• Journal of the Korean Society of Manufacturing Process Engineers
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• v.15 no.5
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• pp.8-17
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• 2016

While greenhouses have been utilized as a sustainable alternative to traditional soil farming, they are often powered by diesel boilers that necessitate vast amounts of non-renewable energy and emit toxic fumes. Thus, geothermal heat pumps have been proposed as a more energy-efficient substitution for diesel boilers. Currently, most horticultural facilities in the United States use shallow geothermal systems, and are often equipped with horizontal underground heat exchangers as well as heat pump equipment. These shallow geothermal systems require a large drilling site and heat pump to function, which results in high maintenance costs. The heat pump itself consumes a large amount of power, which degrades system performance. Conversely, high temperatures can be attained within a single borehole in deep geothermal vertical closing systems without using a heat pump. This setup can dramatically reduce the power consumption and improve system performance. In this study, we have modeled a circulation simulator after the circulation systems in deep geothermal facilities to analyze a 2000-meter borehole in Naju-Sanpo-myeon. The simulator is operated by manipulating various putative parameters affecting system performance to analyze the system's coefficient of performance.

• Journal of Korean Society of Forest Science
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• v.101 no.4
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• pp.558-566
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• 2012

This study was conducted to offer preliminary data for a natural restoration by the actual condition survey of quarries after extracting rock materials. The mountain restoration area according to a farming and fishing village organize project was restored by green landscape after quarry. However, planting tree species were died due to poor maintenance and administration after restoration works and surface soil loss and erosion occurred during a summer rainfall season because of poor slope greening. It will be needed to review restoration constructions to establish a natural friendly and flawless construction through the selection of optimum restoration works and the examination of soil and geological characteristics. In addition, it is necessary to apply cost-reducing program of restoration constructions. Quarry areas could be restored by the selection of simple and optimum construction works because the most areas were dominant in earth-sand rocks, soft-rocks, and weather-rocks. In addition, the restoration construction project should be examined thoroughly by restoration specialists during green restoration planning and review processes.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.2 no.2
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• pp.151-159
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• 1997

Benthic respiration and chemical fluxes were measured at the sediment-water interface underlying the marine fish cages floating on the open coastal waters off Tong-Young, the South Coast of Korea. The effects of cage farming on coastal benthic environment and on mass balance of organic carbon in the benthic boundary layer under the marine fish cages are addressed. In a growing season of caged fishes of June, 1995, benthic chambers and sediment traps were deployed on the sediment-water interfaces of the two sites chosen for this study: 1) Cage Site, directly underlying the fish cages of the farm at 18 m water depth, and 2) Control Site, about 100 m away from the farm at 32 m water depth. Benthic respiration rates and chemical fluxes were calculated from the evolution of dissolved oxygen and chemicals in the chamber water, and mass balance of organic carbon in the benthic boundary layer was constructed based on the vertical flux of particulate organic matter (POM) and chemical fluxes out of the sediment. High organic dumping (6400 mg C $m^{-2}d^{-1}$) and high benthic respiration (230 mmol $O_2\;m^{-2}d^{-1}$) were observed at the Cage Site. Equivalent to 40% of vertical flux of organic carbon into the Cage Site seemed to be decomposed concurrently and released back to overlying waters (2400 mg C $m^{-2}d^{-1}$). Consequently, up to 4000 mg C $m^{-2}d^{-1}$ of organic carbon could be buried into the farm sediment (equivalent to 60% of organic carbon flux into the Cage Site). At the Control Site, relatively less input of organic carbon (4000 mg C $m^{-2}d^{-1}$) and low benthic respiration rate (75 mmol $O_2\;m^{-2}d^{-1}$) were observed despite short distance away from the cages. The influence of cage farming on benthic chemical fluxes might be restricted and concentrated in the sea bottom just below the fish cages in spite of massive organic dumping and high current regime around the fish cage farm.

• Journal of Korean Neurosurgical Society
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• v.63 no.5
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• pp.623-630
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• 2020

