• Korean Journal of Food Science and Technology
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• v.17 no.6
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• pp.415-420
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• 1985

In this study, changes in physical and chemical properties of glutinous rice during various soaking periods (0, 0.08, 1, 3, 5, 7, 10 days) were investigated in order to clarify the relations ship between soaking period and expansion volume in the preparation of Gang Jung. The longer the soaking period was, the greater the expansion volume of Gang Jung was. Higher maximum viscosity and breakdown in amylogram of glutinous rice flour were observed as the soaking period was increased, As the length of soaking period increased, hardness of glutinous rice and size of flour particle significantly decreased, while sweeling power and solubility of glutinous rice flour showed no significant difference. Increased length of soaking period was associated with higher fatty acidity, higher acidity of water extract and lower pH of glutinous rice flour. Control of flour particle size distribution resulted in significantly larger expansion volume of Gang Jung. Brabender's amylogram showed that the increase of expansion volume of Gang Jung associated with the increase of soaking period was related to the change of rheological properties of glutinous rice. It seemed that changes in viscometric properties of glutinous rice was attributed to the different flour particle size distribution resulted from changes in hardness of rice during soaking.

• Journal of the Korean Geotechnical Society
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• v.29 no.11
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• pp.73-84
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• 2013

When a slope failure or a debris flow occurs, a shear strength on failure plane becomes nearly zero and soil begins to flow like a non-cohesive liquid. A consistency of cohesive soils changes as a water content increases. Even a cohesive soil existing at liquid limit state has a small amount of shear strength. In this study, a water content, at which a shear strength of cohesive soils is zero and then cohesive soils will start to flow, was proposed. Three types of clays (kaolinite, bentonite and kaolinite (50%)+bentonite (50%)) were mixed with three different solutions (distilled water, sea water and microbial solution) at liquid limit state and then their water contents were increased step by step. Then, their undrained shear strength was measured using a portable vane shear device called Torvane. The ranges of undrained shear strength at liquid and plastic limits are 3.6-9.2 kPa and 24-45 kPa, respectively. On the other hand, the water content that corresponds to the value of the undrained shear strength changing most rapidly is called flow water content. The flow limit refers to the water content when undrained shear strength of cohesive soils is zero. In order to investigate the relationship between liquid limit and flow limit, the cohesive index was defined as a value of the difference between flow limit and liquid limit. The new plasticity index was defined as the value of difference between flow limit and plastic limit. The new liquidity index was also defined using flow limit. The values of flow limit are 1.5-2 times higher than those of liquid limit. At the same time, the values of new plasticity index are 2-5.5 times higher than those of original plasticity index.

• Korean Journal of Food Science and Technology
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• v.49 no.2
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• pp.151-157
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• 2017

The physicochemical properties of rice flours and quality characteristics of rice cupcake were investigated using the domestic rice varieties Goami, Hanareum, Hanmaeum, Deuraechan, Seolgaeng, and Haiami. Protein and amylose contents were highest in. The final and setback viscosities of Haiami, Hanmaeum, Deuraechan, and Hanareum were higher than those of Goami and Seolgaeng. The specific volume of rice cupcakes was lower with Goami and Haiami than with the others. Seolgaeng cupcake had a dented surface and irregular air pockets, while the Hanareum cupcake was well shaped and had uniform air pockets. The hardness, springiness, and chewiness of Goami and Haiami cupcakes were higher than those of the others, while adhesiveness was observed only in Seolgaeng cupcake. The overall preferences scores of rice cupcakes prepared from Hanareum, Hanmaeum and Deuraechan were higher than for the other cupcakes (p<0.05). These results suggested that amylose content, and final and setback viscosities of rice flour are very important factors in rice cupcakes.

• Journal of the Korean Society for Marine Environment & Energy
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• v.17 no.1
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• pp.13-19
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• 2014

The feed temperature has an effect on the performance during desalination of seawater by membrane separation. When the permeate flux intends to increase using the waste heat, it is necessary to analyze the effect of feed temperature precisely on the membrane performance. The experiments were carried out to investigate the performance of membranes by varying the seawater temperature from $10^{\circ}C$ to $60^{\circ}C$. The increase of permeate flux with increase of feed temperature was interpreted as the change of water viscosity and the membrane itself. While the increase of permeate flux could be predicted by the viscosity change in case of nanoflitration membrane, there exists 30% difference between the experiment data and the prediction by the viscosity change in case of reverse osmosis (RO) membrane, which seems to be due to 8% decrease of the pore size in 60caused by the contraction of membrane with the increase of temperature. Therefore, the desalination of seawater should be carried out within the range that the elevation of temperature does not cause the alteration of membrane itself even for the purpose of increasing the permeate flux.

