자료유형
전체 선택해제
총 18건 검색
본문검색 결과만 보기
-
Fe-9Cr-1Mo 합금의 고온 산화 및 황화 부식거동
김민정, 이경환, 유인선, 이동복 한국열환경공학회 열환경공학 6 Pages
한국열환경공학회 열환경공학 2019, 제 14권 1호 5 43-48 (6 pages)
-
Dear fellow symposium participants -- I am very grateful for this opportunity to introduce to you some observations and information on the open-air museums in Sweden. I hope this will be of interest in an international perspective, as well as for my Korean colleagues whom I understand are actively engaged in expanding the role and the enormous potential of open-air museums here in Korea -- clearly a very worthwile endeavor. As the director of the Museum of Far Eastern Antiquities, I cannot claim...
-
How Do Early Childhood Teachers Understand and Support the Needs of Young English Language Learners?
Carolina Cabezas, Elizabeth Rouse 환태평양유아교육연구학회 Asia-Pacific journal of research in early childhood education 22 Pages
환태평양유아교육연구학회 Asia-Pacific journal of research in early childhood education 2014, Vol.8 No.1 4 57-78 (22 pages)
In Australia, over one third of all children in Early Childhood programs speak a first language other than English. Despite considerable work into teachers’ beliefs on cultural diversity, attention to aspects of second language acquisition in the Early Years has been limited within the Early Childhood field. This paper reports on a small study investigating how four early childhood educators understand theory of Second Language Acquisition (SLA) and bilingualism, and how they cater for... -
The electrical and heating properties of copper-incorporated graphite fibers fabricated using different ultrasonication techniques
Kyeong Min Lee, Min-Ji Kim, Hanjoo Jo, Sang Young Yeo, Young-Seak Lee 한국탄소학회 Carbon Letters 4 Pages
한국탄소학회 Carbon Letters 2017, Vol.24 15 111-114 (4 pages)
Electrical energy can be converted into heat energy through ohmic joule heating. Metallic materials are typically used in electrical heating elements because of their great electrical conductivity. However, metallic materials have several weaknesses, such as corrosion susceptibility, heavy weight, high manufacturing costs, and electromagnetic wave emissions [1,2]. To resolve these problems, carbon materials with good electrical conductivity, such as carbon fibers, graphite fibers, carbon... -
Catalytic hydrogenation-assisted preparation of melt spinnable pitches from petroleum residue for making mesophase pitch based carbon fibers
Dong Hun Lee, Jisu Choi, Young Se Oh, Yoong Ahm Kim, Kap Seung Yang, Ho Jin Ryu, Yong Jung Kim 한국탄소학회 Carbon Letters 8 Pages
한국탄소학회 Carbon Letters 2017, Vol.24 4 28-35 (8 pages)
We demonstrated an effective way of preparing melt spinnable mesophase pitches via catalytic hydrogenation of petroleum residue (fluidized catalytic cracking-decant oil) and their subsequent thermal soaking. The mesophase pitches thus obtained were analyzed in terms of their viscosity, elemental composition, solubility, molecular weight, softening point and optical texture. We found that zeolite-induced catalytic hydrogenation under high hydrogen pressure contributed to a large variation in the... -
Effect of added mesophase pitch during the pitch synthesis reaction of PFO
Ji Hong Kim, Jong Gu Kim, Chul Wee Lee, Ki Bong Lee, Ji Sun Im 한국탄소학회 Carbon Letters 7 Pages
한국탄소학회 Carbon Letters 2017, Vol.23 7 48-54 (7 pages)
This research considers the effect of added mesophase pitch (MP) as an additive during the pitch synthesis reaction of pyrolyzed fuel oil (PFO). Two effects are generated by adding MP. One is an enhancement of thermal stability due to the high thermal property of the additive; the other is that the volatile compounds that were removed by vaporization of PFO during the thermal reaction can participate in the pitch synthesis reaction (PFO→pitch) more efficiently. The effect differs according to... -
Effects of coal tar pitch addition on the wear behavior of carbon/carbon composites
Young Chan Jung, Duk Soo Kang, Kyong Yop Rhee, Soo Jin Park, David Hui 한국탄소학회 Carbon Letters 4 Pages
한국탄소학회 Carbon Letters 2016, Vol.20 9 62-65 (4 pages)
Carbon/carbon (C/C) composites are acknowledged as high performance materials because of their good mechanical properties such as wear resistance, even at the higher temperature, due to their low thermal expansion [1-5]. Their hardness and light weight in addition to their superior mechanical properties at high temperature make C/C composites the best material to make brakes for aircrafts and other high weight vehicles. Accordingly, a number of studies have been conducted on the performance of... -
Mesophase formation behavior in petroleum residues
Subhash Kumar, Manoj Srivastava 한국탄소학회 Carbon Letters 12 Pages
한국탄소학회 Carbon Letters 2015, Vol.16 No.3 3 171-182 (12 pages)
s (CLO-1, CLO-2) obtained from fluid catalytic cracking units of different Indian petroleum refineries, were taken as feed stocks. A third petroleum residue, aromatic extract (AE), was produced by extraction of one of the CLO-1 by using N-methyl pyrrolidone solvent. These petroleum residues were thermally treated at 380°C to examine their mesophase formation behavior. Mesophase pitches produced as a result of thermal treatment were characterized physico-chemically, as well as by instrumental... -
Pitch based carbon fibers for automotive body and electrodes
Kap Seung Yang, Bo-Hye Kim, Seong-Ho Yoon 한국탄소학회 Carbon Letters 9 Pages
한국탄소학회 Carbon Letters 2014, Vol.15 No.3 2 162-170 (9 pages)
Pitch is an attractive raw material for carbon fiber precursors due to its low cost stemming from its availability as a residue of coking and petroleum processes. Ford Motor Company reported a carbon fiber target price of $11.0/kg by using a fast cycle-time manufacturing method with carbon fiber in an inexpensive format, allowing for an average retail price of gasoline of $3.58/gallon. They also recommended the use of carbon fiber with strength of 1700 MPa, modulus of 170 GPa, and 1.5%... -
Preparation of pitch from pyrolized fuel oil by electron beam radiation and its melt-electrospinning property
Jin-Young Jung, oung-Seak Lee 한국탄소학회 Carbon Letters 7 Pages
한국탄소학회 Carbon Letters 2014, Vol.15 No.2 10 129-135 (7 pages)
Spinnable pitch for melt-electrospinning was obtained from pyrolized fuel oil by electron beam (E-beam) radiation treatment. The modified pitch was characterized by measuring its elemental composition, softening point, viscosity, molecular weight, and spinnability. The softening point and viscosity properties of the modified pitch were influenced by reforming types (heat or E-beam radiation treatment) and the use of a catalyst. The softening point and molecular weight were increased in...
