• Title/Summary/Keyword: black sand

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Environmental Changes Due to Planting Pine Trees on the Coastal Dunes Along the East Coast of Korea - Case Study of Osan Beach in Yangyang-gun - (곰솔 조림으로 인한 동해안 사구의 환경변화 - 양양군 오산해변을 사례로 -)

  • Choi, Kwang Hee;Kong, Hak-Yang
    • Journal of The Geomorphological Association of Korea
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    • v.27 no.1
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    • pp.21-31
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    • 2020
  • Planting pine trees on the coastal dunes has been carried out along the East coast as well as West coast of South Korea. Although the artificial forestation has been regarded as a good policy that help to protect the coastal area from natural disasters, but its real effect to the landscapes is still unknown. In this study, we have installed a monitoring site with an automated weather station to study requirements for dune formation and its environmental changes in Osan beach, Yangyang-Gun, Gangwon Province. We analyzed the meteorological data collected from 2010 to 2019 and vegetational changes in the study area. As a result, the wind speed is decreased by around 30% and the pine-covered area is increased by around 300m2 after planting Japanese Black Pine in 2015. At present, it seems that the eolian transport of sand particle is minimal, because the dominant winds are the westerly winds which is not landward but seaward, and because the surface roughness length is about 0.5m which is similar to that in the deciduous forest.

Prediction of Succession and Silvicultural Control in the Black Locust(Robinia pseudoacacia L.) Plantation (아까시나무(Robinia pseudoacacia L.) 조림지(造林地)에서 천이(遷移)의 예측(豫測)과 조림학적(造林學的) 제어(制御))

  • Yun, Chung Weon;Oh, Seung Hwan;Lee, Joon Hyouk;Joo, Sung Hyun;Hong, Sung Cheon
    • Journal of Korean Society of Forest Science
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    • v.88 no.2
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    • pp.229-239
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    • 1999
  • To get ecological information necessary for the prediction on succession and the silvicultural control of the black locust(R. pseudoacacia) plantation, classification of vegetation unit. competition of major species, and succession were analyzed. The results were as follows. Vegetation units classified in R. pseudoacacia forest were Quercus variabilis community, Persicaria perfoliata community, Styrax japonica community, Acalypha australis community, Typical community. Species diversity indices showed significant difference among the vegetation units. As a result of stand ordination by CCA method, arrangement of stands on Axis I was correlated significantly with altitude, sand, silt and available phosphorus contents, and that on Axis II was with total nitrogen, exchangeable calcium and kalium contents. It was judged that R. pseudoacacia plantation would be replaced by the mixed forest including Quercus spp., Acer spp., and Prunus spp. etc., native to Korea with the progression of succession as the results of analyses on competition of major species and successional tendency in R. pseudoacacia plantation.

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Old Service Pipe Cleaning of Polly-pigs Cleaning technique (Polly-pigs를 이용한 노후급수관의 세관에 관한 연구)

  • Lee, Hyun-Dong;Bae, Chul-Ho;Park, Jeong-Hoon;Kim, Gil-Nam
    • Journal of Korean Society on Water Environment
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    • v.18 no.3
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    • pp.303-312
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    • 2002
  • Polly-pigs technique was developed to remove internal rusts and scales from service pipes in the building by using Polly-pigs that were used as various applications in conventional plant pipelines. Results of cleaning experiments on 15mm GSP(Galvanic Steel Pipe) showed that hydraulic cross sectional area was more increased from 3.5% to 15.4% for straight part or elbow parts of several test pieces. Results of optical analysis also showed that rust and scale removed mostly by KDP series(only consisted of Polyurethane) were outside red colored scale ($Fe_2O_3{\cdot}H_2O$), and there was a limitation to the removal of black colored scale($Fe_2O{\cdot}nH_2O$) that was below red colored scale. But it was evaluated that KDPS series coated fine sand with KDP series could remove not only red colored scale but also black colored scale and more increase hydraulic cross sectional areas of 15mm GSP old service pipes from 13.0% to 17.9%. After KDPS series cleaning, hydraulic cross sectional areas of them were recovered from 95.9% to 99.5%. Turning force of Polly-pigs was largely improved by the effect of Helical guide vane(Cleaning v/v) and Rotating wing(Pigs), and the number of pig rotating also more increased sixteen times compared with conventional cleaning system without Helical guide vane and Rotating wing. After KDPC series cleaning of 100mm GSP old service pipes that hydraulic cross sectional areas were 90%, hydraulic cross sectional areas were almost recovered perfectly like new service pipes. Additionally pressure necessary to run Polly-pigs m 100mm GSP was lower and cleaning efficiency also was higher than 15mm GSP cleaning. Therefore it was thought that as the diameter of pipe was more increased, pressure necessary to clean service pipes was more decreased and cleaning efficiency was more increased in Polly-pigs cleaning.