• Applied Biological Chemistry
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• v.38 no.3
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• pp.191-195
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• 1995

Production of a high viscosity exoploysaccharide, methylan, by Methylobacterium organophilum from methanol was carried out in fed-batch cultures and the rheological properties of methylan fermentation broth were studied. Bacterial biomass showed little influence on viscosity, but the accumulation of methylan caused the increase of viscosity. With proceeding fermention, the viscosity at the same concentration of methylan was significantly increased and methylan solution showed slightly higher pseudoplasticity. The composition changes of methylan were investigated at various fermentation times. Contents of total sugar, reducing sugar and methylan were decreased but contents of acids(pyruvic acid, uronic acid and acetic acid) were increased with the culture time. It was considered that the increased content of acids resulted in the increase of the hyrodynamic domain in the solution due to charge repulsion. Consequently, the solution viscosity increased in propotion to the acids contents of methylan. Cell growth and methylan production were severely decreased by the limitation of dissolved oxygen. However, the cellular activity for methylan production was almost constant regardless of the level of dissolved oxygen. As a result, the high speed of agitation increased the methylan production, the specific production rate of methylan, and the methylan yield of the cell.

• Journal of the Mineralogical Society of Korea
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• v.16 no.1
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• pp.33-47
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• 2003

Various applied-mineralogical characterization including measurements of surface area, size distribution, swelling index, and viscosity were done for some domestic bentonites in order to decipher the rheological properties and their controlling factors. The bentonites, which are Ca-type and relatively low-grade (rnontmorillonite contents: 30 ∼ 75 wt%), occur mostly as subhedral lamellas with the size range of 2 ∼ 4 $\mu\textrm{m}$. The size distribution of mineral fractions in bentonite suspension is dominant in the range of 10 ∼ 100 $\mu\textrm{m}$, and though rather complicated, exhibits roughly bimodal patterns. The feature is more conspicuous in the case of zeolitic bentonite. The bentonites have surface areas ranging 269 ∼ 735 $\m^2$/g, which are measured by EGME adsorption method. The EGME surface areas are nearly proportional to the rnontmorillonite contents, moisture contents, or total CEC. In the surface area measurements, zeolitic bentonites have slightly higher values than those zeolite- free types. The measured swelling index and viscosity of domestic bentonites are comparatively low in values. The swelling values of bentonites were measured to be 250∼500% at maximum by progressively mixing amounts of 2 ∼ 5 wt% Na$_2$CO$_3$, which varies depending on the contents of rnontmorillonite and other impurities, especially zeolite. Much amount of sodium carbonate is required for optimum swelling property of zeolitic bentonited which has usually strong Na- exchanged capacity. The bentonites, which are comparatively feldspar-rich and low in size and crystallinity, tend to be higher in viscosity values. Tn addition, the viscosity is largely higher in case of the bentonites with higher pH in suspension. However, the rheological properties of bentonites such as swelling index and viscosity do not show any obvious relationships with rnontmorillonite contents and mean particle size in suspension. In contrast, roughly speaking, the swelling index of bentonites is reversely proportional to the values of surface area which can be regarded as a collective physico-chemical parameter encompassing all the effects caused by mineral composition, surface charge, particle size, morphological farm, and etc. in bentonites. Thus, the rheological properties in bentonite suspension appear to be rather complicated characteristics which mainly depend on the flocculation of clay particles and the mode of particle association, i.e. quasicrystals, controlled by surface charge, morphology, size, and texture of rnon-tmorillonite, and which partly affected by the finer impurities such as zeolite.

