• 제목/요약/키워드: volume change ratio

검색결과 482건 처리시간 0.012초

물과 에탄을 이성분 혼합용매 계에서 부피 및 온도 변화에 관한 연구 (A Study on the Change of Volume and Temperature in Aqueous Binary Solvent with Ethanol)

  • 김용권;임귀택
    • 한국초등과학교육학회지:초등과학교육
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    • 제20권1호
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    • pp.139-147
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    • 2001
  • This paper is to study on the change of volume and temperature of the solution which mixed water with ethanol. And its main purpose is to examine closely how the volume changes, and to find the method to maximize the change of the volume. The summaries for results of the study are; First, we were known that water and ethanol are homogeneously mixed. But two solvents does not mix homogeneously by different specific gravity at early stages. Second, we could see that the volume changed large at homogeneous mixed water with ethanol by stirrer, the change of volume is the largest value when water mixed with ethanol in the ratio of one to one. Third, when water mixed with ethanol in the ratio of one to one, the change of temperature is very large by activated hydrogen bond. We conclude that it is the best result when ratio of water and ethanol is one to one and the solution is well mixed.

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Cold plate를 이용한 휴대용 컴퓨터 냉각 시스템의 열성능에 관한 연구 (A Study on Thermal Performance of Cooling System for a Laptop Computer Using a Cold Plate)

  • 박상희;조남해;최성대
    • 한국기계가공학회지
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    • 제8권4호
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    • pp.83-89
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    • 2009
  • This study investigates two-phase cooling system of close-loop by using FC-72 and PCM(Phase change material). The cooling system consists of evaporator, cold plate, micro pump, and condenser. The heat input on the performance of evaporator is appreciated by visualizing the boiling on the evaporator. The heat performance of cooling system is investigated to determine the effects of volume fill ratio change at working fluid, pump flow rate change, and volume fill ratio change at PCM in cold plate. Experimental results show the ideal condition when the volume ratio of working fluid, the pump flowing, and the volume ratio of PCM are 60%, 6ml/min, and 60% respectively.

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보강 혼합토의 역학적 특성(I) -시멘트 혼합토- (Mechanical Characteristics of Reinforced Soil(I) -Cement Reinforced Soil-)

  • 송창섭;임성윤
    • 한국환경복원기술학회지
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    • 제5권6호
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    • pp.9-13
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    • 2002
  • This study has been performed to investigate the physical and mechanical characteristics of compaction, volume change and compressive strength for reinforced soil mixed with cement. And confirm the reinforcing effects with admixture such as cement. To this end, a series of compaction test and compression test was conducted for clayey soil(CL) and cement reinforced soil. In order to determine proper moisture content and mixing ratio, pilot test was carried out for soil and cement reinforced soil. And the mixing ratio of cement admixture was fixed 3%, 6%, 9% and 12% by the weight of dry soil. As the experimental results, the maximum dry unit weight(${\gamma}_{dmax}$) was increased with the mixing ratio and then shown the peak at 10% reinforced soil, but the optimum moisture content(OMC) and the volume change was decreased with the ratio increase. And the compressive strength volume change was decreased with mixing ratio increased.

실내녹화 부피비율이 실공간의 미세분진농도, 온도 및 상대습도에 미치는 영향 (Change in the Concentration of Fine Particles, Temperature, and Relative Humidity as Affected by Different Volume Ratios of Interior Greening in Real Indoor Space)

