• Korean Chemical Engineering Research
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• v.40 no.6
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• pp.694-702
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• 2002

Activated carbons have been used as adsorbents in various industrial application, such as solvent recovery, gas separation, deodorization, and catalysts. In this study, the effects of residual water on the activated carbon adsorbent surface on the adsorption capacity of $CCl_4$ were investigated. Adsorption behavior in a fixed bed was studied in terms of feed concentration, flow rate, breakthrough curve and adsorption capacity for $CCl_4$. Desorption characteristics of residual water on activated carbon were also studied. The water contents of the activated carbon were varied in the range of 0-20%(w/w) and all experiments were performed at 298.15 K. The adsorption equilibrium data $CCl_4$ on the activated carbon were well expressed by Langmuir isotherm. The adsorption capacity of $CCl_4$ decreased with increasing residual water content. Desorption of residual water in activated carbon decreased expotentially with $CCl_4$ adsorption. The obtained breakthrough curves using LDF(linear driving force) model represented our experimental data.

• Computational Structural Engineering
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• v.2 no.1
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• pp.65-70
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• 1989

An analytical study was conducted using the Galerkin technique to determine behaviour of thin fibrereinforced and laminated composite pipes under soil pressure. Geometric nonlinearity and material linearity have been assumed. It is assumed that vertical and lateral soil pressure are proportional to the depth and lateral displacement of the pipe respectively. It is also assumed that radial shear stress is negligible because the ratio of thickness to the radius of pipe is very small. The above results are verified by the finite element analysis.

• Korean journal of food and cookery science
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• v.30 no.3
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• pp.271-277
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• 2014

The purpose of this study was to investigate Tteokbokki tteok that has properties of five different rice cultivars (Haiami, Samkwang, Goami, Saegyejinmi and, Seolgaeng). The moisture and crude protein contents of rice were 14.13-17.78% and 4.43-7.68%, respectively. The crude lipid and crude ash of rice were 0.45-1.84% and 0.37-0.85%, respectively. The water binding capacity of Goami cultivar was higher than that of other rice flours. Asa the soaking time increased, water absorption was the highest in the Goami cultivar (45.30%). Using a rapid visco analyzer (RVA), the initial pasting temperature of Goami cultivar was the highest; further, the peak viscosities of Samkwang cultivar and Saegyejinmi cultivar were higher than of those of other rice flours. The hardness of the Tteokbokki tteok was the highest the in the Goami cultivar (7,293.08 g); conversely, the Saegyejinmi cultivar had the lowest value (2,502.08 g). In the sensory evaluation of Tteokbokki tteok, the color, texture, and overall acceptability were the highest in the Saegyejinmi cultivar, the appearance was highest in the Samkwang cultivar, and the flavor was the highest in the Seolgaeng cultivar. Lastly, the Goami cultivar yielded the lowest values in the sensory evaluation, except for appearance and color.

• Proceedings of the ESK Conference
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• 1997.10a
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• pp.142-151
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• 1997

