• Aerospace Engineering and Technology
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• v.3 no.1
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• pp.27-34
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• 2004

Tail-wing, gondola and thrust motor mount(EMS) were built by carbon/glass fiber composites. Structural strength & stiffness was verified by specimen tests. Static strength tests for each structural components were conducted separately. Boundary conditions are specially designed for each components to simulate exact joint conditions. Tests shows no detriment deformation at 100% DLL and no failure at 150% DLL.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2004.11a
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• pp.125-128
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• 2004

AFM(Atomic Force Microscope) becomes a versatile tool in the nanoscale measurements and processes. Especially the tapping mode is a very useful mode in AFM operation to measure and process at the nanoscale. Although the tapping mode has a great potential for the novel techniques such as phase imaging, however, it is not clearly known the fundamental mechanics affected by complex tip-sample interactions. This paper shows the various nonlinear dynamic features in tapping mode AFM microcantilevers including hysteretic jumps and period doublings of the microcantilevers. Also it is discussed the complex dynamics of CNT(Carbon Nanotube) probes and the opportunities on the nanoscale nonlinear dynamics.

• Korean Journal Plant Pathology
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• v.1 no.1
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• pp.72-78
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• 1985

The effects of temperature. pH, carbon and nitrogen sources on the growth of Rhizoctonia solani were studied by using five hyphal anastomosis groups(four cultural types, 7 isolates) of the fungus. The ranges of optimum temperature were $20^{\circ}C$ in the AG 2-1, AG 2-2 and AG 4, and $25^{\circ}C$ in the AG 1-IA, AG 1-IB, AG 3, AG 5. The optimum pH for the mycelial growth was 6-7 in the fungus. Glucose in the AG 1-lA, AG 1-IB, AG 2-2, AG 3 and AG 5, sucrose in the AG 2-1 and fructose in the AG 4 were the most effective for the mycelial growth, but glycerine, cellulose and lactose were not effectively utilized as nutrients. $Ca(NO_3)_2$ in the AG 1-IA, AG 1-IB and AG 4, asparagine in the AG 2-1, $KNO_3$ in the AG 2-2 and $NaNO_3$ in the AG 5 were the best nitrogen sources for the mycelial growth, but $NH_4NO_3$ was not easily utilized by the fungus. Nitrate and organic nitrogens for the fungal growth were utilized better than ammonium nitrogen.

• Journal of Korean Society of Forest Science
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• v.105 no.1
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• pp.132-138
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• 2016

The objectives of this study were to infer the parameters of forest stand growth functions of STEMS for Cryptomeria japonica stands of Jeju Hannam Experimental Forest, Korea Forest Research Institute, and to investigate the effects of thinning regimes on the patterns of stand growth and carbon absorption. The forest stand growth functions for the potential diameter growth, modifier, crown ratio and mortality are the major ones composing the independent-tree/distance-free forest stand growth simulator, STEMS. The parameters were inferred using the sets of growth data obtained from stem analyses of 39 trees, chosen from 13 sample plots of the forest stands. The effects of thinning regimes on the patterns of stand growth and carbon absorption were investigated by simulating the stand growth patterns of the case study stand with 3 different thinning regimes: no-thinning, early thinning with low intensity and late thinning with high intensity using the simulator. According to the results of the analyses, the different thinning regimes cause significant effects on the growth patterns of average DBH, average height, diameter distribution and stand volume as well as the amount of carbon absorptions.

• Journal of the Korean Wood Science and Technology
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• v.49 no.3
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• pp.213-225
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• 2021

In this paper, we investigated the carbonization characteristics of lignin hydrochar prepared by hydrothermal carbonization and established a model for predicting the carbonization degree using near-infrared spectroscopy and partial least squares regression. The carbon content of the hydrothermally carbonized lignin at the temperature of 200 ℃ was higher by approximately 3 wt% than that of the untreated sample, and the carbon content tended to gradually increase as the heating time increased. Hydrothermal carbonization made lignin more carbon-intensive and more homogeneous by eliminating the microparticles. The discriminant and predictive models using near-infrared spectroscopy and partial least squares regression approppriately determined whether hydrothermal carbonization has been applied and predicted the carbon content of hydrothermal carbonized lignin with high accuracy. In this study, we confirmed that we can quickly and nondestructively predict the carbonization characteristics of lignin hydrochar manufactured by hydrothermal carbonization using a partial least squares regression model combined with near-infrared spectroscopy.