  • 주진희
    • 한국환경복원기술학회지
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    • 제13권2호
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    • pp.1-7
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    • 2010
  • The study objective was to compare the interior greening volume ratios for the change in concentration of fine particle, temperature and relative humidity, and to identify the level of interior landscape volume ratio as a suitable condition to achieve the desired indoor properties. Plants were moved into a room (88m3) randomly. After moving, the volume ratio of the interior greening level was set at 0%, 1%, 2% and 3%. The concentration of fine particles was measured with a mini-volume portable air sampler (Air Metrics, USA). The temperature and relative humidity were recorded with a digital sensor (Kiwi-LTH, USA) during the experiment under different volume ratios with three replications. 1. The results of the change in concentration of the fine particles revealed a trend towards an increased volume ratio of interior greening with decreasing concentration of fine particles, compared to non-plants (0%). The concentration of fine particles at volume ratios of 0%, 1%, 2% and 3% was 55ug/$m^3$, 233ug/$m^3$, 40ug/$m^3$ and 30ug/$m^3$, respectively. 2. The change in temperature, at volume ratios of 0%, 1%, 2% and 3% was $21.2^{\circ}C$, $17.4^{\circ}C$, $16.7^{\circ}C$ and $18.9^{\circ}C$, respectively, in near interior greening, and $22.1^{\circ}C$, $18.7^{\circ}C$, $18.4^{\circ}C$ and $20.5^{\circ}C$ respectively, at a distance of 3m from the interior greening. These study results suggested that temperature was affected by volume ratio and distance from the interior greening. 3. The relative humidity, at volume ratios of 0%, 1%, 2% and 3% was 34.2%, 32.5%, 36.7%, and 46.9%, respectively, in near interior greening, and 31.2%, 26.9%, 31.4% and 38.3%, respectively, at a distance of 3m from the interior greening. With increasing volume ratio of interior landscape, there were positive and significant results between the distance difference and the relative humidity more than temperature.

불포화 정성토의 체적변화에 대한 연구 (A Study on the Volume Change in Unsaturated Clayey Soil)

  • 장병욱;길상춘
    • 한국농공학회지
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    • 제40권5호
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    • pp.37-42
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    • 1998
  • This study was performed to evaluate the characteristics of volume change is unsaturated clayed soil. The medium-plastic clay was selected and compacted by 50% of Proctor standard compaction energy at 6% higher moisture content than its OMC. A series of isotropic compression tests and triaxial shear tests were performed. The results of the study are summarized as follows. At each matric suction, when the matric suction was increased, the yield stress was increased and slope of volume change was decreased. The more net mean stress was, the less the quantity of volume change was. In shear test, the volumetric strain was much rapidly changed in large matric than in low matric suctions. But the effect of matric suction to volume change disappeared under high net mean stress. At lower deviator stress the more matric suction was, the higher volume change was. But As the matric suction was increasing, the behavior of the unsaturated clayey soil was similar to that of saturated clayey soil. Volume change in the unsaturated clayey soil can be represented as a unique plane in three-dimensional space, which is the axes of net mean stress, matric suction and void ratio.

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보강 혼합토의 역학적 특성(II) -섬유 혼합토- (Mechanical Characteristics of Reinforced Soil(II) -Fiber Reinforced Soil-)

  • 송창섭;임성윤
    • 한국환경복원기술학회지
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    • 제5권6호
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    • pp.37-42
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    • 2002
  • This study has been performed to investigate the physical and mechanical characteristics of compaction, volume change and compressive strength for reinforced soil mixed with polypropylene fiber, and to confirm the reinforcing effects with admixture such as polypropylene fiber. To this end, a series of compaction test and compression test was conducted for clayey soil(CL) and polypropylene fiber reinforced soil. In order to determine proper moisture contents and mixing ratio, pilot test was carried out for natural soil and PFRS(polypropylene fiber reinforced soil). And the mixing ratio of mono-filament fiber and fibrillated polypropylene fiber admixture was 0.1%, 0.3%, 0.5% and 1.0% by the weight of dry soil. From the experimental results, it was found that the optimum moisture contents(OMC) increased with the mixing ratio of fiber, but the maximum dry unit weight and the volume change was decreased with the mixing ratio. It means that the improvement of the workability and the reduction of the weight of embankment was done by the addition of the polypropylene fiber. And, from the compression test results, it was found that the addition of the polypropylene fiber remarkably improved the compressive strength of PFRS. And it was observed in the viewpoint of strength that the fibrillated polypropylene fiber reinforced soil was more effective than the mono-filament polypropylene fiber reinforced soil.

