• Title/Summary/Keyword: equilibrium test

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Vapor-Liquid Equilibria for the Systems of MTBE-Methanol, MTBE-n-Heptane, n-Heptane-Methanol by Using Head Space Gas Chromatography (Head Space Gas Chromatography를 이용한 MTBE-Methanol, MTBE-n-Heptane, n-Heptane-Methanol계의 기액평형)

  • Lee, Ju-Dong;Lee, Tae-Jong;Park, So-Jin
    • Applied Chemistry for Engineering
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    • v.5 no.4
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    • pp.706-713
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    • 1994
  • Isothermal vapor-Liquid equilibrium data have been measured for binary systems MTBE-methanol, MTBE-n-heptane, and methanol-n-heptane at $45^{\circ}C$ and $65^{\circ}C$ by using head space gas chromato-graphy (H.S.G.C). Among these systems a minimum azeotrope was observed in both of MTBE-methanol system and n-heptane-methanol system. Particularly n-heptane-methanol system has a heterogeneous minimum azotrope since it has an immisible region. These equilibrium data were correlated with the excess Gibbs energy model, and the thermodynamic consistency test was also carried out by using Redlich-Kister equation.

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Fluoride Removal from Aqueous Solutions using Industrial Waste Red Mud (산업폐기물인 적니를 이용한 불소 제거)

  • Um, Byung-Hwan;Jo, Sung-Wook;Kang, Ku;Park, Seong-Jik
    • Journal of The Korean Society of Agricultural Engineers
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    • v.55 no.3
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    • pp.35-40
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    • 2013
  • The present study was conducted to investigate the adsorption potential of red mud for fluoride removal. Different operation parameters such as the effect of contact time, initial concentration, pH, competing anions, seawater, adsorbent dose amount, and adsorbent mixture were studied. Nearly 3 hr was required to reach sorption equilibrium. Equilibrium sorption data were described well by Langmuir model and the maximum adsorption capacity of red mud was 5.28 mg/g. The fluoride adsorption at pH 3 was higher than in the pH range 5-9. The presence of anions such as sulfate, nitrate, phosphate, and bicarbonate had no significant effect on fluoride adsorption onto red mud. The fluoride removal by red mud was greater in seawater than deionized water, resulting from the presence of calcium and magnesium ion in seawater. The use of red mud alone was more effective for the removal of fluoride than mixing red mud with other industrial waste such as oyster shells, lime stone, and steel slag. This study showed that red mud has a potential application in the remediation of fluoride contaminated soil and groundwater.

Prediction of Moisture Migration of Concrete Including Internal Vaporization in Fire (화재시 내부증발을 고려한 콘크리트의 수분이동)

  • Lee, Tae-Gyu
    • Fire Science and Engineering
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    • v.23 no.5
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    • pp.17-23
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    • 2009
  • Moisture evaporates, when concrete is exposed to fire, not only at concrete surface but also at inside the concrete to adjust the equilibrium and transfer properties of moisture. The equilibrium properties of moisture are described by means of water vapor sorption isotherms, which illustrate the hysteretical behavior of materials. In this paper, the prediction method of the moisture distribution inside the concrete members at fire is presented. Finite element method is employed to facilitate the moisture diffusion analysis for any position of member. And the moisture diffusivity model of high strength concrete by high temperature is proposed. To demonstrate the validity of this numerical procedure, the prediction by the proposed algorithm is compared with the test result of other researcher. The proposed algorithm shows a good agreement with the experimental results including the vaporization effect inside the concrete.

Green Growth and Sustainability: The Role of Tourism, Travel and Hospitality Service Industry in Korea

