• Journal of the Korean Society of Tobacco Science
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• v.31 no.1
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• pp.9-17
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• 2009

Activated carbon fiber (ACF) was surface modified by nitric acid to improve the adsorption efficiency of the propylamine. Functional groups and textural properties of modified ACF were investigated. The total surface acidity increased about 7 times to that of as-received ACF by modification with 1 M nitric acid solution, carboxylic and phenolic groups mainly increased. However, the specific surface areas and the total pore volumes of the modified ACFs were decreased by 5-8% due to the increased blocking (or demolition) of micropores in the presence of newly introduced complexes. Despite the decrease of textural properties, it was found that the amount of propylamine adsorbed by the modified ACFs was increased by approximately 17%. The oxygen and nitrogen contents on the modified ACF increased by 1.5 and 3 times compared with the as-received ACF. From the XPS results, it was observed that propylamine reacted with strong or weak acidic groups, such as -COOH or -OH on the ACF surfaces, resulting in the formation of pyrrolic-, pyridonic- or pyridine-like structures.

• Journal of the Korean Society of Safety
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• v.20 no.1 s.69
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• pp.107-112
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• 2005

The purpose of this study is to propose and introduce Accidents Prevention Remedies(APRs) and their priorities especially for Accident Causing factors(ACFs) drawn by surveying and analyzing how much foreign workers in Korea have been exposed to dangers at a construction site. At frist as a result of the analysis of the questionnaire which 59 foreign industrial trainees working at the construction sites in Seoul-Kyunggi area had responsed, 12 ACFs and 11 APRs were put out by using the SPSS programme. Then, through the Analytic Hierarchy Process(AHP) about the questionnaire from 96 safety and civil engineers who have experienced in managing foreign labor at the construction sites all over the country, the APRs given their priorities of relative importances are as follows; First, it is absolutely necessary that every working order to foreign workers should be made more definitely in accordance with a concrete process schedule. Second, the owners should increase investments in improving foreign workers' welfare in order to minimize their potential human error. Third, Korean language education programme for simple technical terms should be made and executed at least.

• Journal of the Korean Society of Safety
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• v.36 no.1
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• pp.80-85
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• 2021

Radionuclides, particularly radioactive cesium (Cs), are a concern of human health in some nuclear power accidents. It could lead to a high level of intracellular accumulation due to its high radioactivity and long half-life. Therefore, it is imperative to develop a method to remove Cs from wastewater. Herein, we synthesized activated carbon fibers (ACFs) doped with Prussian blue (PB) via in situ methods. We classified samples by their preparation method as either physical (PB-ACF-A) or physicochemical (PB-ACF-B) syntheses for comparison. The PB-ACF-B sample showed a significant surface loss compared to PB-ACF-A but a better ¹³³Cs adsorption capacity. All samples fit well to Langmuir isotherms and the values of qmax were directly correlated to the amount of PB on the surface of the ACFs. Adsorption characteristics were further confirmed by the calculated free energy, enthalpy, and entropy.

• Applied Chemistry for Engineering
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• v.29 no.2
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• pp.191-195
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• 2018

In this study, the influence of microporous structures of activated carbon fibers (ACFs) on dimethyl methylphosphonate (DMMP) gas sensing properties as a nerve agent simulant was investigated. The pore structure was given to carbon fibers by chemical activation process, and an electrode was fabricated for gas sensors by using these fibers. The PAN based ACF electrode, which is an N-type semiconductor, received electrons from a reducing gas such as DMMP, and then electrical resistance of its electrode finally decreased because of the reduced density of electron holes. The sensitivity of the fabricated DMMP gas sensor increased from 1.7% to 5.1% as the micropore volume increased. It is attributed that as micropores were formed for adsorbing DMMP whose molecular size was 0.57 nm, electron transfer between DMMP and ACF was facilitated. In conclusion, it is considered that the appropriate pore structure control of ACFs plays an important role in fabricating the DMMP gas sensor with a high sensitivity.

• Proceedings of the Korean Fiber Society Conference
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• 2003.04a
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• pp.309-310
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• 2003

활성탄소 (activated carbons, ACs)는 넓은 비표면적을 가지고 있어 흡착용량이 크며, 발달된 미세공을 가지고 있기 때문에 오염물질의 제거능력이 높을 뿐만 아니라 경제적, 환경 친화적인 측면에서도 유리하다. 특히 섬유화된 할성탄소섬유 (activated carbon fibers, ACFs)는 균일한 세공이 표면에 노출되어 있어 흡착속도가 빠르며, 안정성과 재생성이 좋고 섬유상이기 때문에 가공이 용이하며 직포, 부직포, 시트 등의 형태로 만들어져 용매회수, 공업제품의 정제, 오폐수의 처리시설, 소각시설의 유해 배기가스의 흡착등에 널리 사용되고 있다.[1,2] (중략)

• Archives of Craniofacial Surgery
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• v.21 no.2
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• pp.106-108
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• 2020

Premature fusion of one or other of the minor sutures can subtly influence the shape of the human skull. Although infrequently reported or not clinically recognized, it can such contribute to a variety of craniofacial dysmorphisms. We herein report a case of late presenting, isolated bilateral synostosis of the squamosal suture dysmorphologies whose presentation mimics aspects of sagittal synostosis.

• Archives of Craniofacial Surgery
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• v.21 no.1
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• pp.3-6
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• 2020

Nowadays, the incidence of nasal bone fracture is increasing because of social complexity with frequent social activity, and reduction of fractures is relatively simple and can be corrected in short operation time. However, the postoperative results are known to be less satisfied with higher complication rates relatively. These problems could have resulted from inaccurate recognition and interpretation of fracture aspect, inaccurate planning of operation resulting in under or overcorrection, ignoring septal management, complication related nasal packings with removal, postoperative management, and patient satisfaction with complication.

• Archives of Craniofacial Surgery
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• v.19 no.2
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• pp.85-93
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• 2018

Deviated nose deformities have always been a surgical challenge, and it is essential to achieve both functional and esthetic improvements. Various techniques have evolved over time to correct deviated noses but no one method applies in all cases. Successful correction requires a complete understanding of the various surgical techniques and concepts, including the three-dimensional nasal structure and the time-related changes to surgically-treated noses.

• Archives of Craniofacial Surgery
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• v.17 no.2
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• pp.99-101
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• 2016

• Archives of Craniofacial Surgery
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• v.17 no.2
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• pp.93-95
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• 2016