• 제목/요약/키워드: Exchange times

검색결과 814건 처리시간 0.023초

방탄소재 활용을 위한 SLS 유리의 이온교환 효과 (Effect of SLS Glass for Bulletproof Materials by Ion Exchange Technique)

  • 김태윤;심규인;최세영
    • 한국군사과학기술학회지
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    • 제13권1호
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    • pp.114-119
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    • 2010
  • There are a number of studies on chemically strengthened glass. Most of them are strengthened in molten salt bath below transformation range of glass. This research is distinguished from the aforementioned studies in that single $KNO_3$ powder was used by employing screen printing technique. In this study soda-lime-silicate(SLS) glasses for bulletproof glass application with various thicknesses were used. The maximum value of the bending strength is 791MPa heat treated at $480^{\circ}C$, which is about 4.3 times higher than the parent glass, which is the highest strength of all soda-lime glasses. In this study, it is also observed that Vickers hardness increased to $657H_v$, which is about 15% higher than the parent glass($568.7H_v$) and fracture toughness was not changed. Depth profiles measured by electron probe micro analyzer(EPMA) showed a correlation between the migrations of $K^+$ ions with bending strength of ion exchanged glasses.

Comparison of CDI and MCDI applied with sulfonated and aminated polysulfone polymers

  • Kim, Ji Sun;Rhim, Ji Won
    • Membrane and Water Treatment
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    • 제7권1호
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    • pp.39-53
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    • 2016
  • In this study, polysufone (PSf) was used as a base polymer to synthesize sulfonated polysulfone (SPSf) and aminated polysulfone (APSf) as cation and anion exchange polymers, respectively. Then the ion exchange polymers were coated onto the surface of commercial carbon electrodes. To compare the capacitive deionization (CDI) and membrane capacitive deionization (MCDI) processes, the pristine carbon electrodes and ionic polymer coated electrodes were tested under various operating conditions such as feed flow rate, adsorption time at fixed desorption time, and feed concentration, etc., in terms of effluent concentration and salt removal efficiency. The MCDI was confirmed to be superior to the CDI process. The performance of MCDI was 2-3 times higher than that of CDI. In particular, the reverse desorption potential was a lot better than zero potential. Typically, the salt removal efficiency 100% for 100 mg/L NaCl was obtained for MCDI at feed flow rate of 15 ml/min and adsorption/desorption time of 3 min/1 min and applied voltages 1.0 V for adsorption and -0.3 V for desorption process, and for 500 mg/L, the salt removal efficiency 91% was observed.

고려 대외교류국의 고분벽화에 나타난 차구(茶具) (Tea Utensils Represented on the Tomb Mural Paintings of Foreign Exchange Countries with Koryo Dynasty)

  • 고경희
    • 한국식생활문화학회지
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    • 제30권6호
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    • pp.736-749
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    • 2015
  • The present study addresses the tea utensils and tea drinking methods seen in tomb mural paintings of Song, Liao, Jin, and Yuan, which were Koryo's foreign exchange countries. The paintings illustrate the pointing tea method, which was popular during dynasty times. Tea utensils observed in the paintings include a tea mill, mill stone, and tea pestle necessary for making cake tea into powder. The tea stove and boiling bottle are depicted as being required to boil water. Some mural works vividly depict how a tea drinker pours hot water from a boiling bottle into a cup with a stand, mixes it with a tea spoon, and whisks tea powder for foaming with a tea whisk. The tea drinking method of the Southern race Han is also similarly described in the tomb mural paintings of Liao, Jin, and Yuan from Northern nomads. The distribution of tea culture had an enormous influence on the development of tea utensil manufacturing methods. The significance of this study is that these findings can be used as basic data to provide food culture insights into Koryo celadon tea utensils.

평등전계에서 도전성 구형 입자의 운동 (Motion of Conductive Spherical Particle under Uniform Electric Field)

  • 임헌찬
    • 조명전기설비학회논문지
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    • 제25권8호
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    • pp.39-47
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    • 2011
  • The motion of a conductive spherical particle under uniform electric field is investigated in order to find a suitable method for removing the conducting solid impurities contained in liquid plastic. When the positive dc voltage applied to the upper electrode, the vertical up-and-down motion of a charged particle by electrostatic force is observed by a charge-coupled device (CCD) camera or a high-speed video camera. The experimental data of the static threshold voltage by which the particle starts to move toward the counter electrode in air or silicone oil are in good agreement with theoretical value. When the applied voltage is larger than the static threshold voltage, the particle motion pattern in silicone oil consists of four stages: upward motion, stopping at the upper electrode, downward motion and stopping at the lower electrode. The stopping motion on the electrode is thought to be caused by the liquid flow accompanied by the particle motion. The particle charge calculated by integrating the pulse current, which is generated by the charge exchange between the electrode and the particle, is approximately 0.1~0.25 times of the theoretical value. This study is expected to help understand the electric properties of microparticles in oil circuit breaker (OCB) and oil transformer and improve their performance and longevity.