Spatial distribution of vegetation along the environmental gradient on the coastal cliff and plateau of Janggi peninsula (Homigot), southeastern Korea

  • Jung, Song Hie;Kim, A Reum;Lim, Bong Soon;Seol, Jae Won;Lee, Chang Seok
    • Journal of Ecology and Environment
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    • v.43 no.2
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    • pp.117-128
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    • 2019
  • Background: Cliffs are a major plant habitat around the coastal area, but in contrast to sand dunes and salt marshes, they have been little investigated in Korea. There are simple descriptions of cliff vegetation in studies on island vegetation, but there is no published paper, which addressed sea cliff vegetation synthetically. Furthermore, the coastal area where this study was carried out was designated as a conservation reserve. Even though, this area is exposed to intense recreational use such as trekking in these days. This study aims to clarify spatial distribution and structure of vegetation along the environmental gradient on coastal cliff and plateau in the Janggi peninsula (Homigot) located on southeastern Korea. Further, this study has also another objective to prepare a restoration plan to protect this conservation reserve from intense human disturbance. Results: Landscape elements were arranged in the order of sea cliff risen directly on the sea, seashore, coastal cliff, and plateau covered with relatively deep soil in a coastal area of the Janggi peninsula (Homigot), southeastern Korea. Vegetation was sampled at 59 plots arranged from the sea cliff through the seashore and coastal cliff to plateau. The sea cliff, seashore, and coastal cliff, which compose the coastal landscape, were dominated by the seashore spatulate aster (Aster spathulifolius Maxim.) community, dwarf sand sedge (Carex pumila Thunb.) community, and seashore spatulate aster (Aster spathulifolius Maxim.) community. On the plateau corresponding to the ridge of the coastal cliff, black pine (Pinus thunbergii Parl.) community, golden rain tree (Koelreuteria paniculata Laxmann) community, east Asian hackberry (Celtis sinensis Pers.) community, sawleaf zelkova (Zelkova serrata Makino) community, and Korean oak (Quercus dentata Thunb.) community were established in the mentioned order along distance from the sea. Stand ordination showed a vegetation sequence from the seashore through the cliff to the plateau, consistent in its overall pattern among sites. This was dominated by topography. There is evidence for the importance also of salinity, drought and of soil depth. Conclusion: The lack of scientific interest in cliffs to date is in striking contrast to the commonness of cliffs around the whole national territory and to the attraction cliffs have had for humans throughout history. Cliffs provide a unique habitat, rarely investigated from an ecological viewpoint. Cliffs may represent an invaluable type of ecosystem, consisting of some of the least disturbed habitats on earth and contributing more to the biodiversity of a region than their surface coverage would indicate. Although this coastal area where this study was carried out was designated as a conservation reserve, this area is in danger of severe disturbance due to excessive recreational use. We recommended a restoration plan to protect this area from such a disturbance.

A Grain Size Analysis of Bottom Sediments of Yeongil Bay, Korea (한국 영일만 해저퇴적물의 입도분포)

  • Park, Byong-Kwon;Song Moo-Young
    • 한국해양학회지
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    • v.7 no.2
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    • pp.74-85
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    • 1972
  • This paper studied the grain size distribution of bottom sediments of Yeongil Bay which is located at the southeastern part of the Korean Peninsula. Sixty four samples collected with snapper and dredger are analyzed by roe Tap Sieve Shaker and Pipette Method. The moment parameters are calculated with the method of Friedman(1961). Most samples are composed of sand size sediments and a few samples are composed of silt and clay. The Yeongil Bay can be divided into gravel-granule zone, sand zone, and silt-clay zone. The sediments near Yeonam- Dong and Hyongsan river are moderately sorted and others are very poorly sorted according to scheme of Friedman91962). In general, sorting values are ranged from 1.0 to 3.5. The samples near Janggigap and Masin-Dong show negative and others show positive skewness values. Skewness values are ranged from -1 to 2. All samples show the leptokurtic distribution except for the samples near Masin- dong and at the deepest place near Janggigap. Kurtosis values are ranged from -1.5 to 21.9. The samples of gravel-granule zone contain more than 50% and those of silt-clay zone contain less than 50% of CaCO$\_$3/. Four different colors, black, yellow, brown and gray, are shown in the sediments of Yeongil Bay.

