• Korean Chemical Engineering Research
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• v.56 no.1
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• pp.79-84
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• 2018

In the present study, we performed electroporation to deliver protein into microalgae using previously developed digital electroporation system. Green fluorescence protein was successfully delivered into a live microalgae cell nucleus without cell wall removal. By investigating the effects of applied voltage on the protein delivery efficiency, optimal electroporation electric field condition was found (960 V/cm). We also investigated the delivery of Yo-Pro-1 into cell to examine the size effects of delivered materials and found that there is little size effects on the optimal condition. Finally, the implications of the present results and future work are discussed.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.20 no.6
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• pp.67-77
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• 2017

Demands for housing has diversified recently due to low birth rate and the growth of aging population. Also, a share of idle houses and obsolete houses over 20 years old is gradually rising. Therefore, there is a need for a sustainable, environment-friendly improvement policy that is in line with a new housing paradigm and avoids full-scale new construction, such as a customized housing renovation plan considering local economic circumstances. Therefore, afforestation system applicable to buildings are assessed positively, but lack objective performance evaluation. Through one-year, long-term monitoring of replicated obsolete buildings that have poor insulation performance, this study calculated monthly average power consumption and analyzed power charges by applying pricing plans before and after the revision of progressive tax in order to examine economic effects expected by applying the afforestation system. In the obsolete buildings, the study showed that monthly average power consumption was reduced by 16.6kWh with 5.2% average reduction rate. Highest reduction was made in July at 11.3%. Aggregate monthly power consumption charges were relatively high in winter before and after the revision of progressive tax. Power charges reduction effect was highest in March when monthly power consumption was reduced to 300kWh level by applying the afforestation system.

• Journal of Hydrogen and New Energy
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• v.33 no.1
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• pp.95-104
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• 2022

Micro hydropower is a readily available renewable energy source that can be harvested utilizing hydrokinetic turbines from shallow water canals, irrigation and industrial channel flows, and run-off river stream flows. These sources generally have low head (<1 m) and low velocity which makes it difficult to harvest energy using conventional turbines. A horizontal-axis screw turbine was designed and numerically tested to extract power from such low-head water sources. The 3-bladed screw-type turbine is placed horizontally perpendicular to the incoming flow, partially submerged in a narrow water channel at no-head condition. The turbine hydraulic performances were studied using Computational Fluid Dynamics models. Turbine design parameters such as the shroud diameter, the hub-to-shroud ratios, and the submerged depths were obtained through a steady-state parametric study. The resulting turbine configuration was then tested by solving the unsteady multiphase free-surface equations mimicking an actual open channel flow scenario. The turbine performance in the shallow channel were studied for various Tip Speed Ratios (TSR). The highest power coefficient was obtained at a TSR of 0.3. The turbine was then scaled-up to test its performance on a real site condition at a head of 0.3 m. The highest power coefficient obtained was 0.18. Several losses were observed in the 3-bladed turbine design and to minimize losses, the number of blades were increased to five. The power coefficient improved by 236% for a 5-bladed screw turbine. The fluid losses were minimized by increasing the blade surface area submerged in water. The turbine performance was increased by 74.4% after dipping the turbine to a bottom wall clearance of 30 cm from 60 cm. The final output of the novel horizontal-axis screw turbine showed a 2.83 kW power output at a power coefficient of 0.63. The turbine is expected to produce 18,744 kWh/year of electricity. The design feasibility test of the turbine showed promising results to harvest energy from small hydropower sources.

• Horticultural Science & Technology
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• v.33 no.4
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• pp.605-617
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• 2015

The ultimate goal of this research is to develop a botanical biofiltration system that combines a green interior, biofiltering, and automatic irrigation to purify indoor air pollutants according to indoor space and the size of biofilter. This study was performed to compare the stability of air flow characteristics and removal efficiency (RE) of fine dust within a wall-typed (vertical) botanical biofilter depending on humidifying cycle and to investigate RE of volatile organic compounds (VOCs) by the biofilter. The biofilter used in this experiment was designed as an integral form of water metering pump, water tank, blower, humidifier, and multi-level planting space in order to be suitable for indoor space utilization. As a result, relative humidity, air temperature, and soil moisture content (SMC) within the biofilter showed stable values regardless of three different humidifying cycles operated by the metering pump. In particular, SMCs were consistently maintained in the range of 27.1-29.7% during all humidifying cycles; moreover, a humidifying cycle of operating for 15 min and pausing for 45 min showed the best horizontal linear regression (y = 0.0008x + 29.09) on SMC ($29.0{\pm}0.2%$) during 120 hour. REs for number of fine dust (PM10) and ultra-fine dust (PM2.5) particles passed through the biofilter were in the range of 82.7-89.7% and 65.4-73.0%, respectively. RE for weight of PM10 passed through the biofilter was in the range of 58.1-78.9%, depending on humidifying cycle. REs of xylene, ethyl benzene, total VOCs (TVOCs), and toluene passed through the biofilter were in the range of 71.3-75.5%, while REs of benzene and formaldehyde (HCHO) passed through the biofilter were 39.7% and 44.9%, respectively. Hence, it was confirmed that the wall-typed botanical biofilter suitable for indoor plants was very effective for indoor air purification.

