• Title/Summary/Keyword: Sea Sand

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Laboratorial Study for Mechanical Prosperities of Intermediate Soils (중간토의 역학적 특성에 관한 실험적 연구)

  • 박중배;전몽각
    • Geotechnical Engineering
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    • v.11 no.3
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    • pp.113-122
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    • 1995
  • The purposes of this study are to investigate the mechanical prospeities of the inter mediate soils through consolidation tests and triaxial compression shear tests. The intermediate soils used in this study are artificial soils which are composed of sea clay, sand and it's crushed component. The relationship between plastic index and mechanical prosperties (permeability and compressibility) is investigated through series of consoli dation tests. Strain hardening phenomenon under shearing is explored based on several overconsideration ratios and strain rates in undrained shear tests. To make a comparative study difference of drain condition and strain rate, drain shear tests are performed with overconsolidation ratio.

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A Study on the Evaluation for the Safety of Passing Vessel in the Vicinity of the Seasands Gathering Area By Marine Traffic Safety Diagnostic Scheme (해상교통안전진단제도에 따른 바다모래채취 주변수역에서의 통항선박 안전성 평가에 관한 연구)

  • Kim, Se-Won;Park, Young-Soo;Lee, Yoon-Suk
    • Journal of Fisheries and Marine Sciences Education
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    • v.25 no.3
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    • pp.677-689
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    • 2013
  • Recently, the supplying of basic materials for construction of building as sand is big issues due to lack of shoreside supply. For solving this problem, many suppliers attempt to gather aggregate from the sea bottom of the EEZ & west coastal area of Korea. In this regard, the 'Jangantoe' which exists in the westside of the Daesan port is worth noticing as good seasand supplying areas. The Chungnam Aggregate Association have plan to gather of seasand from 'Gaduckdo 5 regions & Igok 3 regions' which lies westside about 6 miles off from the Jangantoe areas. This designated area also locates upper parts of the Gadaeam TSS(Traffic Separation Scheme) which is very useful passing routes for the sailing vessels of Inchon & Daesan ports. In this study, the evaluation of the safety for passing vessels in the vicinity of the seasand gathering area was performed by various methods of radar observations & GICOMS AIS data for marine traffics and vessel traffic-flow simulation of the 'Marine Traffic Safety Diagnostic Scheme'. By the results of this evaluation, I suggested comprehensive countermeasures for the safety of passing vessels in the near the seasand gathering area.

A Sediment Transport of Cape Cod Coast, Massachusetts, USA (미국 매사추세츠주 Cape Cod 해안의 퇴적물 이동)

  • 김동주;은고요나
    • Journal of Environmental Science International
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    • v.6 no.6
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    • pp.589-594
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    • 1997
  • A total of 24 surface sediment samples collected from coastal region and fronting of sea cliff on Cape Cod In southeastern Massachusetts, were analyzed to Investigate the sediment transport mechanism. According to the result of grainsize analysis, the overall trend of g.k size decreases from the north(Wood End Beach) to the south(Nauset Light Beachy. The coarser materials tend to be deposited at the foreshore than at the backshore. Especially gavel content(%) Is very high in northern beaches. The lavel fraction tended to concentrate at the toe of the beach. In addition to gravel. the beach and nearshore bar also tended to be deposite of very coarse sand and the Inner fraction accumulate in the offshore bar, Grainsize analyses of sediment Indicates that the coarsest sands Including gravel accumulate In the beach and nearshore bar, the finer fraction winnowed out by wave action to be deposited In the offshore bar. The beach and nearshore bar sands and gavel are subsequently transported laterally by the wave-driven longshore drift, and finally they come to rest in the distal end of Provincetown Hook. The faller offshore sands are trnasported laterally to the south by net southward-directed longshore current.

