• Title/Summary/Keyword: 평형모델

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OPTICAL PERFORMANCE OF BREADBOARD AMON-RA IMAGING CHANNEL INSTRUMENT FOR DEEP SPACE ALBEDO MEASUREMENT (심우주 지구 반사율 측정용 아몬라 가시광 채널의 광학 시스템 제조 및 성능 평가)

  • Park, Won-Hyun;Kim, Seong-Hui;Lee, Han-Shin;Yi, Hyun-Su;Lee, Jae-Min;Ham, Sun-Jung;Yoon, Jee-Yeon;Kim, Sug-Whan;Yang, Ho-Soon;Choi, Ki-Hyuk;Kim, Zeen-Chul;Lockwood, Mike;Morris, Nigel
    • Journal of Astronomy and Space Sciences
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    • v.24 no.1
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    • pp.79-90
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    • 2007
  • The AmonRa instrument, the primary payload of the international EARTHSHINE mission, is designed for measurement of deep space albedo from L1 halo orbit. We report the optical design, tolerance analysis and the optical performance of the breadborad AmonRa imaging channel instrument optimized for the mission science requirements. In particular, an advanced wavefront feedback process control technique was used for the instrumentation process including part fabrication, system alignment and integration. The measured performances for the complete breadboard system are the RMS 0.091 wave(test wavelength: 632.8 nm) in wavefront error, the ensquared energy of 61.7%($in\;14\;{\mu}m$) and the MTF of 35.3%(Nyquist frequency: $35.7\;mm^{-1}$) at the center field. These resulting optical system performances prove that the breadboard AmonRa instrument, as built, satisfies the science requirements of the EARTHSHINE mission.

Adsorption Characteristics of Flue Gas Components on Zeolite 13X and Effects of Impurity (제올라이트 13X에 의한 배가스 성분의 흡착 특성 및 불순물의 영향)

  • Suh, Sung-Sup;Lee, Ho-Jin
    • Korean Chemical Engineering Research
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    • v.54 no.6
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    • pp.838-846
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    • 2016
  • Most of combustion processess used in industries require recovering or removing flue gas components. Recently a new MBA (moving bed adsorption) process for recovering $CO_2$ using zeolite 13X was developed. In this study, adsorption experiments for carbon dioxide, nitrogen, sulfur dioxide, and water vapor on zeolite 13X were carried out. Adsorption equilibrium and adsorption rate into solid particle were investigated. Langmuir, Toth, and Freundlich isotherm parameters were calculated from the experiment data at various temperatures. Experimental results were consistent with the theoretically predicted values. Also $CO_2$ adsorption amount was measured under the conditions with impurities such as $SO_2$ and $H_2O$. Binary adsorption data were well fitted to the extended Langmuir isotherm using parameters obtained from pure component experiment. However, $H_2O$ impurity less than, roughly, ${\sim}10^{-5}H_2O\;mol/g$ zeolite 13X enhanced slightly $CO_2$ adsorption. Spherical particle diffusion model well described experimentally measured adsorption rate. Diffusion coefficients and activation energies of $CO_2$, $SO_2$, $N_2$, $H_2O$ were obtained. Diffusion coefficients of $CO_2$ and $SO_2$ decreased with small amount of preadsorbed impurity. Parameter values from this study will be helpful to design of real commercial adsorption process.

The Relationship between Health Related Physical Fitness, Depression, and Quality of Life of the Elderly (노인의 건강체력과 우울, 삶의 질 관계 : 인지기능을 매개변수로)

  • Chun, Myung-Up;Choi, Jae-Won;Kang, Sung-Goo;Yoo, Ha-Na;Lee, Kyung-Ha
    • Journal of the Korea Convergence Society
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    • v.10 no.12
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    • pp.387-397
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    • 2019
  • The purpose of this study is to analyze the relationship between health related physical fitness, cognitive function, depression and quality of life variables of elderly people in a comprehensive way based on quantitative evaluation. The subjects of this study were 385 people who voluntarily participated in the elderly welfare center in Gyeonggi and Seoul the elderly people. As for the data collection methods, were measured the characteristics, depression and quality of life, cognitive function questionnaires along with measures of lower and upper body strength, dynamic equilibrium and agility, total endurance and grip strength. As a result, the first was a statistically significant correlation between integrated health of the elderly, cognitive function, quality of life and depression. Second, the analysis of cognitive function, elderly integrated health, quality of life, and depression revealed statistical significance among all variables. Third, there was the partial intervention effect of function in the quality of life and depression of the elderly.

