• Title/Summary/Keyword: sedimentation volume

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Seasonal Changes in Structure and Landscape of Urban Stream Corridor - In the Case of Gongji Stream in Chuncheon- (도시하천 하도구조와 경관의 계절변화 - 춘천시 공지천을 중심으로 -)

  • Jo Hyun-Kil;Han Gab-Soo
    • Journal of Environmental Science International
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    • v.14 no.8
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    • pp.739-748
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    • 2005
  • The purpose of this study is to analyze seasonal changes in structure and landscape of Gongji stream corridor in Chuncheon, and to suggest some guidelines to contribute to creating a desirable close-to- nature stream. The study seasonally surveyed floodplain and revetment conditions, channel micro-topography, streamflow level and velocity, and vegetational cover. Flooding, water level, and vegetation were major factors of affecting seasonal changes in streambed structure and stream landscape. Small sand bars and islands were considerably disturbed by flooding and water level change. However, large islands and sand bars in the upper and middle section of the study stream remained or reappeared even after flooding. Flooding also tended to repeat channel sedimentation at the same spot. Controlling water volume of the Euiam Lake, which is adjacent to the study stream, caused higher water level downstream in the dry seasons. The majority of vegetation in sand bars and islands was washed away by the floods. Vehicle passing, crop cultivation, and ball game were other elements which disturbed vegetation in the floodplain. Creating a close-to-nature stream should reflect micro-topographical changes of channel by flooding, prevent improper vehicle entry and human use, and remove concrete material in the revetment and floodplain.

Bulk-Type Cloud Microphysics Parameterization in Atmospheric Models (대기 모형에서의 벌크형 미세구름물리 모수화 방안)

  • Lim, Kyo-Sun Sunny
    • Atmosphere
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    • v.29 no.2
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    • pp.227-239
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    • 2019
  • This paper reviews various bulk-type cloud microphysics parameterizations (BCMPs). BCMP, predicting the moments of size distribution of hydrometeors, parameterizes the grid-resolved cloud and precipitation processes in atmospheric models. The generalized gamma distribution is mainly applied to represent the hydrometeors size distribution in BCMPs. BCMP can be divided in three different methods such as single-moment, double-moment, and triple-moment approaches depending on the number of prognostic variables. Single-moment approach only predicts the hydrometeors mixing ratio. Double-moment approach predicts not only the hydrometeors mixing ratio but also the hydrometeors number concentration. Triple-moment approach predicts the dispersion parameter of hydrometeors size distribution through the prognostic reflectivity, together with the number concentrations and mixing ratios of hydrometeors. Triple-moment approach is the most time expensive method because it has the most number of prognostic variables. However, this approach can allow more flexibility in representing hydrometeors size distribution relative to single-moment and double-moment approaches. At the early stage of the development of BMCPs, warm rain processes were only included. Ice-phase categories such as cloud ice, snow, graupel, and hail were included in BCMPs with prescribed properties for densities and sedimentation velocities of ice-phase hydrometeors since 1980s. Recently, to avoid fixed properties for ice-phase hydrometeors and ad-hoc category conversion, the new approach was proposed in which rimed ice and deposition ice mixing ratios are predicted with total ice number concentration and volume.

Quality Characteristics of Sponge Cake Supplemented with Soy Fiber Flour (콩섬유 복합분을 첨가한 스펀지 케이크의 품질 특성)

  • Park, Ji-Young;Park, Young-Seo;Chang, Hak-Gil
    • Korean Journal of Food Science and Technology
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    • v.40 no.4
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    • pp.412-418
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    • 2008
  • The replacement of wheat flour with 4 to 24% soy fiber FIBRIM(R)1450 was evaluated to determine its effect on the properties of sponge cake. The volume and specific loaf volume decreased as the amount of soy fiber increased. In addition, the protein content and water holding capacity (WHC) were negatively correlated with the specific gravity of batter and the specific loaf volume of sponge cake, whereas there was no correlation between the mixograph characteristics and specific loaf volume of sponge cake in response to the addition of soy fiber. Furthermore, the symmetry and uniformity indices were not influenced by the addition of soy fiber. However, the L values of sponge cake crust and crumb decreased with increasing amounts of soy fiber, whereas a and b values were not affected. Additionally, the hardness, gumminess, and chewiness of the sponge cake all showed positive correlations with the protein content, sedimentation value, WHC and alkaline water retention capacity. Finally, the results of sensory evaluation indicated that external and internal colors, grain, texture, and flavor were not influenced by the addition of soy fiber, but that supplementation with over 20% soy fiber resulted in a slight decrease in taste and overall acceptability.

