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A research on Hyang-Yack-Ku-Keup-Bang(鄕藥救急方) (Restoration and Medico-Historic Investigation) (향약구급방(鄕藥救急方)에 대(對)한 고증(考證))

  • Sheen, Yeong-Il
    • Korean Journal of Oriental Medicine
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    • v.2 no.1
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    • pp.71-83
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    • 1996
  • Hyang-Yack-Ku-Keup-Bang(鄕藥救急方) is our own, medical work written about the middle of the time of Korea Dynasty. I restored and researched this book because it needed to be illuminated about its medico-historic value and then I came to some conclusions as follows. 1. Hyang-Yack-Ku-Keup-Bang was published in Dae-jang-do-kam(大藏都監) of Kanghaw island(江華島) about the middle of Korea Dynasty. Choi Ja-ha(崔自河) republished it on original publication ground in Euiheung(義興) of Kyungsang-Province(慶尙道) in July, Taejong's(太宗) 17th year of Chosen Dynasty (A.D.1417) and this book was published again in Chungcheng Province(忠淸道) in Sejong's(世宗) 9th year(A.D.1427). The book published in Taejong's days was in the possession of books department of Kung-nae-cheng(宮內廳) in Japan and was the oldest medical book of existing ones. 2. Bang-Jung-Hyang-Yack-Mock-Cho-Bu(方中鄕藥目草部) of this book was originally intended to be adjusted in each division with the title of Bang-Jung-Hyang-Yack-Mock(方中鄕藥目). But Herb part(草部) only followed editing progress of Jeung-Lew-Bon-Cho(證類本草), the rest is not divided into each part and is together arranged at the below of Herb part with the title of Bang-Jung-Hyang-Yack-Mock-Cho-Bu. The Korean inscriptions on some drugstuffs in this book are different between Native Name(鄕名) of three volumes of provisions and general-spoken(俗云) of Bang-Jung-Hyang-Yack-Mock-Cho-Bu. In this, it is estimated that the publishing time and editor of tile volume of provisions and Bang-Jung-Hyang-Yack-Mock-Cho-Bu are different. I think Choi Ja-ha compiled this behind three volumes of provisions when he published. 3. This book picked some prescriptions which consisted of obtainable drugs with ease in Korea in the books of Chell-Keum-Yo-Bang(千金要方), Oi-Dae-Bi-Yo(外臺秘要), Tae-Peong-Sung-Hye-Bang(太平聖惠方), Ju-Hu-Bang(?後方), Kyung-Hum-Yang- Bang(經驗良方) Bo-Je-Bon-Sa-Bang(普濟本事方) Bi-Ye-Baik-Yo-Bang(備預百要方) and so on and got together our own prescriptions. On the whole Bi-Ye-Baik-Yo-Bang was a chief referrence book, On this, other books referred to and corrected. 4. In provisions quoted from Hyang-Yack-Jip-Sung-Bang(鄕藥集成方), there are seven provisions; leg-paralysis part, coughing part, headache part, obstetrics part, etc. don't show in this book. This is why Choi Ja-ha published only certain texts on Dae-jang-do-kam edition his own posession. So we can think the existing edition has a little misses compared with original edition. 5. This book recorded only names of drugstuffs in animal drug department like fowls, crab, goldbug, earthworm, etc. and didn't tell us ways of taking those. This is effect of Buddhist culture on medicine. This is efforts to practice 'Don't murder';one of Five Prohibition of Buddhism. 6. Beacause this book was published at the time, when our originative medicine would be set forth. This followed the Chinese ways in Theory, Treatment, Prescription and used 'Hyang Yack' in Medication out of theory of Korean medicine, which was a transitional form. So this is all important material which tell us aspects of development of 'Hyang Yack' the middle of Korea Dynasty.and this is also the beginning of originative, medical works like Dong-Eui-Bo-Kam(東醫寶鑑), Dong-Eui-Su-Bo-Won(東醫壽世保元). 7. There are few contents based on 'Byen-Jeung-Lon-Chi(辨證論治)'in this book. So we can see this book is not for doctors who study medical thoughts but for general public who suffer from diseases resulted from war. Because this book was written for a first-aid treatmeant, this is an index of medical service for the people those days. And this is also an useful datum for first-aid medicine or military medicine in these modern days. 8. Nowadays, parts of learned world of Korean medicine disregard essential theories and want to explain Korean medicine only by the theories or the methods of Western medicine. Moreover they don't adopt Chinese and Japanese theorys & thoughts about Oriental medicine in our own style and just view in there level. What was worse, there is a growing tendency for them to indulge in a trimming policy of scholarship and to take others' ideas. I think these trends to ignore our own medical thoughts involving growth of 'Hyang Yack' in the middle of Korea Dynasty, Dong-Eui-Bo-Kam and Dong-Eui-Su-Se-Bo-Won. So we, as researchers of Korean medicine, must get out of this tendency, and take over brilliant tradition and try to develop originative Korean medicine.