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Ecological Characteristics and Changes in Plant Community Structure in Mt. Cheongryang, Incheon (인천시 청량산의 생태적 특성과 식생구조의 변화)

  • Lee, Sang-Hee;Han, Bong-Ho;Park, Seok-Cheol
    • Journal of the Korean Institute of Landscape Architecture
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    • v.49 no.2
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    • pp.74-88
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    • 2021
  • In the present study, the characteristics and changes in the vegetation of Mt. Cheongryang, Inchon, were examined to identify and determine appropriate ways to restore the health of the urban forest and to preserve its vegetation. The vegetation of the community of Quercus mongolica (Mongolian oak) on Mt. Cheongryang appeared to decrease in response to the control of the wilt disease of oak trees. The communities of Sorbus alnifolia (Korean mountain ash) and Styrax japonicus (Snowbell tree) have increased. Pinus rigida (Pitch Pine) had its overall territory decrease, but the current state of the Pinus rigida (Pitch Pine) was estimated to be stable due to its dominance as a tree layer species. In regards to Robinia pseudoacacia (Black Locust), the urbanized species of Sorbus alnifolia (Korean mountain ash), and Styrax japonicus (Snowbell tree), their areas have increased with the appearance of Magnolia obovate (Whiteleaf Japanese Magnolia). The biodiversity of Mt. Cheongryang has decreased by simplifying species in the tree layer and understory species thereof, and the initial success of species in marginal areas has increased. The absence of potential succession was attributed to the termination of ecological succession; thereby, the current vegetation structure was concluded to be remaining as it is for the time being. Soil texture in the mountain primarily consisted of sandy loam or loamy sand; the pH of the soil was in the range 4.26-4.86, rendering a mean pH of 4.59. The content of organic matter (O.M.) appeared having a distributing range of 2.18-9.60%, rendering a mean value of 4.33%. To promote species diversity, several methods are suggested, such as prevention of soil acidification, selecting nationally-grown trees from moist soil or valleys for afforestation, preventing species appearing due to urbanization or excessive growth, protecting the understory vegetation and species with hygropreference, and managing the forest to maintain a multi-layered vegetation structure.

Properties of Temperature Reduction of Cooling Asphalt Pavements Using High-Reflectivity Paints (고반사 도료를 사용한 차열성 아스팔트 도로포장의 온도저감특성)

  • Hong, Chang Woo
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.33 no.1
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    • pp.317-327
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    • 2013
  • Air pollution and artificial heat of urban areas have caused the urban heat island in which asphalt pavements absorb solar heat during the daytime and release the heat at night. Hence, in order to improve the environment of urban areas, it is necessary to examine cooling pavements that can reduce heat on road pavements in urban areas. The application of temperature insulation paints on road pavements require to reduce black brightness for visibility, to increase the reflection rate of infrared light and minimize the reflection rate of visible light. In the study, one part of Acrylic-emulsion was used as a main binder, and the changes in black brightness and the changes of addition ratio (0%, 15%, 30%) of hollow ceramics, as well as kinds of paints (carbon black pigment, mixed mineral pigment) were selected as the main experimental factors. The performance of temperature reduction of cooling pavements was analyzed through the reflection rate of spectrum, the reflection rate of solar heat, and the lamp test. Abrasion resistance, UV accelerated weather resistance, and sliding resistance were tested in real situations. In addition, the performance of heat reduction of testing pavements covered with high-reflection paints was analyzed by using an infrared camera. As the test results, when using mixed mineral paints and hollow ceramic of 30%, the reflection rate of spectrum was 43% in the area of near-infrared ray and 17% in the area of visible light at black brightness of $L^*$=42.89 and the reflection rate of solar heat was 27.5%. Total color difference was ${\Delta}E$=0.27 in the test of UV Accelerated Weather Resistance, indicating almost no changes in color. BPN was more than 53 when scattering #2 and #4 silica sand of more than $0.12kg/m^2$. In Taber's abrasion resistance test, abrasion loss was up to 86.4mg at 500 rotations. The performance of heat reduction was evaluated using an infrared camera at the test section applying high-reflection paints to asphalt pavements, in which the results showed that the temperature was reduced by $12.7^{\circ}C$ on CI-30-40 cooling pavements ($L^*$=38.76) and by $14.2^{\circ}C$ on CI-30-60 cooling pavements ($L^*$=57.12).

