• Title/Summary/Keyword: degree of saturation

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Shear Characteristics of Weathered Granite Soils for Degree of Weathering and Saturation (화강토의 풍화도와 포화도에 따른 전단특성)

  • Song, Chang-Seob;Jang, Wong-Hee
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.3 no.3
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    • pp.1-7
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    • 2000
  • The aim of the work described in this paper is to study the shear characteristics of the weathered granite soil. To this end, a series of consolidated undrained triaxial compression tests are carried out to investigate the shear parameters-cohesion and internal friction angle for the degree of saturation and degree of weathering. From the results, it is found that the shear parameters of weathered granite soil are influenced on the degree of saturation, degree of weathering and disturbance. Especially, internal friction angle is more influenced on the upper factors than cohesion. And shear parameters are more acted on the degree of saturation than the degree of weathering in the test range. It is, therefore, recommended that must be considered the conditions of granite soil-degree of saturation, degree of weathering and disturbance etc-in case of the calculation of bearing capacity, stability analysis and other designs with shear parameters.

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Mechanical Characteristics of Weathered Granite Soils for Degree of Weathering and Saturation (풍화도과 포화도에 따른 화강토의 역학적 특성)

  • Lim, Seongyoon;Song, Changseob;Kim, Myeonghwan
    • Journal of The Korean Society of Agricultural Engineers
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    • v.57 no.3
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    • pp.93-100
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    • 2015
  • The object of this paper is to study the shear characteristics of the weathered granite soil. To this end, a series of consolidated undrained triaxial compression tests are carried out to investigate the shear parameters-cohesion and internal friction angle-for the degree of saturation and degree of weathering. From the results, it is found that the shear parameters of weathered granite soil are influenced on the degree of saturation, degree of weathering and disturbance. Especially, internal friction angle is more influenced on the upper factors than cohesion. And shear parameters are more acted on the degree of saturation than the degree of weathering in the test range. It is, therefore, recommended that must be considered the conditions of granite soil-degree of saturation, degree of weathering and disturbance etc-in case of the calculation of bearing capacity, stability analysis and other designs with shear parameters.

Variation of Pull-out Resistance of Geogrid with Degree of Saturation of Soil

  • Yoo, Chungsik;ALI, TABISH
    • Journal of the Korean Geosynthetics Society
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    • v.19 no.1
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    • pp.1-9
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    • 2020
  • This paper presents the results of experimental investigation on the effect of degree of saturation of soil on the pullout behavior of a geogrid. Different test variables were taken into account while performing the experiment including the soil physical conditions based on water content and external loading applied. The soil used was locally available weathered granite soil. The tests included variations in saturation of about 90%, 80%, 70% and 45% (optimum moisture content). The pullout tests were performed according to ASTM standard D 6706-01. The results indicate that increasing the degree of saturation in the soil decreases the pull-out capacity, which in turn decreases the interface friction angle and interaction coefficient. The decrease in the pullout interface coefficient was observed to be around 12.50% to 33.33% depending on the normal load and degree of saturation of the soil. The test results demonstrated the detrimental effect of increasing the degree of saturation within the reinforce soil on the pullout behavior of reinforcement, thus on the internal stability. The practical inferences of the outcomes are analyzed in detail.

Settlement characteristics of rock/soil mixture subgrade of slab track with variation of degree of saturation (포화도 변화에 따른 슬래브궤도 혼합성토 노반의 침하 특성)

  • Park, Seong-Yong;Kim, Dae-Sang
    • Proceedings of the KSR Conference
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    • 2010.06a
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    • pp.1506-1512
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    • 2010
  • In this study, model tests were performed to investigate the settlement characteristics of the rock/soil mixture subgrade with the many portion of mudstone due to the cyclic train loading in high-speed railway. Specially, from the tests varying initial degree of saturation, effects of increment of the degree of saturation in the subgrade due to rainfall or elevation of ground water table under cyclic train loading on the deformation characteristics were analyzed. From the results, in the low degree of saturation, settlement converged to some value. However, in the condition of degree of saturation larger than some value, settlement rapidly increased. Therefore, it was found that it is important to maintain the degree of saturation of subgrade below the specific level to prevent the settlement of subgrade.