• Journal of the Korean Institute of Landscape Architecture
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• v.32 no.5
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• pp.119-128
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• 2004

In 2004, the Incheon Urban Development Corporation held a design competition for the Song-Do apartment complex development. Several projects that won the prize in the recent design competitions were reviewed to look around the current design tendency, and current conditions of the site were surveyed. The authors tried to combine digital and environment-friendly factors, considering the site condition. Because the site is on reclaimed land and is located at the center of the information-technology industrial area, these two factors inform the main concept of this project. The site was divided into two different zones : the Ocean Zone and the Digital Zone. The 'community spaces'(community street, community plaza and so on) were designed for the various activities of the residents. The Patios, 'private' community spaces, included many facilities for play, appreciation, rest, exercise, refreshment and gathering. To avoid common landscape styles in the patios, simple and minimal forms were designed. The environmental sculptures were carefully planned, allocated and shaped with digital technology, based on the 'Present and Future of Song-Do'. The authors also tried to introduce environment-friendly factors, such as the green roof system, wall planting, and the water recycling system. This project is following the M.A. (Master Architect) process, and is still being modified to make the hi-tech and environment-friendly apartment complex.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2006.04a
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• pp.432-435
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• 2006

To evaluate geology and extent of leachate migration around the landfills, electrical resistivity survey were conducted in area of uncontrolled landfills in Cheonan and Wonju. The Cheonan landfill is located above the paddy fields and the resistivity survey lines were crossed to confirm possible pollution of the paddy fields by leakage of the landfill leachate. In Wonju, the landfill and the downgradient paddy fields are divided by a concrete barrier wall. At the bottom of the landfill, there is a leachate settlement system but has not been in operation. And a total of 4 survey line installed (1 parallel and 3 perpendicular to mean groundwater flow direction). According to the resistivity survey results, the landfill leachate in Cheonan appeared to be restricted only within the interior of the landfill, not to migrate into the subsurface of the paddy fields. These results are well consistent with electrical conductivity values of groundwaters obtained from a periodic analysis of water qualities. In Wonju, however, it was inferred that the leachate emanating from the landfill migrated beneath the abandoned leachate settlement system and it would reach the downgradient paddy field.

• 한국신재생에너지학회:학술대회논문집
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• 2010.11a
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• pp.131.1-131.1
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• 2010

This study was conducted for engineering optimization for the gasification process which is the key factor for success of Taean IGCC gasification plant which has been driven forward under the government support in order to expand to supply new and renewable energy and diminish the burden of the responsibility for the reduction of the green house gas emission. The gasification process consists of coal milling and drying, pressurization and feeding, gasification, quenching and HP syngas cooling, slag removal system, dry flyash removal system, wet scrubbing system, and primary water treatment system. The configuration optimization is essential for the high efficiency and the cost saving. For this purpose, it was designed to have syngas cooler to recover the sensible heat as much as possible from the hot syngas produced from the gasifier which is the dry-feeding and entrained bed slagging type and also applied with the oxygen combustion and the first stage cylindrical upward gas flow. The pressure condition inside of the gasifier is around 40~45Mpg and the temperature condition is up to $1500{\sim}1700^{\circ}C$. It was designed for about 70% out of fly ash to be drained out throughout the quenching water in the bottom part of the gasifier as a type of molten slag flowing down on the membrane wall and finally become a byproduct over the slag removal system. The flyash removal system to capture solid particulates is applied with HPHT ceramic candle filter to stand up against the high pressure and temperature. When it comes to the residual tiny particles after the flyash removal system, wet scurbbing system is applied to finally clean up the solids. The washed-up syngas through the wet scrubber will keep around $130{\sim}135^{\circ}C$, 40~42Mpg and 250 ppmv of hydrochloric acid(HCl) and hydrofluoric acid(HF) at maximum and it is turned over to the gas treatment system for removing toxic gases out of the syngas to comply with the conditions requested from the gas turbine. The result of this study will be utilized to the detailed engineering, procurement and manufacturing of equipments, and construction for the Taean IGCC plant and furthermore it is the baseline technology applicable for the poly-generation such as coal gasification(SNG) and liquefaction(CTL) to reinforce national energy security and create new business models.