Retardation Effect and Mobility of a Heavy Metal in a Sandy Soil (사질토양에서의 중금속의 지연효과와 이동성)

  • Kim, Dong-Ju;Baek, Doo-Sung
    • Journal of the Korean Society of Groundwater Environment
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    • v.5 no.3
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    • pp.155-161
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    • 1998
  • Retardation effect of heavy metals in soils caused by adsorption onto the surfaces of solids particles is well known phenomenon. In this study, we investigated the retardation effect on the mobility of a Zn in a sandy soil by conducting batch and column tests. The column test consisted of monitoring the concentrations of effluent versus time known as a breakthrough curve (BTC). We used NaCl and ZnCl$_2$ solutions with the concentration of 10 g/L as a tracer, and injected them respectively into the inlet boundary of the soil sample as a square pulse type, and monitored the effluent concentrations at the exit boundary under a steady state condition using an EC-meter and ICP-AES. The batch test was conducted based on the standard procedure of equilibrating fine fractions collected from the soil with various initial ZnCl$_2$ concentrations, and analysis of Zn ions in the equilibrated solutions using ICP-AES. The results of column test showed that i) the peak concentration of ZnCl$_2$analyzed by ICP was far less than that of either NaCl or bulk electrical conductivity and ⅱ) travel times of peak concentrations for two tracers were more less identical. The relatively low concentration of Zn can be explained by ion exchange between Zn and other cations, and possible precipitation of Zn in the form of Zn(OH)$_2$due to high pH range (7.0∼7.9) of the effluent. The identical result of travel times of peak concentrations indicates that the retardation effect is not present in the soil. The only way to describe the prominent decrease of Zn ion was to introduce decay or sink coefficient in the CDE model to account for irreversible decrease of Zn ions in the aqueous phase.

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A Numerical Study on Dynamic Characteristics of Counter-Rotating Rigid/Deformable Rolls in Press Contact (압착되어 회전하는 강체/변형 롤의 동적 특성에 관한 수치해석 연구)

  • Lee, Moon-Kyu;Lee, Sang-Hyuk;Hur, Nahm-Keon;Seo, Young-Jin;Kim, In-Cheol;Lee, Sung-Jin
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.35 no.8
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    • pp.869-876
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    • 2011
  • It is important to analyze the dynamic behavior of counter-rotating rigid/deformable rolls in the roll-coating process, because the stability of the process is affected by the dynamic characteristics. In the present study, the effects of material property, angular velocity, and gap size on the contact pressure and contact shape of the deformable roll are numerically investigated. The behavior of two rolls with a negative gap was analyzed using the finite element method, and the material property of the deformable roll was applied with the Mooney-Rivlin coefficients of the hyper-elastic model. The contact shape is affected by the gap size, and the contact pressure mainly depends on the stiffness of the deformable roll and the gap size. To maintain a negative gap between two rolls, controls such as load and displacement controls must be used. The results indicate that displacement control can reduce the instability.

Member Sizing Method in IsoTruss® Grid High-rise Building Structures Based on Stiffness Criteria (강성도 기준에 따른 IsoTruss® 그리드 고층건물의 부재선정 방법)

  • Kim, Tae-Heon;Kim, Young-Chan
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.18 no.12
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    • pp.50-56
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    • 2017
  • The perimeter structure in high-rise buildings, which plays a major role in resisting lateral forces, is generally formed by the orthogonal placement of the beam and column, but currently various grid patterns are implemented. In a previous study, the adaptability of the $IsoTruss^{(R)}$ grid (ITG) as a perimeter structure was examined. In this study, a method of estimating the required cross sectional area of a member in a preliminary design is proposed. The members of the perimeter structure are placed in three planes, perpendicular (PPR), parallel (PPL) and oblique (POQ) to the lateral loading, and the stiffness of the members in the POQ was taken into account by projecting them onto the PPL or PPR. Three models are established for member size zoning through the height of the building, in order to investigate the effect of the shear and moment in the calculation of the required cross sectional area. To examine the effectiveness of this study, a 64-story building is designed and analyzed. The effect of the member size zoning was examined by comparing the maximum lateral displacement, required steel amount, and axial strength ratio of the columns. Judging from the maximum lateral displacement, which was 97.3% of the allowable limit, the proposed formula seems to be implemental in sizing the members of an ITG structure at the initial stage of member selection.

Rheological Properties of Rehydrated Suspensions of Freeze Dried Kochujang Powders (동결건조 분말고추장의 재수화시 리올로지 특성)

