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        검색결과 183

        1.
        2025.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구에서는 높은 이산화탄소 투과성과 선택성을 가지는 미세다공성 고분자 PIM-1을 합성하고, 나노미터 수준 에서 두께를 정밀하게 조절할 수 있는 water casting 기법을 적용하여 박막복합막을 제조하였다. 제조된 분리막의 성능을 평 가하기 위해 FTIR-ATR, BET, GPC, XRD, TEM-EDS 등의 분석을 수행하였으며, 기체 투과 시험을 통해 CO2/N2 선택성과 투과도를 측정하였다. 연구 결과, 본 연구에서 제조된 박막복합막은 2700 GPU 이상의 CO2 투과도와 약 25의 CO2/N2 선택도 를 나타내며, 기존의 PIM-1 기반 분리막보다 우수한 성능을 보였다. 이를 통해 water casting 기법을 이용한 PIM-1 기반 분리 막이 경제적이고 효율적인 이산화탄소 분리 기술로 활용될 가능성을 제시하였다.
        4,000원
        2.
        2024.10 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Silicon-based anode materials have attracted significant interest because of their advantages, including high theoretical specific capacity (~4,200 mAh/g), low working potential (0.4 V vs Li/Li+), and abundant sources. However, their significant initial capacity loss and large volume changes during cycling impede the application of silicon-based anodes in lithium-ion batteries. In this work, we propose a silicon oxide (SiOx) anode material for lithium-ion batteries produced with a magnesio-thermic reduction (MTR) process adopting Boryeong mud as a starting material. Boryeong mud contains various minerals such as clinochlore [(Mg,Fe)6(Si,Al)4O10(OH)8], anorthite (CaAl2Si2O8), illite [K0.7Al2(Si,Al)4O10(OH)2], and quartz (SiO2). The MTR process with Boryeong mud generates a mixture of amorphous silicon oxides (SiOx and SiO2), and magnesium aluminate which helps to alleviate the volume expansion of the electrode during charge/discharge. To observe the effects of these oxides, we conducted various analyses including X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier-Transformation infrared spectroscopy (FT-IR), Brunauer-Emmett-Teller (BET) and cyclic voltammetry (CV) galvanic cell testing. The amorphous SiO2 and MgAl2O4 suppressed the volume expansion of the silicon-based anode, and excellent cycle performance was achieved as a result.
        4,000원
        6.
        2022.09 구독 인증기관 무료, 개인회원 유료
        최근 비풀러렌 전자수용체 소재 개발로 태양전지 및 광검출기 등 유기광다이오드 분야의 상당한 진보를 나타내고 있 다. 비풀러렌 소재의 자유로운 구조 개질 가능성을 바탕으로 흡광대역 자유 제어가 가능한 장점으로, 기존 태양전지 에서 구현이 힘들었던 고성능 반투명 태양전지, 실내 저조도 태양전지, 파장선택적 광검출기 등 다양한 응용을 가능 하게 한다. 본 리뷰에서는 유기태양전지를 비롯한 유기광다이오드의 광활성층에 활용되는 유기반도체 소재의 최신 연 구동향에 대해 다루고자 한다.
        4,000원
        7.
        2020.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        1913년부터 2013년까지 국내에서 육성된 172품종에 대한 종실의 단백질, 지방 함량과 지방산 조성의 변이는 다음과 같다. 총 단백질 함량의 평균은 38.6%(31.6~45.3%), 지방함량의 평균은 18.4%(15.3~21.5%), 포화지방산 중 Palmitic acid의 함량은 평균11.11%(8.1~13.5%), Stearic acid의 함량은 평균 3.7%(1.9~5.4%), 불포화지방산인 Oleic acid의 함량은 평균 26.4%(13.1~41.8%), Linoleic acid의 함량은 평균 50.9% (37.2~63.0%), Linolenic acid의 함량은 평균 7.6%(5.7~9.8%), Linoleic(ω-6)/Linolenic(ω-3)acid의 비율은 평균 6.8(5.3~8.9)이여서, 포화지방산이 평균 14.8%(10.8~17.6%), 그리고 불포화 지방산 함량은 평균 84.9%(79.9~88.7%)이었다. 단백질 함량이 가장 높은 품종은 45.3%로 새단백콩이었으며, 지방함량이 가장 높은 품종은 21.5%를 함유한 늘찬콩이었다. 고 Oleic acid 함량인 동시에 저 Linoleic acid 함량인 검정콩1호는 양질의 지방산을 함유한 매우 유용한 품종이었다. 용도에 따른 단백질, 지방 지방산의 평균함량 중 단백질의 함량은 풋콩 및 올콩용 품종이 가장 높았고, 지방 함량은 장류용 품종이 가장 높았으며, 포화지방산은 장류용품종이 가장 낮았고, 불포화지방산의 함량은 풋콩 및 올콩용 품종이 가장 낮았다. ω-6/ω-3의 비율은 밥밑용 품종이 가장 낮았다. 종피색에 따라서는 단백질 함량은 녹색콩이 가장 높았으며 지방함량은 황색콩이 가장 높았다. 포화지방산은 황색콩과 검정콩이 가장 낮았으며, 불포화 지방산은 갈색콩이 ω-6/ω-3의 비율 또한 갈색콩이 가장 낮게 나타났다.
