• Journal of the Korea Organic Resources Recycling Association
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• v.31 no.1
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• pp.85-100
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• 2023

In this study, in order to improve the installation periodical inspection method of waste treatment facilities, we conducted on-site surveys of waste treatment facilities classified into six fields, grasped the problems of inspection methods, and made improvements accordingly. And revised the inspection method for waste treatment facilities. As a result, in the field of incineration and incineration heat recovery, inspection methods such as total temperature measurement and one-year TMS data comparison using a thermal imaging camera were established. And for the safety of the inspected person, it was applied so that the waste can be replaced with a document without opening it. In the case of landfill facilities, the details regarding the use of video information processing equipment and the management of facilities covering the upper part of the landfill facility are presented in the law, but the items that do not have a inspection methods were applied to the inspection method. In the case of Food Waste Treatment Facility, inspection methods were put in place to ensure compliance with standards for foul-smelling fish in odor control, a major cause of complaints. As a result, 10 out of 18 improvement proposals were reflected in the incineration and sterilization grinding, cement kiln, and incineration heat recovery facilities, and 11 out of 12 improvement proposals were reflected in the landfill facility. In the case of food distribution waste treatment facilities, 10 out of 12 improvement proposals were reflected, and a total of 31 inspection methods were improved.

• Geophysics and Geophysical Exploration
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• v.13 no.1
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• pp.61-68
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• 2010

A magnetotelluric (MT) survey has been performed to delineate deeply extended fracture systems at the geothermal field in Seokmo Island, Korea. To assist interpretation of the MT data, geological surveying and well logging of existing wells were also performed. The surface geology of the island shows Cretaceous and Jurassic granite in the north and Precambrian schist in the south. The geothermal regime has been found along the boundary between the schist and Cretaceous granite. Because of the deep circulation along the fracture system, geothermal gradient of the target area exceeds $45^{\circ}C/km$, which is much higher than the average geothermal gradient in Korea. 2D and 3D inversions of MT data clearly showed a very conductive anomaly, which is interpreted as a fracture system bearing saline water that extends at least down to 1.5 km depth and is inclined eastwards. After drilling down to the depth of 1280 m, more than 4000 tons/day of geothermal water overflowed with temperature higher than $70^{\circ}C$. This water showed very similar chemical composition and temperature to those from another existing well, so that they can be considered to have the same origin; i.e. from the same fracture system. A new geothermal project for combined heat and power generation was launched in 2009 in Seokmo Island, based on the survey. Additional geophysical investigations including MT surveys to cover a wider area, seismic reflection surveys, borehole surveys, and well logging of more than 20 existing boreholes will be conducted.

• Journal of the Korean Society of Radiology
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• v.6 no.3
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• pp.197-200
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• 2012

This research investigated Takju alcohol content in the case of irradiation changes in the statistical analysis was performed to visually. Lower proof alcohol fermentation Takju traditional and largely maintained 6 degrees, from the heat sterilization process is controlled through the distribution period. Most of the existing irradiation is focused on preservation of the product, but this study of the quality characteristics of the mechanical changes in alcohol was to seek value. Takju Celsius to $15^{\circ}C$, while maintaining the experiment were kept in the state. Radiation devices Varian Clinac ix, 2010 (Max. 10MV) using the field size $150mm{\times}150mm$, SSD 100 cm at 40kVp 1, 4, 7, 10, 13, 15, 20Gy were vertical. KJELDAHL APPARATUS, C-H6 Alcohol frequency was measured using. The results according to the change of the radiation dose alcohol did not show the sudden change of frequency, were observed at similar levels decreased. This study simply due to the radiation dose to be served, but to find the change in the future with a greater sense of quality changes should be considered.

