• Title/Summary/Keyword: Moisture-free condition

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Determination of Microwave Dielectric Properties of Grain by Free Space Transmission Method (자유공간 전송방법을 이용한 마이크로파 유전특성연구)

  • 김종헌;김기복;노상하
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1997.04a
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    • pp.233-235
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    • 1997
  • A free sparse transmission method using X-band standard gain horn antenna is applied to measure the attenuation and phase shift of microwave signal through the wetted grain such as rough rice, brown rice and barley. The moisture content of grain varied from 11 to 25% based on its wetted condition. The dielectric constant and loss factor, which depend on the moisture content of the wetted grain are obtained from the measured attenuation and phase shift by vector network analyzer. The measured values of dielectric constants as a function of moisture density are compared with values of those obtained using the predicted model for estimating dielectric constants of grain.

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New Density-Independent Model for Measurement of Grain Moisture Content using Microwave Techniques

  • Kim, Jong-Heon;Kim, Ki-Bok;Noh, Sang-Ha
    • Journal of Electrical Engineering and information Science
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    • v.2 no.4
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    • pp.72-78
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    • 1997
  • A free space transmission method using standard gain horn antennas in the frequency range from 9.0 to 10.5GHz is applied to determine the dielectric properties of grain such as rough rice ,brown rice and barley. The dielectric constant and loss factor, which depend on the moisture content of the wetted grain are obtained from the measured attenuation and phase shift by vector network analyzer. The moisture content of grain varied from 11 to 25% based on this wetted condition. The measured values of dielectric constants as a function of moisture density are compared with values of those obtained using he predicted model for estimating dielectric constants of grain. The effect of density fluctuation, high is an important parameter governing the dielectric properties of grain, on the dielectric constant and loss factor is presented. A new density-independent model in terms of measured attenuation an moisture density is proposed of reducing the effects of density fluctuation on the moisture content measurement.

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Effect of Drying Conditions of Steamed Egg Yolk on Acid Value of Duck Egg Yolk Oil (증자 난황 건조 조건이 오리 난황유 산가 변화에 미치는 영향)

  • 류일환;정인택;이갑상
    • The Korean Journal of Food And Nutrition
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    • v.17 no.2
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    • pp.206-211
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    • 2004
  • It is very important to minimize the acid value of oil in the oil and fat industry, because acid value of oil products are a indicator quality. This study was performed to investigate change of moisture content, acid value and free fatty acid content by drying condition such as drying method, temperature and drying time on steamed duck egg york. Also, change of fatty acid composition by acid value. The acid values, moisture contents and free fatty acid contents were showed comparatively lower value by spray drying and freeze drying than by steam drying. but difference that keep in mind between each drying method was not looked. Whereas moisture content, acid value and free fatty acid content of effect of drying temperature reaches in lowest value. also, did not show change until dry 12hours reaching to lowest value by 3.1, 3.0% and 0.98% after dry 9hours both moisture content, acid value and free fatty acid content. Also, acid value increase, free fatty acid was increased, where unsaturated fatty acid showed that decrease rapidly.

Improvement of Moisture Resistance of Aqueous Slip-Resistant Adhesive on the Polyethylene Film (폴리에틸렌 필름에서의 수용성 미끄럼 방지 접착제의 내습 특성 개선)

  • Yoon, Young Ki;Cho, Kuk Young;Seol, Wan Ho
    • Korean Chemical Engineering Research
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    • v.48 no.2
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    • pp.193-197
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    • 2010
  • Stretch wrapping processes that are used to the packaging process had a serious problem of high price and treatment of used wraps. On the other hand, slip-resistant adhesive provides the advantage of simple process, low cost, and free from after-use treatment. In this research, adhesion deterioration of aqueous slip-resistant adhesive adhered to polyethylene film under the moisture condition using aqueous slip-resistant adhesive was observed by the Peel Test. Improvement of adhesive property under the moisturizing condition could be obtained by the selection of appropriate additives. As a result, introduction of maltodextrin reduced the deterioration of slip-resistant adhesion owing to the improved moisture resistance and introduction amount of 10 wt% of maltodextrin showed optimal performance.

Evaluation of Optimum Moisture Content for Composting of Beef Manure and Bedding Material Mixtures Using Oxygen Uptake Measurement

  • Kim, Eunjong;Lee, Dong-Hyun;Won, Seunggun;Ahn, Heekwon
    • Asian-Australasian Journal of Animal Sciences
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    • v.29 no.5
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    • pp.753-758
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    • 2016
  • Moisture content influences physiological characteristics of microbes and physical structure of solid matrices during composting of animal manure. If moisture content is maintained at a proper level, aerobic microorganisms show more active oxygen consumption during composting due to increased microbial activity. In this study, optimum moisture levels for composting of two bedding materials (sawdust, rice hull) and two different mixtures of bedding and beef manure (BS, Beef cattle manure+sawdust; BR, Beef cattle manure+rice hull) were determined based on oxygen uptake rate measured by a pressure sensor method. A broad range of oxygen uptake rates (0.3 to 33.3 mg $O_2/g$ VS d) were monitored as a function of moisture level and composting feedstock type. The maximum oxygen consumption of each material was observed near the saturated condition, which ranged from 75% to 98% of water holding capacity. The optimum moisture content of BS and BR were 70% and 57% on a wet basis, respectively. Although BS's optimum moisture content was near saturated state, its free air space kept a favorable level (above 30%) for aerobic composting due to the sawdust's coarse particle size and bulking effect.

