• Title/Summary/Keyword: Moisture contents

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The Response of soil surface heat budget to the precipitation (지표면 열수지의 강수응답성에 관한 연구)

  • 황수진;진병화
    • Journal of Environmental Science International
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    • v.3 no.2
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    • pp.89-100
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    • 1994
  • It is very important to assess accurately the terms which are included in the heat budget equation of soil surface because they are used in the UM and miso-scale circulation modeling as well as in the micrometeorological studies. Each terms in the heat budget equation change according to the soil moisture content. So, it is necessary to specify clearly the relations between soil moisture content and these terms. Special experiment with micrometeorological measurements was executed to study these relations at Environmental Research Center of Tsukuba University, Japan. The results are as follow: 1. The soil moisture contents of 1 cm and 4 cm depth are oscillated with one day Period in drying process and the amplitude of variation of 1 cm depth is greater than that of 4 cm. 2. Increase in soil moisture contents due to precipitation result in decrease of albedo with step function. 3. Sensible heat is in reverse proportion to the soil moisture content and latent heat is in direct proportion to it. Latent heat is more sensitive than sensible heat according to the soil moisture variation. Net long wave radiation have high correlation with soil moisture. 4. Comparing with the radiative term with the flux term in wetting process due to precipitation, the energy transfer of the aero and thermodynamic flux is greater than that of the radiative heat flux.

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Effects of Cross-Sectional Dimension and Moisture Profile of Small Specimens on Characteristics of Ultrasonic Wave Propagation (목재의 단면적과 수분경사가 초음파 전달 특성에 미치는 효과)

  • Kang, He-Yang;Lee, Kwan-Young
    • Journal of the Korean Wood Science and Technology
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    • v.28 no.2
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    • pp.19-24
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    • 2000
  • Effects of the cross-sectional dimension and moisture profile of wood specimens on the ultrasonic sound velocities of radiata pine heartwood and sapwood. Each moisture profile model specimen was made by composing five wood pieces with various moisture contents. As the cross-sectional dimensions decreased the ultrasonic velocities of both heartwood and sapwood decreased by 4~8%. In the ultrasonic signals transmitted through the specimens low frequency components more dominated than high frequency components as the dimension of cross section increased. The specimens with the same average MCs and different moisture profiles showed different ultrasonic velocities. By plotting the ultrasonic velocities against the average moisture contents of the inner three pieces of the moisture profile model specimens it was revealed that three distinct plot patterns existed.

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Drying Characteristics and Physicochemical Properties of Semi-Dried Restructured Sausage Depend on Initial Moisture Content

  • Kim, Dong-Hyun;Kim, Yea Ji;Shin, Dong-Min;Lee, Jung Hoon;Han, Sung Gu
    • Food Science of Animal Resources
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    • v.42 no.3
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    • pp.411-425
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    • 2022
  • Semi-dried restructured sausages are restructured meat products with a high nutritional and economic value. However, excessively long drying times can have negative effects on the energy consumption, texture, and sensory properties of semi-dried restructured sausages. The objective of this study was to investigate the effects of different water contents on the drying and physicochemical characteristics of semi-dried restructured sausages. Sausages were prepared with different initial moisture contents (0%-50%) and drying time (0-580 min). The drying characteristics, including the drying rate, effective moisture diffusivity, and water activity of sausage were significantly improved as the initial moisture content was increased. When the initial moisture content of the sausage was 50%, physicochemical properties, such as color, porosity, shear force, and volatile basic nitrogen, were improved the most along with the decreased drying time. Scanning electron microscopy data showed greater porosity and pore size in sausages with the increase of initial moisture content. Collectively, our data suggest that an increase in the initial moisture content of semi-dried restructured sausages improves their drying characteristics and physicochemical properties.

