검색결과

검색조건
좁혀보기
검색필터
결과 내 재검색

간행물

    분야

      발행연도

      -

        검색결과 1,075

        802.
        1983.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        가을 김장철에 일시적으로 생산되는 채소잎으로 품질이 좋은 양질 Silage를 생산하기 위하여 본 시험을 실시 하였으며 시험구를 6개구로 설치하여 시험한 결과를 요약하면 1. 채소잎70%, 볏짚20,% 맥강10% 혼합구가 Silage질이 가장 좋았고 유기산 생성량도 많고 낙산 함량은 없었으며 타구에 비하여 가장 우수하였다. 2. 맥강을 첨가한구는 첨가치 않은 구에 비하여 기호성이 좋았고 조단백질 함량도 높았다. 3. 유기산 조성에의한 Silage품질은 총
        4,000원
        803.
        1983.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        4,000원
        804.
        1979.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        4,600원
        805.
        2022.09 KCI 등재 서비스 종료(열람 제한)
        In order to investigate the characteristics of the effects of various emission sources such as ships around the Busan North Port area, PM2.5 samples were analyzed by SEM/EDS (scanning electron microscopy with energy dispersive x-ray spectrometer). In the port city Busan, the main emission source of PM2.5 is ships, and soot was observed as the main exhaust particles of a ship diesel engine. As a result of the individual particle analysis of PM2.5 at the sampling site, carbonaceous particles such as soot and water droplet-shaped, which are considered to be exhausted from ships, were constantly observed. And some spherical Fe-rich particles also appeared.
        806.
        2022.03 KCI 등재 서비스 종료(열람 제한)
        This study investigated the effect of vegetation mat on plant growth and salt reduction in the soil treated with high concentration deicing salt. In order to measure soil chemical characteristics and plant growth, three native groundcover plants (Dendranthema zawadskii var. latilobum, Dendranthema boreale, and Kalimeris yomena) were grown in each of the three plastic containers (50.0 cm width × 35.0 cm length × 8.5 cm deep) with a high concentration treatment of calcium chloride deicing salt. There were two treatments: control, and BVM that combines B (blanket) and VM (vegetation mat). 1,600 g of soil was placed on the top of the drainage layer with 290 g of perlite, 100 seeds each of the three native plants with three repetitions were sowed, and 10 g/L of calcium chloride deicing salt was added in the treatment. As a result of the chemical properties of soil, soil in control treatment was acidic and soil electrical conductivity in BVM was the lowest. Also, exchangeable cations (K+, Ca2+, Na+, and Mg2+) in soil and all the three plants were significantly decreased in the BVM treatment. Meanwhile, the germination rate of Dendranthema zawadskii var. latilobum was the highest under high concentration deicing salt in compared to the two plants. Overall, three native groundcover plant growth was higher in the BVM than control treatment significantly. These results suggest that the treatment of blanket vegetation mat has a positive effect on soil and plant growth in soil damaged by deicing salt.
        807.
        2019.11 KCI 등재 서비스 종료(열람 제한)
        본 연구의 목적은 시멘트계 복합재료의 적층을 위해 증점제를 적용하여 개발한 출력배합의 수축 특성을 평가하고, 프린팅 기법을 이용해 제작한 적층시험체와의 수축 특성을 비교하는 데 있다. 증점제 적용 시 수축이 기준배합과 비교하여 평균 25% 저감(56일 기준)되는 것을 확인하였다. 수축이 저감되는 긍정적인 효과에 반해 압축강도는 약 15% 감소(28일 기준)되는 부정적인 효과도 확인되었다. 출력배합을 이용해 제작한 적층시험체와 몰드시험체를 이용하여 수축을 평가한 결과, 적층시험체의 수축변형률이 약 25% 감소(28일 기준)되는 것을 확인하였다. 본 연구결과를 통해 3D 프린팅을 이용한 시멘트계 복합재료의 출력 시 수축의 진전속도와 수축으로 인한 균열의 발생시점을 예측할 수 있을 것으로 판단된다.
        808.
        2019.10 서비스 종료(열람 제한)
        막 여과는 막을 통해 물을 통과시켜 수중의 오염 물질이나 불순물을 제거하는 기술이며 고도수처리 및 하수 처리와 같은 다양한 분야에서 사용된다. 하지만, 우발적인 수질 오염이나 막 손상의 경우에는 대응하기 어렵다는 단점이 있다. 따라서 여과 과정을 거친 후 식수의 오염을 막기 위해 막의 손상을 모니터링 해야 한다. 본 연구에서는, 압전 센서를 사용하여 고주파 기반 전기역학적 임피던스(EMI)를 측정하여 막 완결성 시험을 수행하였다. 외부 배관에 부착된 압전 센서는 배관 내부 압력 변화로 인한 막의 물리적 특성의 변화를 검출 할 수 있다. 압력 감쇠 시험을 진행하는 동안, 부착된 압전 센서를 통해 EMI 를 측정함으로써 막 손상으로 인한 압력 강하를 측정 할 수 있다. 본 기술을 검증하기 위하여 실제 수원지에서 현장 테스트가 수행되었다. 신뢰성을 높이기 위해 각 측정 단계에서 20 회 실험을 수행 하였고 그 결과, 미세한 압력 강하를 검출함으로써 막의 손상을 모니터링 할 수 있음을 확인하였다.