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불포화 자연토의 포화도에 따른 동전기 정화특성에 관한 실험적 연구

  • 김병일;김익현;김기년;김수삼
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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    • 2003.09a
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    • pp.302-305
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    • 2003
  • The electrokinetic remediation tests for natural soil contaminated by lead are performed on unsaturated conditions, in which the degree of saturation is controlled through the changes in water content and the constant unit weight. At the degree of saturation of 70% the small acid range and electrical potential is developed. The changes in the water content are little above the saturation of 90%. But it is increased by 1.7 times at the degree of saturation of 70%. Finally, the efficiency of extraction is improved at 70% than 100%.

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THE EFFECTS OF THE DEGREE OF SATURATION OF ACIDULATED BUFFER SOLUTIONS IN ENAMEL AND DENTIN REMINERALIZATION AND AFM OBSERVATION OF HYDROXYAPATITE CRYSTALS (유기산 완충용액의 포화도가 법랑질 및 상아질의 재광화에 미치는 영향과 수산화인회석의 AFM 관찰)

  • Park, Jeong-Won;Hur, Buck;Lee, Chan-Young
    • Restorative Dentistry and Endodontics
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    • v.25 no.3
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    • pp.459-473
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    • 2000
  • Dental caries is the most common disease in the maxillofacial area. There are many factors contributing to its development, but complete understanding and prevention is not fully known. Since the structure of the coronal and root portion of the tooth is different, the remineralization and demineralization process is also known to be different. In this study, by using a partially saturated buffer solution, we created artificial enamel and dentin caries and evaluated mineral loss. A remineralization solution with four different degrees of saturation (degree of saturation ; group 1, 0.268, group 2, 0.309, group 3, 0.339, group 4, 0.390, PH 4.3, F-2ppm) was used on a demineralized specimen. The mineral precipitating quantity and depth was evaluated by using microradiography. Using an atomic force microscope (AFM), hydroxyapatite crystals of normal, demineralized, and remineralized enamel and dentin were evaluated. The results were as follows: 1. As the degree of saturation of the remineralizing solution increased, the mineral precipitation in the enamel was increased. In group 4, mineral precipitation was limited near the surface. 2. As the degree of saturation of the remineralizing solution increased, the mineral precipitation in the dentin was decreased and it occurred in a deeper portion. In group 4, however, mineral precipitation occurred on the surface and its quantity increased. 3. There was a statistically significant interaction between enamel and dentin mineral content changes on specimens treated with remineralization and demineralization solution (demineralization r=0.44, remineralization r=0.44, p<0.05). 4. Demineralized hydroxyapatite crystals showed central and peripheral dissolving and widening of intercrystal spaces under the AFM. 5. In dentin remineralization small crystal precipitation occurred between the large crystals. We conclude that by adjusting acidulated buffer solution's degree of saturation, we can control enamel and dentin remineralization. In addition, the AFM is highly useful in evaluating changes in remineralized and demineralized hydroxyapatite crystals.

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Prediction of the Degree of Saturation Using the Soil-Water Characteristic Curves on an Unsaturated Soil (흙-수분 특성곡선 방정식을 이용한 포화도의 예측)

  • Song, Chang-Seob
    • Journal of The Korean Society of Agricultural Engineers
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    • v.46 no.6
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    • pp.61-69
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    • 2004
  • The aim of the work described in this paper was to confirm the application of the equation of the soil-water characteristic curves on an unsaturated soil. A series of suction test for unsaturated soils was conducted on the selected 4 kinds of soil using modified pressure extractor apparatus. And it was carried out to analyse The experimental parameters which can be describe the soil-water characteristics, were determined by using the data obtained from the experiment. From the results, it was found that The matric suction varied according to the grain size distribution, amount of fine grain particles and void ratio. Also it was found that the residual degree of saturation was decreased with in crease of the void ratio, but the pore size distribution index and air entry value were increased with in crease of the void ratio. And The application of the soil-water characteristic curve equation was confirmed for the various conditions and the various state by the comparison between the measured degree of saturation and the predicted degree of saturation.