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Berating on the Historical view in Korea dynasty's Medicine (1) (고려시대(高麗時代) 의학사관(醫學史觀) 질정(叱正)(1) - 고려초기(高麗初期) 의학(醫學)에 관한 김두종(金斗鍾)의 역사인식에 대한 비판 -)

  • Kim, Hong-Kyoon
    • Korean Journal of Oriental Medicine
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    • v.9 no.1
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    • pp.1-33
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    • 2003
  • From the study on Doo-Jong Kims view of history about the early Korea$(Korea\;herewith\;stands\;for\;Korea\;dynasty\;A.D.918{\sim}1392)s$ Medicine, I came to a conclusion as follows. 1. Doo-Jong Kim is stressing on the fact that Early Koreas Medicine inherited from Shilla dynasty and seemingly expressing the pride of national medical science. But actually he distorted the Koreas independent growth with flunkeyism and insisted that Koreas medicine only took over Shilla dynastys which based on Chinese Tang dynastys medical science. As a result, Koreas medicine was blurred and evaluated as nothing but Tangs medicine. But, the reasons of Doo-Jong Kims viewpoints were not based on the fact, but on his speculation. 2. About the medical system, Doo-Jong Kim viewed that Korea copied Chinese Soo & Tangs medical system, But the fact is that Korea only borrowed a part of Chinese medical systems name, for examples, Tae-I-Gam, Sang-Yak-Kook, Sang-Sik-Kook, etc., and its actual functions were different and grew in Koreas own way, As a result, the titles or roles in the system were very different from those of Chinas. Especially, Korea saw much development in Science of Acupuncture and Moxibustion that there was a specialist on Acupuncture, called I-Chim-Sa, and even had much influences on Chinese Acupuncture and Moxibustions growth, exporting Hwang-Je-Ne-Kyong to Chinese Song dynasty. 3. About the education system of medicine, Doo-Jong Kim viewed that Koreas medicine was only a copy of Shilla dynastys which was based on Chinese Tang dynastys, taking the medical examination curriculum as an example. The fact is that Tangs medical curriculum was three, Bon-Cho, Kab-Ul, Maek-Kyong, Shilla had seven, Bon-Cho-Kyong, Kab-Ul-Kyong, So-Moon-Kyong, Chim-Kyong, Maek-Kyong, Myong-Dang-Kyong, Nan-Kyong, and Korea had ten, So-Moon-Kyong, Kab-Ul-Kyong, Bon-Cho-Kyong, Myong-Dang-Kyong, Maek-Kyong, Dae-Kyong-Chim-Kyong, Nan-Kyong, Ku-Kyong, Ryu-Yon-Ja-Bang, So-Kyong-Chang-Jeo-Ron. Simply considering this, it is so clear that Koreas medical curriculum was much more upgraded one than that of China. 4. About the examination system for civil service, Doo-Jong Kim expressed that Shilla dynasty did not have such system, and only expounded knowledge of Shilla medicine, In case of China, Tang danasty Hyang-Kong was only a qualification test for civil service, which the result was completely dependent on applicants social status, Song danasty examination system was composed of three steps of Hyang-Si, Sung-Si, Jeon-Si (See Note1), but it stuck to formality by having Jeon-Si of anti-fraudulence use. On the other hand, examination system for civil service in Korea dynasty started in 958 by an advice of Ssang-Ki, Chin-Si in 977 and K대-Ja-Si (See Note 1), a kind of Hyang-Si, in 1024., Three steps of examination system made employment for civil service strictly fair, Moreover, it was possible for offsprings of concubine to be an applicant. These easily explain that the examination system of Korea dynasty was more upgraded one than that of China, Tang & Song dynasty. Hyang-Si : Exam in local area Sung-Si : Exam in province for those who passed Hyang-Si Jeon-Si : Exam held with Koea Kings supervision for those who passed Hyang-Si Keo-Ja-Si : Selective exam in local area like Hyang-Si. From the reasons above, it is clear that Doo-Jong Kim was much biased by flunkeyism through Japanese colonialisam and expressed his view on Korea Medical History based on such theory of heteronomy and stasis. Moreover, without rigid historical evidence on records, he distored the fact by translating incorrectly on his purpose. Therefore, Doo-Jong Kims Korean Medical History must be reevaluated through rigid historical research and his mistranslation should be corrected.

