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211.

University Instructors Beliefs and Practices Toward Student-Centered Learning

Lee Eunbae 한국교육학회 교육학연구 24 Pages

한국교육학회 교육학연구 2021, 59권 7호 1 1-24 (24 pages)

Lee Eunbae 저
...
- 5,300원
This study explores undergraduate course instructors’ stated beliefs and practices toward student-centered learning. In-depth interviews with four undergraduate course instructors in a variety of disciplines in the United States revealed their beliefs about the roles of instructors’ and students’ as well as student-centered learning. Also, the instructors’ teaching styles are measured and compared with their stated beliefs and practices. Through thematic analysis and deductive and inductive...
212.

Psychometric Properties of Context-Specific Measures of Students’ Interest and Value in Learning Science : A Multinational Examination

Ham EunHye, Jang Hyesuk, Shin TaeSeob 한국교육학회 교육학연구 22 Pages

한국교육학회 교육학연구 2015, 53권 4호 12 305-326 (22 pages)

Ham EunHye, Jang Hyesuk, Shin TaeSeob 저
...
- 5,100원
This study aims to examine how context-specific measures of students' interest and value differ from their context-general measures in psychometric properties across countries. Using PISA2006 Science data, differential effects of item context on assessing interest and value were illustrated in both the individual and country levels. The main findings are as follows: First, correlation between context-specific and context-general measures tended to be slightly higher in value than in interest....
213.

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)

Dong Hun Lee, Jisu Choi, Young Se Oh, Yoong Ahm Kim, Kap Seung Yang, Ho Jin Ryu, Yong Jung Kim 저
...
- 3,000원
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...
214.

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)

Inkyu Rhee, Jin Hee Kim, Sang Hee Park, Sungho Lee, Bong Ryeul Ryu, Yoong Ahm Kim 저
...
- 3,000원
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...
215.

Hole quality assessment of drilled CFRP and CFRP-Ti stacks holes using polycrystalline diamond (PCD) tools

Dave Kim, Aaron Beal, Kiweon Kang, Sang-Young Kim 한국탄소학회 Carbon Letters 8 Pages

한국탄소학회 Carbon Letters 2017, Vol.23 1 1-8 (8 pages)

Dave Kim, Aaron Beal, Kiweon Kang, Sang-Young Kim 저
...
- 3,000원
Polycrystalline diamond (PCD) tools possessing high hardness and abrasive wear resistance are particularly suited for drilling of carbon fiber reinforced plastic (CFRP) composites, where tool life and consistent hole quality are important. While PCD presents superior performance when drilling CFRP, it is unclear how it performs when drilling multi-stack materials such as CFRP-titanium (Ti) stacks. This comparative study aims to investigate drilling of a Ti plate stacked on a CFRP panel when...
216.

Adsorption characteristics of heavy metals ions by physical activation on coal tar pitch-based activated carbon fibers

Bo-kyung Choi, Jae-Kyoung Ko, Soo-Jin Park, Min-Kang Seo 한국탄소학회 Carbon Letters 5 Pages

한국탄소학회 Carbon Letters 2017, Vol.22 10 96-100 (5 pages)

Bo-kyung Choi, Jae-Kyoung Ko, Soo-Jin Park, Min-Kang Seo 저
...
- 1,500원
Due to the increasing population growth of modern society, along with rapid industrial development and urbanization, environmental pollution continues to worsen and has become an important issue, not only domestically but also worldwide. In particular, toxic substances such as heavy metal ions are present in the wastewater produced by various industries. This wastewater flows into rivers, pollutes water supplies, and can contaminate the drinking water supplied to people [1-3]. Powder or...
217.

Synthesis and characterization of carbon doped TiO₂ photocatalysts supported on stainless steel mesh by sol-gel method

JO. Tijani, OO. Fatoba, TC. Totito, WD. Roos, LF. Petrik 한국탄소학회 Carbon Letters 12 Pages

한국탄소학회 Carbon Letters 2017, Vol.22 6 48-59 (12 pages)

JO. Tijani, OO. Fatoba, TC. Totito, WD. Roos, LF. Petrik 저
...
- 4,100원
This study synthesized pure anatase carbon doped TiO₂ photocatalysts supported on a stainless steel mesh using a sol-gel solution of 8% polyacrylonitrile (PAN)/dimethylformamide (DMF)/TiCl₄. The influence of the pyrolysis temperature and holding time on the morphological characteristics, particle sizes and surface area of the prepared catalyst was investigated. The prepared catalysts were characterized by several analytical methods: high resolution scanning electron microscopy (HRSEM), energy...
218.

Thermo-electrical properties of randomly oriented carbon/carbon composite

Thakur Sudesh Kumar Raunija, N. Supriya 한국탄소학회 Carbon Letters 11 Pages

한국탄소학회 Carbon Letters 2017, Vol.22 3 25-35 (11 pages)

Thakur Sudesh Kumar Raunija, N. Supriya 저
...
- 4,000원
The aim of the work was to investigate the thermo-electrical properties of low cost and rapidly produced randomly oriented carbon/carbon (C/C) composite. The composite body was fabricated by combining the high-pressure hot-pressing (HP) method with the lowpressure impregnation thermosetting carbonization (ITC) method. After the ITC method step selected samples were graphitized at 3000°C. Detailed characterization of the samples’ physical properties and thermal properties, including thermal...
219.

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)

Mi-Seon Park, Sangmin Lee, Young-Seak Lee 저
...
- 3,000원
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...
220.

The effect of the spinning conditions on the structure of mesophase pitch-based carbon fibers by Taguchi method

Zhao Jiang, Ting Ouyang, Xiangdong Yao, Youqing Fei 한국탄소학회 Carbon Letters 10 Pages

한국탄소학회 Carbon Letters 2016, Vol.19 11 89-98 (10 pages)

Zhao Jiang, Ting Ouyang, Xiangdong Yao, Youqing Fei 저
...
- 3,000원
Taguchi’s experimental design was employed in the melt spinning of molten mesophase pitch to produce carbon fibers. The textures of the obtained carbon fibers were radial with varied crack angles, as observed by scanning electron microscopy and polarized optical imaging. The diameter, crack angle, preferred orientation, and tensile modulus of the produced samples were examined to investigate the influence of four spinning variables. The relative importance of the variables has been emphasized...

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