• Title/Summary/Keyword: 222 sand

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An Experimental Study on the Physical Properties of Mortar Using EEZ Sand and Crushed Sand (부순모래와 EEZ모래를 혼합사용한 모르타르의 기초물성에 관한 실험적 연구)

  • Park Jong-Ho;Jang Jae-Bong;Na Chul-Sung;Cho Bong-Suk;Kim Jae-Hwan;Kim Moo-Han
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2005.05a
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    • pp.33-36
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    • 2005
  • Recently, Trouble of sand supply is occurred according to exhaustion of natural sand resources. therefore, various measures are proposed for solution of trouble of sand supply. also the government settled trouble of sand supply through application of EEZ sand and crushed sand. but because both EEZ sand and crushed sand are poor against general sand, they lead to lowering of quality of ready-mixed concrete. Therefore, this study evaluated physical properties of mortar using EEZ sand and crushed sand and applied evaluation result to fundamental data The result of this study have shown that quality of mortar using EEZ sand and crushed sand independently is poor against general mortar. but, mortar flow and compressive strength is increased in case of mixing 222 sand and crushed sand properly.

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Comparison of the filtration performance by different media in pretreatment of seawater desalination by reverse osmosis (여재 종류에 따른 역삼투법 해수담수화 시설 전처리 여과공정의 성능비교)

  • Kim, Seung-Hyun;Yoon, Jong-Sup;Lee, Seockheon
    • Journal of Korean Society of Water and Wastewater
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    • v.23 no.2
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    • pp.215-222
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    • 2009
  • This study compares the performance of the filters with various media in pretreatment of seawater desalination by reverse osmosis. For this purpose, Masan bay seawater is used as raw water. The filter performance is evaluated by the filtrate quality and the head loss development. Five media is selected in this study: anthracite, $Filtralite^{(R)}$, sand, Pumice, $AFM^{(R)}$. These media are used in combination for dual media filter and alone for mono media filter. The comparison results show that NC0.8-1.6 is the best $Filtralite^{(R)}$. The dual media filter of NC0.8-1.6 and sand outperformed other filters in particle removal. The dual media filter of anthracite and sand showed good performance in organic removal. The mono media filter of Pumice produced the similar filtrate quality as the mono media filter of sand although the effective size of Pumice is considerably greater than that of sand. Due to big size, head loss development is maintained slow in the filtration of Pumice.

Application of Phytoremediation for Total Nitrogen and Total Phosphorus Removal from Treated Swine Wastewater and Bio-methane Potential of the Biomass (돈분뇨 처리수 유래 질소와 인 제거를 위한 식물정화법 활용과 바이오매스의 바이오메탄 잠재성 연구)

  • Sudiarto, Sartika Indah Amalia;Choi, Hong Lim;Renggaman, Anriansyah
    • Journal of the Korea Organic Resources Recycling Association
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    • v.23 no.4
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    • pp.21-31
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    • 2015
  • The aim of this study is to determine the removal efficiency of total nitrogen and phosphorus from treated swine wastewater by Phragmites australis and Miscanthus sacchariflorus var Geode Uksae-1, and to determine its biomass total energy value and biomethane potential. Plants were grown with a bedding mixture either soil and sand or soil, sand, and bioceramic. Treeated swine wastewater with Total nitrogen (TN) and Total phosphorus (TP) of 222.78 mg/L and 66.11 mg/L, respectively, was utilized. The TN and TP removal is higher in the bio-ceramic-soil-sand bedding media treatment. The highest TN removal of 96.14% was performed by Miscanthus sacchariflorus var Geode Uksae-1, but the elemental analysis shows that Phragmites australis contains more nitrogen than Miscanthus sacchariflorus var Geode Uksae-1, indicating higher nitrogen uptake. The highest TP removal of 98.12% was performed by Phragmites australis. The cellulose content of the plant grown with the bioceramic-soil-sand bedding was approximately 3-6% higher than that of the plant grown in the soil-sand bedding. Different growing substrates may have an effect on the fiber content of plants. The biomethane potential of the produced biomass of the plants was between 57.01 and $99.25L-CH_4/kg$ VS. The lignin content is believed to inhibit the breakdown of plant biomass, resulting in the lowest methane production in the Phragmites australis grown in the soil-sand bedding media.