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A cluster analysis of the audit result on quality management system in architectural design and engineering firms (설계 및 엔지니어링분야의 품질경영시스템 심사결과에 대한 유형분석)

  • Bae Dae-kwon;Kim Soo-Yoo;Kim Jae-Jun
    • Korean Journal of Construction Engineering and Management
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    • v.6 no.2 s.24
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    • pp.120-128
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    • 2005
  • ISO 9001, the quality management system issued by the International Organization for Standardization, is being used by architectural design and engineering firms in order to strengthen the capability of business activities through the implementation of the international and advanced quality management systems. However, there have been significant problems in stable implementation and settlement of ISO 9001 in construction industry, which seem to be caused by key employees' lack of proper recognition and comprehension. The purpose of this research, accordingly, is to find and analyze nonconformity results which were found when the third party registrars audited the conformity of companies' quality management systems for ISO 9001 certification especially in architectural design and engineering firms. For this purpose this research was conducted by a cluster analysis of 647 audit reports out of representative 15 architectural design and engineering firms that have been audited periodically from 1997 to 2003 by the third party registrars. The analysis showed that the most frequent problems were generated in the areas of $\ulcorner$Design and Development$\lrcorner$ , $\ulcorner$production and Service Provision$\lrcorner$ , and $\ulcorner$General requirements$\lrcorner$ of the quality management system. The following, the areas of $\ulcorner$Monitoring and Measurement$\lrcorner$ and $\ulcorner$purchasing$\lrcorner$ were also analyzed as main factors which caused frequent nonconformity results. This research also shows that the corrective actions for nonconformity results are closely connected with the whole management activities in architectural design and engineering firms. Consequently, corrective actions for disposition of nonconformities should be implemented more specifically in order to settle and activate the quality management systems in architectural design and engineering firms.

TACT Productivity Management for Finish Works of Residential Buildings using Productivity Achievement Ratio (PAR) (공동주택 마감공사 TACT 기법 생산성 관리 - Productivity Achievement Ratio를 활용한 생산성 관리 -)

  • Joo, Seonu;Park, Moonseo;Lee, Hyun-Soo;Lee, Kwang-Pyo
    • Korean Journal of Construction Engineering and Management
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    • v.16 no.3
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    • pp.36-48
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    • 2015
  • To complete various types of finish works with higher quality in much less time, TACT, which was mostly used for high-rise buildings, has been adapted to meet the needs for systematic schedule management in construction sites. However, the effectiveness of adapting TACT has not been shown as expected due to the different perspectives on productivity from both general contractor and subcontractors based on unforeseen conditions according to the types of site. Furthermore, not enough theoretical backgrounds, empirical data, and systematic approaches to solve the fundamental problems caused by each participants' different views on productivity has produced obstacles for establishing effective solutions. Therefore, this research aims to analyze the possible main reasons for having different point of views regarding productivity among various participants of residential building sites using TACT based on literature review, site survey, and interviews. Also, case study was conducted to propose obtainable productivity (OP) regression equation and productivity achievement ratio (PAR) with reduction factors (RFs) and actual productivity (AP) data from an actual construction site. The proposed outcome may assist general contractors converting output management with PPC to productivity management with actual data using PAR. On the other hand, subcontractors would be able to estimate theory-based maximum productivity of construction sites with TACT by using OP. The PAR will enhance the communication between general and sub-contractors for their decision making process. Finally, the main RFs derived from PAR could be used as essential keys for productivity management to increase the economical and operational effectiveness of the construction project.