  • Kim, Suk-Shin;Chang, Kyu-Seob;Yoon, Han-Kyo;Lee, Sang-Kyu;Lee, Shin-Young
    • Korean Journal of Food Science and Technology
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    • v.19 no.2
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    • pp.81-88
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    • 1987
  • Rheological properties of rehydrated suspensions of two kinds of freeze dried Kochujang powders, processed at different freezing rates, were compared with raw Kochujang using Brookfield wide-gap rotational viscometer at $25^{\circ}C-60^{\circ}C$. Shear rates ranged from $0.1965\;sec^{-1}$ to $1.9650\;sec^{-1}$ and solid content ranged from 47% to 56%. Rehydrated suspensions of quickly frozen Kochujang powder and slowly frozen Kochujang powder, and raw Kochujang exhibited pseudoplastic behaviors with yield stress and presented thixotropic properties which followed the second-order kinetic behavior proposed by Tiu. Suspensions of Kochujang powders exhibited considerably higher decaying rates than raw Kochujang. The dependency of the equilibrium structure parameter on the shear rate was weak, and there were no significant differences among the values of structure parameters of three samples. The temperature dependency of the apparent viscosity of Kochujang suspension was fully expressed by Arrhenius equation and activation energies of suspensions of quickly frozen Kochujang powder and slowly frozen Kochujang powder, and raw Kochujang were 2.21, 2.18, and 2.32 Kcal/g.mole respectively. Consistency indices of three samples increased with solid content and decreased with temperature. Flow behavior indices of three samples showed no considerable dependency on the temperature and solid content. There were no significant differences in the rheological properties between two Kochujang powders.

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Interactions between Hydrodenitrogenation of Pyridine and Hydrodeoxygenation of m-Cresol over sulfided CoMo/γ-Al2O3 Catalyst (황화 CoMo/γ-Al2O3 촉매상에서 수첨탈질반응과 수첨탈산소 반응의 상호작용)

  • Kim, Hak-Soo;Park, Hea-Kyung;Kim, Kyung-Lim
    • Applied Chemistry for Engineering
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    • v.2 no.2
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    • pp.108-118
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    • 1991
  • Interactions between pyridine hydrodenitrogenation (HDN) and m-cresol hydrodeoxygenation(HDO), and the kinetic analysis were studied over sulfided $CoMo/{\gamma}-Al_2O_3$ catalyst at the range of temperatures between 473 K and 723 K, the total pressures between $10{\times}10^5Pa$ and $50{\times}10^5Pa$, and the contact times between 0.0125 g-cat. hr/ml-feed and 0.03g-cat. hr/ml-feed. HDN of pyridine and HDO of m-cresol were inhibited by each other and the inhibition effect of HDO by pyridine is higher than that of HDN by m-cresol. But reactivity of m-cresol is higher than that of pyridine. The rate equations of pyridine and m-cresol were given to be ${\gamma}_{HDN}=k_{HDN}{\cdot}K_pC_p/(1+K_cC_c+K_pC_p)$ and ${\gamma}_{HDO}=k_{HDO}{\cdot}K_cC_c/(1+K_cC_c+K_pC_p)$ in terms of Langmuir-Hinshellwood-Hougen-Watson model. At each temperature, reaction rate constants and adsorption equilibrium constants were determined and activation energies of pyridine HDN and m-cresol HDO are 13.83kcal/mol, respectively and the heat of adsorption are -6.458 and -5.045kcal/mol, respectively.

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The Effect of Residual Water on the Adsorption Process of Carbon Tetrachloride by Activated Carbon Pellet (활성탄에 의한 사염화탄소 흡착공정에서 잔존수분의 영향)

  • Jeong, Sung Jun;Lee, Dae Lo;Kim, Tae Young;Kim, Jin Hwan;Kim, Seung Jai;Cho, Sung Young
    • 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.

Adsorption and Desorption Dynamics of Ethane and Ethylene in Displacement Desorption Process using Faujasite Zeolite (제올라이트(faujasite)를 이용한 치환탈착공정에서 에탄, 에틸렌의 흡, 탈착 동특성)

  • Lee, Ji-In;Park, Jong-Ho;Beum, Hee-Tae;Yi, Kwang-Bok;Ko, Chang-Hyun;Park, Sung Youl;Lee, Yong-taek;Kim, Jong-Nam
    • Korean Chemical Engineering Research
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    • v.48 no.6
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    • pp.768-775
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    • 2010
  • Adsorption dynamics of ethane/ethylene mixture gas and desorption dynamics during the displacement desorption with propane as a desorbent in the column filled with faujasite adsorbent were investigated experimentally and theoretically. The simulation that adopted heat and mass balance and an ideal adsorbed solution theory (IAST) for the multicomponent adsorption equilibrium well predicted the experimental breakthrough curves of the adsorption and desorption. At the adsorption breakthrough experiments, roll-ups of ethane increased as the adsorption pressure increased and the adsorption temperature decreased. During the displacement desorption with propane in the column saturated with ethane/ethylene mixture gas, almost 100% of ethylene was obtained for a certain time interval. The adsorption strength of the desorbent greatly affected the adsorption and re-adsorption dynamics of ethylene. The re-adsorption capacity for ethylene has been greatly reduced when iso-propane, which is stronger desorbent than propane, was used as desorbent. It was found from the simulation that the performance of the displacement desorption process would be superior when the ratio of ${(q_s{\times}b)}_{C_2H_4}/{(q_s{\times}b)}_{C_3H_s}$ was 0.83, that is, the adsorption strengths of ethylene and the desorbent were similar.