• The Korean Journal of Ecology
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• v.21 no.2
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• pp.169-174
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• 1998

This is the review of vegetational history of the post-glacial period in Korea. most of studies for vegetational changes are located in the lowland alluvial plain, especially below the hilly zone of western and eastern coastal regions of Korea. A couple of methods, pollen analysis and radiocarbon dating, have been employed in these studies. These results lead us to establish the pollen zonation in Korea as the followings. Yasuda et al.(1980) classified six period in Yongrang lake of sokcho. These are as follow I. 17,000-15,000yr B.P.: Picea, Abies, Pinus(Haploxylon), Larix stage, II.15,000-10,000yr B.P:Herb, Pteridophyta stage, III.10.000-6,700yr BP.:Quercus stage, IV.6,700-4,500yr B.P.:Pinus, Quercus, Carpinus stage, V.4,500-1,400yr B.P.:Quercus. Pinus stage, VI.1,400yr B.P.-present: Pinus, Herbs stage. Jo(1979) also divided the period into two stages from the outcomes of analysis done in Jumoonjin and other sites I.10,000-6,000yr B.P.:Quercus stage, II.6,000-present: Pinus-Quercus stage, and three substages: IIa.6,000-3,400 yr B.P.:lower Pinus stage, IIb.3,400-2,000yr B.P.:Pinus-Quercus stage, IIc.2,000-present: Pinus stage. Choi(1993, 1996) divided the period into three stages: I.6,000-5,000yr B.P.:Alnus, Quercus stage, II.5,000-4,000yr B.P.: Alnus, Quercus, Pinus stage, III.4,500-2,600yr B.P.: Alnus, Pinus stage. In the period around 6,000yr B.P. distinct dominant species clearly occupied the lowland of the eastern and western coasts. Thus, this strongly supports the fact that even if Korea experienced its warm and wet climate after the lateglacial, it underwent a different environmental change, dry climate, compared to the regions of Japan.

• Journal of Microbiology and Biotechnology
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• v.8 no.6
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• pp.639-644
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• 1998

Extracellular serine proteases were isolated from a soil bacterium, alkalophilic coryneform bacterium TU-19, which have been grown in a liquid medium optimized at 3$0^{\circ}C$ and pH 10.0. Three different sizes, 120 kDa (protease I), 80 kDa (protease II), and 45 kDa (protease III), of serine pro teases were purified using Sephadex G-150 and QAE-Sephadex chromatography (Kang et al. 1995. Agric. Chem Biotech. 38: 534-540). SDS-PAGE showed that the 120 kDa protease was degraded into the 80 kDa protease in 20 mM Tris-HCI (pH 8.0) buffer solution. This degradation was enhanced in the presence of 0.5 M NaCl and 5 mM EDTA, but was inhibited in the presence of 5 mM $CaCl_2$. These results indicated that the $Ca^{2＋}$ ion seems to stabilize the 120 kDa protease like other proteases derived from Bacillus species. The $NH_2$-terminal amino acid sequences of the 10 residues of both proteases were completely identical: Met-Asn-Thr-Gln-Asn-Ser-Phe-Leu-Ile-Lys. In contrast to this, the 80 kDa protease has 1.5 times higher specific activity than the 120 kDa protease does (Kang et al. 1995. Agric. Chern. Biotech. 38: 534-540). Therefore the C-terminal of the 120 kDa protease seems to be autolyzed to the 80 kDa protease but this autolysis did not decrease the protease activity. Optimum pH and temperature of both 80 kDa and 120 kDa proteases were pH 10.5 and $45^{\circ}C$, respectively, and pH and thermal stability were almost identical. Several divalent ions except the $Fe^{2＋}$ ion showed similar effects on activities of both proteases, which are similarly resistant to three different detergents.

