• 제목/요약/키워드: moisture content

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함수율과 섬유경사각이 목재의 압축강도 및 초음파 전달속도에 미치는 영향 (Effects of Moisture Content and Slope of Grain on Ultrasonic Transmission Speed of Wood)

  • 장상식
    • Journal of the Korean Wood Science and Technology
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    • 제28권2호
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    • pp.10-18
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    • 2000
  • 초음파를 이용한 목재의 비파괴시험은 등급구분 수분 및 결점 탐지, 썩은 정도 평가 등의 용도에 적용되고 있다. 이와 같은 기술을 실제로 적용하기 위해서는 목재 내의 초음파 전달과 목재의 성질 사이의 관계에 대한 기본적인 연구가 선행되어야 한다. 이 연구에서는 함수율과 섬유경사각이 초음파 전달 속도에 미치는 영향을 분석하기 위하여 낙엽송과 소나무를 대상으로 초음파 비파괴시험을 실시하였다. 함수율에 대한 시험을 위한 시험편은 생재상태, 30%, 20%, 10% 및 전건상태의 함수율을 갖도록 준비하였고 섬유경사각에 대한 시험을 위해서는 접선방향으로 0, 15, 30, 45, 60, 75 및 90도의 섬유경사각을 갖는 시험편을 준비하였다. 초음파 전달 속도는 섬유포화점에 근사한 30% 이하의 낮은 함수율 범위에서는 함수율에 반비례하였으며 이보다 높은 함수율 범위에서는 함수율에 관계없이 일정한 경향을 나타내었다. 목재의 압축강도와 함수율 사이의 관계에서도 이와 유사한 경향이 관찰되었다. 목재의 섬유경사각도 초음파 전달 속도 및 압축강도와 반비례하는 경향을 나타내었다. 압축강도와 초음파 전달 속도 사이의 관계는 정비례하는 관계로서 하나의 직선식으로 나타낼 수 있었다.

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해바라기 종실제품의 수분흡착열 (Heats of Moisture Adsorption for Sunflower Nutmeat Products)

  • 목철균;헤티아라치치 엔 에스
    • 한국식품과학회지
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    • 제23권6호
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    • pp.656-660
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    • 1991
  • 해바라기 종실제품(종실, 착유박, 농축단백, 분리단백)의 수분흡착열을 $10,\;20,\;30^{\circ}C$에서 측정한 등습곡선(isostere)으로부터 구하였고, 수분함량에 따른 흡착열의 변화를 Hunter 방정식에 의거하여 해석하였다. Hunter 방정식에 의한 예측치는 실측결과와 잘 일치하였으며 단백질함량이 증가할수록 정확도가 높았다. 흡착열은 수분함량이 높을수록 감소하였으며, 단백질함량이 높을수록 증가하였다. 해바라기종실의 흡착열은 건물기준 수분함량 4-12%에서 11.8-10.6 kcal/mole이었으며 분리 단백의 경우 수분함량 6-20%에서 12.4-11.0kcal/mole 이었다.

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차세대 반도체용 유-무기 나노 복합재료의 에폭시 수지변화에 따른 흡습특성 (Moisture Absorption Properties of Organic-Inorganic Nano Composites According to the Change of Epoxy Resins for Next Generation Semiconductor Packaging Materials)

  • 김환건;김동민
    • 반도체디스플레이기술학회지
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    • 제12권1호
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    • pp.23-28
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    • 2013
  • Epoxy resins are widely used in microelectronics packaging such as printed circuit board and encapsulating for semiconductor manufacturing. Water can diffuse into and through the epoxy matrix systems and moisture absorption at boarding interfaces of matrix resin systems can lead to a hydrolysis at the interfaces resulting in delamination of encapsulating materials. In the study, the changes of diffusion coefficient and moisture content ratio of epoxy resin systems with nano-sized fillers according to the change of liquid type epoxy resins were investigated. RE-304S, RE-310S, RE-810NM and HP-4032D as a epoxy resin, Kayahard AA as a hardener, and 1B2MI as a catalyst were used in these epoxy resin systems. After curing, moisture content ratios were measured with time under the 85 and 85% relative humidity condition using a thermo-hydrostat. The maximum moisture absorption ratio and diffusion coefficient of EMC decrease with the filler content. It can be seen that these decreases are due to the increase of filler surface area and the decrease of moisture through channel with the content of nano-sized filler.

수분공급조절이 질경이 ( Plantago asiatica L. ) 의 생장에 미치는 영향 (Effects of Different Soil Moisture on the Growth of Plantago asiatica L.)

