• 제목/요약/키워드: current moisture content

검색결과 113건 처리시간 0.025초

컴퓨터에 의한 작업장 담배의 수분관리에 관한 연구 (Studies on the moisture control of tobacco processed by using computer)

  • 김기환;한정성;주영석
    • 한국연초학회지
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    • 제9권2호
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    • pp.95-104
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    • 1987
  • 1. Under the current workroom conditions It is very difficult to control the moisture contents of raw materials in season of summer or winter. 2. The moisture absorption of the materials under the contributive conditions showed the efficiency of 65% in relative humidity and temperature of the currant workroom. 3, The results from this study, however , appeared the deviation of moisture content of the products by the order of 0.1% compared to the current deviation of 2.6~2.7%. 4. Equilibrium moisture contents of the tobacco was Inversely proportional to the temperature and directly related to the relative humidity of the workroom. 5. On the basis of the above results , the standard conditions of the workroom obtained from this study considering with the external temperature in winter could reduce energy by 17.4% through 38.4% .

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대형변압기 절연상태 평가 (Assessment of Insulation Condition in Large Transformers)

  • 김희동;공태식;이영준;박재준
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2004년도 하계학술대회 논문집 Vol.5 No.1
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    • pp.499-502
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    • 2004
  • In order to detect of insulation problems an early, transformer has to be performed the several tests. The ac current and tan6 of transformer winding insulation were investigated by Schering bridge. Partial discharge(PD) tests are used to evaluate the insulation condition of transformer. The moisture content measurement was conducted using RVM(recovery voltage meter). The RVM test can show that the problem is affecting the paper insulation of transformer. The value of moisture content was 2.3% in main transformer. The insulations of four transformers were judged to be in good condition.

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Bi-2223/Ag 선재의 전구 분말에서 수분함량에 따른 효과 (The effects of moisture content in precursor powder for Bi-2223/Ag tape)

  • 김성환;유재무;고재웅;김영국;김철진
    • Progress in Superconductivity
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    • 제4권2호
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    • pp.162-167
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    • 2003
  • The critical current value of Bi-2223/Ag tape can be influenced by various factors. In particular, it was known that properties of precursor powders could affect the formation of Bi -2223 and grain growth rate of the same. Since, moistures and organic matters can easily contaminate the precursor powders of Bi-2223 tapes and degrade properties of superconductors, the precursor powders should be kept in optimal conditions to minimize contamination. In this study, the effect of moisture and organic matters has been investigated. A Bi-2223/Ag tape contaminated with a large amount of moisture and organic matter has been characterized by low critical current values and bubbling. It has been found that as the quantity of moisture increases, the Bi-2223 phases are formed at lower temperature and the amount of non-superconducting phase increases.

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Design and evaluation of a distributed TDR moisture sensor

  • Zhang, Bin;Yu, Xinbao;Yu, Xiong
    • Smart Structures and Systems
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    • 제6권9호
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    • pp.1007-1023
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    • 2010
  • This paper describes the development and evaluation of an innovative TDR distributed moisture sensor. This sensor features advantages of being responsive to the spatial variations of the soil moisture content. The geometry design of the sensor makes it rugged for field installation. Good linear calibration is obtained between the sensor measured dielectric constant and soil physical properties. Simulations by the finite element method (FEM) are conducted to assist the design of this sensor and to determine the effective sampling range. Compared with conventional types of moisture sensor, which only makes point measurement, this sensor possesses distributed moisture sensing capability. This new sensor is not only easy to install, but also measures moisture distribution with much lower cost. This new sensor holds promise to significantly improve the current field instruments. It will be a useful tool to help study the influence of a variety of moisture-related phenomena on infrastructure performance.

딥러닝 모델 구조에 따른 모르타르의 단위수량 평가에 대한 비교 실험 연구 (Comparative Experimental Study on the Evaluation of the Unit-water Content of Mortar According to the Structure of the Deep Learning Model)

  • 조양제;유승환;양현민;윤종완;박태준;이한승
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2021년도 가을 학술논문 발표대회
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    • pp.8-9
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    • 2021
  • The unit-water content of concrete is one of the important factors in determining the quality of concrete and is directly related to the durability of the construction structure, and the current method of measuring the unit-water content of concrete is applied by the Air Meta Act and the Electrostatic Capacity Act. However, there are complex and time-consuming problems with measurement methods. Therefore, high frequency moisture sensor was used for quick and high measurement, and unit-water content of mortar was evaluated through machine running and deep running based on measurement big data. The multi-input deep learning model is as accurate as 24.25% higher than the OLS linear regression model, which shows that deep learning can more effectively identify the nonlinear relationship between high-frequency moisture sensor data and unit quantity than linear regression.

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정상상태(定常狀態)에 있어서 목재(木材)의 습기전달(濕氣傳達)과 투습속도(透濕速度) (Moisture Transfer and Velocity of Moisture Transmission by Wood in Steady State)

  • 이원희
    • Current Research on Agriculture and Life Sciences
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    • 제10권
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    • pp.41-47
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    • 1992
  • 목재투습성에 관하여 다음과 같은 결과가 밝혀졌다. 1) 시편두께 0mm에 외삽한 투습저항값이 정(正)이므로 목재표면에서의 수분전달현상을 고려함이 인정되었다. 2) 목재내부의 함수율분포는 함수율 9%를 경계로 두 개의 직선으로 나타났다. 또 시편양측의 공기중 평형함수율이 9%이상일 때는 한 개의 직선으로 나타났다. 수분확산계수는 함수율 9%를 경계로 두 개의 일정한 값을 가지며, 이 값들은 오직 함수율에만 관계한다. 4) 수분이동량은 목재내의 함수율구배에 의존한다. 4) 목재의 수분전달계수는 시편두께에 의존하였다. 이 현상의 기구에 대해서는 아직 알 수 없다.