• Journal of the Korean Institute of Landscape Architecture
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• v.43 no.1
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• pp.16-28
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• 2015

This study is suggested to enlarge the green area and to connect and improve the present green areas by deriving the lines of community greenway using living areas and community spaces close to the life of residence in Nam-gu. The purpose of this paper is to suggest the method of establishing greenway for the formation of community in which the residence can grow the community spirit and love their living space much more. Land-use status, green coverage ratio, and impermeability paving ratio are investigated. The community facilities are classified. The highest is educational facility, which is 7.7%, the green facility is 1.9% and the total area of community facilities which is 21.4%. The total area of Nam-gu is divided into 31 zones in total according to the administrative districts, the mail roads and reserved land of railroad and urban development. The total 20 lines of community greenway lines are chosen and the total length of lines is 18.2km. Finally, the characteristics of community greenway lines are analysed, the characteristics of community greenway lines are overall estimated according to the land-use, the street environment and the community facility. The classification system of community greenway is established on the basis on the function and purpose of greenway, the present status of land-use and the type of community facility. Based on the field investigation, the 6 greenway types are suggested considering the interconnection. The method of establishment of community greenway is suggested according to the principle of function and purpose, the principle of land-use and the principle of use of the facilities. Furthermore, the planting methods suitable to each greenway type are suggested in the building planting case of wall planting, roof planting, veranda planting, etc., and in the complex planting of parks, schools, roads, parking lots and other small areas.

• The Plant Pathology Journal
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• v.20 no.2
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• pp.81-84
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• 2004

Branched broomrape (Orobanche ramosa) is a holo-parasitic flowering plant that attaches to the root of its host, green plant, by means of a specialized structure known as haustorium. Following successful contact and penetration on susceptible plant root, complex tissue of Orobanche cells is formed which is known as the tubercle. Newly formed tubercles contain high activity ofindole-3-acetic acid (IAA). Triiodobenzoic acid (TIBA), as an inhibitor of IAA polar transport, was utilized to investigate the supply and requirement of auxin to the developing O. ramosa on tomato plant. There was no significant reduction in the incidence of O. ramosa per pot of different TIBA treatments. However, infection severity in terms of the number of O. ramosa shoots that emerged per plant and number of attachments per plant root system were significantly reduced by 60 % and 45 % on TIBA treated plants, respectively. Histo-logical studies revealed conspicuous delay in the initiation of xylem vessel differentiation inside tubercles of the TIBA treated tomato plants. Also, differentiated vessels showed thinner secondary wall deposition, and improper alignment within bundles inside those tubercles. They were wider and shorter in diameter in comparison to those of untreated plants. These findings were attri-buted to the short supply of IAA required for normal development, and to the xylem vessel differentiation of O. ramosa tubercles on infected tomato. Hence, this parasitic flowering plant seems to depend upon its host in its requirements for IAA, in a source to sink relation-ship.

• Korean Journal of Construction Engineering and Management
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• v.13 no.6
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• pp.3-12
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• 2012

The slowdown of private building industry resulted in growth of remodeling market as a way to improve energy performance. Remodeling is considered more cost-effective and eco-friendly approach for energy efficient building than new construction. Since 2008, Seoul has promoted Building Retrofit Project (BRP) preponderantly to attract energy-saving renovation by supporting building owners to switch building system into energy-saving system when they remodel their old buildings. According to 2012 press release, 254 Private sectors participated in this green building project and annually reduced 41000ton of greenhouse gas emission, 14000TOE, which also result in 7.5 billion won energy cost savings per year. The paper focuses on the building envelope remodeling as a way to improve energy efficiency. Different components of the building envelope such as wall insulation, window, and shading, were applied to the baseline model and the comparison was analyzed to come up with the ideal solution. This study only assesses the building envelope as to suggest the way to redesign the better energy performing building. Offering solution focusing on the architectural feature is essential because it will provide basic information and standard when remodeling a building for energy efficiency, especially, for the nonresidential buildings used as rental offices.