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631.

실험연구에서 내적 타당도와 외적 타당도의 관계성

정윤철 한국교육학회 교육학연구 15 Pages

한국교육학회 교육학연구 2011, 49권 2호 3 25-39 (15 pages)

정윤철 저
...
- 4,400원
본 논문은 내적 타당도와 외적 타당도 간의 관계성을 다룬다. 일반적으로 내적 타당도와 외적 타당도는 서로 부적 관계에 있다고 여겨져 왔다. 본 논문은 이러한 부적 관계성을 비판하면서 정적 관계의 일반성을 주장한다. 연구방법으로 주로 문헌고찰을 사용하였고 주요 관련 자료는 연구방법, 특히 연구 타당도 관련 서적과 논문이다. 우선 본 논문은 내적 타당도와 외적 타당도의 부적 관계 시각의 문제점을 제기한다. 그리고 저자는 부적 관계를 비판하는 2개의 논점을 제시한다. 첫째로 부적 관계성을 지지하는 실질적인...
632.

디지털 시대의 교육학의 자기변모 : 그 특징과 한계

정민승 한국교육학회 교육학연구 29 Pages

한국교육학회 교육학연구 2007, 45권 3호 3 53-81 (29 pages)

정민승 저
...
- 5,800원
정도의 차이는 있지만 모든 학문은 시대와 교감하면서 성장해왔고, 교육학도 예외는 아니다. 그러나 교육학에 대해서는 시대적 변화 혹은 실천현장의 변화에 둔감하다는 비판 역시 지속적으로 제기되어왔다. 최근, 디지털 문화의 일반화는 이런 문제제기에 보다 힘을 실어주고 있다. 교육학은 진리와 지식의 상대성 및 학교교육의 무력화 속에서 학문적 길찾기를 해야 하는 상황에 놓여있는 것이다. 이 연구는 이런 상황인식 속에서, 전환기의 교육학이 1990년대 이후 어떻게 스스로를 혁신해 왔고, 그 한계와 특징은 무엇인지를...
633.

Physicochemical properties and methane adsorption performance of activated carbon nanofibers with different types of metal oxides

Faten Ermala Che Othman, Norhaniza Yusof, Hasrinah Hasbullah, Juhana Jaafar, Ahmad Fauzi Ismail, Noor Shawal Nasri 한국탄소학회 Carbon Letters 8 Pages

한국탄소학회 Carbon Letters 2017, Vol.24 11 82-89 (8 pages)

Faten Ermala Che Othman, Norhaniza Yusof, Hasrinah Hasbullah, Juhana Jaafar, Ahmad Fauzi Ismail, Noor Shawal Nasri 저
...
- 3,000원
In this study, composite PAN-based ACNFs embedded with MgO and MnO2 were prepared by the electrospinning method. The resultant pristine ACNFs, ACNF/MgO and ACNF/MnO2 were characterized in terms of their morphological changes, SSA, crystallinity and functional group with FESEM-EDX, the BET method, XRD and FTIR analysis, respectively. Results from this study showed that the SSA of the ACNF/MgO composite (1893 m2 g?1) is significantly higher than that of the pristine ACNFs and ACNF/MnO2 which is...
634.

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)

Ji Hong Kim, Jong Gu Kim, Chul Wee Lee, Ki Bong Lee, Ji Sun Im 저
...
- 3,000원
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...
635.

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)

Jae-Seok Choi, Heung Soap Choi, Soo-Jin Park, Myung Kyun Park 저
...
- 3,000원
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....
636.

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...
637.

Disorientation angle influence on the thermal residual stresses in carbon multilayered composite plates of different thicknesses

Olga Bitkina, Ki-Weon Kang, Jang-Ho Lee 한국탄소학회 Carbon Letters 5 Pages

한국탄소학회 Carbon Letters 2017, Vol.21 13 98-102 (5 pages)

Olga Bitkina, Ki-Weon Kang, Jang-Ho Lee 저
...
- 1,500원
One of the most acute problems in studying composite stress-strain states is determining the initial residual stresses during the design of layered construction elements. The full stress?strain state of composite constructions consists of the initial (generated during the manufacturing process) and operating (generated during the working period) stages. A thorough investigation of the initial stage of the stress-strain state is very important to finding the total stresses and deformations, and...
638.

Thermoelectric properties of carbonaceous solids

Francesco Miccio 한국탄소학회 Carbon Letters 5 Pages

한국탄소학회 Carbon Letters 2016, Vol.19 14 107-111 (5 pages)

Francesco Miccio 저
...
- 1,500원
639.

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)

Subhash Kumar, Manoj Srivastava 저
...
- 4,100원
Mesophase pitch is an important starting material for making a wide spectrum of industrial and advanced carbon products. It is produced by pyrolysis of petroleum residues. In this work, mesophase formation behavior in petroleum residues was studied to prepare environmentally- benign mesophase pitches, and the composition of petroleum residues and its influence on the mesophase formation was investigated. Two petroleum residues, i.e., clarified oil s (CLO-1, CLO-2) obtained from fluid catalytic...
640.

Effects of cross-linking methods for polyethylene-based carbon fibers: review

Kwan-Woo Kim, Hye-Min Lee, Jeong-Hun An, Byoung-Suhk Kim, Byung-Gak Min, Shin-Jae Kang, Kay-Hyeok An, Byung-Joo Kim 한국탄소학회 Carbon Letters 24 Pages

한국탄소학회 Carbon Letters 2015, Vol.16 No.3 2 147-170 (24 pages)

Kwan-Woo Kim, Hye-Min Lee, Jeong-Hun An, Byoung-Suhk Kim, Byung-Gak Min, Shin-Jae Kang, Kay-Hyeok An, Byung-Joo Kim 저
...
- 5,300원
In recent decades, there has been an increasing interest in the use of carbon fiber reinforced plastic (CFRP) in aerospace, renewable energy and other industries, due to its low weight and relatively good mechanical properties compared with traditional metals. However, due to the high cost of petroleum-based precursors and their associated processing costs, CF remains a specialty product and as such has been limited to use in high-end aerospace, sporting goods, automotive, and specialist...

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