• Journal of Korean Society of Forest Science
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• v.10 no.1
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• pp.5-6
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• 1970

Abies koreansa Wilson grows at the upper part of Mts. Halla, Chiri, Mudung, Kaji and Dokyu. It was at first collected by Father U. Faurie on the May of 1907 from the Mt. Halla, Quelpaert. Cone colour of this species varies from green to black purple and the typical colour of it is violet purple. A form of black purple was named by Hatushima in 1934. Green and reddish brown or reddish purple colours of this species were discovered recently at the Mt. Halla. All these forms can be identified as the following. for. koreana - Abies koreana Wilson in Journ. Arn. Arb. 1, 188(1920) ; Mori, En. 27(1922) ; Uyeki, Timb. Tr. 117(1926) et Woody Pl. 5(1940) ; Chung et al, Comm. Nam. 12(1937) ; Handb. Kor. Manch. For. 71(1939) ; Kawamoto, III. For. P1. 16(1940) ; T. Lee, Arb. Kor. 12(1947) et Billiogr. Woody P1. 233(1966) ; Nakai, Synopt. 23(1952)-A. nephrolepis sensu Nakai, Rep. Veg. Chirisan 23, no. 27(1915) et Rep. Veg. Quelpaert Isl. 13, no. 142 (1915), non Max. (1866) Strobili violaceo-purpurei, bracteis viridibus juvenilibus vel stramineis matureis. Mt. Halla ( Lee, no. 970527K. ) for. chlorocarpa, forma nova ; Strobili et bracteae viridi sed rubescent in apice juvenili inflerescentiae. Mt. Halla ( Lee, no. 970527C. ) for. rubrocarpa, forma nova ; Strobili et bracteae rubro-purpurei vel rubro-fusui Mt. Halla ( Lee, no. 970527R. ) for nigrocarpa Hatushima, Rep. Exp. For. Kyushu U. 40(1934) ; T. Lee, Arb. Kor. 12(1947) et Bibliogr. Woody P1,233(1966). Strobili et bracteae nigro-purpurei. Mt. Halla (Lee, no. 970527N. )

• Journal of the Korean Society of Environmental Restoration Technology
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• v.15 no.1
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• pp.35-51
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• 2012

The vascular plants in Bukhansan Dulegil, Jingwan-dong Wetland and Bukhan-dong Cheolgeoji were listed 432 taxa (8.9% of all 4,881 taxa of vascular plants); 95 families, 274 genera, 345 species, 2 subspecies, 69 varieties and 16 forms. Divided into woody plants were 145 taxa (33.6%) and herbaceous plants were 287 taxa (66.4%). The Bukhansan Dulegil were listed (Myeongsang-gil 159 taxa, Huingureum-gil 227 taxa, Wooyiryeong-gil 216 taxa, Banghakdong-gil 139 taxa, Boru-gil 199 taxa), Jingwan-dong Wetland were listed 147 taxa and Bukhan-dong Cheolgeoji were listed 129 taxa. Based on the list of rare plants by Korea Forest Service and Korea National Arboretum were Viola albida Palibin (Violaceae), Iris minutiaurea Makino (Iridaceae) and Korea National Arboretum were endemic plants, Philadelphus schrenkii Rupr. var. schrenkii (Saxifragaceae), Weigela subsessilis L.H. Bailey (Caprifoliaceae). Based on the list of floristic regional indicator plants by Korean Ministry of Environment were total 22 taxa; Wisteria floribunda DC. for. floribunda in class IV, 3 taxa (Betula davurica Pall., Mukdenia rossii Koidz., Glechoma grandis Kuprian., etc.) in class III, 5 taxa (Acer triflorum Kom., Viola orientalis W. Becker, Heloniopsis koreana Fuse & Al., etc.) in class II and 13 taxa (Camptosorus sibiricus Rupr., Clematis patens C. Morren & Decne., Cirsium pendulum Fisch. ex DC., etc.) in class I. Based on the list of naturalized plants, 16 families, 35 genera, 37 species, 3 varieties, 1 form, total 41 taxa (Rumex crispus L., Abutilon theophrasti Medicus, Panicum dichotomiflorum Michx. etc.), naturalization rate was 9.5% of all 432 taxa of vascular plants and urbanization index was 13.3% of all 309 taxa of naturalized plants. Ecosystem disturbing wild plants were 5 taxa; Rumex acetocella L., Ambrosia artemisiifolia L., Ambrosia trifida L. var. trifida, Eupatorium rugosum Houtt., Aster pilosus Willd.

