• Journal of Mushroom
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• v.12 no.1
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• pp.41-51
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• 2014

Cauliflower mushroom widely known high concent of ${\beta}$-glucan for farm cultivation invigoration verified characteristics of mycelia growth, genetic diversity, resistance to Trichoderma by replacement culture with Trichoderma and growth characteristics of new variety crossbleeding strain. The result of replacement culture with Trichoderma for verification resistance about Trichoderma, 6951 (T. viride) strain did not show special change after formation of confrontation line and 6952 (T. spp.) strain was showed more formation of spore after formation of confrontation line. But 6426 (T. harzianum) strain found to encroach part of growth area of cauliflower mushroom mycelia. Among 10 kinds cauliflower mushroom strain, JF02-06 strain collected by Gurye, found did not spore of Trichoderma and thought to be resistant to Trichoderma. The result of crossbleeding after selected that mother strain good growth and formation of fruit body, verified good mycelia growth at JF02-47, 49 and 50 strain in Korean pine of wood-chip media. The result of gene sequence about ITS1, 5.8S and ITS4 for analysis of genetic diversity at crossbleeding strain, found high significance to other cauliflower mushroom in registered Genebank. The result of growth characteristic of spore and mycelia of cauliflower mushroom by observation microscope, size of spore showed water drop shape to major axis $6{\mu}m$ and minor axis $5{\mu}m$ and clamp showed 3 types in mycelia. The wide of mycelia was $3{\mu}m$. The characteristic of mycelia of cauliflower mushroom found to grow mycelia in clamp at approximately 50%. The growth speed of mycelia was $0.507{\mu}m/min$ and 2nd mycelia grown similar speed to mother mycelia at parallel with mother mycelia after growth speed at $0.082{\mu}m/min$. The formation of clamp made small clamp for 5 hours after shown transfer of electrolyte in mycelia inside. The septum formation started after 3 hours and then finally completed after 2 hours. In this study, strain of cauliflower mushroom verified resistance of Trichoderma, genetic diversity and characteristic of mycelia growth. Therefore, basic knowledge of cauliflower mushroom will improve and further contribute to development of mushroom industry.

• Korean Journal of Animal Reproduction
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• v.25 no.2
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• pp.163-169
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• 2001

OSBA(oocytes-sperm binding assay) is a tool developed for rapid test of optimal condition of IVF medium and protein source by binding ability of mouse sperm and egg. Mouse oocyte-cumulus complexes were prepared by removing of the cumulus cells with 0.1% hyaluronidase. 10$\pm$2 oocytes per 30 ${mu}ell$ medium drop were inseminated with 3 ${mu}ell$ sperm suspension and were cultured f3r 3 hours and 24 hours, respectively. And the oocytes were recovered gently and the No. of sperm bound on oocytes were counted. In the Exp. 1, the ratio of oocytes bound with one sperm at least were 60.2%(50/83), 2%(2/77) and 100%(79/79) in the medium with no protein, FBS(15%, v/v) and BSA(0.4%. w/v), respectively, Fetal bovine serum(FBS) seriously inhibited sperm binding on oocyte, although bovine serum albumin(BSA) promoted the binding ability. The inhibiting effect of FBS was dependent on the concentration of FBS. The sperm binding ability according to oocyte maturity was tested in the Exp. 2. There was no significant difference between Met. II (mature) and Met. I (intermediate mature) oocytes in the number of oocytes bound with sperm and the number of sperm bound on oocytes. Finally, in Exp. 3, two batches of Ham's F10 medium with good and poor quality by OSBA were tested (The ratios of embryos developed from PN 1-cell stage to hatched blastocyst; 25% vs. 70%). In the medium with good quality, sperm binding ability was significantly increased (P ＜ 0.05). The ratio of oocytes bound with one sperm at least was 66% and 90% in the medium with poor and good quality, respectively. Conclusively, It was possible to test IVF medium condition rapidly and easily by OSBA.

