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        검색결과 9,512

        3661.
        2017.03 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Removal of phosphate from environmental water has become more important to prevent eutrophication. In the present study, sorption behavior of phosphate onto magnesite was investigated under different conditions. The optimum pH of phosphate adsorption was determined to be 6.0. The adsorption capacity was found to decrease with increasing temperature, which indicates that a low temperature was beneficial for phosphate adsorption. The sorption capacity for phosphate was found to be 10.2 mg/g at an initial concentration of 100 mg/L and a dose of 2 g/L. The first order kinetic equation and Freundlich isotherm model fit the data well. Phosphate adsorption on magnesite was explained by electrostatic attraction and weak physical interactions.
        4,000원
        3662.
        2017.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Utilizing a unique capability of AKARI that allows deep spectroscopy at 2.5 - 5.0 μm, we performed a spectroscopy study of more than 200 quasars through one of the AKARI mission programs, QSONG (Quasar Spectroscopic Observation with NIR Grism). QSONG targeted 155 high redshift (3:3 < z < 6:42) quasars and 90 low redshift active galactic nuclei (0:002 < z < 0:48). In order to provide black hole mass estimates based on the rest-frame optical spectra, the high redshift part of QSONG is designed to detect the Hα line and the rest-frame optical spectra of quasars at z > 3:3. The low redshift part of QSONG is geared to uncover the rest-frame 2.5 - 5.0 μm spectral features of active galactic nuclei to gain useful information such as the dust-extinction-free black hole mass estimators based on the Brackett lines and the temperatures of the hot dust torus. We outline the program strategy, and present some of the scientific highlights from QSONG, including the detection of the Hα line from a quasar at z > 4:5 which indicates a rigorous growth of black holes in the early universe, and the Brβ-based black hole mass estimators and the hot dust temperatures (~ 1100 K) of low redshift AGNs.
        4,000원
        3663.
        2017.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        We detected bright mid- to far-infrared emission from the helium nova V445 Puppis in the AKARI all-sky survey data taken in 2006. Assuming an optically thin condition, we decomposed the spectral energy distribution (SED) of V445 Puppis in October 2006 by model tting and found that the SED can be explained by a combination of cold amorphous carbon (125 K and the mass of 4:5+6:6 2:7 X 10-4 M⊙) and warm amorphous carbon (250 K and the mass of 1:8+1:0 -0:5 X 10-5 M⊙). Assuming that the former is pre-existing dust formed in the past nova outbursts and the latter is newly formed dust in December 2000's nova wind, this result suggests that the amount of dust formed around V445 Puppis in a single outburst is larger than 10-5 M⊙, which is larger than those in any other classical novae ever reported.
        3,000원
        3664.
        2017.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        We present results of AKARI/IRC near-infrared (NIR) slit-spectroscopy (2.5{5.0 m, R  100) of Galactic sources, focusing on ice absorption features. We investigate the abundance of H2O and CO2 ices and other ice species (CO and XCN ices) along lines of sight towards Galactic Hii regions, massive YSOs, and infrared di use sources. Even among those di erent kinds of astronomical objects, the abundance ratio of CO2 to H2O ices does not vary signi cantly, suggesting that the pathway to CO2 ice formation driven by UV irradiation is not e ective at least among the present targets.
        3,000원
        3666.
        2017.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Our understanding of dust emission, interaction, and evolution, is evolving. In recent years, electric dipole emission by spinning dust has been suggested to explain the anomalous microwave excess (AME), appearing between 10 and 90 Ghz. The observed frequencies suggest that spinning grains should be on the order of 10nm in size, hinting at polycyclic aromatic hydrocarbon molecules (PAHs). We present data from the AKARI/Infrared Camera (IRC) due to its high sensitivity to the PAH bands. By inspecting the IRC data for a few AME regions, we nd a preliminary indication that regions well- tted by a spinning- dust model have a higher 9 m than 18 m intensity vs. non-spinning-dust regions. Ongoing e orts to improve the analysis by using DustEM and including data from the AKARI Far Infrared Surveyor (FIS), IRAS, and Planck High Frequency Instrument (HFI) are described.
        3,000원
        3667.
        2017.03 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        국내에서 개발중인 콘크리트 저장용기는 방사성 물질의 격납 건전성을 유지하기 위하여 내부에 캐니스터를 포함하고 있다. 본 논문에서는 콘크리트 저장용기 내부 캐니스터의 뚜껑 용접시, 용접시간 저감과 이에 따른 캐니스터 용접부의 구조적 건 전성을 확보하기 위한 방안으로, 정상, 비정상 및 사고조건에서 캐니스터 용접부 균열을 진전시키는 하중에 의해 발생되는 균열 깊이를 분석하여, 용접부의 최대 허용결함깊이를 평가하였다. 정상, 비정상 및 사고조건에서의 구조해석은 범용 유한 요소해석 프로그램인 ABAQUS를 사용하였으며, 허용결함깊이는 ASME B&PV Code Section XI에 따라 막응력과 조합하중 에 대해 평가하였다. 평가결과 콘크리트 저장용기의 캐니스터 용접부의 허용결함깊이는 18.75 mm로 평가되었으며, 이는 NUREG-1536에서 권고하고 있는 임계결함깊이를 만족하고 있는 것으로 나타났다.
