• Title/Summary/Keyword: moisture content distribution

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Factors Affecting Lipid Oxidation In Full-fat Soy Flour (전지 대부분의 유지산화에 미치는 인자)

  • Kim, Chul-Jai;Lee, C.C.;Johnson, L.A.
    • Korean Journal of Food Science and Technology
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    • v.23 no.6
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    • pp.732-738
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    • 1991
  • Corsoy 79 soybeans were ground into 8-(coarse) and 24-mesh (fine) full-fat soy flours. From the particle size analysis, the 8-mesh full-fat soy flours were found to have larger values for geometric mean diameter and geometric standard deviation. However, the distribution moduli of coarse and fine soy flours were similar and indicated soybeans were nearly 'brittle'. Development of hydrolytic and oxidative rancidities of coarsely and finely ground full-fat soy flours were followed from grinding to 24 hrs later. No increases in peroxide value and conjugated dienes in the oil and hexanal content in the headspace of the flour were observed when the moisture was 10.7% or less. At 14.9% moisture and above, lipid oxidation increased with increased moisture content and storage time. Free fatty acid contents increased slightly at all moisture contents. However, hydrolysis did not exceed 0.06% over the moisture range of 4 to 18%, which is of little practical significance. Fine grinding increased oxidative and hydrolytic rancidities, especially at 14.9% moisture and above. these findings indicate that raw soybeans can be ground to full-fat soy flours and stored up to 24 hrs without undergoing significant lipid and flavor deterioration if the moisture content is 11% or less.

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A Numerical Study on Evaporation of Sludge Particles in a Sludge Dryer (열건조기내에서 슬러지 입자의 증발현상에 관한 수치해석 연구)

  • Ku, Bon-Ki;Kim, Sang-Soo
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.22 no.8
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    • pp.1064-1072
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    • 1998
  • The evaporation of sludge particles in a sludge dryer has been numerically investigated with commercial CFX4.1 code. Gas flow field, gas temperature field, sludge particle trajectories, and the moisture content variation of sludge particles are calculated fort various influencing factors, i. e., gas swirl velocity, initial particle distribution, gas temperature. Evaporation of sludge particles increases with gas swirl velocity, several supplying positions, and gas temperature, respectively due to increased residence time, increased contacting surface area, and increased temperature difference between gas and particle.

Three-dimensional and free-edge hygrothermal stresses in general long sandwich plates

  • Ahmadi, Isa
    • Structural Engineering and Mechanics
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    • v.65 no.3
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    • pp.275-290
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    • 2018
  • The hygrothermal stresses in sandwich plate with composite faces due to through the thickness gradient temperature and (or) moisture content are investigated. The layer-wise theory is employed for formulation of the problem. The formulation is derived for sandwich plate with general layer stacking, subjected to uniform and non-uniform temperature and moisture content through the thickness of the plate. The governing equations are solved for free edge conditions and 3D stresses are investigated. The out of plane stresses are obtained by equilibrium equations of elasticity and by the constitutive law and the results for especial case are compared with the predictions of a 3D finite element solution in order to study the accuracy of results. The three-dimensional stresses especially the free edge effect on the distribution of the stresses is studied in various sandwich plates and the effect of uniform and non-uniform thermal and hygroscopic loading is investigated.

On the Decay Rate of Soil Organic Matter and Changes of Soil Microbial populaiton (토양유기물의 분해속도와 Microbial populaiton의 소장에 관한 연구)

  • 김춘민
    • Journal of Plant Biology
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    • v.10 no.1_2
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    • pp.21-30
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    • 1967
  • The aim of present study is to elucidate the relationship between decay rate of soil organic matter, and the change of soil microbial population under the oak and pine forest soils in Kwang-nung plantation stand. The results obtained are as follows: 1) The correlation coefficient between decay rate and the soil bacteria is 0.84 and fungi 0.93. 2) The distribution of soil microbial population is higher in both F horizon of the oak forest soil, and F and H horizon of the pine forest soil. However, the number of soil microorganisms decreases with the depth in each forest soil. 3) The population of soil microbes is related to moisture content, total nitrogen, available phosphorus, and exchangeable calcium, except organic carbon in fungi. 4) The soil organic matter has been mainly decomposed by fungi, and the size of its population are governed by the factors such as moisture content, organic carbon, total nitrogen, available phosphorus, and exchangeable calcium.