• Journal of the Korean earth science society
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• v.38 no.1
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• pp.64-79
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• 2017

We have reported the petrographic properties on the soda straw primarily based on the field measurements and discussed the causes of their traits. 156 soda straws in district B of the Baeg-nyong Cave nominated with the natural monument No. 260 have been investigated to estimate physical, sedimentological and textural characteristics. The soda straws have an average length of 3.05 cm with a standard deviation of 1.7 cm and a mean diameter of 6.0 mm. This result shows that the average diameter of the soda straws measured in this study is thicker than previous reports by 20%. Although the drip rates of cave water from 85.3% of all the soda straws are exceedingly lower than 1 drop per 10 minutes, almost all soda straws have a dripping water. We firstly report growth lamina in the Korean soda straw from 85.3% of all samples, and this textural dominance indicates that the growth lamina are one of the common features of the soda straws at least in the study area. Secondary precipitations inside the soda straw were identified from 68.6%. Notably, the strong inverse correlation between growth lamina and secondary precipitates was represented from 70.5% of all samples. This finding might be explained by the seasonality of cave drip water supplied into the soda straws or the increased opacity caused by secondary precipitates. Based on petrograhic characteristics, the soda straws in the study area can be classified into normal and erratic types. Hopefully our results on the soda straws in Baeg-nyong Cave would provide a basis for the descriptions of soda straws from other caves and paleoclimatic applications.

• Journal of Korean Society of Forest Science
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• v.32 no.1
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• pp.1-8
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• 1976

One of the most common needle leaf species used in planting in Korea is korean pine (Pinus koraiensis S. et Z.), and jack pine (Pinus banksiana Lamb.) is one of the test species for suitability. The relation of nursery bed density of 2-1 korean pine and 1-1 jack pine was studied at the Kwang Nung Nursery, Central Branch Station of Forest Research Institute, and about 40km north of Seoul. Nursery bed density of 2-1 korean pine, which ranged from 36 to 324 trees per square meters and of 1-1 jack pine, which ranged from 25 to 169 trees per square meters, had a marked effect on caliper, height, dry weight and percent and amount of plantable stock. The soil physical and chemical properties is silt plus clay, 50.55 percent; organic matter, 2.09 percent; total nitrogen, 0.13 percent; available phosphorus, 253.25 ppm; exchangeable potash, 0.46 m.e/100g; and pH, 5.58. As the density of the nursery seedling stand of 2-1 korean pine increases, the average tree height increases (Fig. 1A), but in 1-1 jack pine density do not affect to increase or decrease the average tree height. As the density of nursery bed increases, the average stem caliper (at 2cm above ground line) and dry weight decrease (Fig. 1B), but the decreasing rate is more seriously in 1-1 jack pine than 2-1 korean pine (Fig.5). As increasing the density of nursery bed, the T/R ratio of trees of the test species increase. Also the dry weight of leaf, stem and root parts are decreasing in proportion to the increase of stand density, but the drop rate of jack pine is more rapid than korean pine (table. 1) The patent facts of difference of growth characteristics between 2-1 korean pine and 1-1 jack pine were studied. These facts should be used to select the scale of stand density at the nursery bed or the plantable site. Korean pine is demanded high density, on the other hand in jack pine low density are more suitable to manage the stand density. Stands of comparatively low density had the greatest percentage of high-quality stock, and the stands of high density had less than the high quality trees of low density. An important criterion of the best density is percent and number of high-quality trees produced per square meter of bed area. Stem caliper and stem height of seedling is used in most public nurseries to sort seedling into plantable grades. The stock grade standard has set at 4.5mm caliper and 16cm height of 2-1 korean pine as the minimum desired stem caliper and height. By the result studies, the plantable stock grade standards of 2-1 korean pine used at stem height 16cm and stem caliper 4.5mm from public nurseries should be reformed to stem height 18cm and stem caliper 4.0mm by the growth characteristics and the tree distribution of stem height and caliper of relation to density. For the 2-1 korean pine, best density should be about 160 to 200 trees per square meter according to soil fertility. For the 1-1 jack pine, the suitable standard of plantable stock should be at stem height 25cm and caliper 6mm (at 2cm above ground line) and best density was about 100 to 120 trees.