  • Lee, Ho Joon;Soon Ja Kim;Hae Won Kang
    • The Korean Journal of Ecology
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    • 제6권3호
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    • pp.227-235
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    • 1983
  • This research was made over drought resistance and optimum soil moisture needed with Plantago asiatica L. as the material by means of making out the process of its growth under different soil moisture contents. The soil used for the experiment was a mixture of vermiculite and c-layer soil, and the process of growth was compared with each other controlling its soil mositure as: 7%, 15%, 30%, 45%, and 60%. In 7% range of soil moisture which was of low content, the increase of growth was neither significantly indicated nor any permanent seeding done. In view of this phenomenon, Plantago asiatica L. appeared to be highly drought-resistant. It was found rising at 30% range and reaching the optimum state at 45% range and falling down at 60% range range. In viw of this fluctuation indicated above, the optimum soil moisture content needed for the growth of Plantago asiatica L. is thought to be between 30% and 60%. It is thought the number of seed per capsule is not affected by the soil moisture content. It is expected an ecotypic variation by the soil moisture content will bring forth upon Plantago asiatica L.

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Spatial Downscaling of AMSR2 Soil Moisture Content using Soil Texture and Field Measurements

  • Na, Sangil;Lee, Kyoungdo;Baek, Shinchul;Hong, Sukyoung
    • 한국토양비료학회지
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    • 제48권6호
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    • pp.571-581
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    • 2015
  • Soil moisture content is generally accepted as an important factor to understand the process of crop growth and is the basis of earth system models for analysis and prediction of the crop condition. To continuously monitor soil moisture changes at kilometer scale, it is demanded to create high resolution data from the current, several tens of kilometers. In this paper we described a downscaling method for Advanced Microwave Scanning Radiometer 2 (AMSR2) Soil Moisture Content (SMC) from 10 km to 30 m resolution using a soil texture and field measurements that have a high correlation with the SMC. As a result, the soil moisture variations of both data (before and after downscaling) were identical, and the Root Mean Square Error (RMSE) of SMC exhibited the low values. Also, time series analyses showed that three kinds of SMC data (field measurement, original AMSR2, and downscaled AMSR2) had very similar temporal variations. Our method can be applied to downscaling of other soil variables and can contribute to monitoring small-scale changes of soil moisture by providing high resolution data.

사과장아찌 제조를 위한 전처리 공정의 최적화 (Optimization of Pre-treatment Process for Manufacturing Apple Jangachi)

  • 오철환
    • 한국조리학회지
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    • 제24권1호
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    • pp.105-113
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    • 2018
  • In this study, optimized pre-treatment conditions were investigated to improve the quality of gochujang apple jangachi. The moisture content was decreased by 14% in 60% sugar solution and 17% in 30% salt solution during 12 hours. On the one hand, in the case of dry sugar and salt method, moisture content was decreased rapidly by 20% and 24%, respectively during 12 hours. Compared with the sugar and salt solution method, the dry sugar and salt method was more effective in reducing moisture content during 12 hours. In the case of osmotic dehydration of the apple parts in the dry sugar method, the moisture content of the flesh, flesh including peel, and peel of apple decreased by 23%, 20%, and 16%, respectively during 6 hours. However, in the dry salt method, the moisture content of the flesh, flesh including peel, and peel of apple decreased by 19%, 12% and 13%, respectively during 2 hours. During this time, the pH tended to decrease, regardless of the presence of sugar and salt. Total acidity was slightly increased in the case of salt. In hot air drying after osmotic dehydration, the moisture content of flesh including peel of apple decreased from 64% and 67% to 31% and 27%, respectively at 90 minutes, and from 64% and 67% to 11% and 18% at 150 minutes, respectively. The moisture content of the peel decreased from 51% to 10% at 120 minutes. As a result of the sensory evaluation, the overall acceptance of the flesh and flesh including peel was highly evaluated, resultantly, the products were considered to be suitable for the production of gochujang apple jangachi.

Non-destructive and Rapid Prediction of Moisture Content in Red Pepper (Capsicum annuum L.) Powder Using Near-infrared Spectroscopy and a Partial Least Squares Regression Model

  • Lim, Jongguk;Mo, Changyeun;Kim, Giyoung;Kang, Sukwon;Lee, Kangjin;Kim, Moon S.;Moon, Jihea
    • Journal of Biosystems Engineering
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    • 제39권3호
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    • pp.184-193
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    • 2014
  • Purpose: The aim of this study was to develop a technique for the non-destructive and rapid prediction of the moisture content in red pepper powder using near-infrared (NIR) spectroscopy and a partial least squares regression (PLSR) model. Methods: Three red pepper powder products were separated into three groups based on their particle sizes using a standard sieve. Each product was prepared, and the expected moisture content range was divided into six or seven levels from 3 to 21% wb with 3% wb intervals. The NIR reflectance spectra acquired in the wavelength range from 1,100 to 2,300 nm were used for the development of prediction models of the moisture content in red pepper powder. Results: The values of $R{_V}{^2}$, SEP, and RPD for the best PLSR model to predict the moisture content in red pepper powders of varying particle sizes below 1.4 mm were 0.990, ${\pm}0.487%$ wb, and 10.00, respectively. Conclusions: These results demonstrated that NIR spectroscopy and a PLSR model could be useful techniques for measuring rapidly and non-destructively the moisture content in red pepper powder.

