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        검색결과 89

        63.
        2022.12 KCI 등재 서비스 종료(열람 제한)
        Forests are valuable natural resources for people living around the mountains. In particular, the comfortable feeling or healing is one of the most important benefits obtained from forests. This healing can be possible by many aspects of forests, including the landscape, natural sounds, anions, and pleasant aromas. We focused on the volatile organics from forest causing pleasant aromas, phytoncides. Twenty phytoncides were monitored from February to September in a national tree garden (BaekDoDaeGan SooMokWon). Five sites were monitored two times per month and 20 phytoncides were detected. Borneol showed the highest annual average concentration and the order of concentration was borneol > mycene > sabinene > limonene > α-pinene. The average phytoncide concentration was relatively high in spring and summer season when the trees were physiologically active. Daily monitoring showed that the afternoon hours had higher concentrations of phytoncides than the morning hours, which may be due to the stabilized atmospheric conditions at the sites. Among the five sites, coniferous forests gave higher phytoncide emissions than broadleaf tree forests. The current study showed that forests produce several phytoncides that cause a healing effect and a forest bath may be beneficial to the health of visitors to forests.
        64.
        2020.09 KCI 등재 서비스 종료(열람 제한)
        This paper introduces a Feedback Linearization (FL) controller to eliminate the gyro effect on a quadrotor UAV. In order to control the attitude of the quadrotor, the second model equation was differentiated to the 4-th order to induce the control input to be revealed, and then a new control input was derived based on the attitude transformation equation with a gyro effect. For the initial quick posture control of the quadrotor, the existing yaw control was replaced with a separate controller. The simulation was conducted with an experiment in which FL control to remove the gyro effect was applied to the quadrotor and an experiment without removing the gyro effect, from the experimental results, the maximum error seen in each axial direction of the quadrotor was x = 0.22 m, y = 0.20 m, z = 0.16 m. Through the proposed method, the effect of the FL controller for controlling the gyro effect of the quadrotor was confirmed.
        65.
        2018.09 KCI 등재 서비스 종료(열람 제한)
        Quadrotor with limited flight time due to battery level can have the extended mission life by applying energy harvesting technology. Bio-inspiration from the birds' locomotion of flight and perch-and-stare can make energy consumption efficient, and energy harvesting technology can generate energy. In order to charge the battery with solar power, the drones are required to be in a position without shade. In the mountainous terrain, a novel mechanism is required in order to be located stably at the top of the tree or the inclined rock. In this study, we propose an analysis of the origami structure and the concept design of the perching mechanism with two stable equilibrium states. The origami structure composed of compliant material can be applied to the perching mechanism that can be locked passively. Moreover, the experimental results of the trajectory and perching test are discussed.
        66.
        2017.06 KCI 등재 서비스 종료(열람 제한)
        레조시놀다이펜틸에터(1,3-di(pentyloxyl)benzene)의 피부 미백 효과를 확인하기 위해 in vitro 실험 을 통하여 미백 효과를 평가하였다. 레조시놀다이펜틸에터는 resorcinol과 1-bromopentane의 알킬화반응을 통하여 제조하였으며, 반응 결과물을 NMR, MS 등의 분석장비를 통해 확인하였다. 레조시놀다이펜틸에터의 피 부 안전성 평가를 위하여, 피부를 구성하는 세포들(keratinocyte, melanocyte, fibroblast)에 대한 독성을 분석 한 결과 대조군에 비해서 모든 세포주들에서 유사한 cell viability를 확인하였다. 세포생존에 영향을 미치지 않 는 농도인 20 μ g/mL에서 세포 외 멜라닌 분비 저해능을 측정한 결과 20 μ g/mL 농도에서 약 65.75%까지 농도 의존적으로 멜라닌 분비를 억제하는 것을 확인하였으며, 세포 내 멜라닌 생성 억제율을 측정한 결과에서도 약 53.89%를 억제함을 확인하였다. 멜라닌 형성 관련 티로시나제, TRP-1, TRP-2의 mRNA 발현량과 단백질 발현량을 real-time PCR 방법과 western blot으로 측정을 한 결과 레조시놀다이펜틸에터는 멜라닌 억제효과 가 전사(transcription)단계부터 억제하는 것을 확인하였다. 최종적으로 본 연구는 레조시놀다이펜틸에터의 미 백기능성화장품 신소재로서의 적용가능성을 제시하였다.
        67.