        809.
        2019.10 서비스 종료(열람 제한)
        지난 2016년 12월 발표된 제1차 기후변화대응 기본계획(2017∼2036)에 따르면 우리나라는 효율적 기후변화 대응을 통한 저탄소 사회 구현을 목표로, 저탄소 에너지의 보편화, 기후산업의 주류화 등의 다양한 정책을 수립하여 국가 기후변화대응을 위한 지속적인 노력을 기울이고 있다. 이러한 노력으로 태양광 발전 관련 산업이 발전하고 있으며, 구조공학 분야에서도 태 양광 방음벽 등의 설치가 증가하고 있는 추세이다. 그러나 최근 국지적인 돌풍에 의한 산업시설물의 외장재 및 방음벽 피해 가 빈번히 발생하고 있는 추세이다. 본 연구에서는 과거 40년 이상의 기상관측자료를 이용하여 기후변화에 따른 풍속의 특 성을 조사하였고, 풍동실험을 통해 방음벽의 모서리 형상 변화에 따른 풍하중의 특성을 조사하였다.
        810.
        2019.08 KCI 등재 서비스 종료(열람 제한)
        This research aims to identify the possibility of developing A horizon resources that can be used for construction and civil engineering work. As such, the utility of A horizon resources was examined by establishing planting ground through a mixture of soil layers and by analyzing the growth and development of Pinus densiflora. The physicochemical and physical properties of the soil were as follows: the A horizon was sandy clay loam, B horizon was sandy loam, and the mixture of two layers appeared as sandy loam, which was identical to the B horizon. The experimental groups did not show any significant difference in their physical properties of porosity and degree of water-stable aggregates. With regards to chemical properties, the A horizon as well as the mixture of A and B horizon showed acidity while the B horizon showed alkalinity. The figures of organic matter, total nitrogen, available phosphate, and replaceable potassium were greater as the A horizon content increased, whereas the figures of replaceable calcium, replaceable magnesium, and conductivity increased as the A horizon content decreased. As a result of the growth and development of Pinus densiflora in each planting ground, the final survival rates were all above 100%. However, the tree height and the rate of growth for the diameter of root were higher in the order of A horizon > A horizon + B horizon > B horizon,indicating that the increased A horizon content is related to the growth and development of Pinus densiflora. The treatment of soil with improvement agents, used to recover the functions of in-situ soil showing poor growth and development, did not have a clear impact on the soil texture and porosity. However, the degree of water-stable aggregates increased significantly when using O horizon as the soil improvement agent among the types of in-situ soil. In contrast, all items related to the chemical properties showed significant differences following the treatment by soil improvement agents. The survival rate according to the treatment of soil improvement agents for the growth and development of Pinus densiflora was higher in the order of organic horizon = no treatment > compound fertilizer > organic fertilizer + compound fertilizer > organic fertilizer; this result was statistically significant with a marginal significance value of the log-rank test(p < 0.05).
        811.
        2019.04 서비스 종료(열람 제한)
        The purpose of this study is to evaluate the safety of curved orthogonal anisoropic bridge girder oblique plates through structural analysis, load test, and steel non - destructive investigation. As a result of the analysis, it is considered that the stress generated in the oblique plates is within 10% of the allowable stress and that the stress generated in the oblique plates in the actual traffic load state is very small and structurally safe.
        812.
        2019.04 서비스 종료(열람 제한)
