• Journal of Bio-Environment Control
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• v.7 no.1
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• pp.71-77
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• 1998

The root-zone environment is an important factor to the plant growth and it is closely related to the thermal characteristics of the root media. In this study thermal characteristics of root media with ambient environmental conditions were analyzed. The temperatures of nutrient solution as well as inside air of culture bed were measured in Nutrient Film Technique(NFT) and Deep Flow Technique(DFT) systems, and also the temperatures of root media measured in aggregate culture systems , The temperature of nutrient solution of NFT system with as low as 3$\ell$/min of flow rate was 3$^{\circ}C$ higher than that with 5 $\ell$/min of flow rate in the daytime, and the temperature of inside air was 2$^{\circ}C$ higher at night. And the temperature of nutrient solution of DFT system with as low as 0.8 cm of water level was 1-2$^{\circ}C$ higher than that with 1 8 cm in the daytime, and the temperature of inside air was almost same at night. The root-zone temperatures in the perlite and rockwool granulate systems with film mulching were 3$^{\circ}C$ higher than those without film mulching in the daytime. However, the rockwool slab system with film mulching showed the same trend as rockwool granulate system, but relatively higher temperature than any other medium because of the exposure of media surface to the ambient air. Additionally the temperature below the plant was measured 3$^{\circ}C$ lower than that between plants.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.42 no.3
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• pp.292-298
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• 1997

To compare the growth pattern of ginseng plant under between conventional shading(light transmittance rate 3％) and polyethylene net shading(light transmittance rate 10％), the distribution of leaf area, specific leaf weight (S. L. W), leaf and stem dry weight and changes in light intensity were investigated in 2, 4 and 6 year old ginseng plant populations. Light transmittance rate(L.T.R.) was 3％ at front line, 2％ at middle line and 1.5％ at rear line under conventional shading but it was 12, 10 and 8％ under polyethylene net(P.E) shading, respectively. In 2 year old population, there was a little difference in the growth characteristics investigated between conventional and P.E. shading. In 4 year old field, the leaf area, stem and leaf dry weight decreased in large amount in the order of middle, and rear line on ridge under conventional shading, but with a little difference under P.E. shading. And these trends enlarged in 6 year old field with appearance of a large part of shoot over furrow from ridge planted ginseng. Root yield index was much lowered at the rear 3rd, 4th and 5th line of the conventional shading bed, but there was no yield difference among lines except 5th lines under the P.E. shading with higher yield by 28％ than conventional shading.

• Journal of the Korean Wood Science and Technology
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• v.27 no.2
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• pp.62-69
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• 1999

With increased utilization of chemical fertilizer, soil fertility is getting serious problem. As a result, using organic soil conditioner (woody wastes or sawdust compost) would be only solution to recover soil vitality. In this study, manufacturing and characteristics of organic soil conditioner from Shiitake bedlogs (woody wastes) were studied. Also, to investigate the effect of continuous application of this bedlog compost on growth of plants, growth tests for radish and tree seedlings were done. The results are as follows ; Analytical results of decayed and fresh wood materials showed almost same as its wood components. The mixing ratio of raw materials with the other filling materials is essential for the manufacturing as well as good quality of its compost during composting process. In this experiment, mixing 12kg of urea, 25kg of lime, 40kg of chicken shit, and small amount of fermentation aids corresponding to I ton of sawdust resulted in good composts. Their moisture contents were adjusted to about 55%. Temperature of pile, in composting process, rose after I week and kept about above $60^{\circ}C$ for certain period. They were turned two times, 30th and 59th day, respectively, after piling. This bedlog compost contained 81.7% of high organic matter, 1.4% of a little nitrogen, 6.75 of pH and 25 - 30 of C/N ratio. There were no harmful effect on germination and growth of plants, such as radish and softwood and hardwood seedlings. Concerned to the effect of bedlog compost on soil temperature, the compost did not affect plant growth by changing soil temperature abruptly, but compensated the soil temperature such as a little increasing on the early morning, a little decreasing on the mid-day or afternoon (pm 2:00), and increasing on the early evening (pm 6:00).