        4,000원
        8.
        2019.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of this study is to investigate the ELF-MF emissions from UCLs and to compare the ELF-MF emission levels of HVTLs and UCLs. In addition, this study proposes a method and management plan to investigate the effects of exposure to ELF-MF emissions from UCLs. The ELF-MF emissions from the 154 kV UCL were 15.4±24.4 (GM: 7.8)mG, while from the 345 kV line they were 6.0±2.4 (GM: 5.7)mG. Through the comparison between ELF-MF emissions of 154 kV UCL and HVTL, at about 20 m distance from an overhead line the emissions level is 4 mG, while from an underground line at about 10 m distance the emission level was recorded as less than 4 mG. Through comparing the ELF-MF emission amount of the UCL according to the burial method, it was found that the direct ELF-MF emission levels are 15.3±7.4 (GM: 13.9)mG at the direct point, in the conduit type 21.0±30.4 (GM: 10.8)mG, and in the buried form 8.5±12.3 (GM:5.1)mG. In this study, ELF-MF emissions were about 37.0% and 47.5% lower, respectively, compared with the direct power and conduit type. The correlation between ELF-MF emission (mG) and power load (A) was analyzed. The higher the power load, the higher the ELF-MF emission. The correlation between ELF-MF emission at the direct point and depth of the UCL was also analyzed, and it was found that as the depth of line burial increased, ELF-MF emissions decreased.
        4,000원
        9.
        2018.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Unlike common nouns, proper nouns do not depend on the situation. So a proper noun is defined as either pointing to a particular object or pointing to a single object. In philosophy, these proper nouns have been known to play an important role in linking objects only to language and language extrinsic targets. For these reasons, however, proper nouns were not considered as important in foreign language education. However, after ‘the pragmatic turn of linguistics’ in the early 1960s, communication-oriented foreign language education became important. Because communication is closely related to the concept of culture, and culture and proper nouns are closely related. The purpose of this paper is to examine the status of proper nouns in the basic vocabulary of the second foreign language curriculum and how these proper nouns are presented in the College Entrance Trial Test/College Scholastic Ability Test. This paper seeks to analyze how often the same proper nouns are repeated in the test, how the proper nouns are translated, and whether such translations are consistent. Im Gegensatz zu gewöhnlichen Substantiven sind Eigennamen nicht von der Situation abhängig. Ein Eigenname ist also definiert als entweder auf ein bestimmtes Objekt zeigend oder auf ein einzelnes Objekt zeigend. In der Philosophie ist bekannt, dass diese Eigennamen eine wichtige Rolle bei der Verknüpfung von Objekten nur mit extrinsischen Zielsetzungen von Sprache und Sprache spielen. Aus diesen Gründen wurden Eigennamen im Fremdsprachenunterricht jedoch nicht als wichtig erachtet. Nach der “pragmatischen Wende der Linguistik” in den frühen 1960er Jahren wurde jedoch der kommunikationsorientierte Fremdsprachenunterricht wichtig. Es ist wichtig zu beachten, dass es eine enge Beziehung zwischen Kommunikation und Kultur gibt. Kultur und Eigennamen haben miteinander zu tun. Der Zweck dieses Artikels ist es, den Status von Eigennamen im Vokabular des zweiten Fremdsprachenlehrplans zu untersuchen und wie diese Eigennamen im College Entrance Trial Test / College Scholastic Ability Test dargestellt werden. Diese Arbeit versucht zu analysieren, wie oft dieselben Eigennamen im Test wiederholt werden, wie die Eigennamen übersetzt werden und ob solche Übersetzungen konsistent sind.
