• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.16 no.1
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• pp.36-43
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• 2006

The principal aim of this field study was to determine the concentrations and emissions of gaseous contaminants such as ammonia and hydrogen sulfide in the different types of pig buildings in Korea and allow objective comparison between Korea and the other countries in terms of pig housing types. This field study was performed from May to June and from September to October in 2002. Pig buildings investigated in this research were selected in terms of three criteria; manure removal system, ventilation mode and growth stage of pig. Measurements of concentration and emission of ammonia and hydrogen sulfide in the pig buildings were done in 5 housing types and the visited farms were 15 sites per each housing type. Concentrations of ammonia and hydrogen sulfide were measured at three locations of the central alley in the pig building and emission rates of them were estimated by multiplying the average concentration($mg/m^3$) measured near the air outlet by the mean ventilation rate($m^3/h$) and expressed either per pig of liveweight 75kg(mg/h/pig) or per area($mg/h/m^2$). Concentrations of ammonia and hydrogen sulfide in the pig buildings were averaged to 7.5 ppm and 286.5 ppb and ranged from 0.8 to 21.4 ppm and from 45.8 to 1,235 ppb, respectively. The highest concentrations of ammonia and hydrogen sulfide were found in the mechanically ventilated buildings with slats; 12.1 ppm and 612.8 ppb, while the lowest concentrations of ammonia and hydrogen sulfide were found in the pig buildings with deep-litter bed system(2.2 ppm) and the naturally ventilated pig buildings with manure removal system by scraper(115.2 ppb), respectively(p<0.05). All the pig buildings were investigated not to exceed the threshold limit values(TLVs) of ammonia(25 ppm) and hydrogen sulfide(10 ppm). The mean emissions of ammonia and hydrogen sulfide per pig(75kg in terms of liveweight) and area($m^2$) from pig buildings were 250.2 mg/h/pig and 37.8 mg/h/pig and $336.3mg/h/m^2$ and $50.9mg/h/m^2$, respectively. The pig buildings with deep-litter bed system showed the lowest emissions of ammonia and hydrogen sulfide(p<0.05). However, the emissions of ammonia and hydrogen sulfide from the other pig buildings were not significantly different(p>0.05). Concentrations and emissions of ammonia and hydrogen sulfide were relatively higher in the pig buildings managed with deep-pit manure system with slats and mechanical ventilation mode than the different pig housing types. In order to prevent pig farm workers from adverse health effect caused by exposure to ammonia and hydrogen sulfide in pig buildings, they should wear the respirators during shift and be educated sustainably for the guideline related to occupational safety.

• Transactions of the Korean hydrogen and new energy society
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• v.23 no.5
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• pp.484-492
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• 2012

The TMS(Thermal Management System) heater in a fuel cell vehicle has been developed to prevent a decline of fuel cell durability and cold start durability. Main functions of the COD(Cathode Oxygen Depletion) heater are depletion of oxygen in a cathode as heat energy and consumption of electric power for rapid warming up of a fuel cell stack. This paper covers subjects including the design specification of a heater, heater controller for detection of overheat and reliability assessment including coolant pressure cycle test of a heater. To verify the design concept, burst pressure and deformation analysis of plastic housing were carried out. Also, temperature distribution analysis of heater surface and coolant inside of housing were carried out to verify the design concept. By designing the plastic housing instead of a steel housing, the 30% weight lightening and 50% cost reduction were attained. A module-based design of a TMS system including a heater or reducing the watt density of a heater is a problem to be solved in the near future work.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.05a
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• pp.550-553
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• 2006

This study measured corrosion rates for checking and analysis of Hume pipes in the housing sites. According to the result, Concrete pipe is deteriorating for twenty years by hydrogen sulfide(H2S). Investigation method applied phenolphthalein method(depth of neutrality). Phenolphthalein method measured average depth from concrete surface to coloring point by red after spraying phenolphthalein solution. A result of investigation, Life span of Hume pipe in the housing site is investigated of twenty years.