• Economic and Environmental Geology
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• v.12 no.1
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• pp.41-49
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• 1979

A literature review is made on the physical and chemical characteristics of clay minerals in acidic solutions from the mineralogical and hydrometallurgical viewpoints. Some of the important characteristics of clays are their ability to cation exchange, swelling, and incongruent dissolution in acidic solutions. Various clay minerals can take up metallic ions from solution via cation exchange mechanism. Generally, cation exchange capacity increases in the following order : kaolinite, halloysite, illite, vermiculite, and montmorillonite. In acidic solutions, the cation uptake such as copper by clay minerals is strongly inhibited by hydrogen and aluminum ions and thus is not economically significant factor for recovery of metals such as uranium and copper. In acidic solutions, the cation uptake is substial. Swelling is minimal at lower pH, possibly due to lattice collapse. Swelling may be controllable with montmorillonite type clays by exchanging interlayer sodium with lithium and/or hydroxylated aluminum species. The effect of add on clay minerals are : 1. Division of aggregates into smaller plates with increase in surface area and porosity. 2. Clay-acid reactions occur in the following order: (i) $H^+$ replacement of interlayer cations, (ii) removal of octahedral cations, such as Al, Fe, and Mg, and (iii) removal of tetrahedral Al ions. Acid attack initiates, around the edges of the clay particles and continued inward, leaving hydrated silica gel residue around the edges. 3. Reaction rates of (ii) and (iii) are pseudo-1st order and proportional to acid concentration. Rate doubles for every temperature increment of $10^{\circ}C$. Implications in in-situ leaching of copper or uranium with acid are : 1. Over the life span of the operation for a year or more, clays attacked by acid will leave silica gel. If such gel covers the surface of valuable mineral surfaces being leached, recovery could be substantially delayed. 2. For a copper deposit containing 0.5% each of clay minerals and recoverable copper, the added cost due to clay-acid reaction is about 1.5c/lb of copper (or 0.93 lbs of $H_2SO_4/1b$ of copper). This acid consumption by clay may be a factor for economic evaluation of in-situ leaching of an oxide copper deposit.

• The Korean Journal of Mycology
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• v.20 no.1
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• pp.1-10
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• 1992

Fresh fungi were collected during field trips to Ullung Island from August, 1990, to September, 1991. Among them, some polyporoid fungi were recognized to the species. Thirty three species were identified, among which nine fungi were confirmed new in Korea and registered here with descriptions. These fungi are Auriporia aurulenta, Ceriporiopsis gilvescens, Ceriporiopsis subvermispora, Gloeophyllum trabeum, Junghuhnia separabilima, Oligoporus stipticus, Oxyporus similis, Phellinus lavigatus, and Polyporus melanopus.

• Journal of Korean Society of Forest Science
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• v.87 no.4
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• pp.543-548
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• 1998

Portions of chloroplast genes(psbD and rbcL) were amplified from Pinus thunbergii(Japanese black pine : black pine) and Pinus densiflora(Japanese red pine : red pine) by PCR and digested by a restriction enzyme, HaeIII, respectively. Two species specific cpDNA markers were identified. With the observed cpDNA markers, paternal inheritance of cpDNA in pine hybrids was verified in an artificial hybrid family between black pine(Chollanam 37) and red pine(Chungchongbuk 3). On the basis of paternal inheritance of chloroplast genome in a hybrid, 2 portions of cpDNA amplified from 115 individuals of Pinus densiflora for. erecta were screened to detect any traces of black pine specific cpDNA markers in P. densiflora for. erecta which has been postulated as an introgressive hybrid between red pine and black pine(Hyun el al., 1967). All the analyzed individuals of Pinus densiflora for. erects revealed the identical profiles of HaeIII digested psbD and rbcL genes to red pine. This result suggests that there is no introduced chloroplast genome of black pine in Pinus densiflora for. erecta and that there is no concrete evidence of treating P. densiflora for, erecta as an introgressive hybrid between red pine(♀) and black pine(♂).

