• Korean Journal of Fisheries and Aquatic Sciences
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• v.17 no.6
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• pp.492-498
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• 1984

We have reported the seasonal and portional variation in the composition of uronic acid of alginic acid from Ecklonia cava in the previous study. In the present paper, uronic acid block structure of alginic acid from Ecklonia cave was investigated, and some related properties such as viscosity, the dependence on temperature and substitution of metallic ion were also discussed. The proportion M block was highest amnog three blocks in both of frond and stipe. The average values of M and G block ratios were $51.6|%\;and\;32.3\%$ in the frond, whereas $45.7\%\;and\;38.6\%$ in the stipe, respectively. The proportions of alternating blocks in the frond and stipe were similar, and the values were $16.1\%$ in the frond and $15.6\%$ in the stipe. The viscosity of $1\%$ sodium alginate solution was almost inversely proportional to the M/G and/or M block ratio. Viscosities were marked maximum from summer to autumn and minimum winter to spring. In the value of lower M/G and M block ratio, the viscosity seemed to have a considerable dependence on temperature. The temperature dependence was more appearant in the alginic acid from the frond (M/G ratio, 0.95; M block, $54.2\%$) collected in July and the stipe (M/G ratio, 1.61; M block $47.6\%$) in April. The affinity with metallic ion appeared higher in order of $Pb^{2+}>Cu^{2+}>Co^{2+}>Zn^{2+}$. The amounts of metallic ion exchange of the $Pb^{2+},\;Cu^{2+},\;Co^{2+}\;and\;Zn^{2+}$ were ranged from 3.4. to 4.7, 2.5 to 3.2, 1.8 to 2.2 and 1.6 to 1.7 meq/(g. sodium alginate), respectively.

• Journal of Ecology and Environment
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• v.43 no.1
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• pp.1-8
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• 2019

Background: Hibernating bats exhibit ubiquitous winter activity in temperate zones, but there is considerable between- and within-species variety in their intensity and purpose. Bats may fly during winter for sustenance or travel to other hibernacula. This study compared inter-regional variation in the winter activity of the greater horseshoe bat (Rhinolophus ferrumequinum). We predicted that weather and hibernacula-environmental conditions would influence winter activity patterns. Results: Winter activity patterns differed between regions. In the Anseong area, we confirmed movement inside the hibernaculum, but in Hampyeong, we observed movement both inside and between hibernacula. The two regions differ by $4^{\circ}C$ in average winter temperatures. Anseong experiences 22 days during which average daily temperatures exceeded $5^{\circ}C$, whereas Hampyeong experienced 50 such days. During the hibernating period, bat body weight decreased by approximately 17-20% in both regions. Conclusions: Ambient temperatures and winter-roost environments appear to be behind regional differences in hibernating bat activity. As winter temperatures in Korea do not favor insect activity, feeding probability is low for bats. However, bats may need to access water. At Anseong, underground water flows inside the hibernaculum when the reservoir outside is frozen. At Hampyeong, the hibernaculum does not contain a water source, but the reservoir outside does not freeze during winter. In conclusion, water-source location is the most likely explanation for regional variation in the winter activity of hibernating bats.

• 한국신재생에너지학회:학술대회논문집
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• 2009.11a
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• pp.587-589
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• 2009

The districts of underground geologic structure in Jeju island where underground air is distributed are lava cave, pyroclastic, open joint, and crushing zone. Such districts are identified to secure an enough airflow when air ventilation layer is to secure 25-35m in depth. In Jeju, Ground air is used for heating greenhouse and fertilizing natural $CO_2$ gas by suppling directly into greenhouse. But the heating method by suppling ground air into greenhouse directly bring about several problem. The occurrence of disease of the crops by high humidity is worried because the underground air which becomes discharge from underground air layer has over 90% relative humidity. The underground air is inadequate in heating for crops which need high temperature heating such as mangos, Hallbong and mandarin orange because the temperature of it is $15{\sim}18^{\circ}C$. Also There is worry where the ventilation loss becomes larger because the air pressure inside greenhouse is high by supplying underground air directly. In this study the heat pump system using underground air as heat source was developed and heating performance of the system was analysed. Heating COP of the system was 2.5~5.0 and rejecting heat into greenhouse and extracting heat from underground air were 40,000~27,000 kcal/h, 30,000~18,000 kcal/h respectively.

