• 제목/요약/키워드: surplus soil

검색결과 51건 처리시간 0.022초

우리나라 사과, 배, 포도 및 복숭아 주산지 토양의 화학적 특성 (Chemical Properties of Korean Orchard Soils in Main Apple, Pear, Graph and Peach Producing Area)

  • 이주영;정재훈;김석철;황선웅;이춘수
    • 한국토양비료학회지
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    • 제33권2호
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    • pp.79-84
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    • 2000
  • 주요 과수재배지 토양에 대한 화학적 독성을 파악하기 위하여 사과 239, 배 369, 포도 168, 복숭아 101, 합계 877포장에서 주간 중간지점의 토양을 채취분석하여 토양화학적 특성에 따라 토양비옥도를 구분하였다. 주요 과수 주산단지 토양화학성분의 적정수준 비율은 3.0~65.2%로서 대부분의 과수원이 부적지였으며 토양층위별 화학성분은 하층으로 내려 갈수록 일정하게 감소되는 경향을 보여 시비관리가 동일한 지역에서는 표층토 20cm 깊이의 토양 화학성분 함량만 알면 층토의 성분함량을 추정할 수 있으며 또한 과종별 표토의 토양화학성분함량의 과부족율을 추정할 수 있었다.

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굴착잔토를 재활용한 지중 전력케이블 유동성 뒷채움재 이용시 지중연성관의 거동특성 (Behavior of Flexible Pipes with the Accelerated Flowable Backfill Materials Using Surplus Soil for Underground Power Utilities)

  • 오기대;김대홍;이대수;김경열;홍성연
    • 한국지반환경공학회 논문집
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    • 제10권7호
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    • pp.33-41
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    • 2009
  • 지중전력선과 같은 원형 지하매설관의 경우 관의 하단부 다짐효율이 낮아 파손등과 같은 구조적 문제점에 항상 노출되어있다. 이러한 문제점들 때문에 다양한 방법들이 강구되어 왔으며 그중 하나가 유동성이 뛰어난 저강도 콘크리트의 개발이다. 외국에서는 이미 오래전부터 연구개발을 진행하여 전력회사를 중심으로 이미 실용화 단계에 와있다. 따라서 본 연구에서는 개발된 지중 전력케이블 유동성 뒷채움재의 거동특성을 확인하기 위해서 개발된 유동화 뒷채움재와 일반모래를 이용하여 DB-24차량하중에 대해서 매설관의 거동을 평가하기 위해서 실증실험을 수행하고 그 결과를 수치해석 및 이론식과 비교분석하였다. 그 결과 매설관의 변형은 뒷채움재의 종류에 영향을 받는 것으로 나타났다. 유동성 뒷채움재가 모래다짐 보다 관로에 미치는 토압 및 변형 특성이 우수한 것으로 확인되었다. 하지만, 실증실험 결과와 비교검토를 위해서 수행한 수치해석 및 이론식 값들이 실증실험값과 차이가나 향후 유동성 뒷채움재에 맞는 해석방법 개발이 필요할 것으로 판단된다.

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굴착잔토를 재활용한 지중전력구조물 급결성 유동화 뒷채움재의 최적배합비 (Optimal Mixture Contents of Accelerated Flowable Backfill Materials Using Surplus Soil for Underground Power Utilities)

  • 천선호;정상섬;이대수;조화경
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2005년도 지반공학 공동 학술발표회
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    • pp.395-404
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    • 2005
  • This study is to evaluate the physical and mechanical characteristics of flowable backfill and search for the optimal mixture contents of it used for constructing underground power utilities. flowable backfill is known as soil-cement slurry, void fill, and controlled low-strength material(CLSM). The benefits of CLSM include reduced equipment costs, faster construction, re-excavation in the future, and the ability to place material in confined spaces such as narrow parts nearly impossible for compaction or perimeter of underground power cables. The flowable slurry mixture made with 9 types of soil and 6 types of accelerated mixtures in the laboratory were evaluated for bleeding, flowability, heat resistance, and unconfined compressive strength to meet the aim values of this study.

