• Title/Summary/Keyword: Moisture expansion

Search Result 215, Processing Time 0.028 seconds

Quality Properties of Gangjung Added with Detoxified Stem Bark of Rhus verniciflua (RVSB) Extract during Acceleration Storage (무독화 옻 추출물 첨가 강정의 가온저장 중 품질 특성)

  • Kim, Kyung-Mi;Kim, Tae-Young;Kim, Myung-Kon;Kim, Haeng-Ran
    • Korean Journal of Food Science and Technology
    • /
    • v.39 no.4
    • /
    • pp.425-431
    • /
    • 2007
  • The quality characteristics of Gangjung added with detoxified Rhus verniciflua stem bark (RVSB) extract, as well as the changes that occurred in the product during accelerated storage ($60^{\circ}C$, 24 hr), were investigated. The expansion rate of Gangjung was not significantly different (p < 0.05). The L-value of the Gangjung with added detoxified RVSB extract was higher than the control, while the a-value decreased as the addition levels of the detoxified RVSB extract increased. The b-value was highest for the Gangjung prepared with 7% (w/w) detoxified RVSB extract. The moisture content of the Gangjung decreased as the storage period increased, but the addition of detoxified RVSB extract (p < 0.05) did not significantly change this effect. We found no significant difference in the hardness of the Gangjung within the concentration range of 0-7% (w/w) detoxified RVSB extract, and the peak number slightly decreased as the storage period increased. After 16 hr of storage, the acid value was significantly lower for the Gangjung containing detoxified RVSB extract at concentration between 5-7%. Furthermore, after 12 hr of accelerated storage, peroxide and TBA values significantly decreased with additions of detoxified RVSB extract that were over 3% (w/w). These results suggest that the physical texture of Gangjung did not improve by the addition of detoxified RVSB extract; however, its rate of lipid oxidation was reduced.

A Numerical Model of Three-dimensional Soil Water Distribution for Drip Irrigation Management under Cropped Conditions (작물 흡수를 고려한 3차원 토양수분 분포 모델 개발을 통한 최적 점적 관개 연구)

  • Kwon, Jae-Phil;Kim, Seung-Hyun;Yoo, Sun-Ho;Ro, Hee-Myong
    • Applied Biological Chemistry
    • /
    • v.43 no.2
    • /
    • pp.116-123
    • /
    • 2000
  • A numerical model of three-dimensional soil water distribution for drip irrigation management under cropped conditions was developed using Richards equation in Cartesian coordinates. The model accounts for both seasonal and diurnal changes in evaporation and transpiration, and the growth of plant root and the shape of root zone. Solutions were numerically approximated using the Crank-Nicolson implicit finite difference technique on the block-centered grid system and the Gauss-Seidel elimination in tandem. The model was tested under several conditions to allow the flow rates and configurations of drip emitters vary. In general, simulation results agreed well with experimental results and were as follows. The velocity of soil-water flow decreased drastically with distance from the drip source, and the rate of expansion of the wetted zone decreased rapidly during irrigation. The wetting front of wetted zone from a surface drip emitter traveled farther in vertical direction than in horizontal direction. Under this experimental weather condition, water use efficiency of a drip-irrigated apple field was greatest for 4-drip-emitter system buried at 25 cm, resulting from 10% increase in transpiration but 20% reduction in soil evaporation compared to those for surface 1-drip emitter system. Soil moisture retention curve obtained using disk tension infiltrometer showed significant difference from the curve obtained with pressure plate extractor.

  • PDF

Production of Foamed Glass by Using Hydrolysis of Waste Glass(III) - Heat Treatment for Stabilization and Scale-up Test - (폐유리의 가수분해 반응에 의한 발포유리의 제조(III) - 안정화 열처리공정 및 Scale-up Test -)