• Korean Journal of Ecology and Environment
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• v.34 no.2 s.94
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• pp.119-125
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• 2001

Total bacterial density was investigated in the main stream and tributaries of the Kyongan Stream and inlet parts of Paltang Reservoir from September 2000 to February 2001 by acridine orange direct count (AODC) method. Total bacterial number in the Kyongan Stream was mainly under influence of the effluent discharge of sewage wastewater treatment plant (SWTP) located in the upstream or downstream. Decreasing rate with water flowing distance (km) in the main stream is $0.13\;{\time}\;10^6$ cells/ml, and it was estimated to much accumulating quantity on the stream bed during transport to downstream. Average values of total bacterial number in September${\sim}$October, November and December${\sim}$February were range $1.74{\sim}3.10{\time}10^6$, $1.86{\sim}7.30{\time}10^6$ and $4.56{\sim}8.75{\time}10^6$cells/ml, respectively, and were high at low temperature than that of high temperature period. Total bacterial number was more abundant at below $10^{\circ}C$ with $2.1{\sim}3.0$ folds than at above $10^{\circ}C$. Water quality by total bacterial number was classify to eutrophic and the potential of wastewater treated effluent for the microbial contamination assessed to very high. The results of this study indicate that the management of point source, SWTP effluent, is urgent to mitigate bacterial impact of Paltang Reservoir as well as the Kyongan Stream.

• Membrane Journal
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• v.23 no.1
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• pp.12-23
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• 2013

On the subject of river bed water in Seomjin river, it had accomplished the verifying experiment of membrane filtration pilot plant for evaluating the applicability of its process throughout the prediction of membrane fouling as a function of the pore size of membrane and the determination of optimum coagulant dosage. On the result of the experiment for the evaluation of the membrane fouling as a function of the pore size, a increasing rate of irreversible resistance of membrane pore size $0.1{\mu}m$ and $0.01{\mu}m$ was measured each $0.44{\times}10^{12}/m^2$ and $0.42{\times}10^{12}/m^2$, respectively. And on the result of Flux-test, it showed that the optimum coagulant dosage was measured lower than the it of the Jar-test. The result to be operated in a condition of a permeate flux $1.0{\sim}1.5m^3/m^2{\cdot}day$ without coagulation and a permeate flux $1.0{\sim}2.0m^3/m^2{\cdot}day$ with coagulation was maintained at stable trans-membrane pressure (TMP) value for 6 months up to. Therefore it showed that the stable operation without the coagulation was possible on permeate flux $1.0{\sim}1.5m^3/m^2{\cdot}day$ in the operation of membrane filtration process.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.15 no.2
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• pp.1-8
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• 2012

This study is carried out to find the most optimal soil-plant combination in the urban agriculture by analyzing the association of soil base material which is being used in the urban agriculture with the growth of plants. 4 types of easily purchased soil (bed soil(A), animal vermicast soil(B), earth worm soil(C) and matured compost(D)) verified in aspects of effect and safety of soil in terms of growth of crop is selected as experimental soil and B, C, D type soils are mixed with granite soil at the ratio of 7 : 3. And granite soil(E) is set as a controlled soil and is compared to verify the effect of the experimental mixed soil. Herbaceous plants are classified into the fruit vegetables (Lycopersicon esculentum Mill. and Capsicum annuum L.), leafy vegetables (Brassica campestris L. ssp. Pekinensis and Lactuca sativa L.), medicinal vegetables (Chrysanthemum zawadskii var. latilobum and Liriope platyphylla F. T. Wang & T. Tang). The results of comparison of growth of herbaceous plants in different soil types showed that fruit vegetables and leafy vegetables in general had excellent growth in D type soil mixture and A type soil in general and had the poorest growth in E type (controlled) soil. 'Chrysanthemum zawadskii var. latilobum' had the excellent growth in D type, B type, C type mixed soil and A type soil and E type (controlled) soil are followed in order. In the case of 'Liriope platyphylla F. T. Wang & T. Tang', the difference in growth by each soil was shown to be insignificant. Therefore, the soil applied in the urban agriculture varies depending on each species of herbaceous plants, but it is considered effective to cultivate herbaceous plant which is economical and productive by using D type mixed soil which can be recycled and inexpensive compared with other experimental soils in the urban agriculture.