• Journal of the Korea Organic Resources Recycling Association
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• v.20 no.4
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• pp.106-117
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• 2012

Indirected heating dryer is used as one of the food waste treatment technologies for the production of the drier material supplied to the recycling facilities or end user. This study investigated the effect on drying efficiency for the operation of rotating screw with the circulating and falling movements on indirected drying process of food waste. The screw operating condition showed higher drying efficiency despite of the shorter drying time compared to the screw non-operating condition. The moisture content decreased to 14.4% from the initial moisture content of 77.1% after drying 5 hours in the screw operating condition. On the other hand, in the screw non-operating condition, the moisture content decreased slightly to 35.6% after drying 16 hours. During the drying process, variations of the water evaporation rate and particle size showed different tendencies depending on the moisture content regions. In the higher moisture content region above the glue zone(moisture content of about 50%-60%), the particle size increased and the water evaporation rate reached the highest peak. In the range of glue zone, the particle size maximized while the water evaporation rate decreased sharply. In the lower moisture content region below the glue zone, the water evaporation rate and particle size both decreased at the same time. The particle size distribution was widely ranged from 25.0mm to 0.25mm in the screw operating condition while it was narrowly distributed in the screw non-operating condition from 25.0mm to 3.56mm, especially highly concentrated to 25.0mm. It was regarded that the hygroscopic, capillary and gravitational water evaporated more easily from the intra-particle during the circulating and falling movement caused by the rotating of the screw and the difference of the cohesional force of water within intra-particle depending on the moisture content regions. Comparing the effect of the circulating and falling movement on drying efficiency, the water evaporation rates per time and per weight of dry solid in the screw operating condition were higher about 364% and 356%, respectively, than those of the screw non-operating condition.

• Korean journal of food and cookery science
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• v.15 no.6
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• pp.591-594
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• 1999

An instrumental analysis of Sanyakbyung was carried out along with sensory evaluation to find out how its quality characteristics changed by the addition of glutinous rice flour(0%, 10%, 20%, 30%, 40% and 50%). The moisture content of Sanyakbyung decreased in proportion to the increment of glutinous rice flour. In terms of color, L-value increased depending on the increment of glutinous rice whereas a-value and b-value showed a decrease. This could be accounted for by two factors: one is that the protein contained in yam flour contributed to black coloring and the other is that the color of yam flour itself contributed ostensively to the tint of blackish coloring, and also to the tint of yellow and red coloring. ln the two bite compression test, the hardness, gumminess, chewiness, and cohesiveness of Sanyakbyung decreased depending on the increment of glutinous rice flour. The springiness did not show any significant variation among the samples. That is, the more yam flour was added, the more cohesive and gummy Sanyakbyung was produced. There were significant differences(p<0.05) in the sensory characteristics of the samples in which Sanyakbyung with 10% glutinous rice flour was most preferred in color, those with 20% in flavor, and those with 40% in taste. Adhesiveness and consistency in the palate responses also showed significant differences among samples in which the sample with 40% glutinous rice flour was most favored in consistency. When the content of yam increased, the gumminess also increased. Generally, Sanyakbyung with soft but less gummy texture was preferred to strong gummy one which was easily stuck to teeth. In the overall acceptance, Sanyakbyung with 40% glutinous rice four was most preferred.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.7
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• pp.908-914
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• 2007

Sasa borealis (bamboo) is a perennial medicinal plant and its leaves are utilized widely in Korea. In this study, effects of bamboo leaves (Sasa borealis) extract on the physical, textural, and sensory characteristics of cooked rice were examined. Four kinds of cooked rice were prepared with 0.0% (control), 0.2%, 0.3% or 0.4% of the extract (w/w). Moisture content of the cooked rice decreased with increasing amounts of extract. Color of the cooked rice was darkened gradually with increasing amounts of extract and appeared yellowish-brown. Among the four textural properties, only hardness increased significantly by the addition of the extract. Sensory evaluation was significantly different in terms of unique rice flavor, bamboo flavor, color, unique rice taste, bamboo taste, viscosity, hardness, adhesiveness, and coarseness among the control group and the group with 0.2%, 0.3%, and 0.4% of the extract; however, overall acceptancy was not significantly different among the four groups. In conclusion, concerning overall sensory evaluation, cooked rice with 0.2% bamboo leaves (Sasa borealis) extract showed the best result.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.4C
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• pp.137-144
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• 2009

In this research, the ground with smeared zone was reconstructed using the large consolidation test apparatus. And the reconstituted kaolinite samples at different locations were retrieved for the oedometer test. From the oedometer test results the permeability- void ratio-effective stress behavior was investigated. Based on the experimental analysis, spatial differences of permeability according to the drainage distance by both smear and radial drainage consolidation reduced as the consolidation proceeds and eventually disappeared in normally consolidated region. And the spatial variation of permeability by radial drainage consolidation showed larger differences in smaller extent than the spatial variation of permeability by smear.