A Study on the Characteristics of Concentrations of Atmospheric Aerosols in Pusan (부산지역의 입자상 대기오염물질의 농도특성에 관한 연구)

  • 최금찬;유수영;전보경
    • Journal of Environmental Health Sciences
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    • v.26 no.2
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    • pp.41-48
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    • 2000
  • This study has been carried out to determine the seasonal characteristics of concentration of various ionic (CI-, NO3-, SO42-, Na+, NH+, K+, Ca2+) and heavy metallic (Pb, Mn, Cu, Ni) species in Pusan from August 1997 to April 1998. The concentrations of CI-, Na+, K+ were higher during summer with 2.98 ${\mu}{\textrm}{m}$/㎥. Seasonal variation of total concentration of but the concentration of NH4+ was higher during winter with 2.46${\mu}{\textrm}{m}$/㎥. Seasonal variation of total concentration of heavy metals(Pb, Cu, Mn, Ni) were 186.0 ng/㎥ in summer, 222.6 ng/㎥ in autumn, and 135.83 ng/㎥ in winter. Over the seasons inspected, the concentration of Mn was higher in coarse particles than fine particles and concentration of Ni was higher in fine particles than coarse particles. during yellow sand period, the concentration of TSP was increased about two times than that of other period. SO42-, Ca2+ concentrations were higher than other ionic components because of soil particles. The concentration of Ni showed 94.62ng/㎥ was increased about 4~5 times than other period. Principal component of the yellow sand, SO42-, Ca2+ could be discreased by rainfall and washout effect of atmospheric aerosol was higher in coarse particles than fine particles. Results from PCA(principal component analysis) showed that major pollutant was NaCl by seasalt particulate and (NH4)2SO4.

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An Experimental Study on the Flow Characteristics of Mortar use Quenched Blast-Furnace Slag (수재사 모릍의 Flow특성에 관한 연구)

  • Yang, Beom-Seok;Lim, Nam-Gi;Lee, Young-Do;Lee, Jong-Kyun;Chung, Lan;Jung, Sang-Jin
    • Proceedings of the Korea Concrete Institute Conference
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    • 1997.10a
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    • pp.215-222
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    • 1997
  • Flow experimental on not to be solid mortar which use Quenched Blast-furnace Slag as a fine aggregate was carried out for basic research data about fundamental study of application possibility of Quenched Blast-furnace Slag as a fine aggregate. It gives following result. The substitution rate is inversely proportional to Flow and C/S-rate same that. The relation with W/C-rate augment appear proportional : in case of C/S-rate, 1:3 increasing degree is a half of sand mortar that. Consequencely, Quenched Blast-furnace Slag motar is a counteraction to Flow in as same water content per unit. But suitable substitution rate and C/S-rate influence a little to the mortar consistency. And that reason, if C/S-rate and substitution rate will be regulated when we mix the mortar with quenched Blast-furnace Slag. that will be economic mixture.

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Characterization of High Temperature Mechanical Properties of Cast Stainless Steels for Exhaust Manifold (배기다기관용 주강소재의 고온특성 평가)

  • Lee, Kyu-Dong;Ha, Tae-Kwon;Jung, Jae-Young
    • Transactions of Materials Processing
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    • v.18 no.3
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    • pp.217-222
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    • 2009
  • Automobile industries have been focusing their efforts on the development of exhaust manifolds using high temperature stainless steels. Exhaust manifolds fabricated with stainless steels can be categorized into tubular and cast ones. The former is usually manufactured by forming and welding process and the latter by vacuum casting process. In the present study, high temperature mechanical properties of 5 austenitic and 4 ferritic stainless steels were investigated by performing a series of high temperature tensile and low cycle fatigue tests. One of the austenitic stainless steels was vacuum cast and the others sand cast. Fatigue life of ferritic stainless steels was higher than that of austenitic ones.

Distribution and Cycling of Elements in a Pinus resinosa Plantation-Ecosystem, Wisconsin (Wisconsin의 Pinus resinosa 조림지(造林地) 생태계(生態系) 내(內)의 양료분포(養料分布) 및 순환(循環))