풍화잔적토와 체적이 변하는 흙의 흙-수분 특성곡선 (Soil-Water Characteristic Curves of Residual Soils and Deformable Soils)

  • 이인모;이형주;김기섭
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2000년도 봄 학술발표회 논문집
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    • pp.265-272
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    • 2000
  • This study introduces the current theory of the SWCC and tries to verify the theory by performing laboratory tests for the local soils of Korea. First, the SWCCs of Poi-dong soil and Shinnae-dong soil, the most typical weathered residual soils in Korea, were experimentally obtained and the results were compared among others. Second, a SWCC model for deformable soils was proposed. For deformable soils, which show huge volume change during desaturation, the volume change behavior should be considered, and the SWCC should be expressed as a function of void ratio as well as suction.

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Influence of gradation on shear strength and volume change behavior of silty sands

  • Monkul, Mehmet Murat
    • Geomechanics and Engineering
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    • 제5권5호
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    • pp.401-417
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    • 2013
  • The results of an experimental program regarding the effects of gradation on shear strength and volume change behavior of silty sands are presented. Consolidated drained direct shear tests were performed on two clean base sands and twelve silty sands obtained by mixing those base sands with two different non-plastic silts at various fines contents (${\leq}$ 25%). Drained shear strengths were observed to be not significantly influenced by either base sand gradation or silt gradation or fines content for the studied range. Increasing fines content has increased the volumetric contraction of specimens at similar void ratio. However, the amount of increase in volumetric contraction of silty sands were found to be affected by silt gradation when other influencing factors such as fines content, base sand gradation and mineralogy were kept the same. Moreover, the amount of increase in volumetric contraction of silty sands were also found to be affected by base sand gradation when other influencing factors such as fines content, silt gradation and mineralogy were kept the same.

인천지역 항로 준설토의 침강자중압밀시험에 의한 유보율 결정에 관한 연구 (Retention Ratio of Dredged Soil at Incheon Habour Route using Self-Weight Consolidation Test)

  • 신은철;박영진;강정구
    • 한국지반신소재학회논문집
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    • 제16권4호
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    • pp.57-66
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    • 2017
  • 준설 매립 부지의 최종 계획고를 얻기 위한 초기 준설 매립량과 매립두께를 결정하고 자중압밀에 소요되는 시간을 예측하기 위해 인천지역 항로 준설 시료에 대한 자중압밀시험과 공학적 특성을 분석하였다. 준설투기된 시료의 시간경과에 따른 함수비, 간극비 및 체적변화비에 관한 인자를 Yano의 경험식을 이용하여 평가하였다. 세립분 함유율이 낮은 경우 침강압밀계수의 변화폭이 작게 나타났으며, 세립분 함유율 50%에서 가장 크게 나타났다. 자중압밀에 따른 체적변화비를 이용하여 준설매립공사에 제시된 입도별 유보율의 포괄적인 측면을 보완할 수 있는 세립분 함유율에 따른 유보율을 산정하여 제시하였다.

Liguid-gas Ejector의 구동성능 특성에 관한 연구 (A Study on the Characteristics of the Liquid-gas Ejector)

  • 박기태;김진화;정한식;정효민
    • 대한설비공학회:학술대회논문집
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    • 대한설비공학회 2008년도 하계학술발표대회 논문집
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    • pp.1047-1052
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    • 2008
  • The aim of this paper is that studies on the characteristics of the liquid-gas ejector. Could get data about various model using numerical analysis. Compare and analyze result that get by an experiment and numerical analysis. And studied Characteristics of the ejector. In this paper, Numerical analysis model is gotten divided according to each Throat ratio as three types. Each throat ratio is 0, 4 and 7.5. According to the result that analyze basic model, pressure became lower causing the volume flow rate increase. In CFD studies, Fixed volume flow rate by these result and analyzed ejector performance. As a result, there was no change of pressure to Throat's Enterance, and pressure became low while pass the throat. Since, pressure recovered while passing diffuser. The outer flow velocity did not change greatly to change of volume flow rate. This research expects that is utilized to data for performance elevation hereafter.

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