• Title/Summary/Keyword: 인아OM

Search Result 47, Processing Time 0.028 seconds

Textural Characters of the Overwash Mark Sediments on the Berm of the Nobong Beach Environment, East Sea of Korea (동해안 해빈(노봉 해빈) 환경의 Overwash Mark 퇴적물의 조직 특성)

  • 박용안;최경식;김수정
    • The Korean Journal of Quaternary Research
    • /
    • v.14 no.1
    • /
    • pp.1-5
    • /
    • 2000
  • During the last three years (1997∼2000), a research project of beach dynamic environmental process and dynamic nature of the Nobong Beach, East Sea of Korea has been carried out for a better understanding of beach cycle (winter and summer). In fact, however, this paper deals with a particular feature of beach dynamics, that is, overwash process of overwash water and its sediments. The overwash mark sediments (OMS) are analyzed to understand various textural characters.

  • PDF

Microphase Separation and Crystallization in Binary Blends Consisting of Poly (methyl methacrylate)-block-Polystyrene Copolymer and Poly (vinylidene fluoride) (폴리(메틸 메타크릴레이트)-폴리스티렌 이종 블록 공중합체/폴리(비닐리덴 플루오라이드) 블렌드의 미세 상분리와 결정화)

  • 김지선;이광희;조성무;류두열;김진곤
    • Polymer(Korea)
    • /
    • v.28 no.6
    • /
    • pp.509-518
    • /
    • 2004
  • Microdomain structures and crystallization behavior of the binary blends consisting of an asymmetric block copolymer and a homopolymer were investigated using small-angle X-ray scattering (SAXS), optical micro scope (OM) and differential scanning calorimetry (DSC). Poly(methyl methacrylate)-block-polystyrene block copolymer (PMMA-b-PS) (weight fraction of PMMA =0.53) was mixed with low molecular weight poly(vinylidene fluoride) (PVDF). As the PVDF concentration was increased, the morphological change from a lamellar to a cylindrical structure occurred. The crystallization of PVDF significantly disturbed the orientation of the pre-existing microdomain structure, resulting in a poorly ordered morphology. In the blends, PVDF exhibited unique crystallization behavior due to the PMMA block which is preferentially miscible to PVDF and the space constraint imposed by the microdomains.

Representative Physical and Chemical Properties of Korean Soils by the Results from Detailed Soil Survey (우리나라 토양(土壤)의 대표적(代表的)인 물리화학적(物理化學的) 특성(特性) (정밀토양조사결과(精密土壤調査結果)를 중심(中心)으로))

  • Hur, Bong-Koo;Jo, In-Sang;Min, Kyeong-Beom;Um, Ki-Tae
    • Korean Journal of Soil Science and Fertilizer
    • /
    • v.17 no.4
    • /
    • pp.330-336
    • /
    • 1984
  • These studies were aimed to find out the representative values of physico-chemical properties in Korean soils and to serve the basic informations to improve the soil properties for increasing the soil productivity. By the results of detailed soil survey, 14 physico-chemical properties (soil texture, moisture characteristics, organic matter content etc) were collected from 315 series of soils except Cheju soils, computerized the simple mean and the distributed area by weighted mean values with grouping of land use, drainage class and soil type. The results were as follows; 1. Simple mean values within the efficient soil depth in whole country soils were clay 20.0%, organic matter 2.03% and CEC 10.3me/100g. But weighted mean values with land area belonged to the same soil series were clay 18.0%, OM 1.85% and CEC 8.6me/100g. 2. Mean values of paddy soils weighted by area were clay 19.7%, OM 2.0% and CEC 9.1me/100g but those of upland soils were 17.9%, 1.8% and 8.1me/100g and forest soils were 16.7%, 1.8% and 8.6me/100g respectively. 3. Weighted mean values of moderately well soils with covered area were clay 18.9%, organic matter 1.7%, CEC 8.4me/100g but those of imperfectly drained soils were 21.3%, 2.2% and 9.5me/100g, and those of poorly drained soils were 15.1%, 1.8% and 9.9me/100g respectivcly. 4. Simple mean and area weighted mean values of clay content, pH, organic matter contents, cation exchange capacity and base saturation were calculated by the types of paddy and upland.

  • PDF

Nutrient Balance and Application Efficiency of Nitrogen and Potassium in Salt-Accumulated Greenhouse Soil (염류(鹽類)가 축적(蓄積)된 시설재배(施設栽培) 토양(土壤)에서 질소(窒素)와 가리(加里)의 시비효과(施肥效果) 및 양분수지(養分收支))

  • Lee, Sang-Eun;Lee, Choon-Soo
    • Korean Journal of Soil Science and Fertilizer
    • /
    • v.27 no.2
    • /
    • pp.78-84
    • /
    • 1994
  • Yield response of tomato to nitrogen and potassium fertilizer and the balance of the two elements were determined in salt-accumulated greenhouse soil to improve the efficiency of fertilizer appiication. The response of tomato yield to nitrogen and potassium fertilizer application was not significant. The current parameters such as OM and $K/{\sqrt{Ca+Mg}}$ that were used to determine the level of nitrogen and potassium fertilizer in open field were not suitable in salt-accumulated greenhouse soil condition. The temporal and spatial distribution of $NO_3{^-}-N$showed the same pattern to those of $Cl^-$ ion that is non-reactive with soil, while the content of Ex. K was extraordinarily high in soil after harvesting of tomato, which had experienced relatively dry condition during harvesting time. The loss of $NO_3{^-}-N$ and Ex. K out of 28cm below the soil surface was 2~5 and 1.5~3.5 times greater than the amount of nitrogen and potassium uptake by the plant.