• Journal of Korean Society of Environmental Engineers
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• v.36 no.6
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• pp.421-428
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• 2014

For the analysis of water supply network, demand-driven and pressure-driven analysis methods have been proposed. Of the two methods, demand-driven analysis (DDA) can only be used in a normal operation condition to evaluate hydraulic status of a pipe network. Under abnormal conditions, i.e., unexpected pipe destruction, or abnormal low pressure conditions, pressure-driven analysis (PDA) method should be used to estimate the suppliable flowrate at each node in a network. In order to carry out the pressure-driven analysis, head-outflow relationship (HOR), which estimates flowrate at a certain pressure at each node, should be first determined. Most previous studies empirically suggested that each node possesses its own characteristic head-outflow relationship, which, therefore, requires verification by using actual field data for proper application in PDA modeling. In this study, a model pipe network was constructed, and various operation scenarios of normal and abnormal conditions, which cannot be realized in real pipe networks, were established. Using the model network, data on pressure and flowrate at each node were obtained at each operation condition. Using the data obtained, previously proposed HOR equations were evaluated. In addition, head-outflow relationship at each node was analyzed especially under multiple pipe destruction events. By analyzing the experimental data obtained from the model network, it was found that flowrate reduction corresponding to a certain pressure drop (by pipe destruction at one or multiple points on the network) followed intrinsic head-outflow relationship of each node. By comparing the experimentally obtained head-outflow relationship with various HOR equations proposed by previous studies, the one proposed by Wagner et al. showed the best agreement with the exponential parameter, m of 3.0.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.30 no.3
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• pp.42-56
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• 2012

This study was carried out to investigate the construction characteristics and the landscaping design skill for Wiyiam at Ongnyucheon(玉流川) in the rear garden of Changdeok Palace focusing on constructing technique, space composition and transformational process of the site. The results of this study were summarized as follows; First, Wiyiam of Ongnyucheon was constructed as garden ornament which was modified the huge bedrock into the shape of the mountain. The waterfall of Wiyiam was originally made of torrent which water flowed into the bottom, but it was reconstructed to take the effect of Inak(離落: the method to drop water from high place) by carving rock into square shape at the era of King Gojong(高宗). Second, main characteristics of Wiyiam appeared in Donggwoldo was the hill built up with a square pond and ground at the back of Wiyiam and the profound scenery of mountains and stream from the view of Wiyiam. Also, pavilions such as Soyojeong(逍遙亭), Cheongujeong and Taegeukjeong(太極亭) built in Ongnyucheon seemed to be constructed as the spots to appreciate the view and waterfall sound of Wiyiam. Also the spots were not bounded by the function of creating special water systems such as Cheongujeong pond and Taegeukjeong pond and showed the outstanding landscape design skill to make people feel unusual interest from each spot. On the other hand, this study considered that the evening scenery of Wiyiam, beautiful sound of falling water, unusual water system with beautiful plant materials were landscaped for the function of the psychological peace and stability to the appreciators. Lastly, the extreme change of space composition in Ongnyucheon was assumed as a strategy to improve the existing poor drain environment by confirming that the mountain stream and wall of Soyojeong were removed and drainage in both side of Soyojeong was installed in the 21th year of King Gojong's reign(1884).

• The Korean Journal of Air & Space Law and Policy
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• v.34 no.1
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• pp.235-268
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• 2019

Under the Aviation Safety Act of Korea, any person who intends to operate a drone is required to follow the operational conditions listed below, unless approved by the Minister of Land, Infrastructure, Transport and Tourism; (i) Operation of drones in the daytime, (ii) Operation of drones within Visual Line of Sight, (iii) Maintenance of a certain operating distance between drones and persons or properties on the ground/ water surface, (iv) Do not operate drones over event sites where many people gather, (v) Do not transport hazardous materials such as explosives by drone, (vi) Do not drop any objects from drones. Requirements stated in "Airspace in which Flights are Prohibited" and "Operational Limitations" are not applied to flights for search and rescue operations by public organizations in case of accidents and disasters. This paper analyzes legal issues as to definition and regulations of drones in Korean Aviation Safety Act. This paper, also, offers some implications and suggestions for regulations of drones under Korean Aviation Safety Act by comparing the regulations of drones in Japanese Civil Aeronautics Act.