• Korean Journal of Ecology and Environment
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• v.47 no.4
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• pp.258-272
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• 2014

Bats hibernating in caves and unused mines were surveyed during six hibernation periods (from December to February, 2005 and 2011) in Korea. We recorded 13,288 individuals of 11 species at 140 hibernacula (60 caves and 80 abandoned mines): Rhinolophus ferrumequinum (n=3,509), Eptesicus serotinus (n=6), Hypsugo alaschanicus (n=349), Miniopterus fuliginosus (n=5,919), Murina hilgendorfi (n=417), Myotis aurascens (n=294), Myotis bombinus (n=2), Myotis formosus (n=401), Myotis macrodactylus (M.mac, n=151), Myotis petax (n=2,131) and Plecotus ognevi (n=109). We studied the thermal preference and selection of hibernacula of seven dominant bat species. Four species (Myotis petax, Hypsugo alaschanicus, Plecotus ognevi and Murina hilgendorfi) hibernated mainly at the cold site below than $7^{\circ}C$, while three species (Myotis formosus, Rhinolophus ferrumequinum and Miniopterus fuliginosus) hibernated at warm site above than $7^{\circ}C$. Rhinolophus ferrumequinum had broad-ranged temperature zone for their hibernating site. The mean body temperature of each species was $2.64{\pm}0.98^{\circ}C$ for Murina hilgendorfi, $2.76{\pm}1.68^{\circ}C$ for Hypsugo alaschanicus, $2.78{\pm}0.98^{\circ}C$ for Plecotus ognevi, $4.52{\pm}1.02^{\circ}C$ for Myotis petax, $7.83{\pm}1.94^{\circ}C$ for Miniopterus fuliginosus, $9.19{\pm}2.35^{\circ}C$ for Rhinolophus ferrumequinum and $13.64{\pm}0.76^{\circ}C$ for Myotis formosus, respectively. The body temperatures of hibernating bats were closely related to the rock surface temperatures rather than the ambient temperatures. In conclusion, the diversity of bats community in hibernacula were closely related to the range of inner ambient temperature of hibernacula, and more species of bats were occupied at sites presenting a broad range of ambient temperatures.

• Korean Journal of Plant Taxonomy
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• v.35 no.4
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• pp.287-294
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• 2005

Three unrecorded fern species from the flora of Korea, Nephrolepis cordifolia, Athyrium epirhachis, and Asplenium castaneo-viride, are reported here. Nephrolepis cordifolia, recognized as introduced species and cultivation in Korea until now, is found in the wild at the entrance of small cave in Jeju island. Athyrium epirhachis is found under the Quercus acuta forest at about 400 - 500 m alt. in Jeju island. This species is similar to A. otophorum but different from the latter by having once pinnately divided leaf blade and the decurrent base of ultimate segment. Asplenium castaneo-viride is hybrid between A. ruprechtii and A. incisum and is distinguished from parental species by presence of proliferation, shape of leaf blade, pattern of venation, and leaf texture.

• Mycobiology
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• v.48 no.4
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• pp.276-287
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• 2020

An algific talus slope is composed of broken rocks with vents connected to an ice cave, releasing cool air in summer and relatively warmer air in winter to maintain a more stable microclimate all year round. Such geological features create a very unusual and delicate ecosystem. Although there are around 25 major algific talus slopes in Korea, lichen ecology of these areas had not been investigated to date. In this study, we report the first exploration of lichen diversity and ecology at an algific talus slope, Jangyeol-ri, in Korea. A total of 37 specimens were collected over 2017-2018. Morphological and sequencing analysis revealed 27 species belonging to 18 genera present in the area. Of particular interest among these species was Solorina saccata, as it has previously not been reported in Korea and most members of genus Solorina are known to inhabit alpine regions of the Northern Hemisphere. We provide here a taxonomic key for S. saccata alongside molecular phylogenetic analyses and prediction of potential habitats in South Korea. Furthermore, regions in South Korea potentially suitable for Solorina spp. were predicted based on climatic features of known habitats around the globe. Our results showed that the suitable areas are mostly at high altitudes in mountainous areas where the annual temperature range does not exceed 26.6 ℃. Further survey of other environmental conditions determining the suitability of Solorina spp. should lead to a more precise prediction of suitable habitats and trace the origin of Solorina spp. in Korea.