        5,500원
        10.
        2017.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study investigated Extremely Low Frequency-Magnetic Fields (ELF-MF) exposure levels among housewives for a 24-Hour activity pattern to identify related factors for the exposures. To achieve the objective of the study, we surveyed ELF-MF levels using EMDEX II in a living environment from January to December 2016. We also made subjects write a Daily Activity Pattern in order to identify durations for staying and related information in the environment of exposures. Subjects showed that they spent the longest time in sleep and at home, at 487.5 minutes (KOSIS: 479.0 minutes) and 472.1 minutes (KOSIS: 428.0 minutes), respectively. Furthermore, the 24- hour time-weighted average (TWA) of 54 housewives was 1.24 ± 3.48 mG (GM: 0.52 mG). The ELF-MF exposure levels for all Multiuse Facilities were far below the recommended standards of EMF Guideline Korea and ICNIRP. Thus, these results will provide useful data for the determination of ELF-MF management and reduction methods in living environments.
        4,000원
        11.
        2017.11 구독 인증기관·개인회원 무료
        비단 원료인 실크(견사)는 피브로인(Fibroin; 75%)과 세리신(Sericin; 25%)으로 구성된 단백질 복합체이다. 실크단백질은 실크로부터 탄산나트륨을 이용하는 정련과정을 거쳐 세리신을 제거한 100% 피브로인으로 구성되어 있다. 피브로인은 셀룰로스와 같은 β-sheet 형태로 인하여 불용성이면서 일정한 강도를 유지하는 단백질로서 천연섬유로 사용되어 왔다. 21세기에 실크피브로인의 산 처리 분해산물을 이용한 기능성 생활용품을 비롯하여 당뇨, 고혈압, 숙취제거, 생분해성 고분자 등 다양한 식품용 및 인체용 소재로 실용화되고 있다. 산 처리 가수분해 방법은 고온·강산에서 실크단백질을 분해한 이후 중화·탈색·탈취·탈염·농축·건조를 거쳐 실크펩타이드와 실크아미노산을 제조하여 왔다. 산 처리가수분해에 따른 불규칙한 분자량, 낮은 회수율, 환경오염 등의 문제점을 극복하기 위하여 효소분해 방법을 도입하여 생산수율 향상과 저분자량의 실크펩타이드를 제조하고자 하였다. 세리신이 제거된 실크피브로인은 에스에스바이오팜㈜에서 제공받았다, 실크피브로인은 CaCl₂ : EtOH : DW (몰비 1 : 2 : 8) 용액에 20%(w/v)으로 용해시킨 후 투석막(MW cut-off 12 kDa, Sigma)을 이용하여 과잉의 염을 제거하고 잔존하는 불용성 고형물은 원심분리를 통하여 제거한 실크피브로인 용액을 제조하였다. 단백질분해효소는 Biocatalysts, DuPont, DSM Food Specialities, Novozymes사에서 판매하는 효소를 구입하여 사용하였다. 실크단백질 농도는 Lowry 방법, 효소반응에 따른 아미노산 농도는 Ninhydrin 방법, 그리고 실크단백질과 펩타이드 분자량은 SDS-PAGE를 이용하여 측정하였다. Bacterial Protease로 알려진 5종의 단백질분해효소를 실크피브로인의 단백질 량 대비 1%에 해당하는 량으로 24시간 처리한 결과, 실크피브로인은 Protamex®에서 27.6%, Alphalase®에서 39.3%, Delvolase™에서 46.8%, Alcalase®에서 47.4%, FoodPro® Alkaline Protease에서 47.4%가 분해되는 것을 확인하였다. 또한 효소분해에서 좋은 결과를 보여준 FoodPro® Alkaline Protease의 처리량을 실크피브로인의 0.1, 0.5, 1.0%로 증가함에 따라 실크피브로인의 분해는 29.2%, 37.5%, 그리고 47.4%로 증가하는 사실로부터 실크피브로인의 효소분해는 처리하는 단백질분해효소의 량에 의존적으로 이루어졌다. 한편, Alphalase®의 경우에는 실크피브로인 대비 효소처리량을 0.1, 0.5, 1.0%로 증가하여도 실크피브로인의 분해는 22.6%, 23.6%, 그리고 39.3%로 증가하여 실크피브로인의 분해를 위하여 일정수준 이상의 효소처리가 필요하였다. 단백질 분해효소의 처리시간에 따른 실크피브로인의 분자량을 SDS-PAGE로 확인한 결과, 반응시간에 따라 Running Gel의 상단에서 분해되기 시작하는 고분자량의 실크피브로인과 특정 분자량에 해당하는 단백질 밴드가 강하게 생성되는 것을 확인하였다. 향후 실크피브로인을 분해할 수 있는 다양한 단백질분해 효소의 조합과 반응조건을 활용하면 적정한 분자량을 지닌 실크펩타이드의 제조공정을 개발할 수 있을 것이다.