Saturation Prediction for Crowdsensing Based Smart Parking System

  • Kim, Mihui;Yun, Junhyeok
    • Journal of Information Processing Systems
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    • v.15 no.6
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    • pp.1335-1349
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    • 2019
  • Crowdsensing technologies can improve the efficiency of smart parking system in comparison with present sensor based smart parking system because of low install price and no restriction caused by sensor installation. A lot of sensing data is necessary to predict parking lot saturation in real-time. However in real world, it is hard to reach the required number of sensing data. In this paper, we model a saturation predication combining a time-based prediction model and a sensing data-based prediction model. The time-based model predicts saturation in aspects of parking lot location and time. The sensing data-based model predicts the degree of saturation of the parking lot with high accuracy based on the degree of saturation predicted from the first model, the saturation information in the sensing data, and the number of parking spaces in the sensing data. We perform prediction model learning with real sensing data gathered from a specific parking lot. We also evaluate the performance of the predictive model and show its efficiency and feasibility.

Ammonia Removal Model Based on the Equilibrium and Mass Transfer Principles

  • Yoon, Hyein;Lim, Ji-Hye;Chung, Hyung-Keun
    • Bulletin of the Korean Chemical Society
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    • v.29 no.3
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    • pp.555-561
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    • 2008
  • In air stripping of ammonia from the aqueous solution, a new removal model was presented considering the equilibrium principles for the ammonia in aqueous solution and between the aqueous and air phase. The effects of pH, temperature and airflow rate on the ammonia removal were evaluated with the model. In addition, the saturation degree of ammonia in air was defined and used to evaluate the effect of each experimental factor on the removal rate. As pH (8.9 to 11.9) or temperature (20 to 50 oC) was increased, the overall removal rate constants in all cases were appeared to be increased. Our presented model shows that the degrees of saturation were about the same (0.45) in all cases when the airflow condition remains the same. This result indicates that the effect of pH and temperature were directly taken into consideration in the model equation. As the airflow increases, the overall removal rate constants were increased in all cases as expected. However, the saturation degree was exponentially decreased with increasing the airflow rate in the air phase (or above-surface) aeration. In the subsurface aeration the saturation degree remains a constant value of 0.65 even though the airflow rate was increased. These results indicate that the degree of saturation is affected mainly by the turbulence of the aqueous solution and remains the same above a certain airflow rate.

[ $H_{\infty}$ ] Control of Time-Delayed Linear Systems with Limited Actuator Capacities (제한된 구동기 용량을 갖는 시간지연 선형시스템의 $H_{\infty}$ 제어)

  • Yi, Yearn-Gui;Kim, Jin-Hoon
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.56 no.9
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    • pp.1648-1654
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    • 2007
  • In this paper, we consider the design of $H_\infty$ high-gain state feedback control for time-delayed linear systems with limited actuator capacities. The high-gain control means that the control permits the predetermined degree of saturation. Based on new Lyapunov-Krasovskii functional, we derive a result in the form of matrix inequalities. The matrix inequalities are consisted of LMIs those confirm the positive definiteness of Lyapunov- Krasovskii functional, satisfaction of predetermined degree of saturation, reachable set and $L_2$ gain constraint. The result is dependent on the bound of time-delay and its rate, predetermined degree of saturation, actuator capacity, and the allowed size of disturbances. Finally, we give a numerical example to show the effectiveness and usefulness of our result.