A Study on The Coagulation Characteristics of The Aluminium Etching Waste (알루미늄 식각폐액의 응집 특성에 관한 연구)

  • Kim, Jun-Ho;Lee, Chang-Hwan;Lee, Cheol-Ho
    • Clean Technology
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    • v.10 no.1
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    • pp.1-7
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    • 2004
  • In this study, the performance of Aluminium foil etching waste(PWF100) as a cohesive agent was estimated and the methods to commercialize it were investigated through comparison of physical properties between Aluminium foil etching waste(PWF100) and commercial cohesive agent(PAC17). The height of sediment bed was measured according ot the change of the concentration of BKN-100, BKR-110, and BKR-120 prepared by using PWF100. When the concentrations of BKN-100, BKR-110, and BKR-120 were increased, the heights of sediment bed were constant after decreased. Also, the density of sediment bed was investigated according to the change of the concentration of BKN-100. When the concentrations of BKN-100 were increased, the densities of sediment bed were decreased. In addition, based on the concentration of BKN-100, BKR-110, and BKR-120, the sediment rate was experimented. When the concentrations of BKN-100, BKR-110, and BKR-120 were increased, sediment rates were rapid and then slow. Moreover, the volumes of sediment bed were measured according to the change of the concentration of BKN-100. According to increasing the concentrations of BKN-100, the required time for getting to the minimum volume of sedment bed were reduced and then increased. Lastly, the required time for sedimentation based on the concentration of BKN-100, BKR-110, and BKR-120 was investigated. When the concentrations of BKN-100, BKR-110, and BKR-120 were increased, the required times for sedimentation were increased after decreased. From these results, it can be concluded that the PWF100 acts as a cohesive agent.

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Experimental analysis of the sedimentation processes in the movable weir by changing the channel slope considering weir operation (가동보 운영 및 하상경사 변화에 의한 보 상류 퇴사과정의 실험적 분석)

  • Lee, Kyung Su;Jang, Chang-Lae
    • Journal of Korea Water Resources Association
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    • v.51 no.8
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    • pp.729-737
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    • 2018
  • This study investigates the sediment processes the Improved-pneumatic-movable weir through laboratory experiments considering changing channel slopes. Experimental results show that the delta migrates towards the weir and the delta height increases as time passes. Moreover, as the delta approaches the weir, the delta migration speed decreases. As the dimensionless delta location increases, the effective height of dimensionless delta and the dimensionless reservoir capacity increases. Therefore, under the same slope conditions, the sediment deposition volume of the delta is small as the channel slope is mild. This means that the channel slope affects the development of the delta in the upstream of the Improved-pneumatic-movable weir. At the beginning of the experiment, the foreset slope is mild. However, the foreset slope of the delta increases with water depth as the delta migrates downstream. Moreover, as the slope is mild, the ratio of delta front length to delta height is close to 1, and the dimensionless delta height and the dimensionless delta migration speed decrease. As the delta height increases, the water depth, the velocity approaching to the weir and the delta migration speed decrease.

Quality Characteristics and Dough Rheological Properties of Pan Bread with Waxy Barley Powder (찰보리 분말을 첨가한 식빵의 레올로지 및 품질특성)

  • Jeong, Hyun-Chul;Ji, Joung-Lan
    • Culinary science and hospitality research
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    • v.19 no.4
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    • pp.119-135
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    • 2013
  • This study investigates waxy barley powder substituted for wheat flour in bread recipes with the amounts of 0%(control), 5%, 10%, 15% and 20%. Waxy barley powder consisted of 8.33% of moisture content, 10.47% of crude protein, 1.63% of crude fat, and 2.97% of crude ash. Sedimentation value and pelshenke value have decreased as the waxy barley powder content increased. The farinograph measurement result of the bread made with waxy barley powder showed that consistency, water absorption, development time, stability and time breakdown have increased as the waxy barley powder content increased. The amylograph measurement result of the bread made with waxy barley powder showed that T have increased as the waxy barley powder content increased. Their P, H and P-H have decreased as the ingredient contents increased. Baking loss and specific loaf volume have decreased as the waxy barley powder content increased. The chromaticity measurement result of the bread made with waxy barley powder showed no significant difference as the waxy barley powder content increased. The texture measurement result showed that the hardness and gumminess of bread have increased as the waxy barley powder content increased. Their cohesiveness, springiness and chewiness have decreased as the ingredient contents increased. Overall preference scores showed a high acceptability for the bread made with 10% waxy barley powder.

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Quality Characteristics and Dough Rheological Properties of Pan Bread with Perilla Seed Powder (들깨분말을 첨가한 식빵의 레올로지 및 품질특성)

  • Ji, Joung-Lan;Jeong, Hyun-Chul
    • Culinary science and hospitality research
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    • v.19 no.3
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    • pp.142-155
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    • 2013
  • This study investigates perilla seed powder substituted for wheat flour in bread recipes with the amounts of 0%(control), 5%, 10%, 15%, and 20%. Perilla seed powder consists of 9.41% of moisture content, 9.14% of crude protein, 1.12% of crude fat, and 2.97% of crude ash. Sedimentation value and pelshenke value have decreased as the perilla content increased. The farinograph measurement result of the bread made with perilla seed powder showed that consistency, water absorption and tolerance index have increased as the perilla content increased. The amylograph measurement result of the bread made with perilla seed powder showed that T, P, H, F, P-H and F-H have decreased as the perilla content increased. Baking loss and specific loaf volume have decreased as the perilla content increased. The chromatic 'L' and 'b' values were reduced as more perilla was added to more pan bread, while the chromatic 'a' value increased. The texture measurement result showed that the hardness of bread have increased as the ingredient contents increased. Their cohesiveness, spinginess, and chewiness have decreased as the ingredient contents increased. Overall preference scores showed a high preference for the bread made with 15% perilla seed powder.

