• 제목/요약/키워드: Unsaturated

검색결과 2,314건 처리시간 0.029초

Analysis and design of inclined piles used to prevent downhill creep of unsaturated clay formations

  • Poorooshasb, H.B.;Miura, N.;Noorzad, Ali
    • Structural Engineering and Mechanics
    • /
    • 제6권3호
    • /
    • pp.245-257
    • /
    • 1998
  • This paper present an analysis which may be used to obtain a rational design of a system of inclined piles used in preventing downhill creep of unsaturated clay formations. It uses two simple and relatively easy to measure parameters (an estimate of the maximum downhill creep together with a knowledge of the depth of the so called active zone) to calculate the required section size and the optimal spacing (pitch) of the piles for a desired efficiency of the system as a whole. Design charts are provided to facilitate the process.

클로람페니콜의 면역독성에 미치는 식이지방의 영향 (Effect of Dietary Fat on the Immunotoxicity of Chloramphenicol)

  • 안영근;김주영
    • 약학회지
    • /
    • 제29권2호
    • /
    • pp.55-61
    • /
    • 1985
  • The effect of dietary fat on the immunotoxicity of chloramphenicol was investigated in mice, sensitized and challenged with sheep red blood cells. Chloramphenicol suppressed more cell-mediated immunity than humoral immunity. The saturated fat diet elevated humoral and cell-mediated immunotoxicity, whereas the unsaturated fat diet decreased humoral immunotoxicity, but elevated cell-mediated immunotoxicity of chloramphenicol. Especially, the normal diet in saturated and unsaturated fat restored immunosuppressive effect of chloramphenicol compared to the saturated fat diet and the unsaturated fat diet.

  • PDF

흡인력에 따른 불포화토의 전단강도 특성 (Characteristics of Shear Strength for an Unsaturated Soil with the Matric Suction)

  • 송창섭;최득호
    • 한국환경복원기술학회지
    • /
    • 제10권1호
    • /
    • pp.82-90
    • /
    • 2007
  • In order to analyse the strength problems for an unsaturated soil, it is required to examine closely the characteristics of the parameters of shear strength which was changed with the metric suction and void ratio. To this ends, a triaxial compression test was conducted on the three samples-granular soil, cohesive soil and silty soil. The specimen was made by pressing the static pressure on the mold filled soil and was controled the void ratio with the different compaction ratio. And the test was performed by using the modified apparatus of the triaxial compression tester. The range of matric suction was 0-90 kPa.The measured results for the deviator stress and parameters of shear strength were analysed with the void ratio and the compaction ratio, and they were examined closely the characteristics of the strength for an unsaturated soil.

Allyl Alcohol Found in Heated Garlic is a Potent Selective Inhibitor of Yeasts

  • Lee Se-Hi;Woo Yong-Ho;Kyung Kyu-Hang
    • Journal of Microbiology and Biotechnology
    • /
    • 제16권8호
    • /
    • pp.1236-1239
    • /
    • 2006
  • Allyl alcohol (2-propen-l-ol), found in considerable amounts in heated garlic, was able to discriminate yeasts from bacteria and was approximately three orders of magnitude more inhibitory towards yeasts than bacteria. The average minimum inhibitory concentration (MIC) of allyl alcohol for bacteria and yeasts was 5.0% and 0.0056%, respectively. The unsaturated primary alcohols, including allyl alcohol and 2-buten-l-ol, seemed to work differently from all the other saturated alcohols and unsaturated secondary alcohols in inhibiting various yeasts. An alcohol dehydrogenase-negative (ADH$^-$) strain of Saccharomyces cerevisiae was as resistant to allyl alcohol as various bacteria, exhibiting an MIC of 5.0%. The unsaturated primary alcohols were apparently oxidized into the corresponding unsaturated aldehydes before they inhibited the yeasts.

불포화토의 투수특성 (Characteristics of Permeability for an Unsaturated Soil)

  • 송창섭;신창섭
    • 한국농공학회논문집
    • /
    • 제47권4호
    • /
    • pp.35-41
    • /
    • 2005
  • In order to analyse the flow problems for an unsaturated soil, it is required to examine closely the characteristics of the coefficient of permeability which is changing with the matric suction. To this ends, a permeability test was conducted on the three samples;granular soil, cohesive soil and silty soil. The specimen was made by pressing the static pressure on the mold filled with soil and the void ratio was controled with the different compaction ratio. And the test was performed by using the modified apparatus of the steady state method which was proposed by flute (1972). The range of matric suction was 0-90 kPa. The measured results for the coefficients of permeability were analysed with the void ratio and the compaction ratio, and it was examined closely the characteristics of the permeability for an unsaturated soil.

