• Title/Summary/Keyword: fallen leaves

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Studies on the Isolation and Identification of Xylanase and Mannanase Producing Aspergillus niger (Xylanase와 Mannanase를 생산하는 Aspergillus niger의 분리와 동정에 관한 연구)

  • Kim, Byoung-Suk;Cho, Jin-Kook;Song, Jin-Ook;Lee, Hak-Kyo;Hwang, Seong-Gu
    • Journal of Animal Science and Technology
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    • v.51 no.5
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    • pp.427-432
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    • 2009
  • This study was undertaken to screen a high xylanase and mannanase producing microbes. In the first experiment, screening was undertaken against 50 samples of microorganisms having xylanase and mannanase activities from soil and fallen leaves. The screening process has focused on picking out fungi having high xylanase and mannanase activities under the solid-state fermentation. The xylanase and mannanase activities of 6 screened microbes were 0.9~1.6 unit/mL and 0.2~0.4 unit/mL, respectively, under the submerged fermentation condition. However, under the solid-state fermentation, xylanase and mannanase activities were 103.7~220.0 unit/g and 20.1~40.3 unit/g, respectively. Finally one microbe (E-3) was selected and its xylanase and mannanase activities were 197.3 unit/g and 39.9 unit/g, respectively. The morphological and molecular biological classification of E-3 showed 99% homology with the Aspergillus niger.

Study on the Vegetation Restoration of Disturbed Slopes with Latency Seeds in the Forest Topsoil (비탈면 녹화시 표층토내 잠재종자의 활용방안에 관한 연구)

  • Kim, Nam-Choon;Son, Won-Joo;Jung, Sung-Chul;Jung, Ji-Jun;Nam, Sang-Jun
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.7 no.1
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    • pp.30-39
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    • 2004
  • This research is of the rapid industrialization taking place resulting in the destruction of forests. The method that is implemented needs the vegetation to work well with the topsoil in order to restore the environment. In November the researcher collected a depth of 5 cm of topsoil from a well developed forest, after the fallen leaves were cleared. The results of the essential research are as follows : In the case of using the forest topsoil to plant trees latency seeds, during the early stages of tree planting, time is necessary for the desired vegetation to reach a similar state to the vegetation being restored. The results conclude that the best possible affect is obtained through a method utilizing seeded species. Utilizing forest topsoil, slopes that have been too damaged for trees to be planted can be sown with seeds. In addition the rearing of naturally-emerging species had a tendency to decline. When considering rearing naturally-emerging species to flourish in the topsoil, in the early stages of tree planting, the beginning foundation of sowing seeded species has to have a standard of about 1,000parts/$m^2$ This standard has been found to the most successful.

Pyrolysis and Combustion Characteristics of an Oriental Oak Leaf (굴참나무 잎의 열분해 및 연소 특성 연구)

  • Seo, Young-Hoon;Park, Jin-Mo;Lee, Myung-Wook;Kim, Jin-Soo;Kim, Seung-Soo
    • Applied Chemistry for Engineering
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    • v.21 no.5
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    • pp.575-580
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    • 2010
  • Forest fires in Korea, having forest coverage of 70%, have kept increasing in number and scale since the middle of 1990's. Although deposited fallen leaves in forests such as herbaceous plants, conifers, and broadleaf trees are used as a medium for forest fires, the pyrolysis and combustion characteristics of the various species of trees are hardly studied. Oriental oak is the representative broadleaf tree in domestic forests, and pyrolysis and combustion of oriental oak leaf were carried out by thermogravimetic analysis (TGA). The leaf of oriental oak was ignited at $239^{\circ}C$ whereas pyrolysis started at $250^{\circ}C$. The corresponding kinetic parameters including activation energy and pre-exponential factor were determined by differential method over the degree of conversions. The values of activation energies for pyrolysis were increased as the conversion increases from 10% to 80%, whereas those of values were decreased during combustion.