Trend in Research and Application of Hard Carbon-based Thin Films (탄소계 경질 박막의 연구 및 산업 적용 동향)

  • Lee, Gyeong-Hwang;Park, Jong-Won;Yang, Ji-Hun;Jeong, Jae-In
    • Proceedings of the Korean Institute of Surface Engineering Conference
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    • 2009.05a
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    • pp.111-112
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    • 2009
  • Diamond-like carbon (DLC) is a convenient term to indicate the compositions of the various forms of amorphous carbon (a-C), tetrahedral amorphous carbon (ta-C), hydrogenated amorphous carbon and tetrahedral amorphous carbon (a-C:H and ta-C:H). The a-C film with disordered graphitic ordering, such as soot, chars, glassy carbon, and evaporated a-C, is shown in the lower left hand corner. If the fraction of sp3 bonding reaches a high degree, such an a-C is denoted as tetrahedral amorphous carbon (ta-C), in order to distinguish it from sp2 a-C [2]. Two hydrocarbon polymers, that is, polyethylene (CH2)n and polyacetylene (CH)n, define the limits of the triangle in the right hand corner beyond which interconnecting C-C networks do not form, and only strait-chain molecules are formed. The DLC films, i.e. a-C, ta-C, a-C:H and ta-C:H, have some extreme properties similar to diamond, such as hardness, elastic modulus and chemical inertness. These films are great advantages for many applications. One of the most important applications of the carbon-based films is the coating for magnetic hard disk recording. The second successful application is wear protective and antireflective films for IR windows. The third application is wear protection of bearings and sliding friction parts. The fourth is precision gages for the automotive industry. Recently, exciting ongoing study [1] tries to deposit a carbon-based protective film on engine parts (e.g. engine cylinders and pistons) taking into account not only low friction and wear, but also self lubricating properties. Reduction of the oil consumption is expected. Currently, for an additional application field, the carbon-based films are extensively studied as excellent candidates for biocompatible films on biomedical implants. The carbon-based films consist of carbon, hydrogen and nitrogen, which are biologically harmless as well as the main elements of human body. Some in vitro and limited in vivo studies on the biological effects of carbon-based films have been studied [$2{\sim}5$].The carbon-based films have great potentials in many fields. However, a few technological issues for carbon-based film are still needed to be studied to improve the applicability. Aisenberg and Chabot [3] firstly prepared an amorphous carbon film on substrates remained at room temperature using a beam of carbon ions produced using argon plasma. Spencer et al. [4] had subsequently developed this field. Many deposition techniques for DLC films have been developed to increase the fraction of sp3 bonding in the films. The a-C films have been prepared by a variety of deposition methods such as ion plating, DC or RF sputtering, RF or DC plasma enhanced chemical vapor deposition (PECVD), electron cyclotron resonance chemical vapor deposition (ECR-CVD), ion implantation, ablation, pulsed laser deposition and cathodic arc deposition, from a variety of carbon target or gaseous sources materials [5]. Sputtering is the most common deposition method for a-C film. Deposited films by these plasma methods, such as plasma enhanced chemical vapor deposition (PECVD) [6], are ranged into the interior of the triangle. Application fields of DLC films investigated from papers. Many papers purposed to apply for tribology due to the carbon-based films of low friction and wear resistance. Figure 1 shows the percentage of DLC research interest for application field. The biggest portion is tribology field. It is occupied 57%. Second, biomedical field hold 14%. Nowadays, biomedical field is took notice in many countries and significantly increased the research papers. DLC films actually applied to many industries in 2005 as shown figure 2. The most applied fields are mold and machinery industries. It took over 50%. The automobile industry is more and more increase application parts. In the near future, automobile industry is expected a big market for DLC coating. Figure 1 Research interests of carbon-based filmsFigure 2 Demand ratio of DLC coating for industry in 2005. In this presentation, I will introduce a trend of carbon-based coating research and applications.