        2016.12 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        β-Glucan is a natural compound contained in cell walls of yeast or fungi, and cereal’s fiber. It is also known to boost the immune system in human. Aureobasidium is a producer of water-soluble β-1,3/1,6-glucan. In this study, natural killer (NK) cell and macrophage activity were tested to investigate the effects of β-1,3/1,6-glucan isolated from A. pullulans on immune activity. Activation of NK cell was increased about 63-39% by the treatment of 10-200 μg/mL β-1,3/1,6-glucan than control. Besides, only 10 μg/mL of β-1,3/1,6-glucan was enough to boost activation of NK cell. Phagocytosis of macrophage was increased to 15~21% by the treatment of 10~200 μg/mL of β-1,3/1,6-glucan than zymosan-treatment. In LP-BM5 proliferating inhibition test, relative mRNA level of LP-BM5 virus was decreased in β-1,3/1,6-glucan-treated cell about 36~74% than control. The decline of LP-BM5 mRNA level appeared to depend on the concentration of β-1,3/1,6-glucan. These results suggest that pure β-1,3/1,6-glucan from A. pullulans might be contributing to enhancement of immune activity through the activation of NK cell and phagocytosis of macrophage. Moreover, treatment of the β-1,3/1,6-glucan could increase the resistance to virus infection such as LP-BM5 through the restraining of the multiplication.
        68.
        2016.10 서비스 종료(열람 제한)
        Background : Amomum tsao-ko (Zingiberaceae) is widely distributed among several countries in Asia. It’s dried fruit is widely used in Korea for medical plant, China and Japan for the treatment of dyspepsia, eliminates, vomiting, abdominal pain, phlegm, warms the spleen, and malaria. In this study, we describe the structural determination of the new compounds and the inhibitory activities of isolated compounds against LPS-induced NO production in RAW264.7 cells. Methods and Results : The fruits of A. tsao-ko were extracted with 80% EtOH two times at room temperature. The EtOH extract was suspended in distilled water and partitioned with solvent to give CH2Cl2, EtOAc and n-BuOH. The CH2Cl2 was suspended in n-hexane and partitioned with solvent to give 50%, 70% and 90% MeOH. The purification of each fraction by column chromatography separation and HPLC analysis. Consequently, one new benzaldehyde (1) and two new cycloterpenals (2 and 3) along with five known compounds (4 –8) have been isolated from the fruits of A. tsao-ko. The structure and relative stereochemistry were determined from HRMS, 1D and extensive 2D NMR techniques as well as by comparison of their data with the published values. Conclusion : These compounds were identified as Amotsaokonal A (1), Amotsaokonal B (2), Amotsaokonal C (3), methyl linolenate (4), trans-nerolidol (5), (2E)-dodecenyl acetate (6), (2E)-dodecenyl acetate (7), and pyrrole-2-carboxylic acid (8). All isolates were tested for their inhibitory activities on LPS-induced nitric oxide production in RAW264.7 cells.
        69.
        2014.02 서비스 종료(열람 제한)
        재해가 발생하였을 때의 인간의 행동은 임의적이고 즉흥적인 행동으로 여겨지고 있으며, 많은 연구들이 진행되지 못하였다. 피난행태는 상황에 따라 현저히 다른 양상을 보이며, 각각의 행동이 일관성을 가지지 못하기 때문이다. 그러므로 건물과 도로의 재해발생 시 보행자대피모형은 보행자의 피난행태를 평소의 통행패턴과 비슷할 것을 가정하고 있으며, 개개인의 이동속도를 가정하고 속도편자는 높이는 방식으로 거시적, 또는 미시적 모형으로 평가되고 있다. 하지만, 위험으로부터의 피난행동은 비단 인간만의 고유한 행동이 아니며, 동물을 세계에서도 관측이 되고 있다. 즉, 위험으로부터의 피난행태는 실험과 관측이 용이한 동물의 행태와 비교가 가능할 것이라 판단하였다. 본 연구에서는 인간의 본능적 피난행태를 정의하고 포식자로부터 생존을 위한 동물의 행태를 비교하였다. 인간의 행태는 동일본 대지진에서 관측된 영상데이터를 이용하였으며, 피난속도, 속도편자, 방향전환을 중심으로 시사점을 찾고자 하였다. 인간의 피난행태에서는 “빠른 속도로 추종”, “움직이지 못함”, “망설임” 등이 대표적인 대피행태로 나타났다.
        70.