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Performance of fly ash stabilized clay reinforced with human hair fiber

  • Rekha, L. Abi;Keerthana, B.;Ameerlal, H.
    • Geomechanics and Engineering
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    • 제10권5호
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    • pp.677-687
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    • 2016
  • Industrialization and urbanization are the two phenomena that are going relentless all over the world. The consequence of this economic success has been a massive increase in waste on one hand and increasing demand for suitable sites for construction on the other. Owing to the surplus raw materials and energy requirement needed for manufacturing synthetic fibers, applications of waste fibers for reinforcing soils evidenced to offer economic and environmental benefits. The main objective of the proposed work is to explore the possibilities of improving the strength of soil using fly ash waste as an admixture and Human Hair Fiber (HHF) as reinforcement such that they can be used for construction of embankments and land reclamation projects. The effect of fiber content on soil - fly ash mixture was observed through a series of laboratory tests such as compaction tests, CBR and unconfined compression tests. From the stress - strain curves, it was observed that the UCC strength for the optimised soil - flyash mixture reinforced with 0.75% human hair fibers is nearly 2.85 times higher than that of the untreated soil. Further, it has been noticed that there is about 7.73 times increase in CBR for the reinforced soil compared to untreated soil. This drastic increase in strength may be due to the fact that HHF offer more pull-out resistance which makes the fibers act like a bridge to prevent further cracking and thereby it improves the toughness which in turn prevent the brittle failure of soil-flyash specimen. Hence, the test results reveal that the inclusion of randomly distributed HHF in soil significantly improves the engineering properties of soil and can be effectively utilized in pavements. SEM analysis explained the change of microstructures and the formation of hydration products that offered increase in strength and it was found to be in accordance with strength tests.

Effect of Suboptimal Nutritional Status on Mineral Uptake and Carbohydrate Metabolism in Tomato Plants

  • Sung, Jwakyung;Lee, Sangmin;Lee, Suyeon;Kim, Rogyoung;Lee, Yejin;Yun, Hongbae;Ha, Sangkeun;Song, Beomheon
    • 한국토양비료학회지
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    • 제46권5호
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    • pp.351-358
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    • 2013
  • A suitable supply of mineral elements into shoot via a root system from growth media makes plants favorable growth and yield. The shortage or surplus of minerals directly affects overall physiological reactions to plants and, especially, strongly influences carbohydrate metabolism as a primary response. We have studied mineral uptake and synthesis and translocation of soluble carbohydrates in N, P or K-deficient tomato plants, and examined the interaction between soluble carbohydrates and mineral elements. Four-weeks-old tomato plants were grown in a hydroponic growth container adjusted with suboptimal N ($0.5mmol\;L^{-1}\;Ca(NO_3)2{\cdot}4H_2O$ and $0.5mmol\;L^{-1}\;KNO_3$), P ($0.05mmol\;L^{-1}\;KH_2PO_4$), and K ($0.5mmol\;L^{-1}\;KNO_3$) for 30 days. The deficiency of specific mineral element led to a significant decrease in its concentration and affected the concentration of other elements with increasing treatment period. The appearance of the reduction, however, differed slightly between elements. The ratios of N uptake of each treatment to that in NPK sufficient tomato shoots were 4 (N deficient), 50 (P deficient), and 50% (K deficient). The P uptake ratios were 21 (N deficient), 19 (P deficient), and 28% (K deficient) and K uptake ratios were 11 (N deficient), 46 (P deficient), and 7% (K deficient). The deficiency of mineral elements also influenced on carbohydrate metabolism; soluble sugar and starch was substantially enhanced, especially in N or K deficiency. In conclusion, mineral deficiency leads to an adverse carbohydrate metabolism such as immoderate accumulation and restricted translocation as well as reduced mineral uptake and thus results in the reduced plant growth.

