• 한국태양에너지학회 논문집
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• 제33권3호
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• pp.42-50
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• 2013

Solar thermal reactor was studied for hydrogen production with a two step thermochemical cycle including T-R(Thermal Reduction) step and W-D(Water Decomposition) step. NiFe2O4 and Fe3O4 supported by monoclinic ZrO2 were used as a catalyst device and Ni powder was used for decreasing the T-R step reaction temperature. Maintaining a temperature level of about $1100^{\circ}C$ and $1400^{\circ}C$, for 2-step thermochemical reaction, is important for obtaining maximum performance of hydrogen production. The controller was designed for adjusting high temperature solar thermal energy heating the foam-device coated with nickel- ferrite powder. A Pill temperature control system was designed based on 2-step thermochemical reaction experiment data(measured concentrated solar radiation and the temperature of foam device during experiment). The cycle repeated 5 times, ferrite conversion rate are 4.49~29.97% and hydrogen production rate is 0.19~1.54mmol/g-ferrite. A temperature controller was designed for increasing the number of reaction cycles related with the amount of produced hydrogen.

• 한국대기환경학회지
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• 제14권4호
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• pp.293-302
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• 1998

This study was performed to investigate the behavior of chlorobenzenes (CIBZS) and chlorophenols (CIPhs) in a thermally treated MSWI fly ash. The experiment was carried out in a fixed bed reactor at the temperature range of 300~$600^{\circ}C$. Reaction time range was between 30 and 120 minutes, and NB and 02 gases were used as carrier gas. The decomposition rate of CIBZS was more affected by reaction time than by the reaction temperature. The decomposition rate of CIPhs was affected by both parameters. Decomposition rate of CIBZS and CIPhs reached 80.4% and 96.6% at $600^{\circ}C$, 120 min, respectively. Considering the effect of O2 content, decomposition rate of CIBZS and CIPhs was the highest at 10% of O2 content. Declorination and decomposition reactions Pere investigated by analyzing homologue distribution. Higher chlorinated CIBZS and CIPhs homologue decreased but lower chlorinated compounds increased with the increase of temperature. Effect of O2 on the homologue distribution of these compounds was not clear in the range of our experiment conditions.

• 한국정밀공학회지
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• 제24권10호
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• pp.131-136
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• 2007

In this paper, we estimated the effects of different color stimulation on the cognitive function of human quantitatively. For the stimulations we used color lights with 6 color filters such as red, yellow, green, blue, violet and white. The experiment was performed in a soundproof chamber. 50 young male and female subjects were participated in the experiment. To find the appropriate color cognitive function, the endogenous visuospatial attention task(EVAT) and one back working memory task(OWMT) were performed. The reaction time and accuracy degree were measured. The results showed that the reaction time of EVAT was the fastest and the accuracy degree of attention task was the highest in green environment. The reaction time of OWMT was the fastest in yellow and the accuracy degree of memory task was the highest in blue. For physiological parameters, we measured electrocardiogram(ECG) and HRV spectrum analysis, HF/LF color environment. These results can be used as an indicator in the design of color environment and clinical applications.

• 대한인간공학회지
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• 제31권3호
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• pp.463-467
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• 2012

This study aims to empirically investigate population stereotype of burner-control linkage of four-stove gas range for Koreans. Background: The previous studies' results for gas range stereotypes were different depending upon methods adopted, i.e., whether using questionnaires, computer simulation or physical models. It is known that the physical model experiment should not be methodologically replaced by the computer simulation or paper-and-pencil tests. Stereotype of gas range for Koreans was surveyed based on questionnaires, but has not been dealt with by using physical models. Method: An experiment was conducted to investigate stereotype of four-burner gas range, in which 32 subjects participated and a real gas range available in the market was bought and used. Four types of burner-control linkage were used as independent variable, and reaction time as dependent variable. Results: ANOVA revealed that four types of burner-control linkage and subjects' gender were not significant on reaction time. Duncan's multiple range test showed that reaction times for type III was significantly lower than those for the other three types of burner-control linkage(${\alpha}$=0.05). Conclusion: It is concluded based on the results of this study that stereotype of gas range for Koreans is type III. This is in agreement with results of existing studies using questionnaire survey, while different from those based on physical models. Application: The results of this study would be useful as an ergonomic guideline when designing gas ranges or similar equipments for minimizing operation errors.

