• Journal of the KSME
• /
• v.23 no.6
• /
• pp.412-418
• /
• 1983

유동층 연소기술은 선진 각국에서 다투어 개발하고 있는 최첨단 연소기술이나 국내에서 연구되기 시작한 것은 1979년 KAIST의 직경 10"의 원통형 유동층 연소로 제작을 시초로, 그 후 정부 주도하에 정부출연연구소를 중심으로 하여 상압 유동층 연소의 대규모 공정개발을 목표로 하여 기초연구를 끝내, 이미 0.1ton/hr의 pilot plant를 건설, 현재 가동중에 있으며, 그 결과를 기초로하여 1984년 10배의 확대(1ton/hr), 1986년에는 상용화 규모인 10ton/hr의 demonstration plant설치를 계획중에 있는데, 이와같이 단계적인 확장 이유는 scale-up에 있어 최적 운전조건을 위한 많은 기술의 축적이 필요하기 때문이다. 한편 근자에 와서, 각 대학과 일반업체에서도 많은 관심을 가지고 연구에 힘을 기울이고 있는데, 동양화학(주)에서는 120ton/hr의 열병합 FBC 건설을 핀랜드 기술진과 추진하고 있으며 본 연구실에서도 고유황 벙커C유의 유동층 연소를 위해 banch scale 연소로를 제작하여 연구를 수행중에 있다.에 있다.

• International Journal of Highway Engineering
• /
• v.10 no.1
• /
• pp.97-104
• /
• 2008

Many atypical structures on the roadside are exposed to traffics unshielded posing great danger. One way to shield an atypical structure to secure the occupant safety is to stack energy absorbing material modules in front of the structure. This paper presents the analysis method of module type crash cushion made of EPS blocks using simple energy balance of the car and crash cushion and numerical examples for 0.9ton-500km/h, 0.9ton-60km/h and 0.9ton-70km/h impact are presented. This method gives simple estimation of maximum acceleration, time of crash, whether or not the vehicle stops completely before whole cushion is being crushed. However, since the acceleration and velocity data from the analysis is so crudely spaced that calculation of safety indices such is RA and OIV is not possible. Problem is overcome by using data interpolation. The spline and linear interpolation is introduce and safety analysis is made and the results are compared.

• Tunnel and Underground Space
• /
• v.24 no.6
• /
• pp.430-439
• /
• 2014

This study developed a simulation program for truck-loader haulage systems in an underground mine. A limestone underground mine in Korea was selected as a study area and investigated to design the simulation algorithm for truck-loader haulage systems. GPSS/H simulation language was utilized to develop the simulation program. Simulations were conducted to analyze the optimal number of haulage trucks dispatched in the 540 ML loading point by using the developed program. The simulation results showed that 8 trucks can maximize the daily production (2,076 ton). The real production (1,850 ton/day) of limestone ores was very similar to the simulated one (1,850.35 ton/day) when considers 7 trucks dispatched in the 540 ML loading point. In addition, average waiting time at loader were similar (waiting time by time study : 1.39 min, simulated waiting time : 1.35 min).

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.20 no.3
• /
• pp.169-176
• /
• 2000

This experiment was carried out to investigate the effects of application levels of food waste compost andmineral nitrogen in 3 cuttings per annurn on the nutritive value and nutrient yields of orchardgrass (Dactylisglomerata L.). Annual food waste compost (FWC) and mineral nitrogen were applied at levels of 0, 10, 20,40 and 60 ton ha-', and 0, 90, 180 and 270 kg ha-', respectively. The contents of crude protein (CP, %) oforchardgrass were significantly higher at the application levels of 40 ton ha-' yr-' by FWC than those atapplication levels of 0 ton ha-' yr-' (p<0.05), the contents of neutral detergent fiber (NDF, %), acid detergentfiber (ADF, %) and hemicellulose were also higher in FWC applied plots, except for the FWC levels of 10and 60 ton ha-' yr-'. The contents of total digestible nutrient (TDN, %) and relative feed value (RFV) oforchardgrass were significantly higher at FWC levels of 10 and 60 ton ha-' yr-' than at levels of 0 ton ha"yr-'. Annual yields of CP and TDN were increased with increase the FWC levels. The highest contents ofCP of orchardgrass were obtained at 1st cut, NDF and ADF at 2nd cut. As the mineral nitrogen fertilizationwas increased, the contents of CP, NDF, ADF and hemicellulose of orchardgrass were significantly increased,but TDN and RFV were decreased. .Annual yields of CP and TDN of orchardgrass were significantlyincreased with increase the mineral nitrogen fertilization.(Key words : Food waste compost, Mineral nitrogen, Crude protein, Neutral detergent fiber, Acid detergentfiber)rgent fiber, Acid detergent fiber)