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Effect of Defatted Soy flour on the Bread Making Properties of Wheat flour (탈지 대두분 첨가가 제빵 특성에 미치는 영향)

  • Yoo Yang-Ja;Chang Hak-Gil;Choi Young-Sim
    • Korean journal of food and cookery science
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    • v.21 no.3 s.87
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    • pp.301-310
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    • 2005
  • The effects of defatted soy flour on the physicochemical characteristics of dough and bread making properties were studied. Defatted soy flour is added to wheat flour for bread-making in order to maximize the use of isoflavones in the soybean. Different particle sizes of both defatted soy flour and wheat flour were prepared by grinding and sievingwith meshes. In the mixograph test, the addition of defatted soy flour to wheat flour increased the requirement for water and decreased the dough development time. Water absorption rates were also investigated to determine the optimum quantity of water for good dough. As the level of defatted soy flour mixed with wheat flour increased, the sedimentation and P.K. values decreased. In comparison with control, the bread made with defatted soy flour especially had a lower specific loaf volume. Specific loaf volume of wheat flour-defatted soy flour bread prepared (Ed- this is an incomplete sentence, it's only a subject clause, and I don't how what you intend to state). In terms of the staling rate and hardness of the wheat flour-defatted soy flour bread, the increased defatted soy flour had a faster staling rate during storage at 5? than at 25? for 5days. From the result of sensory evaluation, wheat flour-defatted soy flour breads containing up to $4\%$ defatted soy flour were rated as being of high quality.

Determination on the component arrangement of a hybrid rain garden system for effective stormwater runoff treatment (강우유출수 처리를 위한 하이브리드 빗물정원 시스템의 구성요소 배열 연구)

  • Flores, Precious Eureka D.;Geronimo, Franz Kevin F.;Alihan, Jawara Christian P.;Kim, Lee-Hyung
    • Journal of Wetlands Research
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    • v.19 no.3
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    • pp.271-278
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    • 2017
  • Low impact development (LID) technology has been recently applied for the treatment of nonpoint source pollutants. Rain garden is one of the widely used LIDs since it utilizes various mechanisms such as biological and physico-chemical treatment to reduce pollutants. However, problem such as clogging has been one of the issues encountered by the rain garden that do not undergo constant maintenance. Therefore, this research was conducted to develop and determine the component arrangement of a rain garden system for a more efficient volume and pollutant reduction. Two hybrid rain garden systems having different characteristics were developed and evaluated to determine the optimum design and arrangement of the system. The results showed that the components arranged in a series manner showed a volume reduction of 93% and a pollutant reduction efficiency of approximately 99%, 93% and 95% was observed for particulates, nutrients and heavy metals, respectively. While when the system is connected in a combined series-parallel, the volume and average pollutant reduction efficiency for the TSS, nutrients and heavy metals are 65%, 94%, 80% and 85%, respectively. Moreover, the component arrangement in the order of sedimentation tank, infiltration tank and plant bed exhibited a high pollutant reduction efficiency compared when the infiltration tank and plant bed were interchanged. The findings of this research will help in the further development and optimization of rain garden systems.

Evaluation on Flotation Efficiency of Bubble-floc Agglomerates and Operation Characteristics of Hydraulic Loading Rate Using Population Balance in DAF Process (DAF공정에서 개체군 수지를 이용한 기포-플록 응집체의 부상효율과 수리학적 부하율의 운전특성 평가)

  • Kwak, Dong-Heui
    • Journal of Korean Society of Water and Wastewater
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    • v.22 no.5
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    • pp.531-540
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    • 2008
  • The main advantage of dissolved air flotation (DAF) in water treatment process is the small dimension compared with conventional gravity sedimentation and it can be basically reduced by the separation zone performed with the short solid-liquid separation time. Fine bubbles make such a short time possible to carry out solid from liquid separation as a collector on the course of water treatment. Therefore, the dimension of separation zone in DAF process is practically determined by the rise velocity of the bubble-floc agglomerates, which is a floc attached with several bubbles. To improve flotation velocity and particle removal efficiency in DAF process, many researchers have tried to attach bubbles as much as possible to flocs. Therefore, the maximum number of attached bubble on a floc and the rise velocity of bubble-floc agglomerates considered as the most important factor to design the separation zone of flotation tank in DAF process was simulated based on the population balance theory. According to the simulation results of this study, the size and volume concentration of bubble influenced on the possible number of attached bubble on a floc. The agglomerates attached with smaller bubble was more sensitive to hydraulic loading rate in the separation zone of DAF process. For the design of a high rate DAF process applied over surface loading 40 m/hr. it is required a precise further study on the variation of bubble property and behavior including in terms of bubble size distribution.