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Oxide Films Formed on Hot-Dip Aluminized Steel by Plasma Electrolytic Oxidation and Their Films Growth Stages (플라즈마 전해 산화법에 의해 용융알루미늄도금 강판 상 형성한 산화층과 그 성장 과정)

  • Choe, In-Hye;Kim, Chang-Min;Park, Jun-Mu;Park, Jae-Hyeok;Hwang, Seong-Hwa;Lee, Myeong-Hun
    • Proceedings of the Korean Institute of Surface Engineering Conference
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    • 2017.05a
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    • pp.165-165
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    • 2017
  • 지난 수 십 년 동안, 전 세계적으로 자원의 소비가 급격히 증가하게 되면서 최근 자원 고갈은 물론 환경오염이 커다란 이슈로 문제가 되고 있다. 이에 따라 재료 관련 분야에 있어서는 보다 효율적이고 친환경적인 방법으로 자원을 활용해야 된다는 필요성이 대두되었고 이와 같은 관점에서 목적하는 성분이 우수하고 환경 친화적인 표면처리 재료 개발연구가 활발하게 진행되고 있는 실정이다. 그 중 플라즈마 전해 산화(Plasma Electrolytic Oxidation, PEO)는 알루미늄, 마그네슘 등의 경금속의 경도를 향상시키고 높은 내마모성, 내식성을 갖게 하는 표면처리로써 그 관심이 증가하고 있다. 이 플라즈마 전해 산화는 일반적으로 공정비용 대비 효과적이고 환경 친화적이며 코팅 성능 면에서 우수하다고 알려져 있다. 이러한 고유한 특성으로 인해 플라즈마 전해 산화 코팅은 최근 몇 년 동안 기계, 자동차, 우주항공, 의학 및 전기 산업 등의 분야에서 그 적용이 점차 증가하고 있는 상황이다. 한편, 플라즈마 전해 산화 코팅을 하는 모재들의 경우 부동태 산화피막을 용이하게 형성할 수 있는 특성의 모재에 한정되고 있어서 그 응용확대에 한계가 있는 것이 사실이다. 따라서 본 연구에서는 플라즈마 전해 산화법을 사용하여 용융알루미늄도금 강판 상에 산화피막 형성을 시도하였다. 전원공급 장치의 양극은 전해질 속에 잠겨있는 작동전극에 연결하고 음극은 대전극 역할을 하는 스테인레스강 전해질 용기에 연결되었다. 전해질은 Sodium Aluminate 및 기타 첨가제를 함유한 것을 사용하였고 온도는 열교환기를 사용하여 $30^{\circ}C$ 이하로 유지되었다. 또한 여기서 전류밀도는 $5{\sim}10A/dm^2$, 실험 주파수는 700Hz, Duty cycle은 30 및 90%의 각 조건에서 공정처리 시간을 각각 30분 및 60분 동안 진행하였다. 이와 같은 조건에서 형성한 막들에 대해서는 주사형전자현미경(SEM)을 이용하여 코팅 막의 표면 및 단면의 모폴로지를 관찰하였음은 물론 EDS 및 XRD 측정을 통하여 원소조성분포 및 결정구조를 각각 분석하였다. 또한 이 코팅 막들에 대한 내식성은 5% 염수분무 환경 중 노출시험(Salt spray test), 3% NaCl 용액에서의 침지 시험 및 전기화학적 동전위 양극분극(Potentiodynamic Polarization) 시험을 진행하여 평가하였다. 이상의 실험결과에 의하면, 제작조건별 플라즈마 전해 산화 코팅 막의 모폴로지 및 결정구조가 상이하게 나타나는 것을 알 수 있었다. 코팅 막의 모폴로지 관찰 결과, 공정 시간에 비례하여 표면에 존재하는 원형 기공의 수는 감소하였으나 그 크기가 커지고 크레이터의 직경 또한 커진 것이 확인되었다. 이 기공은 마이크로 방전에 의해 형성된다고 알려져 있는데 공정 시간이 증가함에 따라 코팅 두께가 점차 증가하여 마이크로 방전의 빈도수가 줄어들고 그 강도는 증가하게 되어 기공 크기가 증가한 것으로 사료된다. 또한 공정시간이 긴 시편에서 표면에 크랙이 다수 존재하는 것으로 확인되었다. 이것은 방전에 의해 고온이 된 소재가 차가운 전해질과 만나게 되어 생긴 큰 온도구배로 인해 강한 열응력이 발생하여 균열을 초래한 것으로 보인다. 조성원소 분석 결과 원형 기공 주변의 크레이터 영역에는 알루미늄이 풍부하였으며 그 주변에 결절상을 갖는 구조에서는 전해질 성분의 원소가 포함되어 있는 것이 확인되었다. 이러한 코팅 막의 표면 특성은 내식성에 영향을 주게 된 원인으로 사료된다. 동전위 분극측정 결과에 의하면 플라즈마 전해 산화 공정 시간이 길어질수록 부식전류밀도가 증가하였다. 이것은 공정시간이 길어짐에 따라 강한 방전이 발생하여 기공의 크기가 증가하고 크랙이 발생하게 되면서 내식성이 저하된 것으로 판단된다. 종합적으로 재료특성 분석 및 내식성 평가를 분석한 결과, 플라즈마 전해 산화의 공정 시간이 너무 길게 되면 오히려 내식성은 저하되는 것이 확인되었다. 이상의 연구를 통하여 고내식 특성을 갖는 플라즈마 전해 산화 막의 유효성을 확인하였으며 용융알루미늄강판 상에 실시한 플라즈마 전해 산화 처리에 대한 기초적인 응용 지침을 제시할 수 있을 것으로 사료된다.