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Distribution patterns of specice populations along the environmental gradients in mt. moak provincial park, korea (環境傾度에 의한 母岳山 植物個體群의 分布類型)

  • Kim, Jeong-Un;Yim, Yang-Jai
    • The Korean Journal of Ecology
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    • v.15 no.4
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    • pp.365-375
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    • 1992
  • The environmental gradient analyses were applied for the distribution patterns of species populations in mt. moak provincial park in korea. The species populations were sequentially ordered along the environmental gradients such as soil moisture, soil ph, soil organic matter content and elevation and were grouped into seven ecological groups by the two-dimensional analyses of temperature-moisture gradient : zelkova serrata group on mesic-lower parts near the streames and well drained stony slopes, carpinus tschonoskii group on mesic-middle parts, quercus acutissima group on lower parts destroyed by human activities, quercus variabilis group on xeric-middle parts, quercus serrata group on xeric-upper middle parts, quercus mongolica group on xeric-upper parts and pinus densiflora group on xeric-rock ridge lines, hillocks and lower parts interfered by human. Four forest vegetation types, zelkova forest dominated by the c. tschonoskii group on mesic-middle parts, oak forest dominated by the groups of q. acutissima, q. variabilis, q. serrata and q. mongolica on xeric sites and pine forest dominated by the p. densiflora group on dry and poor sites, were separated in mosaic chart by the two-dimensional analysis.

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Analysis of Aging Characteristics in Oil Immerged Pole Transformer (과부하 및 경년 변압기 절연유 열화 특성 분석 연구)

  • Lee, Byung-Sung;Song, Il-Keun;Lee, Jae-Bong;Park, Dong-Bea;Han, Sang-Ok
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2002.05c
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    • pp.203-207
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    • 2002
  • In order to evaluate the aging of mineral oil immersed distribution transformers, it gathered some insulation oil in over loaded and long time(exceed their service life, 13yrs.) aged transformers in the field, we measured moisture content, acid number, dielectric strength of the oil as defined in KS C 2101 standard. And also, it had been measured dielectric constant, specific resistant, $tan{\delta}$ on aged transformer oil at from $10^{\circ}C$ to $130^{\circ}C$. These results are compared with a new mineral oil. From this study, it can be considered that the analysis of mineral oil may be suitable for evaluation of life expectancy in distribution transformers

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The Distribution of Plant Communities on Water Table along the Bukhan Riverside in Chun-seong (춘성지구 북한강유역의 지하수위에 따른 식물군락의 운적적 변화)

  • 이성규
    • Journal of Plant Biology
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    • v.16 no.3_4
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    • pp.1-6
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    • 1973
  • The distribution of plant communities along the Bukhan Riverside in Chun-seong was studied by means of the methods fo Curtis and Pattern. The communities were arranged in a single-dimensioned ordination on the basis of the importance values of the persistent species. Leading dominant species, form the 'low' level to the 'high' levels of the ordination gradient, were Phalaris arundinacea, Salix gilgiana, Artemisia feddei, Zoysia japonica, Pennisetum japonicum, and Arundinella hirta. These species from a continuum from the river to the dry grassland depending upon available soil-moisture. Standing crops in terms of dry weight and the nitrogen content of the above-ground parts of these species showed a good relationship with gradients of available soil-moisture.