  • Lee, Jung Wan;Kwag, Michael
    • Journal of Distribution Science
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    • v.11 no.7
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    • pp.15-22
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    • 2013
  • Purpose - The study investigates the influence of tourism and hospitality industry on economic growth and CO2 emissions. Research design, data, and methodology - In the empirical analysis, unit root tests, cointegration test and vector error correction model regression using time series data of South Korea from the first quarter of 1970 to the third quarter of 2010 are performed to examine the long-run equilibrium relationship and short-run dynamics among the tourism and hospitality industry, CO2 emissions, economic growth and other industry sectors. Results - Results indicate that a long-run equilibrium relationship exists among these variables. Furthermore, the tourism and hospitality industry and CO2 emissions have high significant positive effect on economic growth. The tourism and hospitality industry in Korea, in turns, shows a high significant positive impact on economic growth while the industry sector incursa high significant negative impact on CO2 emissions. Conclusions - The tourism and hospitality industry in Korea may havebeen prompted by several factors such as accelerated process of technological innovation or energy and environmental policies. These findings suggest that the effectively managed tourism and hospitality sector in Korea has resulted in both economic growth and a reduction in CO2 emissions.

Change in rheological properties of radish during salting (염 절임동안에 일어나는 무조직의 유변학적인 변화)

  • Kim, Byung-Yong;Cho, Jae-Sun
    • Applied Biological Chemistry
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    • v.35 no.5
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    • pp.399-403
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    • 1992
  • The amounts of salt diffused into radish after immersing in various concentrations of salt solution at different temperatures were measured and the changes of radish texture by the salt diffusion were estimatedwith the viscoelastic constants of a 3 element solid model determined by a stress relaxation test. While the amount of salt diffused throught radish was increased with increasing the salt concentration and soaking temperature, the istantaneous stress, equilibrium elastic solid and viscoelastic constants of radish were decreased. Also the degree of stress relaxation and equilibrium elastic solid approached the same or zero values, as salt concentration was further increased. Viscoelstic constants as well as salt diffusion were more influenced by lower salt concentration with increased temperatures.

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Long-run Equilibrium Relationship Between Financial Intermediation and Economic Growth: Empirical Evidence from Philippines

  • MONSURA, Melcah Pascua;VILLARUZ, Roselyn Mostoles
    • The Journal of Asian Finance, Economics and Business
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    • v.8 no.5
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    • pp.21-27
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    • 2021
  • The financial sector is one of the most important building blocks of the economy. When this sector efficiently implemented a well-crafted program on banking and financial system to translate financial activities to income-generating activity, economic growth will be realized. Hence, this study analyzed the effect of financial intermediation on economic growth and the existence of cointegrating relationship using time-series data from 1986 to 2015. The influence of financial intermediation in terms of bank credit to bank deposit ratio, private credit, and stock market capitalization and time trend to economic growth was estimated using ordinary least squares (OLS) multiple regression. The results showed that all the financial intermediation indicators and time trend exert significant effect on Gross Domestic Product (GDP) per capita. The positive sign of the time trend indicates that there is an upward trend in GDP per capita averaging approximately 0.06 percent annually. Furthermore, the cointegration test using the Johansen procedure revealed that there is a presence of long-term equilibrium relationship between financial intermediation and time trend and economic growth, and rules out spurious regression results. This study established the idea that financial intermediation in the Philippines has a significant and vital role in stimulating growth in the economy.

Wind field simulation over complex terrain under different inflow wind directions

  • Huang, Wenfeng;Zhang, Xibin
    • Wind and Structures
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    • v.28 no.4
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    • pp.239-253
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    • 2019
  • Accurate numericalsimulation of wind field over complex terrain is an important prerequisite for wind resource assessment. In this study, numerical simulation of wind field over complex terrain was further carried out by taking the complex terrain around Siu Ho Wan station in Hong Kong as an example. By artificially expanding the original digital model data, Gambit and ICEM CFD software were used to create high-precision complex terrain model with high-quality meshing. The equilibrium atmospheric boundary layer simulation based on RANS turbulence model was carried out in a flat terrain domain, and the approximate inflow boundary conditions for the wind field simulation over complex terrain were established. Based on this, numerical simulations of wind field over complex terrain under different inflow wind directions were carried out. The numerical results were compared with the wind tunnel test and field measurement data for land and sea fetches. The results show that the numerical results are in good agreement with the wind tunnel data and the field measurement data which can verify the accuracy and reliability of the numerical simulation. The near ground wind field over complex terrain is complex and affected obviously by the terrain, and the wind field characteristics should be fully understood by numerical simulation when carrying out engineering application on it.