        Magnetic sensing NDE(non-destructive evaluation) method was applied to detect local damages at the steel chain of the escalator. To verify the feasibility of the magnetic sensing based chain inspection method, a magnetic sensor head was fabricated to adapt to the target chain. The fabricated sensor head scanned the notch damaged chain specimen to measure the magnetic flux signals. After obtaining signal, a series of signal processing process including pick picking and enveloping process based on Hilbert transform (HT) was performed to detect the damaged point by clarifying the signal.
        813.
        2019.03 KCI 등재 서비스 종료(열람 제한)
        This study aimed to analyze the growth and physical responsees of Dracaena braunii in response salt accumulation in ornamental water culture and to examine the effect of activated carbon on this growth response. The experiment was conducted in a plant growth chamber and the indoor environmental conditions of the chamber were set at 23 ± 1℃ temperature, 70 ± 3% humidity, and 1,000 lux brightness. The observation of the growth response of plants in the presence of activated carbon showed that the pH with activated carbon maintained sub-acidic to neutral (6.27∼7.32) conditions and showed decreased electric conductivity in the media. As the treatment with added activated carbon showed good growth and physical responses, this indicated that absorption effect of activated carbon had a positive influence on the growth of plants. However, as the absorption effect of activated carbon may decrease over time and the use of high concentrations of activated carbon might cause nutrition shortage, various concentration of activated carbon and their absorption effects need to be investigated in the future.
        814.
        2018.11 KCI 등재 서비스 종료(열람 제한)
        The purpose of this study is to analyze the cases of Asan-si and Hongseong-gun in Chungcheongnam-do to derive the direction of development of the school meal support center and improvement of the school meal policy in connection with local food. We conducted a survey on the importance and performance of school meal support policy and local food supply policy for nutritionists in two areas. In addition, we identified the issues to be improved intensively and the issues to be continuously managed over the medium to long term, and suggested directions for improvement using IPA. As a result of the importance-performance analysis of school meal support policy and local food supply policy, both Asan-si and Hongseong- gun. focused on improving the price and quality of local food.
        815.
        2018.10 서비스 종료(열람 제한)
        Background : The human patch test is a method used to evaluate potential skin irritation after contact with a cosmetic materials. Pectin lyase-modified red ginseng extract (GS-E3D) is a newly developed ginsenoside Rd-enriched ginseng extract. This study was designed to investigate the skin safety of GS-E3D in human patch test. Methods and Results : Thirty two female volunteers were tested with GS-E3D. GS-E3D (20 ㎕) was applied to occlusive patch test devices and was then applied onto the back of subject with normal skin for 24 hours. Cutaneous irritation responses were evaluated and graded according to criterion of International Contact Dermatitis Research Group (ICDRG) at 30 min, 24 hours, and 48 hours after removing of GS-E3D patch. The average age of subjects was 47.3 ± 9.3 years. Skin reactivity calculated from irritation score in GS-E3D treated group was 0.51 and skin irritation score of no application group was 0, respectively. Skin irritancy was no response in both GS-E3D treated group and no application group. From above data, GS-E3D was identified as a non-irritant according to ICDRG guideline that skin irritation score of ‘0.00 - 0.75’ is a non-irritant. Conclusion : These results indicate that GS-E3D can be useful as a safe cometic ingredient.