The Study on Surface Fire Spread in Fuel Bed (Fuel Bed에서의 지표화 확산에 관한 연구)

  • Kim, Jeong-Hun;Kim, Eung-Sik;Kim, Dong-Hyun;Kim, Jang-Whan
    • Fire Science and Engineering
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    • v.28 no.6
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    • pp.22-27
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    • 2014
  • In this study a Fuel bed where surface fire spreads through is made to measure the data such as the flame height, radiation, spread rate and temperature distribution of Fuel bed. As experimental variables species of trees, wind velocities and slop are chosen. Fallen leaves of Quercus Variabilis (Q.V.) and Pinus Densiflora (P.D.) are used as fuel. Wind velocity is controlled by simply designed wind turnnel from 1 to 5 m/s. Slope of fuel bed is changed from $0^{\circ}$ to $30^{\circ}$. For the measurements of temperature distribution and spread rate total 35 of K-type 1.6 mm thermocouples are positioned as a lattice design. Radiant heat flow meters are used besides video camera and thermovision camera.

Soil Characteristics and Management Proposal of the Monument Beobsoo Marsh, Korea (천연기념물 법수늪의 토양특성 및 관리방안)

  • Kim, Do-Gyun;Kim, Yong-Shik
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.14 no.3
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    • pp.15-32
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    • 2011
  • This study was carried out to investigate the soil characteristics and propose the management for the Monument Beobsoo Marsh, Korea. The soil properties of O.M, $Ca^{2+}$, $Na^+$ and CEC were higher and the soil properties of pH_{1:5}$ and $P_2O_5$ were lower the studied sites than other marsh sites in Korea. Although the Heavy metals such as Pb, Hg, Cd, Cu, Zn, Cr and As were lower compare to the safety standard of soil pollution in Korea, the overall conservation management plan based on long-term monitoring should be considered just because it varied by the point and non-point source pollution within the studied marsh. The source of water pollution varied due to non-point polluting origins such as sewage inlet, degraded terrain for agriculture, fishing sites, sites of removed water grasses, pesticides, chemical fertilizers, as well as fallen leaves. The creation of an artificial marsh is recommended due to the soil environment of the studied sites may be changed owing to the accumulated contaminants from the sources of both of point or non-point contaminants. The establishment of the zones of core, buffer and transition which is basic management structure of the UNESCO MaB could be applied to manage the studied site. Simultaneously the promotion of voluntary participation and education of the local residents are needed.

The Role of Phosphorus on Plant Succession of Grassland in Andosol Region II. Accumulation and decomposition of litter in natural grassland community (강산성 화산회토양에 있어서 초원의 천이에 미치는 인산의 역할 II. 야초군락에 있어서 Litter의 집적과 분해)

  • Chung, Chan;Sugawara, Kazuo
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.13 no.1
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    • pp.23-30
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    • 1993
  • This study was investigated about decomposition process of litter that is reduction pathway of phosphorus from plant body to soil That is, in each community of Miscanthus sinensis, SaSa palmalta. Artemisia princeps and Polygonum thunbergii, disappearing speed was calculated from total fallen leaves yield supplied as litter and litter existant yield. Besides, setting up litter bag that put litter in nylon mesh bag. calculated disappearing speed from decreasing speed of the weight of contents and then was compared and examined. The results obtained are summarized as follows : 1. Maximum litter yield was sequently Miscanthus sinensis>SaSa palmalta>Artemisia princeps>Polygonum thunbergii, but, supplied litter yield was sequently Artemisia princeps>Miscanthus sinenis>Polygonum thunbergii>SaSa palmalta. 2. Reduction speed of phosphorus from plant body to soil was Polygonum thunbergii>Artemisia princeps>Miscanthus sinensis>SaSa palmalta. 3. Caculated disappearing speed using litter bag method was shown latter tendency than that of natural condition. 4. It was significantly negative relationship between N contents of litter and disappearing speed of litter.

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Bionomics of Tropidothorax cruciger(Motschulsky) on Cynanchum wilfordii Hemsley in Chinan, Chonbuk Probince (전북 진안지역 백하수오에 발생하는 십자무늬긴노린재의 생활사)

  • Kim, Tae-Heung;Lim, Kil-Young;Kwak, Jun-Su;Kim, Chang-Ju;Choi, Kyu-Hwan;Kim, Ju
    • Korean journal of applied entomology
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    • v.39 no.3
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    • pp.165-169
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    • 2000
  • Life cycle of Tropidothorax cruciger(Motschulsky) was studied on Cynanchum wilfordii Hemsley in the field as well as its development, overwintering patterns, and host preferences. Overwintered adults appeared in early and mid May, and the first generation adults emerged from late June extending to mid August. Second generation adults which usually overwinter, appeared from mid September to early October and were usually found beneath the soil surface or fallen leaves in winter. Adults were not attracted to various light sources. T. cruciger showed host preferences specifically toward Metapiexis japonica and Cynanchum wilfordii, both in the family of Asclepiadaceae.