A Study on the Materials and Technique of Lime Plaster Work in Government Constructions in the Late of Joseon Dynasty(17~19c) - Focused on the Lime Plaster Materials in 'Yeonggeon-Uigwe'(Construction Reports) - (조선후기 관영건축공사의 회(灰)미장재와 공법에 관한 연구 - 영건의궤(營建儀軌)의 유회(油灰), 수회(水灰), 양상도회(樑上塗灰)를 중심으로)

  • Lee, Kweon-Yeong
    • Journal of architectural history
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    • v.18 no.4
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    • pp.63-79
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    • 2009
  • Since the 1970's, UNESCO and ICOMOS have adopted or emphasized on the principles of historic preservation. One of them is what to require a repair have not to be repaired beyond the limits of the features and techniques to have been born in those days of establishment. On the premise, this paper is to examine the materials and technique of lime plaster work in order for roof ridge, and for bond paste of stones and bricks in government constructions in the late of Joseon dynasty(17~19c). The result of this examination will come up with a basic conformity in the case of repairing the building established in the late of Joseon dynasty. This paper is carried out for the proper repair and restoration of architectural cultural properties. Construction reports and other documents in those days are examined for the study. Following conclusions have been reached through the study. The components of old plaster mixtures which agglutinate stones each other were quicklime, perilla oil, and paper fiber. The components of old plaster mixtures which point joint of black bricks consisted of slaked lime, perilla oil, paper fiber, and cereal starch. These components were the same as coat surface of roof ridges. In the case of times, one of the following sand, white clay, sap of boiled elm bark was added to these components for the purpose of high efficiency. These materials and techniques which applied to plaster work of those buildings had developed in the process of making royal tombs. But these materials and techniques were quite different from the present.

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Making Technique Studies of Mural Paintings in the No. 6 Tomb of Songsanri, Gongju (공주 송산리 6호분 벽화의 제작기술 고찰)

  • Han, Kyeong-Soon
    • Journal of Conservation Science
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    • v.27 no.4
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    • pp.451-458
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    • 2011
  • This study aims at identifying wall painting production technique of Songsanri No. 6 tomb based on optical examination and scientific analysis along with the investigation of written records of ancient wall paintings. The result displays that bricks with mortar were used for the construction of the wall, and masonry joint were made of lime, sand and gypsum. The surface of brick were plastered with black and thereafter with white lime. Finely sifted clay on the top of the white surface, were applied not with plasterer's trowel but with a brush for making ground surface. The clay are mineral particles smaller than $30{\mu}m$ of silt. The wall paintings of Sonsanri No. 6 is the only example of making ground layer with clay for painting of Sasindo (literally four heavenly animals painting) among remaining wall paintings of ancient tombs. The historical value of the painting should be attributed not only in terms that it displays a rare production techniques which were never discovered in any other paintings in Korea and Asia, but also it might had been uncompleted when the tomb were closed, even though it considers the fact that the wall painting were discovered in damaged condition in 1933.

Studies on the Utilization of Arkshell 1. Preparation and Quality Stability during Storage of Powdered Dried Arkshell for Instant Soup (피조개의 이용에 관한 연구 1. 피조개 분말수우프의 제조 및 저장중의 품질안정성)

  • Kim, Hee-Yun
    • Journal of Food Hygiene and Safety
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    • v.3 no.4
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    • pp.217-223
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    • 1988
  • For the Effective utilization of the fish resources in coastal regions, investigations on preparation of powdered dried arkshell instant soup., quality stability of the products during storage and utilization as a food material were carried out with arkshell, Anadara broughtonii. Three kinds of powdered instant soup were prespared as 0% table salt(A), 5% table salt (B), 15% table salt(C) and packed with vacuum in laminated film bag. (polyester/nylon: 85${mu}ell$/15${mu}ell$, 18$\times$27cm) Their processing conditions and quality stability during storage at room temperature for 90 days were examined. Powdered instant soup was made by washing raw arkshell to remove visceral, clay, sand and blood, hot air drying(60$\pm$1$^{\circ}C$, 20 hrs) after draining and pulverizing dried arkshell to 35 mesh. Powdered instant soup was made by adding 2% sugar 0% table salt (5% and 15% table salt), 10.5% monosodium glutamate, 0.3% black pepper and 0.3% garlic powder to the pulverized dried arkshell. The condition of moisture and water activity of the products were 5.9-6.9% and 0.42-0.43, respectively. The moisture content s , water activity and pH of the products were showed little change and volatile basic nitrogen of them increased slightly during storage. Thiobarbituric acid value increased up to 60 days of storage and then decreased slightly. In solubility, powdered instant soup were showed no remarkable difference comparing with goods on the market. The color value of th products were showed little change during storage, In sensory evaluation, product B were scored slightly higher, in most cased, in flaver, color. taste and overall acceptability comparing with product A or product C during storage. Judiging form the sensory evaluation, powdered instant soup of 5% table salt (B) were the most desirable, and the quality of the products was stable for 90 days at 20$\pm$3$^{\circ}C$.

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