  • Lee, Chul-Tae;Um, Eui-Heum
    • Applied Chemistry for Engineering
    • /
    • v.17 no.1
    • /
    • pp.73-81
    • /
    • 2006
  • Heat treatment condition for the stabilization of foamed glass block through the foaming process of the hydrolized waste glass was investigated and scale-up test for the manufacturing of foamed glass was also attempted for the actual foaming process. Proper heat treatment condition was quenching from the foaming temperature to $550{\sim}600^{\circ}C$ for stabilization, and then annealing from stabilization temperature to $200^{\circ}C$ and holding up at $200^{\circ}C$ for removal thermal stress, and then annealing to the room temperature with cooling speed of $0.3^{\circ}C/min$. Through this heat treatment conditions, foamed glass block with size of $250mm{\times}250mm{\times}90mm$ was produced successfully. The properties of this foamed glass block showed density of $0.28{\pm}0.06g/cm^3$, thermal conductivity of $0.048{\pm}0.005kcal/hm^{\circ}C$, moisture absorption of $0.5{\pm}0.09vol%$, linear expansion coefficient of $(8.6{\pm}0.2){\times}10^{-6}m/m^{\circ}C$($400^{\circ}C$), flexural strength of $15.0{\pm}0.6kg/cm^2$, and compression strength of $39.5{\pm}0.6kg/cm^2$.

Solubilization of Whole Grains by Extrusion and Enzyme Treatment (전곡립의 압출성형 및 효소처리에 의한 수용화)

  • Shin, Hae-Hun;Lee, Sun-Hee;Park, Bo-Sun;Rhim, Tae-Soo;Hwang, Jae-Kwan
    • Korean Journal of Food Science and Technology
    • /
    • v.35 no.5
    • /
    • pp.849-855
    • /
    • 2003
  • The extrusion effects on solubilization of brown rice, glutinous rice, barley and job's tear were investigated in comparison with raw and roasted whole grains. Whole grains were extruded under 13 different operating conditions, where the process variables were controlled in the following ranges: screw speed, $200{\sim}300$ rpm; temperature, $110{\sim}130^{\circ}C$; moisture, $15{\sim}25%$. Solubilization effects of whole grains by extrusion were characterized in terms of water solubility index (WSI), viscosity, dispersibility and dietary fiber in comparison with those of raw and roasted grains. WSI of whole grains significantly increased by extrusion, especially WSI of glutinous rice containing abundant amylopectin increased twice than WSI of brown rice. The content of soluble dietary fiber was increased due to extrusion treatment, while insoluble dietary fiber decreased concomitantly and the content of total dietary fiber was not nearly changed. Extrusion improved the dispersibility and swelling effects in comparison with that of raw and roasting grains.

Studies on the Frost Heave Revelation and Deformation Behaviour due to Thawing of Weathered Granite Soils (화강암 풍화토의 동상 발현 및 융해에 따른 변형 거동에 관한 연구)

  • 류능환;최중대;류영선
    • Magazine of the Korean Society of Agricultural Engineers
    • /
    • v.37 no.3_4
    • /
    • pp.61-71
    • /
    • 1995
  • Natural ground is a composite consisted of the three phases of water, air and soil paircies. Among the three components, water as a material is weU understood but soil particles are not in foundation engineering. Especially, weathered granite soil generally shows a large volumetric expansion when they freeze. And, the stability and durability of the soil have shown decreased with repetitive freezing and thawing processes. These unique charcteristics may cause various construction and management problems if the soil is used as a construction material and foundation layers. This project was initiated to investigate the soil's physical and engineering characteristics resulting from freezing and freezing-thawing processes. Research results may be used as a basic data in solving various problems related to the soil's unique characteristics. The following conclusions were obtained: The degree of decomposition of weathered granite soil in Kangwon-do was very different between the West and East sides of the divide of the Dae-Kwan Ryung. Soil particles distributed wide from very coarse to fine particles. Consistency could be predicted with a function of P200 as LL=0.8 P200+20. Permeability ranged from 10-2 to 10-4cm/sec, moisture content from 15 to 20% and maximum dry density from 1.55 to 1.73 g /cmΥ$^3$ By compaction, soil particles easily crushed, D50 of soil particles decreased and specific surface significantly increased. Shear characteristics varied wide depending on the disturbance of soil. Strain characteristics influenced the soil's dynamic behviour. Elastic failure mode was observed if strain was less than 1O-4/s and plastic failure mode was observed if strain was more than 10-2/s. The elastic wave velocity in the soil rapidly increased if dry density became larger than 1.5 g /cm$^3$ and these values were Vp=250, Vg= 150, respectively. Frost heave ratio was the highest around 0 $^{\circ}C$ and the maximum frost heave pressure was observed when deformation ratio was less than 10% which was the stability state of soil freezing. The state had no relation with frost depth. Over freezing process was observed when drainage or suction freezing process was undergone. Drainage freezing process was observed if freezing velocity was high under confined pressure and suction frost process was occurred if the velocity was low under the same confined process.