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A Combustion Analysis of Surface Fuel Burning Experiment According to Density Variation (밀도에 따른 지표 연료의 연소실험 분석)

  • Kim, Eung-Sik;Kim, Jang-Hwan;Kim, Dong-Hyun;Park, Hyung-Ju;Kim, Jeong-Hun
    • Fire Science and Engineering
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    • v.24 no.1
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    • pp.1-7
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    • 2010
  • This paper shows combustion characteristics of fallen leaves of Quercus variabilis and Pinus densiflora according to variation of mass densities. Combustion temperature, mass loss rate, flame height, duration of combustion and velocity of hot gas are measured and analyzed. For the experiment 10cm heighted baskets with varying diameters of 20, 30, 40 and 50cm are used for the combustion and the pilot ignition is carried on the top of the fuel. In case of Pinus densiflora mass loss rate, duration of flame, flame height and combustion time become larger as the mass density and diameter of basket increase, on the other hand Quercus variabilis shows saturation characteristics in mass loss rate and flame height. Velocity of hot gas is proportional to flame height.

Pyrolysis and Combustion Characteristics of an Pinus densiflora and Thinning-out Tree (적송 생목과 간벌목의 열분해 및 연소 특성 연구)

  • Choi, Gyeong-Ho;Kim, Seung-Soo
    • Applied Chemistry for Engineering
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    • v.22 no.6
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    • pp.636-641
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    • 2011
  • Since the mid-1990s, the number of fires continue to increase and the size has been also larger. However, the pyrolysis and combustion characteristics of the various species of the medium such as fallen leaves, herbaceous plants, conifers and broadleaf trees have scarcely been studied. In this paper, we investigate the pyrolysis and combustion of the typical domestic needle-leaf tree of Pinus densiflora and thinning-out tree by thermogravimetric analysis (TGA). Pinus densiflora was ignited at $200^{\circ}C$ and pyrolysis from $230^{\circ}C$. In case of thinning-out tree was ignited and pyrolysis at $180^{\circ}C$ and $205^{\circ}C$, respectively. The values of activation energy for pyrolysis were increased as the conversion efficiency increasing from 10% to 80%, whereas the values was decreased during combustion.

The study of habitat characteristics and food sources of Luciola unmunsana - A Case Study of Sansungcheon, Jeonju City - (운문산반딧불이(Luciola unmunsana)의 서식지 특성과 먹이원에 관한 연구 - 전주시 산성천을 대상으로 -)

  • Lim, Hyun-Jeong;Kim, Jong-Man;Jeong, Moon-Sun
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.25 no.3
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    • pp.83-95
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    • 2022
  • This study aims to present primary data for habitat restoration and artificial breeding conditions of L. unmunsana by identifying the habitat conditions and the larvae's food sources. In order to investigate the habitat characteristics of the adult L. unmunsana and land snails, which are the primary food sources for the larvae, field surveys were conducted on a total of 10 habitats in south-central parts of Korea including Sanseongcheon, Jeonju. The results revealed that the L. unmunsana habitat in the Sanseongcheon area had a broadleaf forest with a multi-layered vegetation structure, adjacent water features, and the north/northeast/northwest slopes with little effect of artificial lighting. The adult L. unmunsana in the Sanseongcheon area appeared from the end of May to the end of June, and was especially intensively observed around the middle of June. The most active time was from 23:30 to 00:30 with a temperature range of 19~22℃ and higher than 80% humidity. The peak count of the observed adults L. unmunsana was a total of 774 on June 11, 2021. In the case of land snails, 11 families and 23 species were observed in 10 habitats of L. unmunsana, and Euphaedusa fusaniana was the most extensive and the most observed in the five survey areas. The land snails of L. unmunsana habitats are mostly found under the organic layers of leaves and a fallen tree branch in broadleaf forests, where a thick organic material layer buffers temperature changes and provides high humidity for various snails. These habitat conditions are suitable for the larva of L. unmunsana and land snails to inhabit, feed, hide and hibernate.