        4,000원
        3668.
        2017.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Polycyclic aromatic hydrocarbons (PAHs) are considered to be carriers of the unidentified infrared bands, which are ubiquitously observed in the Universe. PAHs are mainly formed around evolved carbon-rich stars and injected into interstellar space. Planetary nebulae (PNe), a late stage of low- and intermediate stellar mass evolution, are suitable objects to investigate the formation and evolution of PAHs. The shortest PAH feature is located in 3.3 μm, which is important to examine the excitation and size distribution of PAHs. While the number of samples had been limited before, the high sensitivity of AKARI/IRC has drastically increased the number of samples. We obtained the 2-5 μm spectra of Galactic PNe with AKARI/IRC and compiled a near-infrared spectral catalog, containing 73 PNe. We investigate the detection rate and the evolution of the PAH features. The characteristics of the catalog are illustrated and the origin of the evolution of the PAH features is discussed.
        4,000원
        3669.
        2017.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Background: The wall squat is considered an effective exercise because it can reduce the knee load and prevent excessive lumbar movement. However, the relationship between wall squat performance and strength of knee extensors and hip extensors remained unclear. Objects: The purpose of this study was to compare the strengths of the knee extensors and hip extensors between groups with low and high wall squat performance. Method: Nineteen males (low performance group: 9 subjects, high performance group: 10 subjects) participated in this study and performed wall squats. The subjects who were performing less than 30% of the average wall squat count were classified into the low wall squat performance group (less than or equal to 4 times) and the subjects who performed more than 30% of the average wall squat count were classified into the high wall squat performance group (greater than or equal to 8 times). Knee extensor and hip extensor strength were measured with a strength measurement system. An independent t-test was used to compare the strengths of the knee extensors and hip extensors between the groups with low and high wall squat performance. Results: The ratios of knee extensor and hip extensor strength to bodyweight were greater in the high wall squat performance group than in the low wall squat performance group (knee extensors: p<.001; hip extensors: p=.03). In the high- and low-performance groups, the ratios of knee extensor strength to bodyweight were 42.74±5.72 and 30.76±8.54, respectively, and the ratios of hip extensor strength to bodyweight were 31.95±10.61 and 20.66±11.25, respectively. Conclusion: Our findings suggest that knee extensor and hip extensor strength are needed for high wall squat performance. Thus, exercise to increase the knee and hip extensors strength can be recommended to improve squat performance.
        4,000원
        3670.
        2017.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        A wide spectral coverage from near-infrared (NIR) to far-infrared (FIR) of AKARI both for imaging and spectroscopy enables us to eciently study the emission from gas and dust in the interstellar medium (ISM). In particular, the Infrared Camera (IRC) onboard AKARI o ers a unique opportunity to carry out sensitive spectroscopy in the NIR (2{5 m) for the rst time from a spaceborn telescope. This spectral range contains a number of important dust bands and gas lines, such as the aromatic and aliphatic emission bands at 3.3 and 3.4{3.5 m, H2O and CO2 ices at 3.0 and 4.3 m, CO, H2, and HI gas emission lines. In this paper we concentrate on the aromatic and aliphatic emission and ice absorption features. The balance between dust supply and destruction suggests signi cant dust processing taking place as well as dust formation in the ISM. Detailed analysis of the aromatic and aliphatic bands of AKARI observations for a number of Hii regions and Hii region-like objects suggests processing of carbonaceous dust in the ISM. The ice formation process can also be studied with IRC NIR spectroscopy eciently. In this review, dust processing in the ISM divulged by recent analysis of AKARI data is discussed.
        4,000원
        3671.
