• 제목/요약/키워드: Multi-functional groups

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표면처리된 탄소나노튜브의 질소 및 산소관능기 도입에 따른 전기화학적 특성 (Combined effect of nitrogen- and oxygen functional groups on electrochemical performance of surface treated multi-walled carbon nanotubes)

  • 김지일;박수진
    • 한국신재생에너지학회:학술대회논문집
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    • 한국신재생에너지학회 2011년도 춘계학술대회 초록집
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    • pp.214.1-214.1
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    • 2011
  • In this work, the electrochemical properties of the surface treated multi-walled carbon nanotubes (MWNTs) are investigated for supercapacitors. Nitrogen- and oxygen functional groups containing MWNTs are prepared by nitrogen precursors and acidic treatment, respectively. The surface properties of the MWNTs are confirmed by X-ray photoelectron spectroscopy (XPS) and Zeta-potential measurements. The electrochemical properties of the MWNTs are investigated by cyclic voltammetry, impedance spectra, and charge-discharge cycling performance in 1 M $H_2SO_4$ at room temperature. As a result, these functionalized MWNTs lead to an increase in the specific capacitance as compared with the pristine MWNTs. It proposes that the pyridinic and pyridinic-N-oxides nitrogen species influence on the specific capacitance due to their positive charges, and thus an improved electron transfer at high current loads, since they are the most important functional groups affecting capacitive behaviors.

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다중 기능성 그룹을 포함하는 마이크로포어 탄소의 합성 및 전기화학적 특성 (Synthesis of microporous carbons containing multi-functional groups and their electrochemical performance)

  • 김기석;박수진
    • 한국신재생에너지학회:학술대회논문집
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    • 한국신재생에너지학회 2011년도 춘계학술대회 초록집
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    • pp.94.2-94.2
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    • 2011
  • In this work, multi-functional groups, i.e., nitrogen and oxygen, contained microporous carbons (MF-MCs) were prepared by the one step carbonization of the poly(vinylidene chloride-co-acrylonitrile-co-methyl methacryalte) (PVDC-AN-MMA) without activation. The electrochemical performance of MF-MCs was investigated as a function of carbonization temperature. It was found that MF-MCs had a high specific surface area over $800m^2/g$ without additional activation, resulting from the micropore's formation by the release of chlorine groups. In addition, although functional groups decreased, specific surface area was increased with increasing carbonization temperature, leading to the enhanced electrochemical performance. The pore size of the carbon distributed mainly in small micropore of 1.5 to 2 nm, which was idal for aqueous electrolyte. Indeed, the unique microstructure features, i.e. high specific surface area and optimized pore size provided high energy storage capability of MF-MCs. These results indicated that the microporous features of MF-MCs lead to feasible electron transfer during charge/discharge duration and the presence of nitrogen and oxygen groups on the MF-MCs electrode led to a pseudocapacitive reaction.

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Functionalization of Multi-walled Carbon Nanotube by Treatment with Dry Ozone Gas for the Enhanced Dispersion and Adhesion in Polymeric Composites

  • Kim, Jung-Hwan;Min, Byung-Gil
    • Carbon letters
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    • 제11권4호
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    • pp.298-303
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    • 2010
  • A method of functionalization of multi-walled carbon nanotube (MWNT) at room temperature using dry ozone gas is described. The resulting MWNT were characterized by Fourier transform infrared, x-ray photoelectron spectroscopy, and scanning electron microscopy. Combined to these analyses and solubility in liquids, it could be concluded that the dry ozone gas exposure introduces polar functional groups such as carboxylic groups to MWNT similar to acidic modification of MWNT. Particularly, the stable dispersion of MWNT in water after ozone treatment above a critical level could be obtained, implying potential bio-application. The hydrophilic functional groups on the MWNT introduced by ozone oxidation were helpful in improving the interaction with functional groups in PA6 such as $-NH_2$ and -CONH- resulting in improved mechanical properties.

Hydrogen Adsorption of Acid-treated Multi-walled Carbon Nanotubes at Low Temperature

  • Lee, Seul-Yi;Park, Soo-Jin
    • Bulletin of the Korean Chemical Society
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    • 제31권6호
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    • pp.1596-1600
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    • 2010
  • Surface functionalization of multi-walled carbon nanotubes (MWNTs) was carried out by means of acid treatment. The presence of oxygen functional groups on the surface of acid-treated MWNTs was confirmed with the aid of Fourier transform infrared spectroscopy and X-ray spectroscopy. In addition, carboxylic groups generally formed on the surface of acid-treated MWNTs, and the dispersion was increased by the duration of the acid treatment. The zeta-potential indicated the surface charge transfer and the dispersion of MWMTs. Morphological characteristics of acid-treated MWNTs were also observed using a transmission electron microscopy, X-ray diffraction, and Raman analysis, which was revealed the significantly unchanged morphologies of MWNTs by acid treatment. The hydrogen adsorption capacity of the MWNTs was evaluated by means of adsorption isotherms at 77 K/1 atm. The hydrogen storage capacity was dependent upon the acid treatment conditions and the formation of oxygen functional groups on the MWNT surfaces. The latter have an important effect on the hydrogen storage capacity.