Objective : A primary degenerative sagittal imbalance has been considered because of unique lifestyles such as the prolonged crouched posture during agricultural work and performing activities of daily living on the floor. Previous papers have reported that sagittal imbalance disease is often seen distinctly in the farming districts of "oriental" countries such as Korea and Japan. However, this finding was only evaluated with the use of X-ray, and other factors such as magnetic resonance imaging (MRI), muscle volume, compression fracture, and laboratory results were not considered. Thus, using these, we evaluate the agricultural work-associated factors for Korean elderly spinal sagittal imbalance. Methods : We recruited 103 Korean participants who had a sagittal vertical axis (SVA) of >5 cm in this Korean Elderly Sagittal Imbalance Cohort Study. The following were evaluated : radiological parameters, MRI, compression fracture, vitamin D, parathyroid hormone, C-terminal telopeptide, osteocalcin, bone mineral density and muscle fatty change, muscle volume, and health-related quality of life from patients' survey. Moreover, in this survey, the farmers' annual working hours were investigated. Subsequently, we analyzed the associated factors for spinal sagittal imbalance depending on occupation. Results : A total of 46 participants were farmers, and the others were housewives, sellers, and office workers. The farmer group had more SVA (141 vs. 99 mm, p=0.001) and pelvic tilt (31° vs. 24°, p=0.004) and lesser lumbar lordosis (20° vs. 30°, p=0.009) and thoracic kyphosis (24° vs. 33°, p=0.03) than non-farmer group. A significantly positive correlation was noted between the working hour and SVA in the farmer group (p=0.014). The visual analogue scale score for back pain (8.26 vs. 6.96, p=0.008) and Oswestry Disability Index (23.5 vs. 19.1, p=0.003) in the farmer group were higher than that in the non-farmer group, but the Short Form-36 score was not significantly different between the two groups. The Mini-Mental State Exam score was significantly lower in the farmer group than in the non-farmer group (24.85 vs. 26.98, p=0.002). Conclusion : The farmer group had more sagittal imbalance and back pain in proportion to the working hours even though the muscle and bone factors and general laboratory condition were not significantly different between the two groups. These results supported that the long hours spent in the crouched posture while performing agricultural work were a risk factor for severe sagittal imbalance.

• Korean Journal of Ecology and Environment
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• v.39 no.4 s.118
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• pp.508-515
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• 2006

This study was conducted from July to December 2004, in order to find measures to improve the water quality and the function of pond ecosystems which are often negatively affected by phytoplankton and suspended particle matters. Most of the time, the management of ponds in Korea does not consider the ecological concepts such as self-purification and nutrient recycling. Instead, conventional methods depend on other factors such as fish farming and the function of fountains and waterfalls. Sustainability of pond ecosystems must be studied with the highest emphasis given to water quality. Water discharges of inflow and outflow as well as balance adjustment for different factors must be thoroughly studied. There is a great need for studies on sustainability because it can be realized through the horizontal or vertical balances of an ecosystem. Our current research offers useful information to the academia and public on maintaining sustainability in terms of structure and function of the pond.

• Journal of Marine Life Science
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• v.5 no.2
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• pp.64-71
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• 2020

Gloiopeltis tenax is one of the most economically useful species in China and Japan that has been applied to glue and food since ancient times. The material used in the experiment was a large quantity of basal crusts obtained from the culture of tetraspores that were released from the mature tetrasporophytes collected at Gyeokpori, Byeonsan-myeon, Buan-gun, Jeollabuk-do in Korea. The basal crusts were cut into quadrisect under a dissecting microscope so as to monitor the process of regeneration and growth. The cut crusts were cultured under varying conditions, where the photoperiod was 16:8 h L:D; the temperature range was 10, 15, 20, and 25℃; the irradiance range was 30 and 85 µmol photons m^-2s^-1. The quadrisect basal crusts grew to an oval shape, then formed a vertical axis of cylindrical shape. The maximum growth of basal crusts was 9.61±3.59 mm² under the condition of 15℃ temperature and 85 µmol photons m^-2s^-1 irradiance, after 12-weeks culture. The mean relative growth rate after 12-weeks culture showed the maximum rate of 5.15±0.80 %day^-1 at 15℃ and the minimum growth rate was 3.15±0.94 %day^-1 at 10℃, with a statistically significant difference (p < 0.05). In conclusion, it has shown the possibility that growth of basal crusts of G. tenax is one of the good farming method of potential alga.

• Korean Journal of Environmental Agriculture
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• v.25 no.1
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• pp.25-33
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• 2006

Objectives of this experiment were to select of the optimum water plant and to investigate the removal efficiency of the major nutrients in the constructed wetland by natural purification method for municipal sewage treatment in the farming and fishing village. For the experiment we used "constructed wetland" which was consisted of aerobic (vertical filter system) and anaerobic systems (horizontal filter system). Both systems were filled with gravel and filter media, and grew water plants on top of them. And then, we investigated several items such as sewage treatment efficiency, growth status of water plants and the absorbed amount of inorganic element in water plants with periodical periods. In aerobic area, removal efficiencies of BOD, COD, T-N and T-P were over 92%, 74%, 25% and 57%, respectively, and then when the water is passed through anaerobic area, the efficiency was over 96%, 84%, 44% and 71%, respectively, which was increased more treatment efficiency than that of aerobic area. Absorption amount of nitrogen and phosphorous in Miscanthus sacchariflorus BENTH were the highest in the water plants as 17.7 and 2.41 g/plant in the aerobic area, respectively. Absorption amounts of nitrogen and phosphorous in Scirpus tabernaemontani GMEL were the highest in the water plants as 8.7 and 1.13 g/plant in the anaerobic area, respectively. For the selection of optimum water plants in the constructed wetland by natural purification method for municipal sewage treatment, it were observed that there were Miscanthus sacchariflorus BENTH, Phragmites japonica STEUD and Phragmites communis TRINIUS in the aerobic area and were Zizania latifolia TURCZ, Scirpus tabernaemontani GMEL, Typha orientalis PRESL, Iris pseudoacorus L and Cares dispalata BOOTT in the anaerobic area.