• Journal of Satellite, Information and Communications
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• v.12 no.3
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• pp.41-49
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• 2017

This paper will describe lunar lava tubes' five analyzed fields, such as geology, geomorphology, internal configuration, stability, communication and habitats requirements. This research gets through qualitative and qualitative data analysis as following results. A huge size and configuration differences between lunar lava tubes and earth one on geology and landform environments. Exo-genetics activities, such as meteorites, radiation, and sudden temperature bigger affect than Endo-genetic activities, such as effusion and earthquake of the lunar lava tubes. Landform and internal configuration of the lunar lava tubes due to the huge cave perilous landform that gravity difference have a technical limitation from internal approach and data obtain of the huge skylights and sinuous rilles. Stability of the lunar lava tubes deals with geology and landform. It was obvious geo-structural stability elements results generated on low rate of collapsed halls(skylights), low gravity, and relatively thick covers. In terms of the communication capability on the external and internal lunar lava tubes cordless communication techniques will overcome limitations of the sun-power generates supporting communication systems. Through this research it realized obvious differs between potential habitats possibility by accumulative theories by scholars and techniques of the lunar lava tubes. Especially, it is a favorable expectation throughout overcoming attempt on zero gravity, cosmo radiation, lunar dust of the exo-genetic limitations to the steep escarpment of skylights to approach and achieve techniques by the civil engineering, networking and GIS techniques as the endo-genetic environment treatment.

• Journal of The Korean Society of Grassland and Forage Science
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• v.34 no.3
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• pp.179-186
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• 2014

The objective of this study was to determine the best performing switchgrass (Panicumvirgatum L.) cultivar with three different seeding dates as a bioenergy source in Republic of Korea. Split-plot in time with three replications was performed and three switchgrass cultivars, Carthage (CT), Cave-in-Rock (CIR), and Forestburg (FB) were used in this experiment from 2009 to 2012. Plots were seeded on April 23, May 4, and May 13, 2009 and were harvested once in November each year. No fertilizer was applied to the field for the first year; however, in second and third years (June 2010 and May 2011, respectively), N, $P_2O_5$ and K2O fertilizers were applied in 67,45 and 90 kg $ha^{-1}$, respectively. Soil pH (5.9) and climate condition including temperature ($10.4{\sim}17.5^{\circ}C$) and precipitation (89.4~109.8 mm $month^{-1}$) were suitable for switchgrass cultivation. Total dry matter yields were higher in CT and CIR compared to FB and were 16.9, 15.9, and 4.5 ton $ha^{-1}$, for CT, CIR, and FB, respectively (p<0.0001). The samples were analyzed for dry matter (DM), crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF), crude fiber (CF), ether extract (EE), and ash. No significant differences in energy content (p = 0.96) and chemical composition among cultivars (p>0.05) were found. Seeding dates did not affect DM yield (ton $ha^{-1}$), chemical composition and energy content significantly (p>0.05). Significant difference was observed for heights among CT, CIR, and FB (177.59, 169.98, and 94.89 cm, respectively, p = 0.0002). In conclusion, based on soil characteristics and climate condition in Korea compared to other countries, switchgrass can be cultivated successfully. Considering dry matter yield and energy content of these three cultivars of switchgrass CT and CIR adapted better to climate in Middle Eastern of Republic of Korea than Forestburg for bioenergy purpose.

• Journal of the Korean earth science society
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• v.42 no.2
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• pp.185-194
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• 2021

A lava dome and sheet lava flow can be observed at the seashore of Aewol, Jeju island. The cylindrical lobes are characterized by a concentric structure consisting of a massive core and radial joints. Columnar joints with different thickness between the upper and lower parts are developed in the sheet lava flow around the rock salt field in Goeomri. The upper part of the columnar joints is uneven in shape, and has a diameter of 120-150 cm. The lower part of the columnar joints is hexagonal and pentagonal in shape, and has a diameter of about 60 cm. The cylindrical lobes can be divided into two groups based on size and shape. One is a megalobe, with a semicircular outline and a maximum diameter of 30 m. The other is a circular lobe with a diameter of less than 10 m. The columns in the radial joints have hexagonal and pentagonal cross sections and gradually increasing diameter, outward from the core, to a size of 80-120 cm at the rim. The concentric structure observed in the cylindrical lavas is attributable to a combination of four factors. The first is a circular crack caused by the decrease of the temperature and density difference between the inside and outside of the cylindrical lava flow. The second is a concentric chisel mark of the radial joints, which formed at the same time as the radial joints. The third is a flow band, which is a trace left in a round passage when lava flows through. The fourth is a vesicular band formed in a cave by gas bubbles escaping from the lava flow.