• Journal of Energy Engineering
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• v.20 no.1
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• pp.13-20
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• 2011

The high fuel flexibility of Micro Gas Turbine(MGT) has boosted their use in a wide variety of applications. Recently, the demand for biogas generated from the digestion of organic wastes and landfill as a fuel for gas turbines has increased. We researched the influence of firing landfill gas(LFG) on the performance and operating characteristics of a micro gas turbine combined heat and power system. $CH_4$ and $CO_2$ simultaneous recovery process has been developed for field plant scale to provide an isothermal, low operating cost method for carrying out the contaminants removal in Land Fill Gas(LFG) by liquid phase catalyst for introduce into the green house for the purpose of $CO_2$ rich cultivation of the plants. Methane purification and carbon dioxide stripping by muti panel autocirculation bubble lift column reactor utilizing Fe-EDTA was conducted for evaluate optimum conditions for land fill gas. Based on inflow rate of LFG as 0.207 $m^3$/min, 5.5 kg/$cm^2$, we designed reactor system for 70% $CH_4$ and 27% $CO_2$ gas introduce into MGT system with $H_2S$ 99% removal efficiency. A green house designed for four different carbon dioxide concentration from ambient air to 1500 ppm by utilizing the exhaust gas and hot water from MGT system.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.44 no.12
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• pp.1071-1086
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• 2016

The safety of aircraft can be threatened by environmental factors, such as icing, turbulence, and lightning strike. Due to its adverse effects on aircraft structure and electronic components of aircraft, lightning strike is one of the biggest hazards on aircraft safety. Lightning strike can inject high voltage electric current to the aircraft, which may generate strong magnetic field and extreme hot spots, leading to severe damage of structure or other equipment in aircraft. In this work, mechanism of lightning strike and associated direct and indirect effects of lightning on aircraft were studied. First, on the basis of aircraft lightning regulations provided by Aerospace Recommended Practice (ARP), we considered different lightning waveform and zones of an aircraft. A coupled thermal-electrical computational model of ABAQUS was then used for simulating flow of heat and electric current caused by a lightning strike. A study on fuel tank, with and without lightning protection system, was also conducted using the computational model. Finally, electric current flow on two full scale airframes was analyzed using the EMA3D code.

• Journal of the Korean Wood Science and Technology
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• v.44 no.5
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• pp.655-663
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• 2016

Increasing green house gas and it consequent climate change problems are discussed as a global issue. Accordingly, future local green house gas emission will increase up to 40% of the entire local green house gas emission and therefore, efforts to reduce the emission in construction industry is urgently required. Therefore, in this study, heating energy demand was analyzed by using the EnergyPlus simulation according to wood material finishes configuration. EnergyPlus has the entry for a variety of buildings and heating, ventilation, air conditioning (HAVC) system components, in particular buildings, air conditioning systems, and performs simultaneous integrated calculated through the feedback between the heat source unit, a verification program according to the ASHRAE Standard 140-2007 to be. The climate data for the simulation we used the data IWEC in Incheon and Gwangju provided by EnergyPlus. The analysis of simulation model was farm and fishing house standard design drawings: 2012, presented at the Korea Rural Community Corporation. The results of simulation of central region and southern region were effected by wood products of simulation model into the interior finish, exterior finish, windows, wooden structure. Also, it was confirmed that the reduced heating energy demand.

• Journal of the Korea Concrete Institute
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• v.15 no.5
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• pp.670-678
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• 2003

Recently, since industrial waste and life waste leaped into a pollution source, the building material used now a days is striking the limit. The purpose of this paper is to investigate an application of recycled coal ash using non-sintering method in the construction field. Accordingly, compressive strength, elastic modulus and drying shrinkage were experimentally studied for hardened coal ash using the non-sintering method. Also, Lineweaver and Burk method were applied to the regression analysis of drying shrinkage for the proposal equation. Elastic modulus, compressive strength of material become the basis properties of structural design. And these properties by age for hardened coal ash are important because of change by pozzolan reaction. This hardened coal ash is weak for tensile stress like that of concrete. And drying shrinkage is very important factor to make huge tensile force in early age. In the results, although some differences were shown when comparing coal ash with mortar or concrete, the application as a building material turned out to be possible if further researches were carried out. And the shrinkage characteristic of hardened coal-ash reveals to be similar to that of moderate heat cement.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.1
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• pp.36-42
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• 2005