불포화토의 거동예측을 위한 구성식 개발(I) -불포화토의 거동특성 연구- (Development of Constitutive Model for the Prediction of Behaviour of Unsaturated Soil(I) -Study of Characteristics of Unsaturated Soil-)

  • 송창섭;장병욱
    • 한국농공학회지
    • /
    • 제36권4호
    • /
    • pp.87-94
    • /
    • 1994
  • The aim of the work descrihed in this paper is to study a characteristics of an unsaturated soil for the different matric suctions. To this end, a series of suction controlled isotropic and triaxial compression tests is conducted on silty sands. Matric suction is controlled by the axis translation technique using high air entry ceramic disk. Total volume change, air and water volume changes are measured by the device made for the experiment. The specimens are compacted using a half of Proctor compaction energy and with the water contents of 5% drier than the optimum moisture contents. Isotropic compression and triaxial compression tests are conducted on the specimen at each equilibrium state of matric suction. From test results, volume changes and deviator stresses are analyzed at each state and their relationships are formulated.

  • PDF

불포화지방산(不飽和脂肪酸)의 비색정량법(比色定量法) (Colorimetric Method of Determining Unsaturated Fatty Acids in Animal Tissues)

  • 허린수;장인호
    • Journal of Nutrition and Health
    • /
    • 제15권1호
    • /
    • pp.9-14
    • /
    • 1982
  • The present paper describes a colorimetric method of determining the free and total unsaturated fatty acids in animal tissues. The procedure is based in three steps on the following principles : First step is that the tissue homogenates are extracted in chilled acetone in order to eliminate the interfering substance, such as phospholipids, sulfatides and proteins. At next step, after centrifugation acetone layer is decanted and evaporated to dryness. Then the extract is shaken with heptane to solve in the solvent. That the characteristic nature of copper salts of unsaturated fatty acids are freely soluble in heptane and those of saturated acids are not is the bases of separating one from another. Thus unsaturated fatty acids can be isolated in heptane as their salts from saturated acids and other lipid mixture by shaking with copper reagent. Finally the yellowish brown color developed by adding color reagent (0.2% sodium diethyldithiocarbamate in n-butanol solution) which reacts with the copper salts of the acids and produces the color is measured colorimetrically.

  • PDF

불포화 압축 벤토나이트에서의 수확산 및 재포화 (Water Diffusion and Resaturation in Unsaturated Compacted Bentonite)

  • 고은옥;이재완;조원진;현재혁;전관식
    • 한국지하수토양환경학회:학술대회논문집
    • /
    • 한국지하수토양환경학회 1998년도 공동 심포지엄 및 추계학술발표회
    • /
    • pp.216-220
    • /
    • 1998
  • Experimental studies were carried out to investigate water diffusion in unsaturated compacted bentonite for a landfill of hazardous wastes. Water content distributions were measured and water diffusion coefficients were determined when the dry densities of compacted bentonite were in the range of 1.4 - 1.8 g/㎤. Resaturation times were also calculated to analyze the ability of the compacted bentonite to retard water movement. The results obtained were as follows: Diffusion model described properly the water migration in unsaturated compacted bentonite. Water diffusion coefficients ranged from 4.30$\times$10$^{-6}$ $\textrm{cm}^2$/sec to 1.93$\times$10$^{-6}$ $\textrm{cm}^2$/sec, and decreased with increasing the dry density. The dry density of compacted bentonite was found to be an important factor to control the resaturation time by water. This study suggests that the domestic compacted bentonite should be a good barrier material against water movement in a landfill of hazardous wastes.

  • PDF

모관흡수력을 고려한 불포화토의 전단강도에 대한 연구 (A study on the shear strength considering matric suction for an unsaturated soil)

  • 오세붕;김태경
    • 한국지반공학회:학술대회논문집
    • /
    • 한국지반공학회 2008년도 춘계 학술발표회 초청강연 및 논문집
    • /
    • pp.105-110
    • /
    • 2008
  • The behaviour of an unsaturated soil was analyzed by performing $K_0$ consolidated triaxial tests. Unsaturated triaxial tests were performed with matric suctions for weathered soils and could catch stress paths under consolidation and stress-strain relationships under shear. As a result, both isotropic and $K_0$ conditions had similar shear strength envelopes in the same matric suction. Especially, strength parameters could obtain by stress variables based on critical state theory reasonably which was better than those by Mohr circles at failure.

  • PDF

불포화 강도특성을 고려한 도로 입상재료의 한계하중 평가 (Evaluation of Limit Load of Granular Pavement Materials Considering Unsaturated Shear Strength Characteristics)

  • 전혜지;박성완
    • 한국지반공학회:학술대회논문집
    • /
    • 한국지반공학회 2010년도 춘계 학술발표회
    • /
    • pp.673-678
    • /
    • 2010
  • In this paper, the limit load of granular materials was evaluated considering unsaturated shear strength. The unsaturated shear strength parameters were estimated using the results from triaxial compression test and soil-water characteristic curves test. In addition, the limit load of different rates of materials was compared. Also, two important design parameters, yield and failure load were defined utilizing 2-D nonlinear finite element analysis respectively.

  • PDF