• Applied Biological Chemistry
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• v.18 no.2
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• pp.65-70
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• 1975

The cultivation of ginseng plant (Panax ginseng C.A. Meyer) in Korea as an eminent medicinal herb may be traced far back in history. However, the practices in cultivation have not much improved in terms of efficiency and scientific farming. In the present study some experiments were undertaken for the search of the soil and nutrition conditions, because of the nutritional requirement of ginseng plant shaws quite unique compared with other crops. In both the seed bed and the field 'Yakto' has been traditionally employed or the prime source of nutrition of the crop. Yakto is a complex matter prepared from raw foliage of the broad-leaved trees as the main portion with the admixture of a variety of organic nitrogen source through fermentative processes. The composition of Yakto may be classified coarsely into the decomposed and undecomposed substances, the former being further fractionated according their solubilities, comprising also various colloidal matters whose composition and structure are yet to be known. The Yakto-fractions were subjected to analyze for search of its nature and coarse composition in terms of the distribution of nitrogen, contents of organic functional groups such as -COOH, phenolic-OH, alcholic-OH and methoxyl and hydrolysable sugars. Furthermore, absorption-spectra of each fraction were determined in visible and infrared region and compared the results each other.

• Journal of Korean Society of Environmental Engineers
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• v.28 no.3
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• pp.276-285
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• 2006

When polluted stream water was treated with biological aerated filter(BAF) in pilot plant, all operation with 90, 60, 45 and 30 min of EBCT at fixed $0.1m^3air/m^2min$ of aeration showed 80% or higher treatment efficiency of particle materials(SS, turbidity and Chl.-a) and 85% or higher efficiency of ammonia nitrogen removal. It was thought that, in case of BOD, biological stability may sufficiently be assured with BAF because grade III or IV inflow water was changed to grade I for outflow water. In case of $COD_{Mn}$, about 60% of removal efficiency was found. When the mechanism of the result was investigated, about 30% of COD materials was produced by algae clogged in the reactor. There was almost no biological decomposition because specific substrate utilization rate of algogenic organic materials were $0.0245mg{\cdot}COD_{Mn}/mg{\cdot}VSS{\cdot}day$, thus partial backwashing(washing the media in 1 m upper of the reactor once a day) was required. It is thought that elevation of removal rate about 10% of $COD_{Mn}$ and 5.5% of $BOD_5$ could be obtained with partial backwashing resulting in assurance of biologically more stable raw water and that saving backwashing water may be significant.

• Clean Technology
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• v.22 no.4
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• pp.292-298
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• 2016

In this study, the pyrolysis process was carried out in order to upgrade of heavy oil contained in the resources from Indonesia. In order to investigate the composition and basic properties of the heavy oil contained in the resources, the various analytical methods was used and then the TGA (thermogravimetric) method was especially used for the thermal degradation characteristics of heavy oil in the pyrolysis. From the results obtained from the various analytical methods, the reaction conditions such as the reaction temperature was collected for the pyrolysis process and the pyrolysis using the resources containing the heavy oil was conducted using the fixed-bed reactor under the various reaction conditions. Consequently, We found that the content of heavy oil contained in the resources was about 35% and the conversion of heavy oil and the recovery efficiency of thermal degradation oil were about 21 and 80%, respectively.

• Korean Journal of Ecology and Environment
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• v.49 no.4
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• pp.334-342
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• 2016

In this study, we explain the environmental variables that mainly influence the spatial and seasonal pattern of Galerucella nipponensis in 38 wetland and stream located at mid-low Nakdong River. G. nipponensis were found at total of 32 wetland, was strongly positively correlated with the biomass of Trapa japonica (t=2.173, $r^2=0.013$, p<0.05). In result of seasonal distribution during 3 years, the largest density of G. nipponensis adult were observed in summer (7~8 months), egg and larva was recorded in only early spring (4~5 months). Rainfall were negatively related with the seasonal distribution of G. nipponensis. They were more abundant in dry season (2015 year) than rainy seasons(2013~2014 year). Stable isotope analysis showed that the G. nipponensis consumed as food source no submerged leaf of T. japonica than other plant. However, utilization of T. japonica on Galerucella nipponensis were not influence to plant biomass and/or species composition in vegetated bed. Those considered as adaptive strategies for sustainable habitat maintenance that because T. japonica use as not only food source but also their lives for G. nipponensis.