특수기능성섬유가 성장기 운동선수의 수면 중 성장호르몬 분비에 미치는 영향 (Effect of Multi-functional Fabric on EEG and Growth Hormone Level during Sleep)

  • 이명수;이진희;고경찬;문성록
    • 한국의류산업학회지
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    • 제5권1호
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    • pp.77-81
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    • 2003
  • The purpose of this study was to investigate the effect of multi-functional fabric on EEG and growth hormone (GH) during sleep and quality of sleep with the 9 young female athletes. The subjects participated in separated experimental procedure; sleeping in multi-functional fabric wear (experimental group) and cotton wear (control group) for 450min. During the night (22:00-05:30), we recorded the changes of nocturnal polysomnographic sleep recording and GH were measured every 60min. The results show that there are significant differences in percentage of stage 1, 2 and slow wave sleep (SWS) between two groups(S1, p<.05; S2, SWS, p<.01). The SWS percentage of experimental group is 1.89 times higher than control group. The changes of GH secretion varied depending on two experimental procedures. The peak of GH secretion in experimental group is more than controls by 2.4time (p<.001). The quality of sleep in experimetal group is significantly higher than control (p<.01). These results suggest muti-functional fabric wear is effective in inducing the deep sleep and increasing GH and quality of sleep.

가쪽위관절융기 통증 환자에서 복합 부위와 단일 부위에 기능적 마사지와 스트레칭을 적용할 때 통증, 압통 역치와 악력에 미치는 영향 (Effects of Multi-site and Single-site Functional Massage and Stretching on Pain, Tenderness Threshold and Grip Strength in Patients with Lateral Epicondylalgia)

  • 정민근;전재국;신의주
    • 대한정형도수물리치료학회지
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    • 제29권3호
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    • pp.13-22
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    • 2023
  • Background: The purpose of this study was to investigate the effects of functional massage and stretching, applied to the elbow and shoulder joints, on pain, tenderness threshold, and grip strength. Methods: A total of 29 individuals were assigned to a single site (n=15) or multiple sites (n=14). Pain measured through the visual analogue scale (VAS), tenderness threshold (TTH), and grip strength (GI) were measured before and four weeks after the intervention. Results: After four weeks of treatment, visual analogue scale significantly decreased in both groups (p<.05), and the tenderness threshold and grip strength significantly increased in both groups (p<.05). There was also a significant difference between the two groups (p<.05). Conclusion: The reduction of visual analogue scale and the increase in the tenderness threshold and grip strength were more significant in the multi-site treatment group than in the single-site treatment group.

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일반고와 미용특성화고 학생의 뷰티 및 제품 관심도와 뷰티행동 비교 연구 (The Research Compared the General High School and Beauty Specialized High School Student's Interests of Beauty and Beauty Products, and Beauty Behavior)

  • 방기정
    • 패션비즈니스
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    • 제18권4호
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    • pp.153-167
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    • 2014
  • In this study, changes in the timing of puberty physicality and mentality and beauty characteristics of high school students were characterized for high school students and the general high school population in order to distinguish between interest and beauty and beauty products and beauty behavior for comparative analysis. First, for beauty characteristics of high school students and the general high school population, differences in beauty action and beauty characteristics of high school students were higher than this beauty behavior. Secondly, for the high school students and high school beauty characteristics of general high school population for beauty and beauty products, the difference between interest and multi-functional beauty products that characterize high school students has beauty and beauty products with multi-functional beauty products interest being high. Third, high school students and high school beauty characterize the general high school population of beauty is different from behaviors on its factors with common factors including the psychological gratification 'for reasons of appearance management looks for reasons that do not' have time to manage the response. Two groups of factors that characterize the differences in appearance and beauty as areason to manage high school students interested in the 'style' order, high school students do not manage reasons for lack of interest in the 'general' as a response. Beauty characteristics of high school students in the beauty, beauty products, and products demonstrated a multi-functional information gathering with lots of attention, and much ability can have an active beauty behavior. The general high school population lacks the ability to gather information in accordance with interested beauty behavior being passive. The two groups and beauty behavior patterns of consumption could see that a difference occurred.