• Economic and Environmental Geology
• /
• v.41 no.5
• /
• pp.497-507
• /
• 2008

This study identified and quantified the hidden flows for steel and iron production in Korea using MIPS (Material Input per Service) methodology. In order to estimate the input orientated impact on the environment caused by the manufacture or services of a product, MIPS indicates the quantity of resources used for this product or service. In 2005, 71 million tons of raw materials were used to produce $17.6 million of added value and 4.8 thousand tons of finished steel. The amount of natural resources extracted from natural environments for the purpose of steel production was 245 million tons of TMR(Total Material Requirement), 1524 million tons of water, and 34 million tons of air. The material intensities for steel production by natural inputs (raw materials and energy) was 4.3 ton/ton of TMR, 28 ton/ton of water, and 0.5 ton/ton of air.

• Journal of Biosystems Engineering
• /
• v.13 no.3
• /
• pp.44-51
• /
• 1988

The objective of this study is to develop a grain handling system for loading, unloading and transporting of rough rice stored at the in-bin drying and storage (IBDS) developed by the Korea Advanced Institute of Science and Technology(KAIST). A mechanized Fain handling system consisted of a portable auger and a gate was developed and tested. The test results can be summarized as the following: 1) The loading capacity of the handling system developed is $16.2m^3/h$ (8.3 ton/h) for the Indica type rice and $13.0m^3/h$(7.3 ton/h) for the Japonica type. It is greater than that of manual handling as much as 2.5 - 2.7 times. 2) The unloading capacity of the handling system developed is $16.0m^3/h$(8.2 ton/h) for the Indica type rice and $12.6m^3/h$(7.0 ton/h) for the Japonica type. It is greater than that of the manual as much as 4.7 - 5.5 times. 3) For 3-ton capacity of the storage, the loading and unloading can be performed for 20 and 30 minutes by one man operation of equipment. while 60 and 120 minute for the manual of 2 men, respectively. 4) The volumetric efficiency of the system developed is 0.42 - 0.54 and the power efficiency is 4.0 - 4.4. 5) The break-even quantity of the handling system developed is about 38.6 ton($68.7m^3$) of rough rice and the initial investment for the system would be returned within five years for the most owners of the KAIST IBDS system.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2008.05a
• /
• pp.529-533
• /
• 2008

본 연구는 미래기후변화가 공간해상도(5, 10, 30m)에 따른 토양유실량의 변화에 미치는 영향을 분석하고 자하였다. 연구대상지역은 경안천 최상류에 위치한 $1.16km^2$의 농촌 소유역을 대상으로 공간해상도별(5, 10, 30m) RS 및 GIS 자료를 생성하고, GIS 기반의 RUSLE(Revised Universal Soil Loss Equation) 모형을 채택하여 토양유실량을 분석하였다. 기후변화 시나리오는 IPCC(Intergovernmental Panel on Climate Change)에 서 제공하는 GCM(Global climate model) 중에서 MIROC3.2 hire의 A1B, B1 시나리오를 이용하였으며, 과거 30년간(1977-2006)의 기상자료 통계정보를 기준으로 Change Factor Downscaling 기법을 적용하여 2020s년 (2010-2039), 2050s년(2040-2069), 2080s년(2069-2099) 전후의 각 30년간의 미래 강우량을 재생산하여 사용하였다. 그 결과 강수량은 2080s년에 A1B 시나리오의 경우 연평균 강수량은 270.37mm, 최대 강수량은 65.71mm 증가하였고, B1 시나리오의 경우 연평균 강수량은 37.11mm, 최대 강수량은 48.46mm 증가하는 것으로 나타났다. 구축한 미래 강우량을 RUSLE 인자 중 R 인자에 적용하여 2020s년, 2050s년, 2080s년의 토양유실량을 분석한 결과, 미래강수량이 증가함에 따라 공간해상도별 토양유실량도 증가하는 것으로 분석되었다. 평균토양유실량을 시나리오별로 보면, A1B 시나리오의 경우 2080s을 기준으로 1/5,000 scale에서는 약 0.18 ton/ha/year, 1/25,000 scale에서는 약 0.07 ton/ha/year, 1/50,000 scale에서는 약 0.07 ton/ha/year의 유실량이 각 공간해상도별로 증가하였다. B1 시나리오의 경우 2080s을 기준으로 1/5,000 scale에서는 약 0.03 ton/ha/year, 1/25,000 scale에서는 약 0.01 ton/ha/year, 1/50,000 scale에서는 약 0.01 ton/ha/year의 토양유실량이 증가한 것으로 분석되었다.