조선 전기 중국 서적의 사입(賜入)과 구입 - 『조선왕조실록(朝鮮王朝實錄)』의 수록 내용을 중심으로 (The Offers and Purchases of Chinese Books during the Early Chosun Dynasty: Focusing on the Contents of The Annals of The Chosun Dynasty)

  • 서원남;이소연
    • 비교문화연구
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    • 제19권
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    • pp.79-99
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    • 2010
  • The purpose of this study is to compare the books exchange between china and Joseon dynasty. Books, ancient and modern are an essential part to publish, propagate, administer the books which is a matter of grave concern among nations. Also they are the most important information and the symbol of the government power. As a result the rulers had brought many necessary books from China and it is a national policy to govern in Joson dynasty. This study will discuss the introduction of chinese books from the Annals of the Joson Dynasty, especially from the first king of the Joson Dynasty, Yi Seong-gye to the ninth king. At that times, Joson Dynasty had attempted to reign various policies. So many books related with the absolute authority of China. In accordance with the book classification method in ancient china, they are have been categorized. Furthermore, it should have been a important clue to check the influence by being brought many books from China.

The Role of Central Bank Rate on Credit Gap in Indonesia: A Smooth Transition Regression Approach

  • SUHENDRA, Indra;ANWAR, Cep Jandi
    • The Journal of Asian Finance, Economics and Business
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    • 제8권1호
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    • pp.833-840
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    • 2021
  • This paper examines the effect of the interest rate set by Bank Indonesia on financial system stability as measured by the credit gap in Indonesia for quarterly data for the period 1976 Q1 to 2019 Q4. We suppose that the relationship between the Central Bank rate and the credit gap is non-linear. Hence, this study applies a smooth transition regression (STR) model to investigate the relationship between these variables. Our results are: first, by performing STR estimation we obtained a threshold level of Central Bank rate of 2.01. Second, a decrease in the Central Bank rate results in a reduction in the credit gap when the Central Bank rate is above or below the threshold level. The effect of the Central Bank rate is five times greater for the high regime than for the low regime. Third, we find evidence that the effect of the exchange rate, economic growth, inflation, and GDP per capita on the credit gap for the high regime is the opposite of the low regime. We suggest that policymakers need to keep the Central Bank interest rate low and stable so that the role of the bank as a financial intermediary remains stable and conducive to strengthening financial stability.

The Effect of Non-Oil Diversification on Stock Market Performance: The Role of FDI and Oil Price in the United Arab Emirates

  • BANERJEE, Rachna;MAJUMDAR, Sudipa
    • The Journal of Asian Finance, Economics and Business
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    • 제8권4호
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    • pp.1-9
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    • 2021
  • UAE has rapidly developed into one of the leading global financial hubs, with significant transformations in its stock exchanges. In its attempt at economic diversification in the last two decades, the country has also taken a lead in the GCC region in introducing extensive reforms to attract FDI to the Emirates. However, oil price volatilities have posed a significant challenge to all oil-exporting countries. The main aim of this study is to explore the impact of economic diversification and oil price on the UAE stock market. The study applies Granger Causality and Vector Autoregressive Model on monthly Abu Dhabi stock exchange index, Dubai Fateh crude oil spot price, and FDI inflows during 2001-19. The short-term interbank rate has been included as a monetary policy variable. The results show a substantial difference between the two phases of reforms. Oil price and Abu Dhabi stock index show bidirectional relationship during 2001-09 but no causality was found during 2010-19. Furthermore, the second phase was characterized by unidirectional causation from FDI to ADX index. This study highlights FDI inflows as a key driver of stock market performance during the last decade and emphasizes the success of the intense reforms in the UAE initiated for the diversification of its economy.