냉동건조를 이용한 쌀기본 이유식 제조에 있어서 건조조건의 최적화 (Optimization of the Preparation of Rice-based Infant Foods Using Freeze Drying Process)

  • 김광옥;최호정
    • 한국식품과학회지
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    • 제27권5호
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    • pp.680-689
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    • 1995
  • 본 연구는 $4{\sim}6$개월의 유아들을 위하여 재수화시킨 후 숟가락으로 떠먹일 수 있도록 쌀을 기본으로 하고 당근, 쇠고기 및 계란을 각각 주재료로 한 냉동건조 이유식 제조의 최적조건을 결정하기 위하여 수행되었다. 본 연구에서 얻어진 결과를 요약하면 다음과 같다. 당근, 쇠고기 및 계란이유식에서 모두 냉동건조시간은 수분함량이 높고 가열판온도가 낮을수록 증가하였다. 파쇄성은 수분함량이 감소하고 가열판온도가 증가함에 따라 증가하였다. 관능적 특성 중 수화속도, 균질성 및 매끄러운 정도는 수분함량이 증가하고 가열판온도가 감소할수록 증가하였고, 뜨기 쉬운 정도는 수분함량이 증가할수록 증가하였으나, 가열판온도의 영향은 거의 받지 않았다. 또한 피막형성성은 수분함량과 가열판온도가 증가할수록 증가하였다. 이유식 제조의 최적조건은 당근이유식의 경우 수분함량 88.5%와 가열판온도 $34^{\circ}C$로, 쇠고기이유식에서는 수분함량 88.5%와 가열판온도 $28^{\circ}C$로, 그리고 계란이유식에서는 수분함량 87.3%와 가열판온도 $39^{\circ}C$로 결정되었다.

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찰벼 수확시기 및 건조정도에 따른 찹쌀 외관 품질특성 구명 (Identification of Chalkiness Development of Milled Waxy Rice Grains with Harvest Times and the Moisture Contents)

  • 정응기;이춘기;최윤희;김정태;김석;손종록
    • 한국작물학회지
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    • 제53권1호
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    • pp.58-63
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    • 2008
  • 1. 수확시기에 따른 도정수율은 메벼의 적기수확시기보다 5일정도 늦게 수확하는 것이 높았으며 품종에 따라서는 보석찰벼와 해평찰벼가 도정수율이 높았다. 2. 찹쌀의 특징인 불투명한 유백색은 수분함량 14.0%이상부터 점차 소실되기 시작하여 15.0%대에 마치 멥쌀이 섞인 것처럼 보이다가 16.0%이상에 도달될 경우는 거의 대부분이 멥쌀과 같은 외관을 나타냈다. 3. 수분 증가에 따른 찹쌀의 유백색 소실은 조기에 수확된 벼에서 더 민감하게 나타나기 때문에 가능한 수확시기를 적기 이후로 정하는 것이 건조효율이나 찹쌀 수율 측면에서 더 유리하다고 판단된다. 4. 찹쌀 고유의 유백색 발현을 최대로 하기 위해서는 찰벼 건조수분의 critical point은 13.5%이하였다.

바이오디젤 원료용 유채 함수율 센서 개발 (Development of a Moisture Content Sensor for Rapeseed as Biodiesel Raw Material)

  • 이충근;최용;전현종;정광식
    • Journal of Biosystems Engineering
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    • 제34권1호
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    • pp.15-20
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    • 2009
  • This study was conducted to develop a moisture sensor for rapeseed, a bio-diesel material. A typical rapeseed, SUNMANG, was used as a raw material. The rapeseed moisture content sensor consists of three components, such as upper and bottom electrodes, a test material dish, and a fixing housing. To evaluate the performance, a data acquisition system was equipped with the rapeseed moisture sensor, computer, printer, and main board. The findings of this study were: 1) the rapeseed moisture content was inversely proportional to electric resistance, and 2) values of electric resistance were recorded in a range of $10{\sim}100\;M{\Omega}$, depending upon a change of the moisture content. The determination of coefficient ($R^2$) and standard error between rapeseed moisture content and electric resistance were 0.9921 and ${\pm}0.289$, which indicated a highly correlative relationship. The response of rapeseed moisture sensor to temperature change was also observed for further performance test. Satisfying results were obtained, such as the determination of coefficient ($R^2$) of 0.9918, predicted standard error of ${\pm}0.373%$, deviation of 0.103%, measurement error of $0.14{\sim}0.48%$, standard deviation of $0.01{\sim}0.22%$, and measurement time of 28.3 s per point, respectively.