본 연구는 주부들의 주활동공간인 부엌가구와 공간의 설계에 있어사용하기 편리하며 가사활동에 따 른 피로를 경감시키고 요통과 같은 주부직업병을 예방할 수 있는 부엌가구와 공간의 개발에 그 목적을 두었다. 연구는 먼저 수도권의 32평형 규모의 아파트150가구를 대상으로 설문조사를 실시하였으며, 만 24시간동안의 실제 가사활동을 Video로 촬영하여 동작분석을 실시하였다. 그 결과 주부들은 수납의 용 이성과 공간의 크기, 작업대의 높이 등을 가장 많은 개선사항으로 지적하였으며, 절반이상의 주부들이 앉은 자세에서 작업이 이루어졌으면 좋겠다고 응답하였다. 또한 동작분석 결과 작업의 70%이상이 개수 대를 중심으로 조리대와 가열대 주변의 한정된 공간에서정적으로 선 자세에서이루어지는 것으로 파악 되었다. 이러한 선 자세에서의 작업에 따른 피로도를 감소시키기 위하여 입좌식 의자를 도입하였으며, 개수대를 씽크대의 'ㄱ'자 코너에 위치하여 주방활동시의 이동거리를 단축하고자 하였다. 피로도의 경감 을 측정하기 위하여 입좌식 의자를 도입한 개선된 씽크대와 기존의 입식씽크대에서 가사활동시 요구되는 주부들의 에너지 대사량을 비교하기 위하여 심장박동수와 산소호흡량을 측정하였다. 실험결과에 따르면 주방에 입좌식의자를 도입한 경우가 가사활동에 요구되는 에너지 소모량이 심장박동수와 산소호흡량의 기준에서 각각 평균적으로 30%와 57.5% 이상이 감소하는 것으로 파악되어 이러한 부엌가구의 도입으로 주부들의 가사활동에따른 피로도가 절반 가까이 감소될 수 있음을 니타내었다. 또한 부엌가구의 재배치 에따른 가사활동시 이동거리가 평균적으로5.5%이상이 감소하는 것으로 나타났다. 본 연구결과를 주방설 계에 적용할 경우 가사활동의 효율성과 편리성이 향샹됨은 물론 가사활동에따른 피로도를 경감 시키고 요통 등의 주부직업병을 예방할 수 있을 것으로 기대된다.1일 1회씩 4회 투여한 군에서도 암수에 상관없이 전 농도 군에서 염색체이상을 나타내지 않아 유전독성을 나타내지 않음을 관찰하였다. 특히 vitamin C와 E의 병용투여는 상승적으로 적용하여 간세포손상을 더욱 억제시킴을 알 수 있었다.mance and on TFP(Total Factor Productivity) growth which is a pure measure of firm performance. To utilize the advantage of panel data, FEM(Fixed Effect Model) and REM(Random Effect Model) were used. The empirical result shows that the entropy index as a measurement of inter-business relatedness is not significant but technological relatedness index is significant. OLS estimates on pooled data were considerably different from FEM or REM estimates on panel data. By introducing interaction effect among the three variables for business portfolio properties, we obtained three findings. First, only VI (Vertical integration) has a significant positive correlation with ROS. Second, when using TFP growth as an dependent variable, both TR(Technological Relatedness) and f[ are signif

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2017.05a
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• pp.559-562
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• 2017

In city, tracing of power transmission lines is difficult due to compound installation of overhead and underground lines, transposition, bad view caused by trees or big buildings. It is hard problem for electrical technician on site to trace power transformers or power lines to serve customers in 3 phase -4 wires power distribution systems. It is necessary that the correct and fast tracing method is required for load balancing among distribution lines. Old technology use to trace off-lines with high power impulse injection. Our proposed method use to trace live lines with very small power high frequency signal injection. Typical power transformers in the distribution system prevent propagating the higher frequency carrier signal. The proposed method uses the limited propagation ability to identify the power transformer to serve customers. Two end communication terminals are required to be synchronized between them for determination on electrically same phases. Challenging issue is to achieve synchronization without GPS providing synchronizing time. A novel power transformer and wire identification system is designed and implemented. The system consists of a transmitter and a receiver with power-line communication module. Some experiments are conducted to verify the theoretical concepts in a big commercial building. Also some simulations are done to help and understand the concepts by using MATLAB Simulink simulator.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.05a
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• pp.505-508
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• 2016

In city, tracing of power transmission lines is difficult due to compound installation of overhead and underground lines, transposition, bad view caused by trees or big buildings. It is hard problem for electrical technician on site to trace power transformers or power lines to serve customers in 3 phase -4 wires power distribution systems. It is necessary that the correct and fast tracing method is required for load balancing among distribution lines. Old technology use to trace lines with high power impulse injection. Our proposed method uses to trace lines with very small power high frequency signal injection. Simulation models for 3-phase power transformers, 3-phase wire lines, and customer loads are described to investigate the transmission characteristics of high frequency power line carrier. Distribution lines have only a limited ability to carry higher frequencies. Typically power transformers in the distribution system prevent propagating the higher frequency carrier signal. The proposed method uses the limited propagation ability to identify the power transformer to serve customers. The system consists of a transmitter and a receiver with power-line communication module. Some experiments are conducted to verify the theoretical concepts in a big commercial building. Also some simulations are done to help and understand the concepts by using MATLAB Simulink simulator.