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Spatial Distribution of Fine Roots in Quercus mongolica and Quercus acutissima Stands (신갈나무와 상수리나무 숲에서 細根의 空間分布)

  • Kwak, Young-Se;Kim, Joon-Ho
    • The Korean Journal of Ecology
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    • v.17 no.2
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    • pp.113-119
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    • 1994
  • Vertical and horizontal distribution and seasonal changes of fine roots as well as inorganic nitrogen content in soil were determined in Quercus mongolica and Quercus acutissima stands in Mt. Taemosan, Seoul. The vertical distribution of fine rooth phytomass showed a power-functional decrease as descending soil depth. Fine root phytomass was 170 g $DM/m^2$(46%) and 225 g $DM/m^2$(47%) in top soil of 5 cm depth, and 370 g $DM/m^2$ and 480 g $DM/m^2$ from soil surface to 50 cm depth in Q. mongolica and Q. acutissima stands, respectively. Fine roots in relation to the distance from the nearest tree were evenly distributed horizontally in both stands. Fine roots phytomass in top soil of 5 cm depth reached a peak in June, and thereafter decreased gradually in both stands. Patterns of seasonal changes in fine root phytomass were closely related to inorganic nitrogen and moisture content.

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Determination of Degree of Hydration, Temperature and Moisture Distributions in Early-age Concrete (초기재령 콘크리트의 수화도와 온도 및 습도분포 해석)

  • 차수원;오병환;이형준
    • Journal of the Korea Concrete Institute
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    • v.14 no.6
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    • pp.813-822
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    • 2002
  • The purpose of the present study is first to refine the mathematical material models for moisture and temperature distributions in early-age concrete and then to incorporate those models into finite element procedure. The three dimensional finite element program developed in the present study can determine the degree of hydration, temperature and moisture distribution in hardening concrete. It is assumed that temperature and humidity fields are fully uncoupled and only the degree of hydration is coupled with two state variables. Mathematical formulation of degree of hydration Is based on the combination of three rate functions of reaction. The effect of moisture condition as well as temperature on the rate of reaction is considered in the degree of hydration model. In moisture transfer, diffusion coefficient is strongly dependent on the moisture content in pore system. Many existing models describe this phenomenon according to the composition of mixture, especially water to cement ratio, but do not consider the age dependency. Microstructure is changing with the hydration and thus transport coefficients at early ages are significantly higher because the pore structure in the cement matrix is more open. The moisture capacity and sink are derived from age-dependent desorption isotherm. Prediction of a moisture sink due to the hydration process, i.e. self-desiccation, is related to autogenous shrinkage, which may cause early-age cracking in high strength and high performance concrete. The realistic models and finite element program developed in this study provide fairly good results on the temperature and moisture distribution for early-age concrete and correlate very well with actual test data.

Groundwater Recharge Assessment via Grid-based Soil Moisture Route Modeling (격자기반의 토양수분 추적에 의한 지하수함양량 추정기법 개발)

  • Kim, Seong-Jun;Chae, Hyo-Seok
    • Journal of Korea Water Resources Association
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    • v.33 no.1
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    • pp.61-72
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    • 2000
  • The purpose of this study is to improve the method of evaluating groundwater recharge by using grid-based soil moisture routing technique. A model which predicts temporal variation and spatial distribution of soil moisture on a daily time step was developed. The model uses ASCII-formatted map data supported by the irregular gridded map of the GRASS(Geographic Resources Analysis Support System)-GIS and can generate daily and monthly spatial distribution map of surface runoff, soil moisture content, evapotranspiration within the watershed. The model was applied to Ipyunggyo watershed($75.6\;\textrm{km}^2$) located in the upstream of Bocheongchun watershed. Seven maps; DEM(Digital Elevation Mode]), stream, flow path, soil, land use, Thiessen network and free groundwater level, were used for input data. Predicted streamflows resulting from two years (l995, 1996) daily data were compared with the observed values at the watershed outlet. The results of temporal variations and spatial distributions of soil moisture are presented by using GRASS GIS. As a final result, the monthly predicted groundwater recharge was presented.sented.

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