        2017.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        목적: 재질이 다른 하루 교체용 소프트 콘택트렌즈(daily disposable soft contact lens: DDCL)의 자각적 증상, 타각적 증상 및 눈물막을 비교하였다. 방법: 소프트 콘택트렌즈를 착용하고 있는 33명(남: 2명, 여: 31명 ; 평균 21.94±1.58세)을 대상으로 재 질이 다른 세 종류(A;Nesofilcon A, B;Omafilcon A, C;Etafilcon A)의 DDCL을 단일맹검법을 사용하여 하 루 8시간 이상 2주 동안 양안에 착용하도록 하고 콘택트렌즈 피팅상태(중심잡기, 래그, 푸쉬업 검사), 자각 적 증상의 빈도와 정도, 타각증상 및 눈물막 검사 결과를 비교하였다. 결과: 세 종류의 콘택트렌즈 모두 피팅 상태가 적합한 것으로 나타났고, A 렌즈가 다른 렌즈보다 중심이 탈이 적고(p=0.000), 래그(Lag), 푸쉬업(push-up) 움직임이 적었다(p<0.01). 자각적 증상의 빈도(frequency) 와 정도(intensity) 평가에서는 재질에 따른 차이가 없었고, 타각적 증상은 A 렌즈가 다른 렌즈보다 결막충 혈과 염색(staining)이 더 많았고(p<0.05), NIBUT(noninvasive break-up time)와 TBUT(tear break-up time)는 A 렌즈가 다른 렌즈보다 길었다(p=0.000, p=0.008). 결론: 재질이 서로 다른 세 종류의 DDCL 착용 후 재질에 따른 자각적 증상은 차이가 없었고, 눈물막 안 정성과 타각적 증상은 차이가 있었으나 눈물막 안정성, 자각적 증상 및 타각적 증상 사이에 상관성은 확인할 수 없었다.
        4,200원
        3672.
        2017.03 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        방사성폐기물 발생기관의 가용데이터를 기반으로 산출된 핵종재고량을 적용하여 예비안전성평가를 수행한 결과 처분안전성과 운영측면에서 많은 어려움이 예상됨을 확인하였다. 본 논문에서는 전체처분시설 예비안전성평가를 수행하였으며, 평가결과 성능목표치 초과핵종에 대해 방사능량이 큰 비중을 차지하는 단위포장물을 선별하고, 높은 표면선량률의 포장물을 처분대상에서 제외하는 방식으로 처분시설의 처분방사능량제한을 도입하였다. 처분방사능량제한은 안전기준 만족을 위한 처분시설별 인수기준과 처분기준 설정에 기초자료로 활용할 것이며, 경주 처분시설의 안전한 종합개발계획수립 및 처분시 설의 안전성 최적화를 위한 Safety Case 구축에 기여할 것으로 판단된다.
        5,200원
        3673.
        2017.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The zodiacal light emission is the thermal emission from the interplanetary dust and the dominant di use radiation in the mid- to far-infrared wavelength region. Even in the far-infrared, the contribution of the zodiacal emission is not negligible at the region near the ecliptic plane. The AKARI far-infrared all-sky survey covered 97% of the whole sky in four photometric bands with band central wavelengths of 65, 90, 140, and 160 m. AKARI detected the small-scale structure of the zodiacal dust cloud, such as the asteroidal dust bands and the circumsolar ring, in far-infrared wavelength region. Although the most part of the zodiacal light structure in the AKARI far-infrared all-sky image can be well reproduced with the DIRBE zodiacal light model, there are discrepancies in the small-scale structures. In particular, the intensity and the ecliptic latitude of the peak position of the asteroidal dust bands cannot be repro- duced precisely with the DIRBE models. The AKARI observational data during more than one year has advantages over the 10-month DIRBE data in modeling the full-sky zodiacal dust cloud. The resulting small-scale zodiacal light structure template has been used to subtract the zodiacal light from the AKARI all-sky maps.
        3,000원
        3674.
        2017.03 구독 인증기관 무료, 개인회원 유료
        Starting in 1990, the Jeju Branch of Teachers conducted a 4.3 history trip for the nation’s teachers. Discussion of 4.3 used to be prohibited but with the rise of conscious history teachers, they started to share the sites of pain from 4.3 along with sites of pain from modern history. Starting in 2001, Nationwide 4.3 joint classes were implemented; 4.3 learning CDs were produced and distributed to classrooms and other learning sites which cause a lot of friction with the Office of Education. It was painful but the groundwork for 4.3 education was being laid. In 2003, The Provincial Office of Education published “Jeju 4.3 Incident Education Materials: Overcoming Pain and talking of Peace” which provided an opportunity for teachers to officially educate about 4.3. After this in 2008, The third edition of “Overcoming 4.3’s pain and talking of Peace” Teaching materials for Elementary school students, Middle school students, and teachers and the 4.3 Damage Report were published. However, for eight years, 4.3 Educational materials have not been issued.
        4,000원
        3675.
        2017.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Presently, the number of known asteroids is more than 710,000. Knowledge of size and albedo is essential in many aspects of asteroid research, such as the chemical composition and mineralogy, the size-frequency distribution of dynamical families, and the relationship between small bodies in the outer solar system or comets. Recently, based on the infrared all-sky survey data obtained by IRAS, AKARI, and WISE, the large asteroid catalogs containing size and albedo data have been constructed. In this paper, we discuss the compositional distribution in the main belt regions based on the compiled data on size, albedo, and separately obtained taxonomic type information.