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.34 no.1
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• pp.85-95
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• 1998

The broadband ultrasonic transducers have been designed to use in obtaining the broadband echo signals from fish schools in relation to the identification of fish species. The broadening of bandwidth was achieved by attaching double acoustic matching layers on the front face of a Tonpilz transducer consisted of an aluminum head, a piezoelectric ring, a brass tail and to evaluate the performance characteristics, such as the transmitting voltage response(TVR) of transducers. The constructed transducers were tested experimentally and numerically by changing the parameters such as impedances and thicknesses of the head, tail and matching layers, in the water tank. Also, the developed transducer was excited by a chirp signal and the received chirp waveforms were analyzed. According to the measured TVR results, the available 3 dB bandwidth of the transducer with double matching layers of an $Al_O_3/epoxy$ composite of 7 mm thick and a polyurethane window of 18 mm thick was 7.3 kHz with a center frequency of 38.8 kHz, and the maximum and the minimum values of the TVR in this frequency region were 135.7 dB and 132.7 dB re $1\;{\mu}Pa/V$ at 1 m, respectively. Also, the available 3 dB bandwidth of the transducer with double matching layers of an $Al_O_3/epoxy$ composite of 11 mm thick and a polyurethane window of 15 mm thick was 6.2 kHz with a center frequency of 38.6 kHz, and the maximum TVR value in the frequency region was 136.3 dB re $1\;{\mu}Pa/V$ at 1 m. Reasonable agreement between the experimental results and the numerical results for the TVR of the developed transducers was achieved. The frequency dependant characteristics of experimentally observed chirp signals closely matched to the measured TVR results. These results suggest that there is potential for increasing the bandwidth by varying other parameters in the transducer design and the material of the acoustic matching layers.

• Korean Journal of Environment and Ecology
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• v.27 no.1
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• pp.71-84
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• 2013

This study investigated some of the specific ecological characteristics Torreya nucifera forest and its health conditions so that was drawn from four different management strategies, such as Types A, B, C, and D, for protected areas of forest genetic resources. Type A refers to passive management which routinely keeps the current status of forests by removing competitive trees or curing damaged ones. Type B, as active one which improves Torreya nucifera forest, includes increase of soil pH and removal of Sasa borealis, Phyllostachys bambusoides, and deciduous broad-leaved trees such as Quercus variabilis, Carpinus tschonoskii et al.. Type C is another passive one which reduces soil acidity within Chamae cyparisobtusa forest and maintains the existing forests. Type D is another active one which decreases soil acidity and simultaneously reduces problems associated with competitive and invasive plants to nurture the young trees. At last, it is important to note that the protected areas for forest genetic resources need to be entitled to categories III(natural monument) or IV(habitat/species management area) in accordance with protected area management guidelines of IUCN.

• Journal of the Mineralogical Society of Korea
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• v.26 no.4
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• pp.229-244
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• 2013

Arsenic contamination may be brought about by a variety of natural and anthropogenic causes. Among diverse naturally-occurring chemical speciations of arsenic, trivalent (As(III), arsenite) and pentavalent (As(V), arsenate) forms have been reported to be the most predominant ones. It has been well known that the behavior of arsenic is chiefly affected by aluminum, iron, and manganese oxides. For this reason, this study was initiated to evaluate the applicability of manganese slag (Mn-slag) containing high level of Mn, Si, and Ca as an efficient sorbent of arsenic. The main properties of Mn-slag as a sorbent were investigated and the sorption of each arsenic species onto Mn-slag was characterized from the aspects of equilibrium as well as kinetics. The specific surface area and point of zero salt effect (PZSE) of Mn-slag were measured to be $4.04m^2/g$ and 7.73, respectively. The results of equilibrium experiments conducted at pH 4, 7 and 10 suggest that the sorbed amount of As(V) was relatively higher than that of As(III), indicating the higher affinity of As(V) onto Mn-slag. As a result of combined effect of pH-dependent chemical speciations of arsenic as well as charge characteristics of Mn-slag surface, the sorption maxima were observed at pH 4 for As(V) and pH 7 for As(III). The sorption of both arsenic species reached equilibrium within 3 h and fitting of the experimental results to various kinetic models shows that the pseudo-second-order and parabolic models are most appropriate to simulate the system of this study.