Temporal Changes in N Assimilation and Metabolite Composition of Nitrate-Affected Tomato Plants

  • Sung, Jwakyung;Lee, Suyeon;Lee, Yejin;Kim, Rogyoung;Lee, Juyoung;Lee, Jongsik;Ok, Yongsik
    • 한국토양비료학회지
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    • 제45권6호
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    • pp.910-919
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    • 2012
  • The role of inorganic nitrogen assimilation in the production of amino acids, organic acids and soluble sugars is one of the most important biochemical processes in plants, and, in order to achieve normally, nitrate uptake and assimilation is essential. For this reason, the characterization of nitrate assimilation and metabolite composition from leaves, roots and xylem sap of tomato (Solanum lycopersicum) was investigated under different nitrate levels in media. Tomato plants were grown hydroponically in liquid culture under five different nitrate regimes: deficient (0.25 and 0.75 mM $NO_3{^-}$), normal (2.5 mM $NO_3{^-}$) and excessive (5.0 and 10.0 mM $NO_3{^-}$). All samples, leaves, roots and xylem sap, were collected after 7 and 14 days after treatment. The levels of amino acids, soluble sugars and organic acids were significantly decreased by N-deficiency whereas, interestingly, they remained higher in xylem sap as compared with N-normal and -surplus. The N-excessive condition did not exert any significant changes in metabolites composition, and thus their levels were similar with N-normal. The gene expression and enzyme activity of nitrate reductase (NR), nitrite reductase (NIR) and glutamine synthetase (GS) were greatly influenced by nitrate. The data presented here suggest that metabolites, as a signal messenger, existed in xylem sap seem to play a crucial role to acquire nitrate, and, in addition, an increase in ${\alpha}$-ketoglutarate pathway-derived amino acids under N-deficiency may help to better understand plant C/N metabolism.

토양조건이 더덕의 생육특성 및 향끽미물질 발현에 미치는 영향 (The effects of soil condition on the agronomic characters and aromatic substances in cultivated Codonopsis Lanceolata)

  • 오세명;정형진;권순태
    • 한국자원식물학회지
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    • 제12권4호
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    • pp.282-288
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    • 1999
  • 더덕을 야생지 및 재배지 토양으로 분 재배하여 토양조건 및 혈당 재식 주수가 더덕의 생육특성 및 향끽미 물질발현에 미치는 영향을 구명하고자 수행해 본 결과는 다음과 같다. 1. 재배지 토양에서 폿트 재배시 더덕의 길이 생장은 토양수분보다는 혈당 주수에 영향을 미쳤고, 재배지와 야생지 토양 공히 수분조건이 과습>적습>과건 순으로 두께가 컸고, 혈당재배주 수간에는 혈당 재배주수가 증가 할 수록 두께는 작아지는 경향이고, 개체 및 혈당수량은 수분조건별로 과습>적습>과건 순으로 높았다. 2. 야생지토양에 비하여 재배지 토양에서의 더덕재배는 수분, 환원당, 조단백질의 함량이 높았고, 조섬유 및 석유에텔 추출물 함량이 낮았다. 3. 야생지 토양에 비해 재배지 토양에서 생육한 더덕근에서 유기산인 malic산의 함량이 낮았고, 지방산함량은 비슷하였다. 4. 토양수분처리간에는 조사된 주요 정유성분들의 대부분이 적습>과습>과건 순으로 함량이 높았고, 특히 3-methylpentanoic acid와 squalene의 함량은 적습구가 과습 및 과건 처리 구에서 보다 2-5배 정도 높았다.

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아스팔트 안정처리토의 역학적 특성 연구 (Mechanical Characteristics of Asphalt Stabilized Soil)