        12.
        2017.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The objective of this study was to investigate ELF-MF exposure levels of the elderly groups in their living environments using 24-hour personal measurement. In addition, EMF risk perception was investigated. Through evaluations of ELF-MF exposure levels in the proximity of the participants of 58 elderly groups, it was found that TWAam was 1.31 mG (TWAgm: 0.84). ELF-MF exposure levels of the elderly group that live in the proximity of a non-visible power line was high, but there were no statistically significant differences between the non-visible power line elderly group and visible power line elderly group. Moreover, there were no statistically significant differences in ELF-MF exposure according to gender, age, city classification, incomes, residence type, and size. The results showed that the perception of the ELF-MF was very low, as indicated by more than roughly 58.6% of the elderly surveyed saying that they did not know what ELF-MF was. In addition, there was no awareness among the group of how to avoid behavior of EMF from some electric equipment and facilities. Thus, these results will provide useful data for the determination of ELF-MF management and risk communication methods in the living environment for elderly people.
        4,000원
        13.
        2016.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The objective of this study was to investigate ELF-MF exposure levels in infant living environmental spaces at daycare centers. To achieve the objective of the study, we surveyed ELF-MF levels using EMDEX II at daycare centers from October 2013 to October 2014. The ELF-MF level of 53 daycare centers in terms of arithmetic mean (AM) and geometric mean (GM) were 0.59 ± 0.76 mG and 0.33 mG, respectively. And the ELF-MF level of 260 daycare center classrooms was 0.50 ± 0.71 mG (GM: 0.28 mG). The exposure levels of ELF-MF for all daycare centers were far below the recommended standards cited in guidelines in Korea (833 mG) and international reference levels proposed by WHO or ICNIRP (2,000 mG). Furthermore, we discovered out that as distance increased, ELF-MF emission levels decreased significantly in all electrical instruments. Below the 2 mG ELF-MF levels when an electrical instrument moved away stage 1 (Grade). Thus, these results will provide useful data for the determination of ELF-MF management and reduction methods at infant daycare centers.
        4,000원
        14.
        2016.11 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The objective of this study was to investigate the physicochemical characteristics of bear, pig, and cow biles to determine their authenticities for safe food distribution. The main bile acids of bear bile were tauroursodeoxycholic acid and taurochenodeoxycholic acid, while glycochenodeoxycholic acid and taurochenodeoxycholic acid for pig bile and taurocholic acid and glycocholic acid for cow bile were majorly detected by HPLC analysis. HPLC analysis was effective in monitoring of several samples imported as bear bile if employed to determine the authenticity of each bile. After the analysis of fatty acid composition by GC analysis, the ratio of the oleic acid of bear bile was relatively low compared to pig and cow biles. The ratio of the linoleic acid of bear bile was also similar to pig bile, whereas it had a tendency to be high compared to cow bear. The genetic analysis of the imported bile samples was mostly in agreement with the results of HPLC and GC analysis to identify the origin of imported biles. Finally, this study on the identification of bile origin by physicochemical analysis can give basic information to monitor the origin of biles and further to establish a reliable system for bear bile distribution.
        4,000원
        15.
