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자기조절전략, 성취목표지향과 대학생의 학습양식간의 관계*
한국교육학회 교육학연구 2012, 50권 1호 3 55-79 (25 pages)
교수자들이 학생들이 가지고 있는 다양한 학습양식의 차이를 이해하고, 수업계획을 세운다면 학습 효 율성을 높이는 하나의 방안이 될 수 있을 것이다. 본 연구의 목적은 대학생의 학습양식과 자기조절전략, 성취목표지향의 관계를 검증하고, 또한 성적이 우수한 대학생과 일반대학생들 간에 학습양식, 자기조절 전략, 성취목표지향에 차이가 있는가를 살펴보려는 것이다. 학습양식의 측정은 Oxford(1993)의 11가지 학습양식을 이용하였다. 연구대상자로 224명의 대학생을 대상으로 자료가 수집되었으며 Pearson의 적률 상관, 단계적... -
Graphitization of PAN-based carbon fibers by CO₂ laser irradiation
Liangbo Yao, Weimin Yang, Sanyang Li, Yang Sha, Jing Tan, Ying An, Haoyi Li 한국탄소학회 Carbon Letters 6 Pages
한국탄소학회 Carbon Letters 2017, Vol.24 13 97-102 (6 pages)
Graphite fibers are materials with a high specific modulus that have attracted much interest in the aerospace industry, but their high manufacturing cost and low yield are still problems that prevent their wide applications in practice. This paper presents a laser-based process for graphitization of carbon fiber (CF) and explores the effect of laser radiation on the microstructure of CF. The obtained Raman spectra indicate that the outer surface of CF evolves from turbostratic structures into a... -
Flexural, electrical, thermal and electromagnetic interference shielding properties of xGnP and carbon nanotube filled epoxy hybrid nanocomposites
Young Sil Lee, Yeon Ho Park, Kwan Han Yoon 한국탄소학회 Carbon Letters 6 Pages
한국탄소학회 Carbon Letters 2017, Vol.24 6 41-46 (6 pages)
the xGnP based composite was almost zero. The flexural modulus of the CNT-xGnP based epoxy composite continuously increased to 3.32 GPa with combined filler content up to 10 wt% while that of the CNT based epoxy composites slightly decreased to 1.96 GPa at 4 wt% CNT, and dropped to 1.57 GPa at 5 wt% loading, which is lower than that of epoxy. The CNT and CNT-xGnP samples had the same EMI SE at the same surface resistivity, because samples with the same surface conductivity have the same amount o... -
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... -
Mechanical and electrical properties of cement paste incorporated with pitch-based carbon fiber
Inkyu Rhee, Jin Hee Kim, Sang Hee Park, Sungho Lee, Bong Ryeul Ryu, Yoong Ahm Kim 한국탄소학회 Carbon Letters 8 Pages
한국탄소학회 Carbon Letters 2017, Vol.23 4 22-29 (8 pages)
The compressive strength and electrical resistance of pitch-based carbon fiber (CF) in cementitious materials are explored to determine the feasibility of its use as a functional material in construction. The most widely used CFs are manufactured from polyacrylonitrile (PAN-based CF). Alternatively, short CFs are obtained in an economical way using pitch as a precursor in a melt-blown process (pitch-based CF), which is cheaper and more eco-friendly method because this pitch-based CF is basically... -
Comparative numerical evaluation for the low velocity impact behavior of T300 and T800 composite system
Jae-Seok Choi, Heung Soap Choi, Soo-Jin Park, Myung Kyun Park 한국탄소학회 Carbon Letters 7 Pages
한국탄소학회 Carbon Letters 2017, Vol.22 9 89-95 (7 pages)
Carbon fiber reinforced polymer (CFRP) composites have been used for many decades for extreme light weight design purposes in various areas, such as the aerospace industry, automobiles, sports goods and etc. because they provide the advantages of high specific strength and high rigidity [1]. In particular, the fuselage and wings of various aircraft, as well as the load bearing structures and components of mechanical and civil engineering systems are currently being manufactured with CFRP.... -
The effects of carbon coating onto graphite filler on the structure and properties of carbon foams
Ji-Hyun Kim, Do Young Kim, Young-Seak Lee 한국탄소학회 Carbon Letters 5 Pages
한국탄소학회 Carbon Letters 2017, Vol.21 16 111-115 (5 pages)
Carbon foams (CFms) are of crucial importance in electrical and mechanical devices due to their high thermal conductivity used for eliminating high heat flow and maintaining low temperatures [1]. The most common CFms are types of aluminum alloys, copper and diamond. However, the mechanical properties of metal-based heat sink materials are difficult to control at temperatures over 550°C [2,3]. Thus, CFms are actively investigated as heat sink materials because of their good properties, such as... -
Mechanical properties of epoxy composites reinforced with ammonia-treated graphene oxides
Mi-Seon Park, Sangmin Lee, Young-Seak Lee 한국탄소학회 Carbon Letters 7 Pages
한국탄소학회 Carbon Letters 2017, Vol.21 1 1-7 (7 pages)
The effects of ammonia-treated graphene oxide (GO) on composites based on epoxy resin were investigated. Ammonia solutions of different concentrations (14?28%) were used to modify GO. Nitrogen functional groups were introduced on the GO surfaces without significant structural changes. The ammonia-treated GO-based epoxy composites exhibited interesting changes in their mechanical properties related to the presence of nitrogen functional groups, particularly amine (C-NH2) groups on the GO... -
Effects of carbon additives on heat-transfer and mechanical properties of high early strength cement mortar
Dae-Geun Lee, Kyung Hoon Kim, Hyeong Gi Kim, Young-Seak Lee 한국탄소학회 Carbon Letters 4 Pages
한국탄소학회 Carbon Letters 2016, Vol.20 11 72-75 (4 pages)
The repair of mortar-based structures is critically important because mortar-based structures such as buildings, bridges, tunnels, highway and roads are inevitably degraded by deterioration or damage. To save expense during construction and to avoid traffic congestion during repair work, it is very important to reduce construction time as much as possible. In order to reduce construction time, therefore, the setting time of mortars has to be shortened. The mortars which have short setting times... -
Effects of maleic anhydride content on mechanical properties of carbon fibers-reinforced maleic anhydride-grafted-polypropylene matrix composites
Hyun-Il Kim, Woong Han, Woong-Ki Choi, Soo-Jin Park, Kay-Hyeok An, Byung-Joo Kim 한국탄소학회 Carbon Letters 8 Pages
한국탄소학회 Carbon Letters 2016, Vol.20 6 39-46 (8 pages)
In this work, the effects of maleic anhydride (MA) content on mechanical properties of chopped carbon fibers (CFs)-reinforced MA-grafted-polypropylene (MAPP) matrix composites. A direct oxyfluorination on CF surfaces was applied to increase the interfacial strength between the CFs and MAPP matrix. The mechanical properties of the CFs/MAPP composites are likely to be different in terms of MA content. Surface characteristics were observed by scanning electron microscope, Fourier transform infrared...