• Journal of Environmental Impact Assessment
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• v.27 no.6
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• pp.685-694
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• 2018

We measured ecological niche space (ENS) using carbon and nitrogen stable isotope ratios of benthic macroinvertebrates to estimate its applicability for large river assessment. In particular, we compared ENSs of selected macroinvertebrates between upper and lower area of Seungchon Weir in Yeongsan River to estimate the impact of weir on biological community. We also measured basic water quality and community indices including benthic macroinvertebrates index (BMI) to estimate their correlations with calculated ENS. ENS was calculated using the Bayesian Stable Isotope in R statistics (package "SIBER"). The results showed that seasonal variations in water quality and community indices were found, but there was no apparent tendency between upper and lower area of the Seungchon Weir in June (before rainy season) and August (after rainy season). However, ENS of benthic macroinvertebrates markedly decreased across the weir in both June and August regardless of changes in water quality. This means the physical change of the stream due to the weir cause decrease of ecological isotopic niche space of benthic macroinvertebrates regardless of water quality, suggesting physical modification by the weir can affect the interaction between habitat condition and macroinvertebrates. Therefore, the ecological isotopic niche space can be a useful supplementary indicator for the river ecosystem assessment.

• Journal of Bio-Environment Control
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• v.32 no.4
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• pp.278-284
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• 2023

Recently, a closed-type plant factory has been receiving attention as a advanced agricultural method. It has diverse advantages such as climate-independence, high productivity and stable year-round production. However, high energy cost caused by environmental control system is considered as a challenges of a closed-type plant factory. In order to reduce the energy cost, investigation about energy load which is directly connected to energy consumption needs to be conducted. In this study, energy load changes of a plant factory have been analytically analyzed according to the environmental changes. The target plant factory was a lettuce growing container farm. Firstly, the impact of photoperiod, set temperature and relative humidity change were examined. Under the climate condition of Daejeon in South Korea, increase of photoperiod and set temperature rose a yearly energy demand of a container farm. However, increase of set relative humidity decreased a yearly energy demand. Secondly, the climate environment effect was compared by investigating the energy demand under 9 different climate conditions. As a result, the difference between maximum and minimum value of the yearly energy demand showed 21.7%. Lastly, sensitivity analysis of each parameter (photoperiod, set temperature and relative humidity) has been suggested under 3 different climate conditions. The ratio of heating and cooling demand was varied depending on the climate, so the effect of each parameter became different.

• The Korean Journal of Food And Nutrition
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• v.18 no.1
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• pp.39-47
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• 2005

Using the bacteria isolated from Chungkookjang, Bacillus sublilis MG410 which is excellent in fibrinolytic enzyme activity was isolated. In increase the high production of fibrinolytic enzyme from Bacillus sublilis MG410, the effect of various carbon sources, nitrogen sources, inorganic sources, the initial pH of medium were investigated. The most effective carbon and nitrogen sources were founded cellobiose 0.5%(w/v) and soybean meal 2%(w/v) respectively. None of inorganic sources examined had any detectable stimulating effect on fibrinolytic enzyme production except Na₂HPO₄·12H₂O. The initial optimum pH for fibrinolytic enzyme production ranged from 5∼6 and agitation speed was effect at 150rpm. In jar fermentor experiments under optimal culture conditions, the activity of fibrinolytic enzyme reached about 5.050 unit after 48hours.