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Quality Improvement of High Volume Fly Ash Concrete due to Early Strength Gain Admixture (조강형 혼화제에 의한 플라이애시 다량 치환 콘크리트의 품질 향상)

  • Han, Cheon-Goo;Park, Jong-Ho;Lee, Joung-Ah
    • Journal of the Korean Recycled Construction Resources Institute
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    • v.4 no.4
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    • pp.117-124
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    • 2009
  • The purpose of the study was to improve quality of high volume fly ash concrete. The study evaluated on the possibility of early quality improvement of high volume fly ash concrete with early strength gain admixture ('GA' below) developed by the preceding research. The study regarded applying naphthalene admixture ('NA' below) to mix proportion substituting FA 15 % to be plain. In the event of substituting FA 20, 25 and 30 %, the study compared engineering properties of concrete with plain by applying GA. Because of features of fresh concrete, fluidity falls down when GA is applied. Therefore, its use amount shall be increased. Only, in W/B 60 %, it was beneficial since slump loss was reduced about 35~70 mm than plain. The study could see that AE use should be increased proportionally since air content was reduced by coming from AE absorption operation of unburned coal content included in FA according to an increase in the amount of FA use. Reduction effect of bleeding could be anticipated since the amount of bleeding appeared at least in FA 20 %. Because of hardened concrete, time of setting appeared in the same level as plain when GA was applied. Therefore, it is judged that delay of setting can be reduced. In compressive strength, the study could check the same strength development as plain when GA was applied, having nothing to do with W/B and curing temperature. However, it is thought that we shall pay attention to GA use in the event of FA 30 % substitution. Freezing and melting resistance had less early value than plain. However, it is judged that there will be no problem of frost resistance since there is no a large difference between freezing and melting resistance and plain in overall. In accelerated neutralization, it was analyzed that a problem of weakening in neutralization appointed as a demerit when FA was applied in mass in proportion with GA use could be settled to some extent.