• 한국지반공학회지:지반
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• 제8권2호
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• pp.59-70
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• 1992

지질구조의 일례를 모형화하여 3종류 시료에 대해 간극수압계를 사용하여, 가압수두와 간극비 변화에 따른 간극수압 변화측정을 60회의 실험을 통하여 실시하였다. 본 연구는 불포화 붕적토층에서 간극비와 가압수두 변화에 따른 간극수압의 변화를 기록하여 최종간극수압 VWT와 공기간극수압 Ua를 구하여 이들의 변화를 최종반응률과 공기반응률로 나타냈으며, 시료별로 투수계수와 간극비의 관계를 수식화 하였다. 실험결과 시료에 따라 간극수압 변화 형태가 계단형과 파형으로 나타났으며, 최종간극수압까지의 시간 지체는 모래, 사질실트, 점토질 모래 순이었다.

• Nuclear Engineering and Technology
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• 제54권2호
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• pp.653-660
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• 2022

The interaction between UN and CdCl₂ in the LiCl-KCl molten eutectic was studied at 1023 K. The chlorination was monitored by sampling and recording the redox potential of the medium. At 1023 K the chlorination of UN with cadmium chloride in the molten LiCl-KCl eutectic proceeds completely and results in the formation of uranium chlorides. The melts of the LiCl-KCl-UCl₃ or LiCl-KCl-UCl₄ compositions can be obtained by the end of experiment depending on the presence of metallic cadmium in the reaction zone. The higher the concentration of the chlorinating agent, the faster the reaction rate. At [CdCl₂]/[UN] = 1.65 (10% excess) the reaction proceeds to completion in about 7.5 h. At [CdCl₂]/[UN] = 7 the complete chlorination takes 2.5-3 h.

• 한국수소및신에너지학회논문집
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• 제33권4호
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• pp.337-342
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• 2022

In this study, a water electrolysis was studied to investigate the effect of ammonia on current density and H2 gas production. A H type cell with three electrodes was used and KOH solution was used as electrolyte. The conventional platinum foil was used for working electrode, whereas nickel foam was used for counter electrode. CV experiment was performed to see the activity of ammonia oxidation reaction. In addition, CP experiment was done to examine the dependence of Faraday efficiency of hydrogen on current density and NH3 concentration. The CV result shows the 0.5M NH3 concentration required for highest current density and reliable operation. The CP result shows the increased current density leads to higher H2 generation. The higher H2 production and subsequent energy efficiency was observed for 0.5M NH3 using a Pt/13%Rh coil for a cathode as compared to those in water electrolysis.

• 한국주조공학회지
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• 제25권4호
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• pp.161-167
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• 2005

The experiment of hot dip interaction tests was carried out in order to study the formation behavior of interfacial reaction layer between as-received STD61 hot work tool steel and a commercial pure aluminum melt, Al-xwt.%Fe(x=0.2, 0.5, 0.8 and 1.1) alloys melt and Al-xwt.%Si(x=1.0, 4.0, 7.0 and 10.0) alloys melt, respectively. The results show that the reaction layer, over 300 ${\mu}m$ in thickness, is easily formed by the dissolution of silicon from as-received tool steel. When the iron content in the aluminum alloy is higher than 1.1 wt.%, the thickness of reaction layer decreases below 180 ${\mu}m$ by preventing iron dissolution from the tool steel. The silicon dissolved from tool steel acts as a strong promoter on the formation of reaction layer, but the alloyed silicon in molten aluminum alloys acts as an inhibitor on the formation of reaction layer.

• 동력기계공학회지
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• 제20권3호
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• pp.57-63
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• 2016

This paper presents the experimental result and theoretical analysis result to investigate the correlation between the operating force, angle and locking torque for vehicle hood frame. Also, we derived the experimental equation that using the results for experiment and theory. The hood frame is switching-devices used for opening and closing the vehicle hood. It needs the correlation data between locking torques of each joint, operating force and angle of hood frame. The correlation data for torque and reaction force of hood frame obtained through experiment and theory analysis. Finally, the experimental equation of the locking torque prediction for the hood frame is derived.

• 한국대기환경학회지
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• 제11권2호
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• pp.131-136
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• 1995

The experiment for decomposing CFF-113 by a honeycomb catalyst was carried out in this study. Benzene and water were used as decomposing agents. The reaction of decomposition was from 600 .deg.C to 900.deg.C. Benzene was injected at 900.deg.C and then the catalyst was heated to 1100.deg.C by the heat of combustion of it. The electric power of the reactor was turned off when the combustion was started. The reaction temperature, however, was main trained and the decomposition of CFC-113 continued at that time. It was found that the highest decomposition efficiency was 80% at the ratio of benzene/CFC-113 of 20/1 in this experiment.