        2013.06 KCI 등재 서비스 종료(열람 제한)
        콩 관련 제품을 생산하는 과정에서 발생되는 부산물은 가축의 사료 및 퇴비 등에 이용되고 있으나 일부는 폐기물로처리되어 추가 비용 및 각종 환경오염을 유발하는 등 사회적인 문제점으로 지적되고 있다. 따라서 본 연구에서는 가공 부산물로 다량 발생되는 콩 배아를 활용하여 생리활성물질인 isoflavone과 soyasaponin을 동시에 분리하는 방법을개발하고자 실시하였다.1. 콩 배아 methanol 추출물을 preparative C18 column에 주입하고, 210 nm의 파장에서 0.5% 초산 용액 30%로부터100% acetonitrile까지 분당 15mL의 유속으로 53분간흘려주어 isoflavone과 soyasaponin 분획을 동시에 분리하였다.2. Preparative C18 column으로 분리된 isoflavone 및 soyasaponin분획은 동결건조시켜 isoflavone 분말 ISF-1과 soyasaponinSAP-1, SAP-2, SAP-3 및 SAP-4의 분말을 얻었다.3. Isoflavone 분획 ISF-1의 재분리는 젤투과 컬럼에서100% acetonitrile을 분당 5 mL가 되도록 흘려주면서254nm 파장에서 관찰하여 2종의 분획 ISF-1-1 및ISF-1-2을 분리하였다.4. 분리된 2종의 isoflavone 중 ISF-1-1은 그 조성이daidzin, glycitin 및 genistin 이고, ISF-1-2는 genistin 단일물질이 주성분인 것으로 나타났다.5. 분리된 4종의 soyasaponin 중 SP-1은 soyasaponin A계열인 Aa(MW: 1364), Ab(MW: 1436), Ac(MW: 1420),Ae(MW: 1202), Af(MW: 1274), SAP-2는 B계열인 Ba(MW: 958), Bb(MW: 942), Bc(MW: 912)와 E계열인Bd(MW: 956), Be(MW: 940), SAP-3는 B계열인 Ba,Bb, Bc, E계열인 Bd, Be와 DDMP계열인 βg(MW:1068), SAP-4는 B계열인 Ba, Bb, Bc, E계열인 Bd, Be와 DDMP계열인 βg, βa(MW: 1038)가 주성분임을 알 수 있었다.
        71.
        2012.11 서비스 종료(열람 제한)
        The slope adjacent to the road, when it is difficult to observe the shape and if not at the bottom of the upper slopes or steep high due to the presence of the upper slopes of the exact visual inspection is difficult, there is a direct investigation lengthy complaints. In this study, the disadvantages of having the inspection personnel based complementary and mixed low-cost single global region is the number of slope maintenance and safety can be managed efficiently so that helicopters and hexa mobile survey vehicle was developed. Equipment developed difficulties in spatial or temporal slope Visually inspect efficient investigation to be able to support. Survey vehicle computer to the Internet environment because it contains Slope check immediately to determine test results sent to the Center, and the efficient maintenance can be performed.
        72.
        2010.10 KCI 등재 서비스 종료(열람 제한)
        Since biodiesel as bioenergy is defined as ester compounds formed by esterification of animal/vegetable oils, in this study three vegetable cooking oils (market, waste and refined waste ones) were esterified by reactions of alkali catalyst and immobilized enzyme. The fatty acid composition of the formed ester compounds was analyzed to investigate the feasibility of biodiesel production. By lipolysis (i.e, hydrolysis of Triglyceride (TG)), all three vegetable oils used in this study were found to produce Diglyceride (DG), Monoglyceride (MD) and Fatty acid ethylester (FAEE). However, the amount of produced FAEE (which can be used as an energy source) was in the increasing order of market cooking oil, waste one and refined waste one. With NaOH catalyst, FAEE was produced about 24.92, 17.63 and 11.31 % for the respective oils while adding Lipozyme TL produced FAEE about 43.54, 38.16 and 24.47 %, respectively. This indicates that enzyme catalyst is more effective than alkali one for transesterification. In addition, it was found that the composition of fatty acids produced by hydrolysis of TG was unchanged with alkali and immobilized enzyme reactions. Thus it can be expected that stable conditions remain in the course of mixing with gasoline whose composition is similar to that of the fatty acids.
        73.