• Proceedings of the Korean Society of Organic Agriculture Conference
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• 2009.12a
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• pp.304-305
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• 2009

시설재배지의 토양화학성 변화는 작물재배 기간 시비한 화학비료에서 유래된 무기성분 뿐만아니라, 가축분퇴비의 질소성분의 토양잔류량이 요소비료 보다 9.4배 많아 염류집적 주 요인이라는 보고('05 경기도)가 시사하는 봐와 같이 유기자원으로 시용하는 가축분 등의 부산물비료의 무기화에서 유래된 비료성분이 토양염류집적 및 토양환경악화에 더 큰 영향을 미칠 수 있다. 시설재배지의 유기물자원 시용기준이 토양의 특성에 관계 없이 작물에 따라 양적인 시험성적이 주로되어 있으며, 토양검정에 의한 시용기준도 유기물함량에 따라 볏짚, 우분, 돈분 및 계분으로 돠어 있다. 일반노지와 달리 시설재배지에서는 유기물함량이 토양의 비옥도 및 작물생육에 영향을 미치는 것 보다는 토양의 전기전도도(EC)가 더 중요한 작물생육 조건이 될 수 있다. 따라서 토양의 특성에 따라 물질순환에 의한 유기자원 시용기준으로 개선할 필요성이 있다. 시설재배지의 장기적인 토양관리를 위하여 유기물자원에 의한 토양환경 개선 효과를 구명하고자. 무처리, 가축분부산 물비료 관행 시용 기준 대비 볏짚 등 5개의 유기자원을 토양의 무기태질소 함량 대비 유기자원의 탄소함량을 C/N율 10 조절량을 시용하여 시험하였고, 또한 토양의 전기전도도(EC)가 상이한 3개( <2.0 dS/m, 2.0~6.0 dS/m, 6.0 dS/m<)토양에 유기물자원(우드칩)을 C/N율 10, 20, 30 조절하여 수박을 시험작물로 비닐하우스에서 재배하여 수행하였다. 시험 후 토양의 전기전도도(EC)는 시험 전에 비하여 시험 후 토양에서 가축분부산물비료는7% 증가되었으나 유기물자원 처리는 26~33% 경감되는 효과가 있었다. 수박의 과중은 무처리를 제외하고 처리간에 차이가 없었다. 유기물자원 C/N율 조절간에는 시험전 토양의 EC에 따라 차이가 있어 C/N 10 조절에서는 26~44%, C/N 20 조절에서는 30~51%, C/N 30 조절에서는 27~48% 경감효과가 있었으며, 3토양의 평균 토양EC 경감율은 C/N 10, 20, 30 조절에서 각각 34, 39 및 38 % 이었다. 수박의 생육 및 과중은 토양의 C/N율 조절간에는 차이가 없었으나, 토양의 EC 간에는 토양의 EC가 6.0dS/m 이상 토양에서 가장 낮았다. 따라서 탄소원의 유기자원을 C/N율 조절에 의한 시용기준 개선으로 토양의 무기태질소와 토양의 전기전도도(EC)를 경감시켜 친환경적 토양관리와 수박의 수량과 품질을 향상시킬 수 있을 것으로 평가되었다.

• The Korean Journal of Mycology
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• v.15 no.3
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• pp.142-148
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• 1987

The results investigated of the effect of light, pH, and nutrients in vitro and the levels of fertilizer(P,K and Ca) in vivo in order to find out the effect of environmental factors in forming an appressorium of Colletotrichum truncatum were as follows; The ratio of appressorium formation promoted more in a light treatment than in a dark treatment according to investigation after three and six hours passed away. But after the period, the ratio of appressorium formation promoted highly in both treatments. Reasonable pH of appressorium formation was pH 6-pH 8. The ratio of appressorium formation was the most favorable at none nutrient level in every treatment of C-source and N-source, and suppressed in a high concentration of C-source and N-source. But according as the time passed away, the ratio of appressorium formation promoted in C-source and N-source. When their quantities were increased in P and K treatments, the ratio of appressorium formation was somewhat suppressed but it was highly suppressed in the gradual order of none fertilizer level < standard fertilizer level < doubled fertilizer level in Ca treatment according to investigation after the first three hours passed away. But after the period, the ratio of appressorium formation promoted highly regardless of the level of fertilizer.