다양한 함수를 이용한 확장성 있는 데이터 가시화 (Scalable Data Visualization with Various Functional Representations)

  • 장윤
    • 한국정보과학회:학술대회논문집
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    • 한국정보과학회 2012년도 한국컴퓨터종합학술대회논문집 Vol.39 No.1(C)
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    • pp.413-414
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    • 2012
  • Currently the amount and variety of data being generated is unprecedented and dramatically changes the way individuals, groups, and societies act and make decisions. Visualization is one of the most important commonly used methods of analyzing and interpreting digital assets and the interactive environments are necessary to enable effective discovery and decision making. In this paper we present several examples and approaches to scalable functional representations and interactive visualization and analysis. The functional representations provide us unified, compact, continuous, multi-scale, and compressed representations in the data domain.

다중벽 탄소나노튜브의 표면처리에 따른 전기이중층 커패시터의 특성 (Surface Treatment of Multi-walled Carbon Nanotubes for Increasing Electric Double-layer Capacitance)

  • 김지일;김익준;박수진
    • 대한화학회지
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    • 제54권1호
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    • pp.93-98
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    • 2010
  • 본 연구에서는 Urea와 산 처리로 질소 및 산소 관능기가 도입된 다중벽 탄소나노튜브를 각각 제조하였으며, 표면처리에 따른 전기이중층 커패시터 (EDLCs) 특성을 관찰하였다. XPS, zeta-potential, 및 BET 분석방법을 이용하여 구조특성을 확인하였으며, 전기화학적 특성은 1 M 황산용액의 전해질에서 각각 50 $mVs^{-1}$과 100 $mVs^{-1}$의 주사속도로 순환전류 전압곡선 특성 실험을 통해 고찰하였다. 실험 결과로부터 MWNTs의 질소 원소구성비가 늘어날수록 축전용량이 증가하는 것을 확인하였으며, Urea 처리된 MWNTs의 축전용량이 가장 높은 수치를 나타내었다. 이는 전극 표면과 전하 활성종 간의 젖음성이 증가하고, 표면 관능기의 밀도가 증가하기 때문인 것으로 사료된다.

노년기 인지기능과 일상생활기능장애 변화에 대한 연구 - 치매발생집단과 정상유지집단 간 차이 - (Changes in cognitive function and functional disability in older adults - Comparison of groups converted and not converted to dementia among cognitively normal older adults -)

  • 이현주
    • 사회복지연구
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    • 제44권2호
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    • pp.327-358
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    • 2013
  • 본 연구는 노년기 인지기능과 일상생활기능장애 변화양상을 분석하고, 이에 대한 인구사회학적 요인의 영향력을 검증하는 것을 목적으로 하였다. 특히 인지손상정도에 따라 변화양상과 인구사회학적 요인의 영향력이 다를 것이라는 가정 하에, 정상인지를 가진 지역사회 거주노인에서 이후 6년여의 추적조사 기간 동안 치매가 발생한 집단(치매발생집단)과 정상인지를 유지하고 있는 집단(정상유지집단)에 따른 차이를 분석하는 것에 초점을 두었다. 분석 자료는 경기도 연천지역에 거주하는 65세 이상 노인 966명을 대상으로 3년여 간격으로 3회 추적 조사된 역학조사 자료를 사용하였다. 자료 분석은 구조방정식모형을 활용한 잠재성장모형(Latent growth model)과 다중집단분석(Multi-group analysis)을 실시하였으며, 통계프로그램은 AMOS 18.0을 사용하였다. 연구 결과, 치매발생집단은 치매로 진단되기 수년 전부터 정상유지집단에 비해 인지기능이 유의하게 낮을 뿐 아니라 이후 인지저하가 약 3.5배가량 빠르게 진행되었다. 일상생활기능장애 궤적의 경우 초기에는 집단 간 유의한 차이가 없다가, 이후 치매발생집단의 일상생활기능장애가 정상유지집단에 비해 약 3배가량 더 급속히 악화되는 것으로 나타났다. 인지기능과 일상생활기능장애에 대한 인구사회학적 요인의 영향력을 살펴본 결과, 인지저하는 여성에서 더 급격한 반면, 일상생활기능저하는 남성에서 더 현저하게 나타났으며, 생애초기에 결정되는 학력이 생애후기의 인지기능에 강력한 영향력을 갖는 것으로 나타났다. 이러한 연구결과에 근거하여 노년기 인지기능과 일상생활기능장애에 대한 개입에서 주목해야 할 고위험군과 그에 대한 실천적 함의를 논의하였다.