• Korean Chemical Engineering Research
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• v.49 no.4
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• pp.423-431
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• 2011

Recentincreasing awareness of the environmental damage caused by the $CO_2$ emission of fossil fuelsstimulated the interest in alternative and renewable sources of energy. Fuel cell is a representative example of hydrogen energy utilization. In this study, Molten Carbonate Fuel Cell system is simulated by using $Aspen^{TM}$. Stack model is consisted of equilibrium reaction equations using $ACM^{TM}$(Aspen Custom Modeler). Balance of process of fuel cell system is developed in Aspen $Plus^{TM}$ and simulated at steady-state. Analysis of performance of the system is carried out by using sensitivity analysis tool with main operating parameters such as current density, S/C ratio, and fuel utilization and recycle ratio.In Aspen $Dynamics^{TM}$, dynamics of MCFC system is simulated with PID control loops. From the simulation, we proposed operation range which generated maximum power and efficiency in MCFC power plant.

• Korean Chemical Engineering Research
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• v.49 no.6
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• pp.840-845
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• 2011

Degradation products of agarose are biologically active and thus used as an ingredient in pharmaceuticals or functional cosmetics. Furthermore, it has been strongly considered as a substrate for bio-ethanol fermentation. Recently, we isolated new agarase-producing microorganism, Pseudoalteromonas sp. from south sea of Korea. In this study, we aimed to separate and purify the agarase from culture broth of this strain. Separation of agarase was performed by ion- exchange chromatography on DEAE-Sepharose resin. Equilibrium pH and volume ratio of resin to the amount of protein were optimized for the efficient adsorption of protein. 410 ${\mu}g$ of protein was completely adsorbed to 3 mL of resin at pH 7.5. The total amount of eluted protein increased as NaCl concentration increased to 400 mM at isocratic elution. Agarase was separated by linear gradient elution of NaCl (0~1,000 mM). Three major protein peaks were observed and the presence or absence of agarase in these eluted proteins was measured by Lugol's staining technique. Only six eluted protein fractions showed strong agarase activity.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.7
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• pp.239-247
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• 2014

The CTSIB (Clinical Test of Sensory Integration on Balance) using high sensitive pressure sensors is normally used to assess the sense of balance in hospital. It takes an objective measurement of the amount of sway that occurs in the body trunk by observing the change in the center of pressure (CoP) on the foot at the upright posture. In this paper, we would like to propose method to easily measure trunk sway in home. Although the Wii balance board(WBB) is used for games, it can measures the center of pressure, which is highly correlated. The Wii remote controller(WRC) is inexpensive compared to the WBB, but it has problems with estimation of trunk sway because it can't measure pressure directly like WBB. We collected data from 10 normal subjects (5 males, 5 females) from two devices in order to compare the CoP from WBB and the center of mass (CoM) from WRC. The results of WRC and WBB was similar when the data were analyzed by the convex hull and ellipse area.

• Korean Journal of Environmental Agriculture
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• v.7 no.2
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• pp.96-101
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• 1988

It is important to assess the effects of ionic strength and type of anions when studying the adsorption of heavy metals on zeolite because the background salt may complex with heavy metals and compete for adsorption sites. This experiment was carried out to determine the effect of ionic strength and anion species($Cl^-$, $SO^{2-}\;_4$, and $ClO^-\;_4$) on heavy metal adsorption. Heavy metal adsorption by zeolite from solutions in the range of 10 to 50ppm was studied in the presence of NaCl, $Na_2SO_4$ and $NaClO_4$, with different concentrations. The ionic strength ranged from 0.01 to 1.00. Adsorption of heavy metal cations could be described by the Freundlich isotherm equation. Increasing the ionic strength of equilibrium solutions, the amounts of heavy metal adsorbed on the zeolite surfaces decreased in all three of the anion systems. This fact could be attributed to the competition of background salt cation and the decrease in initial activity of heavy metal cations. In the presence of Cl anion, less adsorption resulted than in the presence of $SO_4$ or $ClO_4$ anions of the same ionic strength, indicating the presence of uncharged and negatively charged complexes of heavy metal with Cl ligands.