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An Experimental Study on Recycled Aggregate Concrete for Artificial Fishing Reefs (인공어초 개발을 위한 재생골재 콘크리트의 실험적 연구)

  • 홍종현;김문훈;우광성
    • Journal of Ocean Engineering and Technology
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    • v.17 no.4
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    • pp.16-22
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    • 2003
  • The mechanical characteristics of newly recycled aggregate concrete on the basis of the proposed mix design model have been studied to develop the precast artificial fishing reefs. In the first task, the experimental test for the recycled aggregates taken from Jeju Island has been carried out to verify the material properties in terms of specific gravity, percentage of solids, absorption and abrasion of coarse aggregates. In the second task, the experimental parameters of newly recycled aggregate concrete are investigated to meet with the requirements of guidelines with respect to slump, unit weight, pH, ultrasonic velocity, void ratio, and compressive strength which are made of sea-shore sand ad slag cement. The natural aggregate and polypropylene fiber are added to newly recycled aggregate concrete to improve the compressive strength and quality. The optimal mix proportions for compressive strength are W/C=30%, S/a=15%, NA/G=50% in porous concrete case, W/C=40%, S/a=45% in plain concrete case, and W/C=40%, S/a-45%, PF=1.0kg/㎥ in fiber reinforced concrete case.

Design Example of Gravel Mat for Horizontal Drains (쇄석Mat를 이용한 수평배수공법 설계사례)

  • Jeong, Kyeong-Han;Lee, Young-Keun;Lee, See-Woo;Kim, Jae-Sung;Kim, Byung-Tak
    • Proceedings of the Korean Geotechical Society Conference
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    • 2005.10a
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    • pp.174-187
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    • 2005
  • Recently, because of environment, cost, supply and demand factors, though applying sea-sand as horizontal drains is getting difficult that usage of Gravel has been growing in large size of construction sites, Study on engineering properties and behavior characteristics of Gravel stratum is not thoroughgoing enough. We have applied Gravel Mat as the horizontal drains in O O construction site. We also conducted several field tests such as Material property test, Geosynthetics damage test with Repeated load, Discharge capacity test performed by inflow of upper soil and In-situ PBD Penetration test to review the application of Gravel Mat. Test results show that Gravel Mat is not only advantageous in Trafficability and Water drainage by Consolidation due to its great Internal friction angle and Permeability, but also easy to penetrate with Mandrel and has great discharge capacity and guarantee of the stability against geosynthetics damage at the same time. With these benefits Gravel Mat shows great application in fields.

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Seasonal Patterns of Sediment Supply to Coastal Foredune of Seungbong Island, Korea

  • Woo, Han-Jun;Seo, Jong-Chul;Kweon, Su-Jae;Je, Jong-Geel
    • Ocean and Polar Research
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    • v.24 no.1
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    • pp.39-45
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    • 2002
  • The seasonal patterns of sediment supply were investigated during the period of June 1999 to June 2000 on a coastal foredune of Seungbong Island, Korea. Sediment supply was determined from measurements of geomorphic changes in the foredune and beach along six lines. Most sands were deposited on the dunefoot and foredune area during the winter and spring, from November to April. The largest amount of sands was deposited along the lines 5 and 6 near the sea-dike in the southern tip of the dune area. In general, the sand on the beach was gradually eroded in spring, summer and fall but deposited in winter. Total sediment accumulation over the study period was $484m^3$ for the foredune and $345m^3$ for the beach. The volume of the foredune increased in the winter and spring, whereas the volume of beach increased in the winter. Variation in sediment deposition appears to be controlled primarily by variations in the seasonal wind regime.

Identification of a Bacterium which Produced D-Glucose Isomerase and Partial Purification on the Enzyme (포도당 이성화효소 생산균의 동정 및 그 효소의 부분정제)

  • Rhee, In-Koo;Seu, Jung-Hwn
    • Microbiology and Biotechnology Letters
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    • v.8 no.2
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    • pp.125-133
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    • 1980
  • A microorganism which produced D-glucose isomerase was identified to be similar to Streptomyces antibioticus on the morphological, cultural and physiological characteristics except the spore chain and the utilization of sucrose. D-xylose grown cells of Streptomyces sp. strain K-17 were disrupted by grinding with sea sand. D-glucose isomerase was partially purified with the fractionation by ammonium sulfate, Mn-treatment, DEAE-cellulose column chromatography, DEAE-sephadex (A-50) column chromatography and gel filtration of sephadex G-200. The enzyme was purified about 380 fold with 25 % recovery.