• Journal of agriculture & life science
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• v.46 no.2
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• pp.163-168
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• 2012

The objective of this study is to quantify the levels of ammonia and hydrogen sulfide inmechanically ventilated slurry-pit swine house according to pig's growth stage and seasonal condition. Mean concentrations of ammonia and hydrogen sulfide in the housing room of gestation/farrowing pigs were 5.60 (${\pm}2.48$) ppm and 178.4 (${\pm}204.8$) ppb in spring, 2.51 (${\pm}3.08$) ppm and 86.6 (${\pm}112.5$) ppb in summer, 4.96 (${\pm}2.84$) ppm and 182.3 (${\pm}242.6$) ppb in autumn, and 6.82 (${\pm}3.42$) ppm and 206.3 (${\pm}356.8$) ppb in winter, respectively. Mean concentrations of ammonia and hydrogen sulfide in the housing room of nursery pigs were 7.18 (${\pm}3.26$) ppm and 486.0 (${\pm}190.2$) ppb in spring, 4.23 (${\pm}2.95$) ppm and 206.4 (${\pm}186.9$) ppb in summer, 7.02 (${\pm}2.65$) ppm and 465.4 (${\pm}156.8$) ppb in autumn, and 9.25 (${\pm}3.68$) ppm and 618.4 (${\pm}298.3$) ppb in winter, respectively. Mean concentrations of ammonia and hydrogen sulfide in the housing room of growing/fattening pigs were 9.26 (${\pm}3.02$) ppm and 604.4 (${\pm}186.8$) ppb in spring, 6.78 (${\pm}3.88$) ppm and 312.5 (${\pm}215.4$) ppb in summer, 9.34 (${\pm}2.14$) ppm and 578.2 (${\pm}248.1$) ppb in autumn, and 14.65 (${\pm}3.15$) ppm and 825.3 (${\pm}316.9$) ppb in winter, respectively. As a result, mean concentrations of ammonia and hydrogen sulfide in terms of pig's growth stage were highest in growing/fattening housing room followed by nursery housing room and gestation/farrowing housing room (p<0.05). The swine house showed the highest levels of ammonia and hydrogen sulfide in winter followed by spring, autumn and summer. However, there was no significant difference of ammonia and hydrogen sulfide among seasons (p>0.05).

• Transactions of the Korean hydrogen and new energy society
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• v.33 no.4
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• pp.267-283
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• 2022

In these day, the environmental issues of climate change have been continuously highlighted and there is an active discussion on the transition from fossil fuel-based energy to eco-friendly energy use. This study considered psychological attitudes as a major influencing factors for successful implementation of a hydrogen society totally based on the use of hydrogen energy, which is regarded as an alternative energy for future. Accordingly, familiarity, risk perception, and acceptability of psychological factors were investigated. In addition, this study identified whether there are differences in psychological factors according to the general characteristics of gender, age, occupation, and housing type. The results showed that awareness of hydrogen cars and fuels is below the average level, and we also have obtained the implication that social knowledge sharing should precede the implementation of hydrogen policy. Although we found that the degree of urban acceptance of hydrogen energy was high, it was also confirmed that the charging infrastructure was generally perceived as having a high risk. Our findings implicate that it is necessary to figure out policy strategies for suitable locating charging infrastructure in order to promote the use of hydrogen energy more.

• Journal of the Korean Society of Safety
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• v.36 no.4
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• pp.71-79
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• 2021

In this study, a real-scale fuel-cell room of volume 1.36 m³ is constructed to confirm the explosion characteristics of hydrogen-air mixture gas in a hydrogen-powered house. A volume concentration of 40% is applied in the fuel-cell room as the worst-case scenario to examine the most severe accident possible, and two types of doors (made of plastic sheet and wood) are fabricated to observe their effects on the overpressure and impulse. The peak overpressure and impulse based on distance from the ignition source are experimentally observed and assessed. The maximum and minimum overpressures with a plastic-sheet door are about 20 and 6.7 kPa and those with a wooden door are about 46 and 13 kPa at distances of 1 and 5 m from the ignition source, respectively. The ranges of impulses for distances of 1-5 m from the ignition source are about 82-28 Pa·s with a plastic-sheet door and 101-28 Pa·s with a wooden door. The amount of damage to people, buildings, and property due to the peak overpressure and impulse is presented to determine the safe distance; accordingly, the safe distance to prevent harm to humans is about 5 m based on the 'injuries' class, but the structural damage was not serious.