• Economic and Environmental Geology
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• v.54 no.1
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• pp.105-115
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• 2021

The geological CO2 sequestration in underground geological formation such as deep saline aquifers and depleted hydrocarbon reservoirs is one of the most promising options for reducing the atmospheric CO2 emissions. The process in geological CO2 sequestration involves injection of supercritical CO2 (scCO2) into porous media saturated with pore water and initiates CO2 flooding with immiscible displacement. The CO2 migration and distribution, and, consequently, the displacement efficiency is governed by the interaction of fluids. Especially, the viscous force and capillary force are controlled by geological formation conditions and injection conditions. This study aimed to estimate the effects of surfactant on interfacial tension between the immiscible fluids, scCO2 and porewater, under high pressure and high temperature conditions by using a pair of proxy fluids under standard conditions through pendant drop method. It also aimed to observe migration and distribution patterns of the immiscible fluids and estimate the effects of surfactant concentrations on the displacement efficiency of scCO2. Micromodel experiments were conducted by applying n-hexane and deionized water as proxy fluids for scCO2 and porewater. In order to quantitatively analyze the immiscible displacement phenomena by n-hexane injection in pore network, the images of migration and distribution pattern of the two fluids are acquired through a imaging system. The experimental results revealed that the addition of surfactants sharply reduces the interfacial tension between hexane and deionized water at low concentrations and approaches a constant value as the concentration increases. Also it was found that, by directly affecting the flow path of the flooding fluid at the pore scale in the porous medium, the surfactant showed the identical effect on the displacement efficiency of n-hexane at equilibrium state. The experimental observation results could provide important fundamental information on immiscible displacement of fluids in porous media and suggest the potential to improve the displacement efficiency of scCO2 by using surfactants.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.59 no.4
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• pp.511-520
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• 2014

Kenaf (Hibiscus cannabinus L.) was recognized as a potential source of forage. To reduce the production cost, we should insure large cultivation area. The one of the best candidate places to expand the useful kenaf production was 'Saemangeum' reclaimed land. To confirm the possibility of kenaf growth in reclaimed land, we seeding and cultivated the kenaf in 'Saemangeum'. The germination percentage of kenaf on 5.0 dS/m soil salinity was 18%. It is less 66% than that of 4.0 dS/m soil salinity and at 6.0 dS/m, the germination percentage of kenaf was under 10%. The growth and development of kenaf in reclaimed land grew worse with increasing soil salinity. The stem diameter which the most important factor that decide the value and yield of product was upper 2.6 cm when soil salinity maintained under 4.0 dS/m, but if soil salinity marked over 4.0 dS/m, the stem diameter of kenaf was drop under 2.0 cm and it deteriorate the number of leaves per plant by 20~46%. The necrosis on older tip and marginal leaves were noted approximately first month after seeding which was correlated directly with the salinity levels of reclaimed soil. Reduction of total yield was coincide with increasing levels of EC. If soil salinity over 5.0 dS/m, the amount of decreased by soil salinity was 51% than that of non-reclaimed region. The allowable soil salinity level of which could be maintained within 20% reduction rate was 4.2 dS/m. Consequently kenaf can be grown successfully with moderately saline soil condition. However, salt levels in excess of 4.2 dS/m severely have restricted plant growth and development and will result in significant yield reduction.

• Journal of Biosystems Engineering
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• v.7 no.2
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• pp.30-35
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• 1983

To investigate the factors affecting the transportability of spray droplets, the maximum distance, the effective distance, the ratio of even distribution, and the diameters of particles were measured in accordance with the different pressure levels of power sprayer using 3 hole swath type nozzle, and the results are summerized as follows; 1. The distance of the most dense point from the nozzle was shortened by 0.5 meter with the 100-meter-long hose. The maximum reaching distances were reduced by 1.5 and 1.0 meters for the 13m/m and the 8.5 m/m hoses respectively, and the effective distance were reduced by 0.5 meter for both cases. 2. The effective distance can not be extended beyond 14 meters even if the length of hose is minimized at the rated pump pressure 28 kg/$cm^2$, it was 1 meter longer for 13m/m hose compared to the 8.5m/m one. 3. In case of 13m/m hose, the most dense point can be extended further by 0.5 meter increasing the pump pressure by 8 kg/$cm^2$, and the maximum distance and effective distance were increased by 2.0 and 0.5 meters respectively. There was no significant effect of pressure changes on the transportability in case of 8.5m/m hose. 4. Both the reduction of hose length and the increase of pump pressure influenced in large extent to the atomization effect of droplets. It was noticed that the diameter of droplet is related to the pump pressure and inside diameter of hose. 5. The pressure drop in 100-meter-long and l3m/m hose was 5~7kg/$cm^2$ at the pump pressure range of 25~33kg/$cm^2$, and it is an equivalent of 2% per 10 meter length of hose.