  • Bockheim, J.G.;Lee, S.W.;Leide, J.E.
    • Korean Journal of Agricultural Science
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    • v.9 no.2
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    • pp.507-518
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    • 1982
  • Biogeochemistry of a 34-year-old red pine plantation on a Typic Udipsamment was investigated in the central sand plains of Wisconsin Biomass and net primary production were $106Mg\;ha^{-1}$ and $11.0Mg\;ha^{-1}y^{-1}$ respectively. Concentrations of elements in the vegetation were greatest in the 2- to 3-year-old needles, followed by current needles, current twigs, bole bark, live branches, dead branches, bolewood production, and bolewood. For a given tree component (excluding the current twigs), elemental concentrations were greatest in the upper one- third and least in the lower one- third of the tree. Total elements in the vegetation are ranked: N($222kg\;ha^{-1}$), Ca(217), K (85), Mg(38), S(31), and p. The soil contained from 60 to 89% of the readily available P, K, Ca, Mg, and S in the ecosystem. Whereas precipitation was the major source of N and S, weathering supplied the bulk of the Ca, Mg, P, and K. Output of a given element by leaching was less than $7kg\;ha^{-1}y^{-1}$ except for S which was $12kg\;ha^{-1}y^{-1}$ Whereas throughfall returned the greatest amounts of N, K, and S to the forest floor, litterfall accounted for the greatest returns of Ca, Mg, and P. Because of foliar leaching, net loading of all elements studied in the throughfall exceeded that of the precipitation. Ammonium in net precipitation was reduced by a factor of three within the upper 7.5cm due to uptake by fine roots.

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Difference in Black-tailed Gull (Larus crassirostris) diet during the breeding season for the last 10 years in the South Sea of Korea

  • Kwon, Young-Soo;Noh, Hyung Soo;Kim, Miran
    • Journal of Ecology and Environment
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    • v.36 no.4
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    • pp.217-222
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    • 2013
  • Sea temperature in the South Sea of Korea has been increased over the last decades. Seabirds are sensitive to changes in food availability in marine environment. In this study, we investigate the diet of Black-tailed gulls (Larus crassirostris) during the breeding season to identify changes of marine environment and biological response such as breeding performance in the South Sea of Korea. A total of 22 fish species or family (n = 128) from regurgitates by chicks were collected on Hongdo Island in 2002 and 2012. The most important prey item was Japanese anchovies (Engraulis japonicas). Proportion of Anchovy in diet increased in 2012 (70.5%) compared to 10 years ago (27.5%). Some species were newly found in 2012: Spotted chub mackerel (Scomber australasicus), Pacific sand lace (Ammodytes personatus), White ventral goby (Acanthogobius lactipes), Silver-strip round herring, Multicolorfin rainbowfish (Halichoeres poecilopterus), Silverside (Hypoatherina tsurugae), Surfperch (Neoditrema ransonneti) and Spotnape ponyfish (Leiognathus muchalis), but not in 2002. Especially, sub-tropic fish such as Kammal thryssa (Thryssa kammalensis), and Rosefish (Helicolenus hilgendorfi) were frequently observed in the diet of 2012. These results might reflect the increase of sea temperature in the South Sea of Korea.

Growth Characteristics and Available Component of Saururus chinensis Baill in Different Soil Texture (토성에 따른 삼백초 생육특성과 유효성분 함량)

  • Kim, In-Jae;Kim, Min-Ja;Nam, Sang-Young;Yun, Tae;Kim, Hong-Sig;Jong, Seung-Keun;Hong, Seong-Su;Hwang, Bang-Yeon
    • Korean Journal of Medicinal Crop Science
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    • v.14 no.3
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    • pp.143-147
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    • 2006
  • This study was carried to investigate the effect of soil texture on the growth and the contents of quercetin-glycoside and lignans, and to improve the qualities of Saururus chinensis Baill. Soil texture resulted no significant effects on the number of nodes, the number of leaves, the number of branches and dry matter ratio. However, the shoot dry weight was higher in sandy loam, loam, silt loam and sand soil in that order. Although the weight of rhizomes of below 5 mm in diameter was not significantly different among soil textures, the weight of rhizomes between 5.1 and 10.9 mm and the weight of rhizomes of above 11 mm in diameter ranged $437{\sim}465\;g$ and was larger in clay loam than in other soil textures. No significance difference was showed in rhizome dry ratio ranging from 19.1 to 20.8%. The amount of quercetin-glycoside in leaves was higher in loam and sandy loam and ranged from 219.3 to 222.4 mg/100 g of quercetin-glycoside quercitrin, rutin, isoquercitrin and hyperin were higher in that order. On the other hand, quercetin-glycoside contents in stem were 14.8 mg/100 g and 12.4 mg/100 g in sandy and sandy loam, respectively, and were higher than in other soil textures of quercetin-glycoside constituents, the content of rutin was the highest. The content of lignans was increased in clay loam, loam, sandy loam, and sandy in that order of lignans, the manassatin B was the highest.