        2009.12 KCI 등재 서비스 종료(열람 제한)
        Recent studies have shown that alum addition to litter results in many environmental and economic advantages, such as reductions in metal runoff, lower ammonia emission and improved poultry performance. However, no research has been conducted to evaluate the effects of different types of alum on soluble metals in poultry litter. The objective of this study was conducted to investigate changes in soluble metal from poultry litter with different types of aluminum sulfate (alum) under laboratory condition. The treatments used in this study, which were mixed in the upper 1 cm of litter or sprayed onto the litter surface, were 4 g alum, 8 g alum, 8.66 g liquid alum, 17.3 g liquid alum, 11.2 g A7 (high acid alum), and 22.4 g A7 (high acid alum)/100 g litter. Applying different types of alum to poultry litter reduced (P<0.05) concentrations of soluble Fe (9 to 54%), Cu (9 to 49%) and Zn (11 to 40%), relative to untreated litter, whereas it increased Ca and Mg (P<0.05). Mean soluble Fe and Cu levels in poultry litter from different types of alum decreased in the order: 22.4 g A7 (54% and 49%) > 17.3 g liquid alum (48% and 42%) > 8 g alum (48% and 31%) > 4 g alum (28% and 10%) > 8.6 g liquid alum (10% and 9%) > 11.2 g A7 (8.6% and 9%). Additionally, the high reduction in soluble Zn concentration was 4 g alum (40%), followed by 8 g alum (26%), 22.4 g A7 (25%), 17.3 g liquid alum (23%), 8.66 g liquid alum (18%), and 11.2 g A7 (11%), respectively. In conclusion, the current studies suggest that treating poultry litter with different types of alum can be applied to reduce soluble metal (Fe, Cu, and Zn) and to develop a production to merchandise for poultry litter that would result in reduction in pollutants from these materials. Furthermore, in order to improve environmental management in the poultry industry, the use of alum, liquid alum and high acid alum all should be provided a valid means of reducing negative environmental impact.
        76.
        2007.02 KCI 등재 서비스 종료(열람 제한)
        한국의 전통적인 민간 약재로 사용되어져온 흰민들레의 잎절편체로 부터 기관형성을 통한 재분화를 시도하였다. 잎 절편체를 BA (0-4mg/L)와 2,4-D (0-1mg/L)가 혼합 첨가된 MS 기본 배지에 치상하여 배양한 결과, 배양 3주후부터 신초가 발생되었다. 신초 분화율은 2mg/L BA 첨가된 조건에서 가장 높았으며, 배양 4주째 4mg/L BA 첨가된 조건에서는 캘러스가 유기되었다. 잎령에 따른 부정아 형성율, 발생빈도, 건량, 생중량을 조사한 결과, 발아 후 7주된 잎 절편체에서 평균 11.5개의 신초를 형성하였다. 유도된 신초는 0.5mg/L NAA가 첨가된 배지에서 발근되었으며, 화분에 옮겨 완전한 식물체로 재분화 되었다.
        77.
        2004.01 KCI 등재 서비스 종료(열람 제한)
        An author has been known that A-type zeolite supported with silver ions has excellent antibacterial activity. However, it is no research of concern in the antibacterial activity of eluted silver ions. This study tested the elution of silver ions from A-type zeolite silver ions in deionized distilled water and NaNO3 aqueous solution. In NaNO3 aqueous solution of 74mM to 588mM, it was found that the concentration of silver ions and electric conductivity increased with the increasing concentration of sodium ions, and equilibrated at 15 min, and the ion exchange equilibrium coefficient, k, is 1.3×10-3. However, deionized distilled water is not equilibrated to pass 6 months. A-type zeolite sodium ions showed no antibacterial activity. It was found that antibacterial activity was exhibited even at the concentration of 10 nM of eluted silver ions, and E-coli died with the incorporation of 2.43×108 Ag ion/cell. antibacterial activity of A-type zeolite silver ions were mainly attributed to hydroxyl radical.
        79.
        2002.06 KCI 등재 서비스 종료(열람 제한)
        대황(Rheum undulatum L.)의 형질전환된 뿌리의 기내(in vitro)배양으로부터 quinone계 알칼로이드 물질인 anthraquinone의 생산성을 확인하고자 하였다. 형질전환된 뿌리로부터 anthraquinone의 생산에 있어서 배지, 초기 pH, 탄소원의 농도, 광 그리고 elicitors의 영향을 조사 하였다. 형질전환된 뿌리는 6% sucrose와 0.5 mg/l GA3 그리고 50 mg/l chitosan이 첨가된 WPM 배지에 치상한 후 16/8의 광조건(16μmol m2s1)하에서 배양시 0.18 mg(생중량)의 anthraquinone의 생산성을 보여주었다. 이와같은 함량은 재배근의 약 1.3배에 해당된다.
        80.
        1999.06 KCI 등재 서비스 종료(열람 제한)
        소 배반포로부터 배아주 (embryonic stem, ES) 유사세포를 분리하기 위해서는 영양외배엽 (trophectoderm, TE) 세포를 제거하는 것이 효과적이다. 따라서 본 실험은 효과적으로 TE를 제거하기 위한 calcium ionophore A23187 (CIPA) 처리조건을 확립하고, 분리해낸 ES 유사세포의 in vitro 다능성 (pluripotency)을 검증하고자 수행하였다. CIPA 농도 및 처리시간을 달리 하였을 때 50 M에서
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