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하천 돌망태 호안에 적용된 토목섬유보강토공법의 녹화 특성 (A Study for Characteristics of Geofiber Reinforced Soil System Practiced on Stone Gabion Bank of River)

  • 정대영;김재환;심상렬
    • 한국환경복원기술학회지
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    • 제11권6호
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    • pp.81-90
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    • 2008
  • Recently, geofiber(polyester) reinforced soil was added on soil-seed mixture spray to control erosion and to improve vegetation growth on rocky slope sites. This research was conducted to compare vegetation effects and soil hardness on three types of soil-seed mixture spray on stone gabion river bank [A type : soil-seed mixture spray underlying 30cm thick sand with geofiber(geofiber reinforced soil system), B type : soil-seed mixture spray underlying 30cm thick sand without geofiber, C type : soil-seed mixture spray]. Evaluation were made concerning vegetation coverage, soil hardness and moisture content. The results of this study showed that A type system was effective for the growth of vegetation and soil hardness when compareed to B type and C type. A type and B type showed higher covering rate than C type on stone gabion river bank, and especially A type showed the highest covering rate. Soil hardness and water content were high on A type vegetation system compared to B type and C type. We noted that high soil hardness and high moisture content with geofiber(geofiber reinforced soil system) were effective both to control erosion from water current impact and to be high coverage and species of vegetation on stone gabion river bank.

뇌임펄스전압에 의한 불평등전계에서 토양방전특성 (Soil Discharge Characteristics in Inhomogeneous Field Caused by Lightning Impulse Voltages)

  • 유양우;김승민;김유하;이복희
    • 조명전기설비학회논문지
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    • 제29권4호
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    • pp.95-101
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    • 2015
  • This paper presents experimental results about characteristics of soil discharge as a function of moisture content when the $1.2/50{\mu}s$ lightning impulse voltage is applied. The laboratory experiments, for this study, were carried out based on factors affecting the transient behavior in soils. The electrical breakdown in soils was measured over a 0-6% range of moisture content for sands and a 0-4% range of moisture content for gravels. Needle-plane electrode systems was used As a result, the conduction current prior to ionization growth in dry soil is a little, but it in wet soil is increased with the applied voltage because the wet soil particles act as conductors. The soil impedance curves show an abrupt reduction just after breakdown. The general tendency measured in different soils is that the higher the water content, the lower the breakdown voltage and the shorter the time-lag to breakdown.

석회 혼입 점토의 강도 특성 (Strength properties of lime-clay mixtures)

  • 여재호;권무남;구정민;김현기
    • Current Research on Agriculture and Life Sciences
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    • 제18권
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    • pp.61-69
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    • 2000
  • This study was conducted to investigate most effective the optimum lime content for lime-clay modification. To achieve the aim, characteristics of compaction and compressive strength were tested by adding of 0, 5, 10, 15 and 20% lime (Hydrated lime) of dry weight of the clay. Distilled water was added 10, 15, 20 and 25% of dry weight of lime-clay mixture. In this test, the compressive strength of the specimens was measured according to the following curing period : 7, 21, 28, 35 and 49 days. The results are as follows. (1) As lime additive increased, the optimum moisture content of lime-clay mixture was increased and the maximum dry density was decreased. (2) The soil mixture of 20% of the moisture content and 10% of lime additive was shown the maximum compressive strength. (3) As curing period longer, the compressive strength was increased but after 21 curing days, the increasing rate of compressive strength was low as compared with earlier its value. (4) In the range of 20% of the moisture content, compressive strength of mixture of 10% lime additive increased twice compared with that of mixture of 0% lime additive. (5) All of the lime-clay are possible to use for an sub-base material and 20% of moisture content of lime-clay mixture is possible to use for a base material.

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DRYING CHARACTERISTINCS OF THIN-LAYERS OF WHEAT AND BARLEY AT NEAR-AMBIENT TEMPERATURE

  • Sun, Da-Wen;J.J.Woods
    • 한국농업기계학회:학술대회논문집
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    • 한국농업기계학회 1993년도 Proceedings of International Conference for Agricultural Machinery and Process Engineering
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    • pp.896-905
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    • 1993
  • Thin-layers of wheat and barley are dried at near-ambient temperatures(3.5$^{\circ}C$ -5$0^{\circ}C$) in order to obtain the intrinsic drying data. The well established apparatus was modified to enable it to record all the sample weight data in still air by using a purpose -built automatically controlled sliding valve. The air could be diverted in less than 0.5seconds and a 7 second period was required to attain a steady weight reading. With this apparatus, very smooth drying curves were obtained. The data of sample weight , drying temperature and dew point temperature wee recorded continuously . The drying process was terminated when the moisture content change in 24 hours was less than 0.004 d.b. This was achieved by drying a sample for about a week . The final points were recorded as the dynamic equilibrium moisture content(EMC). The drying data were than fitted to the exponential Newton model and the dynamic EMC data were fitted to the Modified-Chung-Pfost Model . All the fitted parameters are given and comparison is made with previous published data. The comparisons who that the current drying constants are lower than the previous data, the dynamic EMC data obtained for wheat and barely agree with the previous data. The results show that to obtain the drying constant in the exponential Newton model, adequate drying time is necessary.

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