Comparing Resistances to Pitting Corrosion of Additive Manufactured Ti-6Al-4V Alloys in NaCl and NaBr Aqueous Solutions (NaCl과 NaBr수용액에서 적층가공으로 제조된 Ti-6Al-4V 합금의 공식 저항성 비교)

  • Seo, Dong-Il;Lee, Jae-Bong
    • Corrosion Science and Technology
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    • v.18 no.3
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    • pp.110-116
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    • 2019
  • Resistances to pitting corrosion of additive manufactured (AM) Ti-6Al-4V alloys in 0.6 M NaBr and 0.6 M NaCl aqueous solutions were compared using micro-droplet cell techniques. With respect to the pitting corrosion resistance, this study focused on two different types of halide anions in aqueous solutions, i.e. $Br^-$ and $Cl^-$. The differences between $Br^-$ and $Cl^-$ halide anions for breakdown on passive films of AM Ti-6Al-4V alloy were explained using Langmuir adsorption model with their equilibrium adsorption coefficients. The results of the analysis showed that the lower resistance to pitting potential of AM Ti-6Al-4V alloy in $Br^-$ aqueous solution was attributed to the higher equilibrium adsorption coefficient of Br-. In addition, micro-electrochemical test results showed that the pitting corrosion resistance of dark grains in additive manufactured Ti-6Al-4V alloy was lower as compared to that of bright grains due to the larger volume of ${\alpha}^{\prime}$ phase that caused the susceptibility to pit initiation.

Econometric Analysis of the Determinants of Real Effective Exchange Rate in the Emerging ASEAN Countries

  • RAKSONG, Saranya;SOMBATTHIRA, Benchamaphorn
    • The Journal of Asian Finance, Economics and Business
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    • v.8 no.3
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    • pp.731-740
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    • 2021
  • This research aims to investigate the determinants of real effective exchange rate in emerging ASEAN countries, including Indonesia, Malaysia, Philippines, Thailand, and Vietnam. The research was conducted by using quarterly time series data set from 1980Q1 to 2020Q3. Cointegration and the error correction model (ECM) methods were applied to test the long run and short run relationship of the real effective exchange rate and its determinants. The results indicate that the ratio of foreign direct investment to GDP and the government spending have significantly positive impact on real effective exchange rate in the Emerging ASEAN countries. The trade opening had influencing real effective exchange rate in most the Emerging ASEAN countries, except Vietnam. In addition, the international reserve (INR) had significant long-run impacts variables on real effective exchange rate in Malaysia, Thailand and Vietnam. In the short run equilibrium, the error collection term suggest that Indonesia and Malaysia are the fastest speed adjustment to equilibrium. In addition, the term of trade influence the real effective exchange rate in Indonesia, Malaysia, and the Philippines but it is not in Thailand and Vietnam. However, FDI is a major factor of the real effective exchange rate in Vietnam, but not for other countries.

Mid-Temperature Operation Characteristics of Commercial Reforming Catalysts: Comparison of Ru-Based and Ni-Based Catalyst (상용 개질촉매의 중온 영역 운전 특성: Ru 촉매와 Ni 촉매 비교)

  • KIM, YOUNGSANG;LEE, KANGHUN;LEE, DONGKEUN;LEE, YOUNGDUK;AHN, KOOKYOUNG
    • Transactions of the Korean hydrogen and new energy society
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    • v.32 no.3
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    • pp.149-155
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    • 2021
  • Most of the reformer experiments have been conducted only in high-temperature operation conditions above 700℃. However, to design high efficiency solid oxide fuel cell, it is necessary to test actual reaction performance in mid-temperature (550℃) operation areas. In order to study the operation characteristics and performance of commercial reforming catalysts, a reforming performance experiment was conducted on mid-temperature. The catalysts used in this study are Ni-based FCR-4 and Ru-based RuA, RuAL. Experiments were conducted with a Steam-to-carbon ratio of 2.0 to 3.0 under gas hourly space velocity (GHSV) 2,000 to 5,000 hr-1. As a result, RuA and RuAL catalysts showed similar gas composition to the equilibrium regardless of the reforming temperature. However, the FCR-4 catalyst showed a lower hydrogen yield compared to the equilibrium under high GHSV conditions.