  • 박태순;최필호
    • 한국지반공학회논문집
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    • 제19권5호
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    • pp.189-197
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    • 2003
  • 건설공사에서 발생되는 건설잔토는 처리 및 운반에 소요되는 비용이 고가이기 때문에 현장에서 재활용하기 위한 공법의 개발이 오래 전부터 요구되어 왔다. 본 연구는 현장에서 발생하는 토사를 아스팔트에 혼합하여 제조된 아스팔트 안정처리토의 역학적 특성을 평가하기 위한 실내시험 연구이다. 아스팔트와 토사의 혼합은 폼드(foamed)장치라고 불리는 장치를 사용하여 아스팔트에 거품을 발생시켜 토사와 혼합하는 방법을 사용하였다. 아스팔트가 토사와 혼합되었을 때 성능 향상을 조사하기 위해서 마샬안정도, 간접인장강도, 회복탄성계수, 크리프 시험 및 비압밀 비배수 삼축압축시험을 실시하였으며 조건을 달리하여 제작한 시료(일반토사, 시멘트 2% 보강 토사)와 결과를 비교 분석하였다. 시험 결과 아스팔트의 혼입은 안정도, 회복탄성계수, 수분저항성이 향상되는 것으로 나타났으며 시멘트의 첨가는 이러한 역학적 성능을 더욱 크게 향상시키는 것으로 나타났다. 아스팔트 안정토는 토사의 혼합 함수비, 습윤상태는 시험 결과에 영향을 미치는 것이 확인되었는데 배합 설계시 혼합함수비, 세립분의 량을 조절함으로써 아스팔트 안정토의 역학적 특성을 향상시킬 수 있는 것으로 발견되었다.

식량수급(食糧需給)에 따른 비료수요(肥料需要) 전망(展望) (Long-run Estimation of Fertilizer Demand in Korea to Meet the National Food Supply)

  • 이윤환
    • 한국토양비료학회지
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    • 제9권3호
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    • pp.133-147
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    • 1976
  • 1. The purpose of this study is to provide a series of statistical "bench marks" from which one can begin to think systematically about the required development of the Korean food and fertilizer needs over the next quarter-century. 2. The Korean population has been estimated by the characteristics of the population and its social and political situations today. Because fertility and mortality rates are relatively stable and are under control of politics concerned, the estimation rates were established with 1.6% over 1975-1980, 1.3% over 1981-1990, and 1.0% over 1991-2000. 3. Annual per capita absorption of milled rice has fluctuated rather closely around 140kg, since 1968, with no evidence of declining trend. Per capita absorption of barley and wheat around 120 kg, and legumes around 10.6kg, However because the case of wheat and corn productions are rather difficult the self-sufficiency in the future, the rice is considered to be accelerate its yield growth surplus the level of self-sufficiency to export. 4. The fertilizer demand in each element has been calculated by mechanical multiplication of "the recommend index of fetilizer application" to yield a unit production over the need of national food supply by crop year. 5. As a results refer to Table (8), the estimated quantities of total fertilizer demand to meet the national food supply of the years of 1974, 1980, 1985, 1.990, 1995, and 2000 are reached around 871500, 1138150, 1375480, 1515030, 1652090 and 1799850 metric tons in each year.

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완효성 탄소원 정제 내 citric acid의 생물학적 탈질소화 영향 (Assessing the Role of Citric Acid in Denitrification of Nitrate in Slow-releasing Carbon Source Tablet)

  • 한경진;염여훈;김영;권수열
    • 한국지하수토양환경학회지:지하수토양환경
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    • 제27권3호
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    • pp.41-49
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    • 2022
  • This study utilized citric acid as a floating agent in biological denitrification process and assessed its role under different carbon supplying conditions. Several microcosm tests including citric acid active (CAA), precipitating tablet release active (PTRA) and floating tablet release active (FTRA) were conducted to evaluate nitrate denitrification efficacy. In CAA reactors, nitrate removal was accompanied by the formation of denitrification by-products such as nitrite and nitrous oxide, with the extent of nitrate removal being proportional to citric acid concentration. These results suggest that citric acid induced heterotrophic biological denitrification. PTRA reactor that incorporated CAA and the same electron donor showed a similar denitrification efficiency to CAA reactor. FTRA reactor, which contained the same amount of fumarate as PTRA, enhanced denitrification by 7% as compared to the PTRA reactor. The overall results of this work indicate that surplus citric acid can be efficiently utilized in heterotrophic denitrification.