are many natural hot springs and mineral springs as well as the cultural heritage of the three kingdoms period in the Geum River basin including Chungcheong region. No specific regeneration and publicity plans for deteriorated facilities in this area has been presented. This study aims to suggest promising hot spots and complex water culture belt in the Chungcheong region and Geum River basin through the spatial interpretation of resources. The northern part of the Geum River basin is expected to become a therapeutic spring belt with many hot springs and CO₂-rich springs. In the central and southern parts of the Geum River basin, it is considered that it will be possible to promote convergence publicity by using groundwater resources and cultural assets.

• Journal of the Ergonomics Society of Korea
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• v.36 no.1
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• pp.23-36
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• 2017

Objective: This paper presents a study to evaluate the WBGT index for assessing the effects of a wide range of outdoor weather conditions on human responses. Background: The Wet Bulb Globe Temperature (WBGT) index was firstly developed for the assessment of hot outdoor conditions. It is a recognised index that is used world-wide. It may be useful over a range of outdoor conditions and not just for hot climates. Method: Four group experiments, involving people performing a light stepping activity, were conducted to determine human responses to outside conditions in the U.K. They were conducted in September 2007 (autumn), December 2007 (winter), March 2008 (spring) and June 2008 (summer). Environmental measurements included WBGT, air temperature, radiant temperature (including solar load), humidity and wind speed all measured at 1.2m above the ground, as well as weather data measured by a standard weather station at 3m to 4m above the ground. Participants' physiological and subjective responses were measured. When the overall results of the four seasons are considered, WBGT provided a strong prediction of physiological responses as well as subjective responses if aural temperature, heart rate and sweat production were measured. Results: WBGT is appropriate to predict thermal strain on a large group of ordinary people in moderate conditions. Consideration should be given to include the WBGT index in warning systems for a wide range of weather conditions. However, the WBGT overestimated physiological responses of subjects. In addition, tenfold Borg's RPE was significantly different with heart rate measured for the four conditions except autumn (p<0.05). Physiological and subjective responses over 60 minutes consistently showed a similar tendency in the relationships with the $WBGT_{head}$ and $WBGT_{abdomen}$. Conclusion: It was found that either $WBGT_{head}$ or $WBGT_{abdomen}$ could be measured if a measurement should be conducted at only one height. The relationship between the WBGT values and weather station data was also investigated. There was a significant relationship between WBGT values at the position of a person and weather station data. For UK daytime weather conditions ranging from an average air temperature of $6^{\circ}C$ to $21^{\circ}C$ with mean radiant temperatures of up to $57^{\circ}C$, the WBGT index could be used as a simple thermal index to indicate the effects of weather on people. Application: The result of evaluation of WBGT might help to develop the smart clothing for workers in industrial sites and improve the work environment in terms of considering workers' wellness.

• Journal of Korean Medical classics
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• v.19 no.3
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• pp.228-254
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• 2006

1. King Hyeonjong(1641-1674) mainly suffered from eye disease and abscess. He specially took a hot spring bath for cure of eye and skin problems. He probably died of septicemia and the following gastro-intestinal infection at the age of 34, quite early for his age. 2. King Sukjong(1661-1720) was not very well all through his life, but lived quite longer than other Kings in the Joseon Dynasty. He suffered from various diseases like heart-based heat, abscess, edema, upper respiratory infections, etc. He frequently took the treatments of acupuncture and moxibustion. He presumably died of dysfunction of liver and kidney at the age of 60. 3. King Gyeongjong(1688-1724) suffered from political problems from birth to death, so he may have had excessive mental stress for his poor health. He mainly suffered from heart-based heat and abscess. It is quite not sure why he died in only one month from the onset of his symptoms, so many people thought that he was poisoned to death. He probably died of septicemia and the following gastro-intestinal infection at the age of 37. 4. King Yeongjo(1694-1776) lived for 83 years, which is the longest of all the Kings in the Joseon Dynasty. He mainly suffered from hypofunction of gastro-intestinal system with cold symptoms, coughs, uneasiness. He took various kinds of herbal medicine, of which he took ginseng the most. He is supposed to be dead due to his old age at 83.