  • PDF

Physico-Chemical Environment and Productivity of the Phytoplankton Community in the Jido Pond Ecosystem (지도지생태계의 물리화학적환경과 식물성 플랭크톤군집의 생산성)

  • Song Seung-Dal;M. Anwarul Huque
    • Journal of environmental and Sanitary engineering
    • /
    • v.5 no.2
    • /
    • pp.117-122
    • /
    • 1990
  • The Jido Pond system was investigated from April, 1979 through March, 1980, in respect of seasonal changes in physico-chemical factors: i.e., temperature, pH, DO, BOD, COD, $Cl^-, \; Mg^{++}$, alkalinity, detergent, $SiO_2, PO_4\;^{3-}, NH_4\;^+, NO_2\;^-, NO_3\;^-$, total N, OM and OC; phytoplankton community growth; and the ecosystem metabolism. The phytoplankton community was represented by 23 species belonging to Chlorophyta, Bacillariophyta and Cyanophyta; each sharing 11, 9 3 respectively. The Chlorophyceans dominated the phytoplankton community contributing 75% of the total ?미 counts. The ranges of biotic diversity indices were, d, 0.85~2.80; H, 1.10~2.40; c, 0.13~0/40; and 3, 0.56~0.90. The chlorophyll standing crop varied in between 0.043 and 0.385g/$\textrm{cm}^2$ surface area. The ranges of photosynthetic and respiratory rates were 0.36~4.50; and 0.10~1.40 $O_2$ mg/1/hr, respectively. The monthly areal net primary production varied from 23.9 to 305.1C g/$\textrm{m}^2$/month. The Eu of the net production seasonally varied in between 0.31 and 7.80%, and the annual mean was 2.44%. The annual turnover times of phosphorus and nitrogen were 20 and 3 days, respectively.

  • PDF

Residual Life Assessment of mod HP Reformer Tubes Using Surface Replication Methods (표면복제를 사용한 mod HP강 개질로 튜브의 잔여수명 평가에 대한 연구)

  • Ryu, Hyung Ki;Le, Thi Giang;Bang, Hyo Jung;Yoon, Kee Bong
    • Journal of the Korean Institute of Gas
    • /
    • v.25 no.5
    • /
    • pp.30-36
    • /
    • 2021
  • Residual life assessment of reformer tubes of mod HP steel used in the refinery and petrochemical industry were investigated by quantitative metallographic evaluation method. Area fractions of precipitated carbides were measured by using surface replication and its relationship with the remaining life of the tube was investigated. The microstructures of the virgin and other tubes were examined using optical microscopy (OM) for service periods of 1.8, 6.0, 7.2, 8.5, 9.7, and 16.2 years at 950 ℃ and the area fractions of the precipitates were measured by image analysis using ImageJ software. As the area fraction of the precipitates increased, the residual life was decreased accordingly. The results showed that the LMP was the highest in the virgin and the LMP decreased as the service time increased and the residual life decreased. A regressional equation showing the relation between the area fraction of carbides and LMP was experimentally derived. The obtained relationship can be used with the surface replication method for on-site residual life assessment.

Numerical Approach for Evaluation of Forest Soil Fertility (수치적(數値的) 접근방법(接近方法)에 의(依)한 산림토양(山林土壤)의 비옥도(肥沃度) 평가(評價))

  • Ma, Sang Kyu
    • Journal of Korean Society of Forest Science
    • /
    • v.35 no.1
    • /
    • pp.1-8
    • /
    • 1977
  • Forest soil fertility was evaluated through the approach of numerical method. In this study, the soil chemical properties analyzed for 35 different soil series as table 2 were cited in numerical analysis. Minimum contents of essential nutrients in the surface soil for a satisfactory growth of tree in the plantation were evaluated by comparing with Wild's standard as table 1. Demanding level of fertilization were evaluated by using the formula 1 as table 5. Similar relation of soil chemical properties between soil series were calculated through formula 2, and then classified into 5 groups in soil chemical properties. 1. General chemical properties of surface soil in case of 35 soil series. About 40 percent of 35 different soil series are less than 2 percent in organic matter, 10 ppm in available phosphorus, 1.25m.e/l00g in exchangeable calcium and 0.5m.e/l00g in exchangeable magnesium. Generally, shortage of exchangeable potash are not found. CEC less than 10m.e/l00g are in two thirds and strong acid soil less than PH 5.5 are in about four fifths. 2. Soil series requested or not the fertilization are indirectly evaluated from the formula 1 using the relative figure of chemical components of CEC, OM and MgO. Through this analysis, 8 different soil series have very poor quality in soil chemical capacity so that demands highly the fertilization. On the other hand, other 13 different soil series group have not been thought to need the fertilization according to chemical guality. 3. By the results comparing the similarity of chemical properties of forest soil, it is thought to be suitable that the forest soil fertility are divided into 5 groups as follows: 1. Low CEC soil 1-1 Low organic matter soil less than 2 percent 1-2 Medium organic matter soil less than 4 percent 2. High CEC and organic matter soil 2-1 Low magnesium soil 2-2 High magnesium soil 3. High magnesium and calcium soil as lime stone.