Moisture Absorption Properties of Liquid Type Epoxy Encapsulant with Nano-size Silica for Semiconductor Packaging Materials (나노크기 실리카를 사용한 반도체용 액상 에폭시 수지 성형재료의 흡습성질)

  • Kim, Whan-Gun
    • Journal of the Semiconductor & Display Technology
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    • v.9 no.2
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    • pp.33-39
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    • 2010
  • The moisture absorption properties such as diffusion coefficient and moisture content ratio of liquid type epoxy resin systems with the filler were investigated. Bisphenol A type and Bisphenol F type epoxy resin, Kayahard MCD as hardener and 2-methylimidazole as catalyst were used in these epoxy resin systems. The nano-sized spherical type fused silica as filler were used in order to study the moisture absorption properties of these liquid type epoxy encapsulant according to the change of filler size. The temperature of glass transition (Tg) of these epoxy resin systems was measured using Dynamic Scanning Calorimeter (DSC), and the moisture absorption properties of these epoxy resin systems according to the change of time were observed at $85^{\circ}C$ and 85% relative humidity condition using a thermo-hygrostat. The diffusion coefficients in these systems were calculated in terms of modified Crank equation based on Ficks' law. An increase of Tg and diffusion coefficient with filler size in these systems can be observed, which are attributed to the increase of free volume with Tg. The change of maximum moisture absorption ratio according to the filler size and filler content cannot be observed; however, the diffusion coefficients of these systems decreased with filler content. The diffusion via free volume is dominant in the epoxy resin systems with low nano-sized filler content; however, the diffusion with the interaction of absorption according the increase of the filler surface area is dominant in the liquid type epoxy encapsulant with high nano-sized filler content.

Effect of external compressive load during a continuous radio-frequency /vacuum process on movement behavior

  • Lee, Nam-Ho;Jin, Young-Moon
    • Journal of the Korea Furniture Society
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    • v.17 no.1
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    • pp.1-10
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    • 2006
  • Movement behavior, shrinkage and equilibrium moisture content (EMC), in this experiment reflected a change of hygroscopicity mainly affected by continuously compressive load during radio-frequency/vacuum (RF/V) drying and humidity changes during equilibrating. As a result of interaction of the compressive load and moisture content changing under the RF/V condition, the shrinkages in loading direction were significantly increased while those perpendicular to loading direction were decreased. The shrinkages were affected most in tangential, and least in longitudinal direction. The shrinkages showed higher values in continuous drying than in intermittent drying. In the direction of increased shrinkage, all the movements were also increased, for example, the tangential movement for the loaded-RS and the radial movement for loaded-TS; in the direction of decreased shrinkage, all the movements except the tangential movement for the loaded-TS were decreased such as the tangential and radial movements for the loaded-ES, and the radial movement for the loaded-RS, comparing with those of the load-free. EMCs of the loaded specimens were all higher than that of the load-free specimen, and the highest for the loaded-TS, the lowest for the loaded-ES. The transverse hygroscopicity of specimen was reduced for the loaded-ES, but increased for the loaded-TS.

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The Changes of Nutrient Composition in the Edible Potato Varieties during Storage (식용감자 품종의 저장기간별 영양성분 변화)

  • Youn, Jong-Tag;Kwon, Hye-Jeong;Hong, Geo-Pyo;Ahn, Mun-Seob;Heu, Nam-Ki;Lim, Hak-Tae;Kim, Kwang Ho
    • Horticultural Science & Technology
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    • v.17 no.4
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    • pp.467-469
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    • 1999
  • This study was conducted to examine the changes of nutritive substances in the edible potato varieties ('Superior', 'Atlantic', 'Irish Cobbler', 'Dejima') during storage under low temperature condition($4^{\circ}C$, 85-90% RH) from January to May. The items examined in this experiment were moisture, free soluble sugars, starch and vitamin C. The contents of starch and vitamin C decreased with increasing storage period. The rates of decrease in starch and vitamin C contents were high in February and low after that. The contents of moisture and free soluble sugars did not show a constant tendency during storage period. The contents of glucose and fructose were the highest in February and March. Among the four varieties, 'Superior' contained highest vitamin C, free sugar, and moisture, while 'Atlantic' contained the highest starch.

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The Effect of Water Soluble Polymer on the Flexural Strength and Moisture Sensitivity in MDF Cement Composites (MDF 시멘트 복합재료의 휨강도와 수분민강성에 미치는 수용성 폴리머의 영향)

  • 김태현;최상흘
    • Journal of the Korean Ceramic Society
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    • v.29 no.4
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    • pp.298-304
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    • 1992
  • Flexural strength, microstructure, hydration reaction and moisture sensitivity in macro defect-free (MDF) cement, which basically prepared of high alumina cement (HAC) and hydroxypropyl methylcellulose (HPMC) and polyvinylalcohol (PVA) as water soluble polymer were investigated. Cement composites based on HAC-PVA system were improved in flexural strength than that of HAC-HPMC system especially, the strength of specimens added to 10 wt% of polyvinylalcohol was 160 MPa. These improvements of flexural strength were attributed to not only the effect of water soluble polymer in elimination of macropores (above 100 $\mu\textrm{m}$) and cement grain bridging, but the effect of unhydrate cement as an aggregate. Moisture sensitivity and flexural strength in wet condition of MDF cement composites immersed in water at 80$^{\circ}C$ for 3 days were decreased.

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