A Study on the Fermentation Characteristics of Garbages by the C/N Ratio Control using Kudzu Creeper and Sawdust (칡넝쿨 및 톱밥을 이용한 C/N비 조절에 따른 음식물찌꺼기의 발효특성에 관한 연구)

  • 박진식;안철우;문추연
    • Journal of environmental and Sanitary engineering
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    • v.15 no.3
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    • pp.24-30
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    • 2000
  • In this study, to determine the optimum fermentation process for the feed production of food wastes and estimate the practical value of fermented feed using kudzu creeper and sawdust as bulking agent. This study considered initial C/N ratio control as the fermentation process variables. The result are summarized as follows. Minimum water contents of byproducts in the fermentation feed production showed 39%(kudzu), 37%(sawdust) at the C/N ratio 25 and 45%(kudzu, sawdust) at the C/N ratio 35. Temperature variations in the fermentation feed production at the C/N ratio 25 indicated $68^{\circ}C$(kudzu), $70^{\circ}C$(sawdust). Optimum condition of fermentation process of water content, C/N ratio and permeability (porous structure of the mixture). For optimum fermentation gravitationally dewatered garbage, the proper mixing ratios of kudzu(moisture contents : 17.3%) and sawdust(moisture contents : 13.2%) were 41% and 39%, respectively. Major biological reaction in the aerobic fermentation feed production occurred during 12~24hrs.

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The Effect of Extrusion Conditions on Water-extractable Arabinoxylans from Corn Fiber

  • Jeon, Su-Jung;Singkhornart, Sasathorn;Ryu, Gi-Hyung
    • Preventive Nutrition and Food Science
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    • v.19 no.2
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    • pp.124-127
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    • 2014
  • The effect of feed moisture contents (30%, 40%, and 50%) and screw speed (200 rpm, 250 rpm, and 300 rpm) on the corn fiber gum (CFG) yield and soluble arabinoxylans (SAX) content of destarched corn fiber was investigated. The CFG yields and SAX contents of extruded, destarched corn fiber were higher than that of destarched corn fiber. In extruded, destarched corn fiber, increased screw speed and decreased feed moisture contents resulted in a higher SAX contents. The maximum yields of CFG obtained from extruded, destarched corn fiber were $79.1{\pm}19.0g/kg$ (30% feed moisture content) and $82.3{\pm}11.30g/kg$ (300 rpm screw speed). The highest SAX content was also observed at a screw speed of 300 rpm. The results of the present study show that water extraction and extrusion combined have the potential to increase CFG and SAX yields from corn fiber.

Changes of Colors and Pungent Principles of Red Pepper Powder with Different Seed Contents and Particle Sizes During Storage (종자 혼입율과 입도를 달리한 고추가루의 저장 중 색과 매운맛 성분의 변화)

  • 이선미;황인경
    • Korean journal of food and cookery science
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    • v.14 no.5
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    • pp.584-588
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    • 1998
  • Red pepper powders with variuos seed contents (0%, 10%, 20%) and particle sizes were stored at 0$^{\circ}C$, 20$^{\circ}C$, and 30$^{\circ}C$ for 90 days, and the changes in their characteristics were monitored. The initial moisture content was about 13%, and the powders were packed in 0.1 mm-thick polypropylene (PP) bags. Moisture content of each power remained constantly, so PP bags appeared to be effective to prevent moisture transmission. All the values of L*, a* and b* were higher in fine particles than in coarse particles. Storage at 0$^{\circ}C$ did not change any color values, however, overall color values devreased apparently when stored at 30$^{\circ}C$ for 90 days. Capsanthin contents decreased gradually at all storage temperatures and more rapidly at higher temperature. The contents of capsaicinoids in fine particles (49∼59 mg%) were twic as much as those in coarse particles (15∼36 mg%), and they did not change throughout the storage.