  • PDF

Digital simulation model for soil erosion and Sediment Yield from Small Agricultural Watersheds(I) (농업 소류역으로부터의 토양침식 및 유사량 시산을 위한 전산모의 모델 (I))

  • 권순국
    • Magazine of the Korean Society of Agricultural Engineers
    • /
    • v.22 no.4
    • /
    • pp.108-114
    • /
    • 1980
  • A deterministic conceptual erosion model which simulates detachment, entrainment, transport and deposition of eroded soil particles by rainfall impact and flowing water is presented. Both upland and channel phases of sediment yield are incorporated into the erosion model. The algorithms for the soil erosion and sedimentation processes including land and crop management effects are taken from the literature and then solved using a digital computer. The erosion model is used in conjunction with the modified Kentucky Watershed Model which simulates the hydrologic characteristics from watershed data. The two models are linked together by using the appropriate computer code. Calibrations for both the watershed and erosion model parameters are made by comparing the simulated results with actual field measurements in the Four Mile Creek watershed near Traer, Iowa using 1976 and 1977 water year data. Two water years, 1970 and 1978 are used as test years for model verification. There is good agreement between the mean daily simulated and recorded streamflow and between the simulated and recorded suspended sediment load except few partial differences. The following conclusions were drawn from the results after testing the watershed and erosion model. 1. The watershed and erosion model is a deterministic lumped parameter model, and is capable of simulating the daily mean streamflow and suspended sediment load within a 20 percent error, when the correct watershed and erosion parameters are supplied. 2. It is found that soil erosion is sensitive to errors in simulation of occurrence and intensity of precipitation and of overland flow. Therefore, representative precipitation data and a watershed model which provides an accurate simulation of soil moisture and resulting overland flow are essential for the accurate simulation of soil erosion and subsequent sediment transport prediction. 3. Erroneous prediction of snowmelt in terms of time and magnitute in conjunction with The frozen ground could be the reason for the poor simulation of streamflow as well as sediment yield in the snowmelt period. More elaborate and accurate snowmelt submodels will greatly improve accuracy. 4. Poor simulation results can be attributed to deficiencies in erosion model and to errors in the observed data such as the recorded daily streamflow and the sediment concentration. 5. Crop management and tillage operations are two major factors that have a great effect on soil erosion simulation. The erosion model attempts to evaluate the impact of crop management and tillage effects on sediment production. These effects on sediment yield appear to be somewhat equivalent to the effect of overland flow. 6. Application and testing of the watershed and erosion model on watersheds in a variety of regions with different soils and meteorological characteristics may be recommended to verify its general applicability and to detact the deficiencies of the model. Futhermore, by further modification and expansion with additional data, the watershed and erosion model developed through this study can be used as a planning tool for watershed management and for solving agricultural non-point pollution problems.

  • PDF

Development of White Bread Using Fermented Wild Grape Sourdough (머루를 이용한 Sourdough 식빵 개발)

  • Bing, Dong-Joo;Kim, Won-Tae;Chun, Soon-Sil
    • Journal of the Korean Society of Food Science and Nutrition
    • /
    • v.43 no.12
    • /
    • pp.1896-1905
    • /
    • 2014
  • The purpose of this study was to manufacture white bread by substituting bakery yeast with natural starter. The general composition of wild grape, was 81.22% moisture, 0.81% ash, 0.74% crude fat, 1.58% crude protein, and 15.65% carbohydrate contents. Fermented wild grape extract was made by culturing for 4 days at $25^{\circ}C$. Flour was added three times to fermented wild grape extract and incubated for 36 hours at $20^{\circ}C$ to manufacture sourdough. We investigated the quality characteristics of white bread with different amounts of fermented wild grape sourdough. The pH of dough decreased with increasing amounts of sourdough, whereas total titratable acidity of dough significantly increased. Fermentation power of dough expansion significantly increased with increasing incubation time, and control showed the highest value of 126.67%. White bread specific volume was highest in, 50% sourdough at 4.76 mL/g. Water content increased with increasing amounts of sourdough, whereas water activity was not significantly different between the samples. For texture, hardness of 50% sourdough was lowest at 19.23 g. In the sensory evaluation, color, flavor, softness and overall acceptability decreased with increasing amounts of sourdough. As a result, 50% sourdough can be considered as a baker's yeast substitute for making natural fermented bread.