An Investigation into the Historical Context of a Kimono and Its Sartorial Relevance in Western Societies in 2022

  • Elizabeth J, Burton
    • 패션비즈니스
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    • 제26권6호
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    • pp.14-31
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    • 2022
  • Worn by both males and females the kimono is the national dress of Japan. Previous research highlights that this national dress is fading from tradition and evolves to develop with the times and fashion trends. This research aims to investigate what a kimono represents both historically and currently within Western society. The idea of the kimono being more than a national dress representing Japan, the main three themes researched will be (1) Shape (2) Narrative (3) Journey from East to West. Based on both primary and secondary sources this research indicates that there is a strong relationship between the universal increase of kimono wearers in Eastern and Western societies from history through to present day. Primary research is utilised in the form of two types of interviews. Primary outcomes bring a personal perspective to how and why kimono is worn nowadays within Europe. Secondary sources include online lectures held by kimono specialists as well as subject relevant books. From the 19th century where the Dutch were the only European country to trade with Japan, an exchange of fabrics took place which later led to the exchange of: fit, fashion and pattern (primarily within Western womenswear fashion.) This distinct garment never gets discontinued and evolves with social demands within society today.

[CoFe/Pt/CoFe]/IrMn 다층박막의 수직자기 이방성 각도에 따른 상호교환결합력 특성 (Anisotropy Angle Dependence of Interlayer Exchange Coupling of Perpendicular Magnetic [CoFe/Pt/CoFe]/IrMn Multilayers)

  • 이상석;최종구;황도근;이장로
    • 한국자기학회지
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    • 제18권6호
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    • pp.232-236
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    • 2008
  • [CoFe/Pt/CoFe]/IrMn 다층박막에 대하여 반강자성체 IrMn층 두께 의존성 및 열적안정성, 수평으로 전환하는 각도에 의존하는 수직자기 이방성 특성을 관찰하였다. IrMn층을 통해 유도된 강자성체/비자성체/강자성체 구조인 [CoFe($10{\AA}$)/Pt($8{\AA}$)/CoFe($10{\AA}$)]/IrMn 다층박막은 IrMn 두께 $7{\AA}$부터 상호교환결합력이 형성되었고, 열처리 온도 $250^{\circ}C$까지 열적안정성을 유지하였다. 수직자기 이방성 [CoFe/Pt/CoFe]/IrMn 다층박막에서 바닥 CoFe층과 Pt층을 사이에 두고 반강자성체인 IrMn층에 의해 고정되어 있는 상부 CoFe층간의 상호교환결합력은 이방성 측정 각도가 $0^{\circ}$, $60^{\circ}$일 때 각각 1,000 Oe, 1,500 Oe로, $90^{\circ}$일 때 $\infty$ Oe로 나타났다.

국립공원 타당성검토에 따른 공원재계획 평가 - 한려해상국립공원 구역조정을 중심으로 - (Evaluation of Park Re-planning by Feasibility Study in Korea National Parks - Focusing on Area Adjustment of Hallyeohaesang National Park -)

  • 조우
    • 한국환경생태학회지
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    • 제38권1호
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    • pp.79-89
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    • 2024
  • 본 연구는 국립공원계획 타당성검토의 구역조정 기준과 방법을 한려해상국립공원에 적용하여 평가 하는 것을 목적으로 하였다. 구역조정 대상지 도출에 이용되는 생태기반평가 결과 편입 검토가 가능한 생태기반평가 I등급은 10.0%, II등급 40.4%로 분석되었다. 해제 검토가 가능한 V등급은 9.9%이었다. 편입 및 해제 적합성 평가 결과 편입대상 면적은 35.150km2(육상 3.669km2, 해상 31.481km2)이었고 해제 대상 면적은 육상 0.071km2이었다. 지자체와 지역주민이 공익상 또는 주민편의를 위해 공원구역 해제를 요구하는 곳에서는 총 면적이 변화되지 않는 범위 내에서 해제 검토가 가능하며, 이것을 상호교환이라 한다. 상호교환에 의해 결정된 해제 면적은 10.386km2이었다. 이것은 해제 적합성 평가에 의해 도출된 면적의 146배에 달했다. 상호교환으로 해제되는 지역을 생태기반평가와 매칭한 결과 해제를 절대 할 수 없는 I,II등급에 해당하는 곳이 70.6%(7.321km2) 이었다. 결과적으로 한려해상국립공원 타당성검토의 구역조정은 생태기반평가나 해제 적합성 평가 결과가 매우 제한적으로 적용되었음을 알 수 있었다. 또한 상호교환이 국립공원 계획 타당성검토 중 구역조정의 핵심이었다.