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Some effects of rice weevil (Sitophilus oryzae L.) on the moisture contents of polished rice (쌀바구미(Sitophilus oryzae Linne)의 현미함수량에 미치는 영향)

  • HYUN Jai Sun
    • Korean journal of applied entomology
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    • v.1
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    • pp.20-25
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    • 1962
  • A. The increases moisture contents of grain at R.H $75\%,\; and\; 28^{\circ}C$ 1) The moisture contents of polished rice were $0.4\%,\; 1 \%,\; 3.3\%$ higher than control after 4weeks in which had been infested with 100, 200, 500 individuals of weevil at the beginning. respectively. 2) The greatest moisture contents of polished rice was $16.26\%$ for 500 individual infested grain and the lowest one was $14.86\%$ for the 100 individual weevil infested grain after 4 weeks. 3) The increases in moisture contents of grain were proportionally greater with the size of the weevil population. B. Changes in moisture contents of polished rice at the three levels of cylinder which contain 3kgs of grain and 1000 weevils were infested at the beginning of the experiment. 1) The moisture contents of the grain at all the levels of the cylinder which was not infested with weevil, were consistantly decreased in 12 weeks. 2) The moisture contents of the grain at all the levels of the cylenders which had been infested with 1000 weevils at the beginning of the experiment, were increased except top lovel, that were $15.6\%$ for middle, $41.55\%$ for the bottom levels after 12 weeks. 3) The moisture contents of the grain were greater toward bottom in both weevil infested grain and in control. 4) The moisture content increase might be caused by the respiration of the weevils and deterioration of the grain by microorganisms. 5) There were no tendency to confine the weevils at any definite levels, but as the deterioration of the grain goes on, the weevil moved to top levels of cylinders. 5) The decreases in moisture contents of the grain at the top levels of the cylinders might be caused by diffusion of water to the environment. 7) The differences in temperature at three levels of the cylinder from enviroment were little or negative in control but were greater and positive. and the bottom were higher than top in experimental cylinders. 8) The increases of temperature might be caused by the respiration of the weevil and microorganisms.

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

  • Kim, Gi-Hwan;Han, Jeong-Seong;Joo, Yeong-Seok
    • Journal of the Korean Society of Tobacco Science
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    • v.9 no.2
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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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Development of Continuous Cross-Flow Rice Drying Model and Drying Speed Control System Using Fuzzy Logic(II) - Drying Speed Control - (벼의 횡류 연속식 건조 모델 개발과 퍼지논리를 이용한 건조 속도 제어에 관한 연구(II) - 건조속도제어 -)

  • 송대빈;고학균;조성인
    • Journal of Biosystems Engineering
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    • v.23 no.5
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    • pp.457-464
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    • 1998
  • A drying speed control system using fuzzy logic was developed in order to minimize the damage of rice quality for a large capacity continuous dryer. The performance of the system was tested at two object moisture content of 17% and 25% on a wet basis. For object moisture content of 17% on a wet basis, the final output moisture contents from 20.46%, 20.96%, 18.98% on a wet basis were 17.99%, 17.6% and 17.23% on a wet basis, respectively. For object moisture content of 25% on a wet basis, the final output moisture contents from 28.85%, 26.95%, 28.11%, 27.8% on a wet basis were 25.24%, 24.9%, 25.23% and 25.09% on a wet basis, respectively.

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Development of Fuzzy Control System For Uniform Drying in Continuous Dryer

  • Song, D.B.;H.K.Koh;Cho, S.I.;Lee, J.H.
    • Proceedings of the Korean Society for Agricultural Machinery Conference
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    • 1996.06c
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    • pp.668-678
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    • 1996
  • A control system using fuzzy logic for a large capacity continuous dryer has been developed in order to minimize the damage of rice quality. The system has been verified in the case of 17% of object moisture content. With the initial input moisture contents of 20.46%(wb), 20.96%(wb) and 18.98%(wb), the final moisture contents of 17.99%(wb), 17.6%(wb) and 17.23%(wb) are obtained, respectively. The results show that the system controls the moisture content with the maximum error of 0.99% of the object moisture content.

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