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INTRODUCTION OF COMS SYSTEM

  • Baek, Myung-Jin;Han, Cho-Young
    • Proceedings of the KSRS Conference
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    • v.1
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    • pp.56-59
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    • 2006
  • In this paper, Korea's first geostationary Communication, Ocean and Meteorological Satellte(COMS) program is introduced. COMS program is one of the Korea National Space Programs to develop and operate a pure civilian satellite of practical-use for the compound missions of meteorological observation and ocean monitoring, and space test of experimentally developed communication payload on the geostationary orbit. The target launch of COMS is scheduled at the end of 2008. COMS program is international cooperation program between KARI and ASTRIUM SAS and funded by Korean Government. COMS satellite is a hybrid satellite in the geostationary orbit, which accommodates multiple payloads of MI(Meteorological Imager), GOCI(Geostationary Ocean Color Imager), and the Ka band Satellite Communication Payload into a single spacecraft platform. The MI mission is to continuously extract meteorological products with high resolution and multi-spectral imager, to detect special weather such as storm, flood, yellow sand, and to extract data on long-term change of sea surface temperature and cloud. The GOCI mission aims at monitoring of marine environments around Korean peninsula, production of fishery information (Chlorophyll, etc.), and monitoring of long-term/short-term change of marine ecosystem. The goals of the Ka band satellite communication mission are to in-orbit verify the performances of advanced communication technologies and to experiment wide-band multi-media communication service mandatory.

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Factor Analysis of the Continental Shelf Sediments off the Southeast Coast of Korea and Its Impplication to the Depositional Environments (한반도 동남해역 대륙붕 표층퇴적물의 요인분석과 그 퇴적역사)

  • Park, Yong-Ahn;Choi, Jin-Yong
    • 한국해양학회지
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    • v.21 no.1
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    • pp.34-45
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    • 1986
  • A Q-mode factor analysis for 115 surficial bottom sediments on the continental shelf off the southeast coast of Korean Peninsula(the Korea Strait) has been carried out to determine the depositional environments. The first four factors are taken as the "principal" factors, and the results are considered to represent the depositional history and sedimentary processes in relation to the Holocene sea-level changes. The fact implies that the sediments are grouped as outer-shelf relict sand sediments, inner-shelf modern muddy sediments, and finally the palimpsest sediments that are mainly distributed within and around the Korea Trough.

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Review of Literature on Food Preservation of the Early Joseon Dynasty (조선전기 고문헌에 수록된 식품저장법에 대한 문헌고찰)

  • Kim, MyeongJun;Cha, GyungHee;Chung, HyeJung
    • Journal of the Korean Society of Food Culture
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    • v.35 no.1
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    • pp.28-54
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    • 2020
  • This study aims to investigate the food preservation methods adopted by the Joseon Dynasty, which existed before the 17th century. A total of 232 food preservation methods were discovered in 25 books, and could be classified by their targeted food types: vegetables (84), sea foods (60), meats (41), fruits (37), and others (10). Depending on the preservation method applied, they are classified as food drying, soaking, mud cellar preservation, and other preservation. Food drying is further classified into 8 sub-types: drying, sun-drying, shadow-drying, wind-drying, dry heat, combined drying, smoking, and others. Soaking could be sub-divided into using salt, ash, dry sand, bran, fermented paste, wet distillers grains, oil, and others. Mud cellar preservation is sub-classified into installing shelf inside the mud cellar, making the mud cellar for food preservation, and making hole or underground tunnel for food preservation. Other food preservation methods include minimizing moisture loss by applying beeswax on a section of the vegetable stem, and cutting the vegetables or fruits with their branches and leaves for food preservation.