• Korean Journal of Soil Science and Fertilizer
• /
• v.35 no.3
• /
• pp.169-174
• /
• 2002

The aim of this study was to test a utilization possibility of hairy vetch as a green manure in rice cultivation. The effect of hairy vetch on yield and nitrogen uptake or rice was investigated for three years. The yield of rice increased by 7% when hairy vetch was supplied at 2~3 weeks before rice transplanting compared to that of 1 week. The proper amount of hairy vetch incorporated into soil without nitrogen fertilization was $15{\sim}20ton\;ha^{-1}$. There was a severe lodging of rice with yield reduction when hairy vetch was supplied over $25ton\;ha^{-1}$. When $20ton\;ha^{-1}$ of hairy vetch was supplied the rice yield increased by 6% due to the increase of panicle number per square meter 20%.

• Economic and Environmental Geology
• /
• v.40 no.1 s.182
• /
• pp.103-113
• /
• 2007

The empirical USLE and the physically-based GeoWEPP which were distributed model linked with GIS (Geographical Information System) were applied to small natural catchment located in Icheon-si, Gyeonggi-do, South Korea. The results using by two models were total sediment yield from study catchment between January, 2004 and January, 2005. During the study period, the observed total sediment yield was 270.54 ton and the total sediment yield computed by USLE and GeoWEPP model were 358.1 ton and 283.30 ton, respectively. Each of results computed by USLE and GeoWEPP overestimated more than the observed total sediment yield, but, based on the results, the total sediment yield computed by GeoWEPP approximated to the observed result. We suggest that the reason why the total sediment yield using by models overestimated was that computed amounts by two models did not contain the amount of suspended sediment flowed over the weir.

• The Korean Journal of Ecology
• /
• v.1 no.2
• /
• pp.57-65
• /
• 1977

The biomass and net production of alder and oak trees was estimated by allometric method. The productivity of the two stands of alder and oak was obviously different judging from the rate of photosynthesis productive structure and vertical distribution of light. The amounts of net photosynthesis under the saturated light were 2.31, 1.42mg $CO_2/dm^2\cdot$hr. in the sun and shade leaves of alder tree and 1.58, 0.84mg $CO_2/dm^2\cdot$hr in that of the oak, respectively. Total annual respiration loss calculated from the respiration measured at $25^{\circ}C$ and the mean air temperature from every 10 days were 13.56ton/ha.yr in the alder stand and 19.83 ton/ha.yr in the oak. The productive structure and the vertical distribution of light in the stand were assumedly more effective to produce dry matter in the oak stand than in the alder. The biiomasses measured in 1975 and 1976 were 51.51 and 56.82 ton/ha in the alder stand and 73.35, 86.77 ton/ha in the oak one, respectively. Annual net production and gross production were 8.56 and 22.12 ton/ha.yr in the alder stand but those were 17.90 and 37.74 ton/ha.yr in the oak stand. The ratios of respiration to gross procution (R/Pg) were prespectively 0.61 and 0.53 inthe alder and oak stands. Efficiencies of solar energy utilizaztion of net production during the growing season(May-Oct.) were 0.67 and 1.40% and those of gross production were 1.72 and 2.94% in the alder and oak stands respectively.