  • PDF

Effect of Humified Straw Used as a Medium of Trickling Filter with Livestock Wastewater on the Growth of Bunching Lettuce (Lactuca sativa L., var. crispa) and Soil Chemical Properties (축산폐수(畜産廢水) 살수여상충전재(撒水濾床充塡材)인 볏짚의 부숙처리가 상추(Lactuca sativa L., var. crispa)의 생육(生育)과 토양화학성(土壤化學性)에 미치는 영향(影響))

  • Kim, Jeong-Je;Yang, Jae-E;Shin, Young-Oh
    • Korean Journal of Soil Science and Fertilizer
    • /
    • v.29 no.2
    • /
    • pp.137-144
    • /
    • 1996
  • A feasible way to utilize small-scale livestock farm wastewater was explored. In place of common support materials rice straw was employed as a support medium of trickling filter for pig farm wastewater treatment. The straw medium which was humified for 20 days after wastewater treatment and mixed with soil significantly enhanced in general the development of bunching lettuce grown under greenhouse conditions. Improvement of soil chemical properties in terms of fertility was also achieved by the addition of humified straw medium after wastewater treatment. It was found that rice straw served as a satisfactory support medium of trickling filters with the wastewater treatment concerning removals of biological oxygen demand, chemical oxygen demand, and suspended solids.

  • PDF

Formation of Cobalt Ferrite Epitaxial Iron Oxide and Their Magnetic Properties(II) (코발트 훼라이트 에피탁시얼 산화철의 생성과 자기특성(II))

  • Byeon, T.B.;Kim, D.Y.;Lee, J.Y.;Lee, H.;Sohn, J.G.;Han, K.H.
    • Journal of the Korean Magnetics Society
    • /
    • v.2 no.1
    • /
    • pp.15-21
    • /
    • 1992
  • Acicular ${\gamma}-Fe_{2}O_{3}$ particles were heated at $90^{\circ}C$ in alkaline solution containing mixed solution of dyadic metal with $Co^{+2}/Fe^{+2}$ ratio of 0.5. When cobalt content was increased, the coercivity of resultant product increased linearly, and surface area decreased. The cobalt ferrite was grown epitaxially on the surface ${\gamma}-Fe_{2}O_{3}$ crystal, and the increase of coercivity was attributed to the crystalline magnetic anisotropy of the cobalt ferrite which is conform to coating layer. We can expect superior magnetic properties above normal ratio of 2. The progress of reaction has an effect on coercivity of cobalt ferrite epitaxial iron oxide. The stability of temperature and the change om standin& of $Co-{\gamma}-Fe_{2}O_{3}$ was largely influenced by the composition of coating layer.

  • PDF

A Study on the Property and Performance Characteristics of Different Kind Engine Oil by Endurance Test of Heavy-duty Diesel Engine (대형 디젤엔진 내구 시험에 의한 다른 종류 엔진오일의 물성 및 성능 특성에 관한 연구)

  • Lee, Minho;Kim, Jeonghwan;Song, Hoyoung;Kim, Giho;Ha, Jonghan
    • Transactions of the Korean Society of Automotive Engineers
    • /
    • v.22 no.7
    • /
    • pp.48-56
    • /
    • 2014
  • Engine oil is an oil used for lubrication of various internal combustion engines. The main function is to reduce wear on moving parts; it also cleans, inhibits corrosion, improves sealing, and cools the engine by carrying heat away from moving parts. In engines, there are parts which move against each other. Otherwise, the friction wastes the useful power by converting the kinetic energy to heat. Those parts were worn away, which could lead to lower efficiency and degradation of the engine. It increases fuel consumption, decreases power output, and can induce the engine failure. This study was conducted to evaluate the relation between engine oil property changes and engine performance for the diesel engine. This test was performed by using 12L, 6 cylinder, heavy duty engines. Low SAPS 10W30 engine oil (two type engine oils) was used. Test procedure and method was in accordance with the modified CEC L-57-T97 (OM441LA) method. In this study, TAN, TBN, KV and metal components, engine power, blowby gas, A_F were presented to evaluate the relation with engine oil property changes and engine performance. TAN, TBN, KV and metal We found that the components were generally increased but engine performance did not change. This results mean that property changes did not affect on engine performance because those were not enough to affect engine performance.