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Application of PCM Technology to Concrete II : Effects of SSMA(Sulfonated Styrene-Maleic Anhydride) on the Properties of the 1-Dodecanol Micro-Capsule (PCM 기술의 콘크리트 적용 II : 계면중합법에 의한 1-도데카놀 마이크로 캡슐에 있어서 계면활성제로 사용된 SSMA의 표면활성도가 마이크로 캡슐의 특성에 미치는 영향)

  • Shin, Se-Soon;Jung, Jae-Yun;Lim, Myung-Kwan;Choi, Dong-Uk;Kim, Young-Ho
    • Journal of the Korean Recycled Construction Resources Institute
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    • v.1 no.1
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    • pp.17-25
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    • 2013
  • Thermal storage technology used for indoor heating and cooling to maintain a constant temperature for a long period of time has an advantage of raising energy use efficiency. This, the phase changing material, which utilizes heat storage properties of the substances, capsulizes substances that melt at a constant temperature. This is applied to construction materials to block or save energy due to heat storage and heat protection during the process in which substances melt or freeze according to the indoor or outdoor temperature. The micro-encapsulation method is used to create thermal storage from phase changing material. This method can be broadly classified in 3 ways: chemical method, physical and chemical method and physical and mechanical method. In the physical and chemical method, a wet process using the micro-encapsulation process utilized. This process emulsifies the core material in a solvent then coats the monomer polymer on the wall of the emulsion to harden it. In this process, a surfactant is utilized to enhance the performance of the emulsion of the core material and the coating of the wall monomer. The performance of the micro-encapsulation, especially the coating thickness of the wall material and the uniformity of the coating, is largely dependent on the characteristics of the surfactant. This research compares the performance of the micro-capsules and heat storage for product according to molecular mass and concentration of the surfactant, SSMA (sulfonated styrene-maleic anhydride), when it comes to micro-encapsulation through interfacial polymerization, in which Dodecan-1 is transformed to melamin resin, a heat storage material using phase changing properties. In addition, the thickness of the micro-encapsulation wall material and residual melamine were reduced by adjusting the concentration of melamin resin microcapsules.

Evaluation of Performance Based Design Method of Concrete Structures for Various Climate Changes (다양한 기후변화에 따른 콘크리트 구조물의 성능중심형 설계 평가)

  • Kim, Tae-Kyun;Shim, Hyun-Bo;Ahn, Tae-Song;Kim, Jang-Ho Jay
    • Journal of the Korean Recycled Construction Resources Institute
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    • v.1 no.1
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    • pp.8-16
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    • 2013
  • Currently, global warming has advanced by the usage of fossil fuels such as coal and petroleum. and the atmosphere temperature in the world of 100 years(1906~2005) has been risen $0.74^{\circ}C{\pm}0.18^{\circ}C$, IPCC announced that the global warming effect of last decade was nearly doubled compared to the changes($0.07^{\circ}C{\pm}0.02^{\circ}C$/10year) in the past 100 years. Moreover, due to the global warming, heat wave, heavy snow, heavy rain, super typhoon, were caused and are increasing to happen in the world continuously causing damages and destruction of social infrastructures, where concrete structures are suffering deterioration by long-term extreme climate changes. to solve these problems, the new construction technology and codes are necessary. In this study, to solve these problems, experiments on a variety of cases considering the temperature and humidity, the main factors of climate factors, were performed, and the cases are decided by temperature and humidity. The specimens were tested in compressive strength test and split tensile test by the curing age(3,7,28 days) morever, performance based design(PBD) method was applied by using the satisfaction curve developed from the experiment date. PBD is the design method that gathers the current experimental analysis and past experimental analysis and develops the material properties required for the structure, and carries out the design of concrete mix, and it is recently studied actively worldwide. Also, it is the ultimate goal of PBD to design and perform on structures have sufficient performance during usage and to provide the problem solving for various situations, Also, it can achieve maximum effect in terms of functionality and economy.