• Transactions of the Korean hydrogen and new energy society
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• v.25 no.5
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• pp.509-515
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• 2014

At the fuel processing system (FPS) of fuel cell vehicle, hydrogen recirculation blower (HRB) is used for the recirculation of remained hydrogen after reaction. In this paper, noise and vibration improvement of HRB is studied by changing design and control. It is checked the campbell diagram and critical speed for stability of rotor, and housing stiffness is improved using simulation of frequency response function (FRF). A method is suggested that can decrease the unbalance amount of the rotor and impeller which main source of noise and vibration. In order to reduce the noise during deceleration of blower, electrical braking is applied and tested the risk impact of durability. Founded the optimum switching frequency of the motor control, and reduced the idle rpm by increasing of aerodynamic performance. The superiority of paper is proved by measurement of the improved product's noise and vibration.

• Asian-Australasian Journal of Animal Sciences
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• v.26 no.3
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• pp.433-442
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• 2013

This study aimed to compare the dynamics of air temperature and velocity under two different ventilation and housing systems during summer and winter in Korea. The $NH_3$ concentration of both housing systems was also investigated in relation to the pig's growth. The ventilation systems used were; negative pressure type for the enclosed pig house (EPH) and natural airflow for the conventional pig house (CPH). Against a highly fluctuating outdoor temperature, the EPH was able to maintain a stable temperature at 24.8 to $29.1^{\circ}C$ during summer and 17.9 to $23.1^{\circ}C$ during winter whilst the CPH had a wider temperature variance during summer at 24.7 to $32.3^{\circ}C$. However, the temperature fluctuation of the CPH during winter was almost the same with that of EPH at 14.5 to $18.2^{\circ}C$. The NH3 levels in the CPH ranged from 9.31 to 16.9 mg/L during summer and 5.1 to 19.7 mg/L during winter whilst that of the EPH pig house was 7.9 to 16.1 mg/L and 3.7 to 9.6 mg/L during summer and winter, respectively. These values were less than the critical ammonia level for pigs with the EPH maintaining a lower level than the CPH in both winter and summer. The air velocity at pig nose level in the EPH during summer was 0.23 m/s, enough to provide comfort because of the unique design of the inlet feature. However, no air movement was observed in almost all the lower portions of the CPH during winter because of the absence of an inlet feature. There was a significant improvement in weight gain and feed intake of pigs reared in the EPH compared to the CPH (p<0.05). These findings proved that despite the difference in the housing systems, a stable indoor temperature was necessary to minimize the impact of an avoidable and highly fluctuating outdoor temperature. The EPH consistently maintained an effective indoor airspeed irrespective of season; however the CPH had defective and stagnant air at pig nose level during winter. Characteristics of airflow direction and pattern were consistent relative to housing system during both summer and winter but not of airspeed. The ideal air velocity measurement favored the EPH and therefore can be appropriate for the Korean environment. Further emphasis on its cost effectiveness will be the subject of future investigations.

• Transactions of the Korean hydrogen and new energy society
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• v.28 no.5
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• pp.502-511
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• 2017

Design, manufacture and operate the 700W Solid oxide fuel cell system suitable for housing. Except for BOP not produced domestically, most of the domestic BOPs were applied as much as possible. Finally, the system size was 350 liter. System performance was electric efficiency 44.64%, thermal efficiency 40.99%, total efficiency 85.62% at certificate authority. The system was operated for 4,500 hours, this operation time include automatically system on/off, E-stop for emergency stop, load trip for blackout and inverter error. There were that the system on/off were 26 times. System performance remains intact after system on/off.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.25 no.8
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• pp.70-81
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• 2011

In this paper, a multi-agent control system for DC-coupled photovoltaic (PV), fuel cell (FC), ultracapacitor(UC) and battery hybrid power system is studied for commercial buildings & apartment buildings microgrid. In this proposed system, the PV system provides electric energy to the electrolyzer to produce hydrogen for future use and transfer to the load side, if possible. Whenever the PV system cannot completely meet load demands, the FC system provides power to meet the remaining load. A multi-agent system based-power management and control algorithm is proposed for the hybrid power system by taking into account the characteristics of each power source. The main works of this paper are hybridization of alternate energy sources with FC systems using long and short storage strategies to build the multi-agent control system with pragmatic design, and a dynamic model proposed for a PV/FC/UC/battery bank hybrid power generation system. A dynamic simulation model for the hybrid power system has been developed using Matlab/Simulink, SimPowerSystems and Stateflow. Simulation results are also presented to demonstrate the effectiveness of the proposed multi-agent control and management system for building microgrid.