        2016.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The objective of this study was to assess RF-EMF exposure levels in indoor daycare centers in a Metropolitan city. RF-EMF measurements were collected and surveyed from 50 volunteer daycare centers in the Korea between October 2013 and October 2014. Through our research, it was found that the main exposure source for indoor daycare centers is the frequency bands for TV and Radio broadcasting (FM: 88.1~107.9 MHz), mobile phone (869~894 MHz, 1840~1870 MHz, 1885~2170 MHz), wireless LAN and home electronics, etc., including TRS, Wireless Data Communication. The RF-EMF exposure levels for all daycare centers were far below the recommended standards of EMF Guideline Korea and international reference levels proposed by ICNIRP (International Commission on Non-Ionizing Radiation Protection). However, in terms of long term health effects some uncertainty exists, and thus minimizing exposure may reduce this uncertainty. The data we collected will be useful data for determining RF-EMF management and risk communication at daycare centers.
        4,000원
        16.
        2016.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Radon (222Rn) gas is a main source of ionizing radiation of natural origin. It typically moves up through the ground to the air above and into building or home through cracks and other holes in the foundation. Significantly, the Surgeon General has warned that radon is the second leading cause of lung cancer in the United States today. This survey covers the determination of indoor radon concentrations at home from 2013 to 2014 in some areas of Gangwondo, every three months (seasonal) during one year using an alpha-track detector. The results showed that the annual average concentration of indoor radon was 84.5 Bq/m3 (GM: 64.5 Bq/m3) at homes. Indoor radon level was the highest in winter and the lowest in summer. Geometric mean radon concentration in winter was 1.03~2.58 times higher than other seasons. The data obtained from this study provide a basis for the preparation of legal regulation and public health protection manuals in this area.
        4,000원
        17.
        2015.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, ELF-MF levels of subway trains were measured to understand the status of the intensity of ELFMF. The measurement points for the train are selected in the center of each train compartment(pantagraph compartment, motor-driven compartment and the compartment that is not connected to any other electric equipment) using EMDEX II. ELF-MF levels of trains were measured from the starting to the terminal station in each lines(Seoul line 1-9, Incheon line 1, Incheon international airport line, Gyungui line, Bundang line, Gyeongchun line, Joongang line, Suin line). We found that the mean and range of ELF-MF levels in the DC power subway train are 2.4 and 0.1~125.9 mG, respectively, while the mean and range of ELF-MF levels in the AC power subway train are 10.4and 0.0~156.3 mG, respectively. Furthermore, the maximum ELF-MF level(156.3 mG) was lower than the reference level(ICNIRP 833 mG, 60Hz). The findings of this study in relation to the characteristics of ELF-MF for subway will be useful to derive the ELF-MF exposure coefficient from our living environment in a subsequent study.
        4,000원
        19.
        2014.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Cathode materials and their precursors are prepared with transition metal solutions recycled from the thewaste lithium-ion batteries containing NCM (nickel-cobalt-manganese) cathodes by a H2 and C-reduction process. Therecycled transition metal sulfate solutions are used in a co-precipitation process in a CSTR reactor to obtain the tran-sition metal hydroxide. The NCM cathode materials (Ni:Mn:Co=5:3:2) are prepared from the transition metal hydroxideby calcining with lithium carbonate. X-ray diffraction and scanning electron microscopy analyses show that the cathodematerial has a layered structure and particle size of about 10 µm. The cathode materials also exhibited a capacity ofabout 160 mAh/g with a retention rate of 93~96% after 100 cycles.
        4,000원
        20.
        2013.12 KCI 등재후보 구독 인증기관 무료, 개인회원 유료
        The light trespass problem still has not been solved for a long time because of the complex influences of the reflection or overlap lights. To solve the light trespass problem, the assessment of the characteristics of the spilt light carry out firstly. In this study, we estimated the light trespass reducing performance of various load lightings using by RELUX lighting simulation program. In the simulation program, we designed the lighting environment according to the streetlight installation guideline by the ministry of land, transport and maritime affairs. And we estimated the light trespass caused by roadway lighting from first floor position to fourth floor position. And we compare the light trespass caused by back light of the roadway lighting with the light trespass caused by forward light. Then we estimated the effect of light trespass by improving the light distribution of roadway lighting from Backlight rating 3 to Backlight rating zero. From the research, we find that the light trespass caused by roadway lighting maximize at the first floor position of the house. And the light trespass contribution rate by backlight and forward light is 66 percentage and 33 percentage respectively. And we estimated that the light trespass can be decreased about 40 % by improving the backlight. The result derived from this research will be helpful to establish the light pollution reduction plan to minimize the adverse effect by the spilt light from the roadway lighting.
        4,000원
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