        816.
        2018.10 서비스 종료(열람 제한)
        Background : Pectin lyase-modified red ginseng extract (GS-E3D) is a newly developed ginsenoside Rd-enriched ginseng extract. This study was designed to investigate the acute oral and dermal toxicity of GS-E3D in rat. Methods and Results : The acute oral toxic effects of GS-E3D in female SD rats were examined at dosages of 300 ㎎/㎏ and 2,000 ㎎/㎏. In acute dermal toxicity study, 500, 1,000 and 2,000 ㎎/㎏ of GS-E3D were applied onto the shaved skin of male and female SD rats. The weights of rats were recorded at 0, 1, 3, 7, and 14 days and clinical observation were checked once a day for a period of 14 days. All rats were scarified on 14th day and complete gross examination was conducted to detect any gross change of organs after necropsy. GS-E3D did not produce orally or dermally treatment-related clinical signs of toxicity or mortality in all rats during the 14-day observation period. The oral and dermal LD50 values of GS-E3D were over 2,000 ㎎/㎏ in rat. The oral and dermal administration of GS-E3D revealed no significant change in body weight and gross pathology examination compared to control group. Conclusion : These results indicate that GS-E3D can be used as a food and cosmetic materials without critically adverse effect.
        817.
        2018.10 서비스 종료(열람 제한)
        Structural behavior of blast-resistant door composed with steel plate and inner con’c core was analyzed according to composite and non-composite condition. The results showed that maximum and permanent deflection decrease in the case of composite condition. And as the impact on blast-resistant door increases and radical deformation occurs, there is not much difference in the deflection of the door.
        818.
        2018.10 서비스 종료(열람 제한)
        In this study the design sensitivity of blast-resistant door composed with steel plate and inner RC core was analyzed according to increased steel ratio of plate and rebar. The results showed that compressive failure of inner concrete decreased rapidly in the case of specific steel ratio, and that the overall structural performance such as deflection did not changed substantially.
        819.
        2018.05 KCI 등재 서비스 종료(열람 제한)
        이 논문은 압축강도 수준(100, 140, 180 MPa급)에 따른 HPFRCC의 동적충격 인장강도를 평가하였다. 먼저 100, 140, 180 MPa급 HPFRCC의 압축응력-변형률 관계를 분석한 결과 압축강도는 각각 112, 150, 202 MPa로 나타났으며, 압축강도가 높아짐에 따라 탄성계수도 증가하는 경향을 나타내었다. 100, 140, 180 MPa급 HPFRCC의 정적 인장강도는 각각 10.7, 11.5, 16.5 MPa로 나타났으며, 압축강도가 높아질 수록 인장강도도 증가하는 경향을 나타내었다. 반면 100 및 140 MPa급 HPFRCC에서의 인장강도 및 에너지 흡수능력은 압축강도 수준에 따라 큰 차이를 보이지 않았다. 이는 시험체의 규격 및 강섬유의 배열에 영향을 받은 것으로 판단된다. HPFRCC의 동적충격 인장강도를 평가한 결과, 변형률 속도가 10-1/s에서 150/s로 증가할수록 모든 HPFRCC의 인장강도와 동적증가계수는 증가하는 경향을 보였다. 한편 동일한 범위의 변형률 속도에서 HPFRCC의 압축강도가 낮을수록 인장강도에 대한 DIF가 높게 측정되어 효율적인 측면에서는 100 MPa급 HPFRCC가 가장 우수한 것으로 나타났다. 따라서 높은 수준의 인장성능이 요구되는 경우 높은 압축강도를 가지는 HPFRCC를 사용하는 것이 유리하며, 폭발과 같은 고속변형률 속도에서 보다 효율적인 접근을 위해서는 목표 압축강도에 근접한 HPFRCC를 사용하는 것이 바람직한 것으로 판단된다.
        820.
        2018.04 서비스 종료(열람 제한)
        Blast-resistant doors are installed to protect human life, precious equipments and materials in the plant and other similar industrial facilities, national important SOC, evacuation facilities and military shelter. In this study structural behavior according to the boundary condition is analyzed. For the simulation the FE program LS-DYNA is used. Anaylsis results will be used to design blast-resistant door in detail.