Effect of Green Tea Powder on the Quality Characteristics of Yukwa (Korean Fried Rice Cake) (가루녹차가 유과의 품질 특성에 미치는 영향)

  • Park, Jae-Nam;Kweon, Seok-Yim;Kim, Jong-Gun;Park, Jin-Gyu;Han, In-Jun;Song, Beom-Seok;Kim, Jae-Hun;Byun, Myung-Woo;Lee, Ju-Woon
    • Food Science and Preservation
    • /
    • v.15 no.1
    • /
    • pp.37-42
    • /
    • 2008
  • This study investigated the effects of green tea powder (GTP) on the quality characteristics of Yukwa during storage, to improve shelf-stability and sensory quality. The crude lipid contents of Yukwa decreased with increasing levels of GTP, but significant changes in moisture contents were not found. 'The blowhole size and expansion rate of Yukwa decreased with increases in GTP. The hardness of Yukwa samples with over 2% (w/v) GTP significantly increased, but no notable changes in hardness during storage were found. Sensory evaluation tests indicated that all sensory characteristics decreased with increasing GTP levels, but there was no significant difference in overall acceptability between Yukwa samples with 1% (w/v) GTP and control. Antioxidant activity increased as the concentration of GTP increased 'The results indicate that addition of 1% (w/v) G1P yielded optimal quality of Yukwa during storage.

Distribution Pattern of Ageratina altissima Along Trails at Mt. Umyeon in Seoul, Korea (우면산 등산로 주변 서양등골나물의 분포 경향)

  • Kim, Hyonook;Jang, Yoo Lim;Park, Pil Sun
    • Korean Journal of Agricultural and Forest Meteorology
    • /
    • v.16 no.3
    • /
    • pp.227-232
    • /
    • 2014
  • Ageratina altissima is an invasive plant species known to threaten native plant communities in Korea. A. altissima is thought to invade shady forests from disturbed open areas; however, uncertainty remains as to how shade and litter depth might affect establishment. A study of A. altissima distribution characteristics in areas adjacent to trails was undertaken at Mt. Umyeon in Seoul, Korea. Increasing densities of A. altissima were found to correlate with greater light availability and decreasing litter depth (p < 0.001) within 10 m distance from trail locations and on ridges rather than further within forests and valleys. The effects of soil moisture content, soil gravel content and soil pH on distribution were not found to be significant, suggesting that A. altissima is adaptable to a broad range of soil conditions. Results indicate that forest areas close to trails may be particularly susceptible place to A. altissima invasion, demonstrating the need to carefully consider implications for A. altissima expansion in trail management.

A Basic Study on the Development of Backfill Material with Fly Ash and Bottom Ash of Circulating Fluid Bed Combustion (순환유동층보일러의 Fly Ash, Bottom Ash를 활용한 채움재 개발에 관한 기초연구)

  • Cho, Yong-Kwang;Lee, Yong-Mu;Nam, Seong-Young;Kim, Chun-Sik;Seo, Shin-Seok;Jo, Sung-Hyun;Lee, Hyoung-Woo;Ahn, Ji-Whan
    • Journal of the Korea Institute of Building Construction
    • /
    • v.18 no.1
    • /
    • pp.25-31
    • /
    • 2018
  • In this study, the Controlled Low Strength Material (CLSM) was investigated to utilize the bottom ash and fly ash generated in the Circulating Fluidized Bed Combustor (CFBC). It was confirmed that the CFBC fly ash (CFBC-F) and CFBC bottom ash (CFBC-B) had an irregular particle shape through SEM measurement. According to the results of the hazard analysis, it was also confirmed that they were environmentally safe. In the case of mixing with CFBC-F, the unit quantity was increased. Regarding the rate of change of length, shrinkage in the range of -0.05~0.50% occurred in the air dry curing condition and expansion in the range of 0.1~0.6% in the sealed curing condition. Compressive strength was increased in the sealed curing condition compared to the air dry curing condition because there was enough moisture for hydration reaction in the long term. Therefore, the results of this study are likely be used as basic research data of mine filler materials.