        3,000원
        3676.
        2017.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The seroprevalence of major infectious abortion agents was investigated in native Korean goats from Jeonnam province using ELISA. A total of 98 blood samples were collected from goats. Overall, 48 (49.0%), 11 (11.2%), and 1 (1.0%) serum samples tested positive for C. burnetii, T. gondii, and C. abortus, respectively, while none of the samples were positive for B. abortus or N. caninum. Moreover, a PCR assay conducted to detect C. burnetii antigens in goats with a history of abortion revealed 18 (38.3%) of 47 goats were C. burnetii positive by both the ELISA and PCR assay.
        4,000원
        3677.
        2017.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study aims to present a strategic direction in revitalizing tourist destinations using the concept of “functional adaptation” and applying it to the Yedang National Tourism Resort located in Yesan-gun in Chungcheungnam-do, which is losing its functionality as a tourist attraction. The term “functional adaptation” as used in this study refers to applying an intervention to natural changes while maintaining the existing functions, adapting them to changing tourism marketing paradigms. First, problems and potential functions were derived from relevant literature, on-site surveys, and in-depth interviews with insiders from the target resort. Indicators of revitalizing tourist destinations were then preselected from the reviewed literature data, and the final function-adaptive activation indicators were developed after subjecting the preselected preliminary indicators to reliability testing through a Likert-scale questionnaire survey with experts. Finally, the analytic hierarchy process (AHP) was employed for an importance-analysis of individual elements of the developed indicators. The analyses revealed the tourism resort’s “storytelling development” as having the highest importance, followed by “transport connectivity”, and “amusement/leisure programs offered”. The function-adaptive activation indicators developed in this study were applied to the Yedang National Tourism Resort for the importance-analysis of its functions, but the generalizability in applying the proposed indicators to other tourist sites has not yet been established. The findings of this study are expected to serve as an input for setting up strategies for tourist site revitalization in future in-depth research.
        4,300원
        3678.
        2017.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The Infrared Camera onboard the AKARI satellite carried out spectroscopic observations with a grism mode named NG, whose wavelength coverage was 2.5{5.0 m. We reinvestigate the current ux calibration for the NG grism mode, with which calculated ux density implausibly decreases at 4.9 m especially for red objects due to the second-order light contamination. We perform a new spectral response calibration using blue and red standard objects simultaneously. New response curves which contain both the rst- and second-order light are able to separate each contribution consistently and useful for studies of red objects such as CO ro-vibrational absorption in active galactic nuclei.
        3,000원
        3679.
        2017.03 KCI 등재후보 구독 인증기관 무료, 개인회원 유료
        Programmed cell death (PCD) is decisive in eliminating affected cells in human cancers, whereas there are increasing cases of cancer-related death due to side effects of modern treatment methods. There is an urge for new methods of growth inhibition and elimination of cancer cells with a lower cytotoxicity to normal cells. Irregularity along PCD pathways plays a crucial role in cancer cell carcinogenesis. Apoptosis is a distinct cell death mechanism occurring in multicellular organisms and also called type one programmed cell death. Autophagy and paraptosis are non-apoptotic PCD occurring in multicellular organisms. Natural compounds are the fundament of pharmacological treatments, and flavonoids are natural polyphenolic compounds which are unique due to their diverse chemical structures and various biological active mechanisms like anticancer, anti-inflammatory, antioxidative and much more. This gives an increasing number of studies indicating that some flavonoids from medicinal plants could be promising candidates for new natural anticancer drugs, which attract high interests of academic researchers and advanced users. An understanding of the underlying mechanism of PCD induced by flavonoids in cancer cells is important as it plays a pivotal role in the pathogenesis of many diseases. This systematic review is to report flavonoids and their derivatives as new anticancer candidates to stimulate PCD with a different mechanism based on the pharmacological evidence.
        4,000원
        3680.
        2017.03 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        본 연구에서는 오염된 점토 내 Cs을 제거하기 위하여, 계면활성제의 소수성 알킬사슬의 길이에 따른 Cs의 탈착특성을 연구 하였다. 양이온성 계면활성제로 Alkyl trimethyl ammonium bromide를 사용하였고, 소수성 알킬사슬은 octyl-, dodecyl-, cetyl- 으로 변화시켰다. 소수성 알킬사슬이 길어질수록 montmorillonite 내 계면활성제의 흡착량이 증가하였고, 계면활성제의 층간 흡착으로 층간거리가 증가하는 것으로 나타났다. Cs의 탈착률도 알킬사슬의 길이가 증가함에 따라 향상되었고 cetyl 그룹을 갖는 양이온성 계면활성제는 최대 99±2.9%의 Cs 제거율을 나타냈다.
        4,000원