Stellite bearings for liquid Zn-/Al-Systems with advanced chemical and physical properties by Mechanical Alloying and Standard-PM-Route

  • Zoz, H.;Benz, H.U.;Huettebraeucker, K.;Furken, L.;Ren, H.;Reichardt, R.
    • Proceedings of the Korean Powder Metallurgy Institute Conference
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    • 2000.04a
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    • pp.9-10
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    • 2000
  • An important business-field of world-wide steel-industry is the coating of thin metal-sheets with zinc, zinc-aluminum and aluminum based materials. These products mostly go into automotive industry. in particular for the car-body. into building and construction industry as well as household appliances. Due to mass-production, the processing is done in large continuously operating plants where the mostly cold-rolled metal-strip as the substrate is handled in coils up to 40 tons unwind before and rolled up again after passing the processing plant which includes cleaning, annealing, hot-dip galvanizing / aluminizing and chemical treatment. In the liquid Zn, Zn-AI, AI-Zn and AI-Si bathes a combined action of corrosion and wear under high temperature and high stress onto the transfer components (rolls) accounts for major economic losses. Most critical here are the bearing systems of these rolls operating in the liquid system. Rolls in liquid system can not be avoided as they are needed to transfer the steel-strip into and out of the crucible. Since several years, ceramic roller bearings are tested here [1.2], however, in particular due to uncontrollable Slag-impurities within the hot bath [3], slide bearings are still expected to be of a higher potential [4]. The today's state of the art is the application of slide bearings based on Stellite\ulcorneragainst Stellite which is in general a 50-60 wt% Co-matrix with incorporated Cr- and W-carbides and other composites. Indeed Stellite is used as the bearing-material as of it's chemical properties (does not go into solution), the physical properties in particular with poor lubricating properties are not satisfying at all. To increase the Sliding behavior in the bearing system, about 0.15-0.2 wt% of lead has been added into the hot-bath in the past. Due to environmental regulations. this had to be reduced dramatically_ This together with the heavily increasing production rates expressed by increased velocity of the substrate-steel-band up to 200 m/min and increased tractate power up to 10 tons in modern plants. leads to life times of the bearings of a few up to several days only. To improve this situation. the Mechanical Alloying (MA) TeChnique [5.6.7.8] is used to prOduce advanced Stellite-based bearing materials. A lubricating phase is introduced into Stellite-powder-material by MA, the composite-powder-particles are coated by High Energy Milling (HEM) in order to produce bearing-bushes of approximately 12 kg by Sintering, Liquid Phase Sintering (LPS) and Hot Isostatic Pressing (HIP). The chemical and physical behavior of samples as well as the bearing systems in the hot galvanizing / aluminizing plant are discussed. DependenCies like lubricant material and composite, LPS-binder and composite, particle shape and PM-route with respect to achievable density. (temperature--) shock-reSistibility and corrosive-wear behavior will be described. The materials are characterized by particle size analysis (laser diffraction), scanning electron microscopy and X-ray diffraction. corrosive-wear behavior is determined using a special cylinder-in-bush apparatus (CIBA) as well as field-test in real production condition. Part I of this work describes the initial testing phase where different sample materials are produced, characterized, consolidated and tested in the CIBA under a common AI-Zn-system. The results are discussed and the material-system for the large components to be produced for the field test in real production condition is decided. Outlook: Part II of this work will describe the field test in a hot-dip-galvanizing/aluminizing plant of the mechanically alloyed bearing bushes under aluminum-rich liquid metal. Alter testing, the bushes will be characterized and obtained results with respect to wear. expected lifetime, surface roughness and infiltration will be discussed. Part III of this project will describe a second initial testing phase where the won results of part 1+11 will be transferred to the AI-Si system. Part IV of this project will describe the field test in a hot-dip-aluminizing plant of the mechanically alloyed bearing bushes under aluminum liquid metal. After testing. the bushes will be characterized and obtained results with respect to wear. expected lifetime, surface roughness and infiltration will be discussed.

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