This study examined the feasibility of producing sulfuric acid and ammonia water from ammonium sulfate solution using two-compartment electrodialysis with a bipolar membrane (EDBM). Electrodialysis experiments were carried out with 20 wt% ammonium sulfate at different current densities and sulfuric acid concentrations in a concentrate compartment. The current efficiency increased with the current density from 25 to $100\;mA/cm^2$. Nevertheless, the efficiency was relatively low compared with that of general desalting electrodialysis, owing to the diffusion of sulfuric acid from the concentrate compartment to the diluate. The diffusion rate through the anion exchange membrane increased with the sulfuric acid concentration in the concentrate compartment, which decreased the current efficiency. Conversely, the electrical resistance decreased with increasing current density owing to the Joulian heat generated during water dissociation in the transition region of the bipolar membrane under a high electric field. From the experimental results, we concluded that operating at a higher current density is effective from the perspective of current efficiency and electrical resistance when producing sulfuric acid and ammonia water from ammonium sulfate using a two-compartment EDBM process. Further studies on the effects of increasing the sulfuric acid concentration on current efficiency are required to apply the EDBM process practically.

• KSBB Journal
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• v.25 no.4
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• pp.303-310
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• 2010

Probiotics beneficially affect the health of the host via various mechanisms in the intestine. Recent developments in probiotic products have mainly been made to maximize probiotic effects in human. In this regard, probiotic products containing doubly coated or encapsulated cells, multi-species probiotics, or high viable cell number (1010 viable cells/gram or more) have been developed and are already available in the market. Until now, the majority of probiotics contain live cells but little attention has been paid to other alternative products such as heat-killed cell or bacteriocin-containing ones, which could have broad applications due to advantages over live cell-based probiotics, such as safety and stability. In addition, genetically engineered lactic acid bacteria could be of great importance in the field of alimentary health if they are carefully designed for biological safety. Although a number of probiotics are marketed by claiming health benefits, regulations for health claims will be more stringent. Therefore sufficient scientific and clinical evidences supporting the safety and efficacy of the potential probiotic strain will be required by the regulatory authority for a health claim, which thus may have a huge impact on the future probiotic market.

• Applied Chemistry for Engineering
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• v.28 no.4
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• pp.420-426
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• 2017

Recently, solvent-resistant nanofiltration membranes have been studied for the separation of solvents or solutes using a molecular weight cut-off system of the polymer which is resistant to a specific solvent. Required conditions for these membranes must have are excellent physical properties and solvent resistance. Polybenzimidazole, which is known to be one of the most heat-resistant commercially available polymers, has an excellent inherent solvent resistance and it is even insoluble in stronger organic solvents when cross-linked. Therefore, in this study, the applicability of polybenzimidazole as a solvent resistant nanofiltration membrane was discussed. The membrane was fabricated using the non-solvent induced phase separation method and showed a suitable morphology as a nanofiltration membrane confirmed by field emission scanning electron microscopy. In addition, the permeance of the solvent in the presence or absence of cross-linking was investigated and the stability was also confirmed through long operation. The permeance test was carried out with five different solvents: water, ethanol, benzene, N, N-dimethylacetamide (DMAc) and n-methyl-2-pyrrolidone (NMP); each of the initial flux was $6500L/m^2h$ (water, 2 bar), $720L/m^2h$ (DMAc, 5 bar), $185L/m^2h$ (benzene, 5 bar), $132L/m^2h$ (NMP, 5 bar), $65L/m^2h$ (ethanol, 5 bar) and the pressure between 2 and 5 bar was applied depending on the type of membrane.