• Title/Summary/Keyword: L/W ratio

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A Study on Development of the Secondary Reverse Vortex in Building Canyon (건물협곡에서의 2차 역회전 소용돌이 형성에 관한 연구)

  • Son, Minu;Kim, Do-Yong
    • Journal of the Korean Society for Environmental Technology
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    • v.19 no.6
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    • pp.528-535
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    • 2018
  • In this study, the effect of obstacle aspect ratio on vortex in building canyon was numerically investigated using a computational fluid dynamics(CFD) model. The sensitivity experiments were performed in the cases of increasing building length(L) and height(H) by the width(W) of building canyon. The wind vector fields and secondary reverse vortex in building canyon were discussed in this study. For the horizontal vortex, the vortex zone increased as the building length increases, but the vectors at the middle of building canyon began to change in the case of L/W=2.5. In the case of L/W=3.0, the smaller primary vortex was presented with the secondary reverse vortex. For the vertical vortex, the vortex zone increased as the building height increases, but the direction of vectors at the bottom of building canyon began to change in the case of H/W=2.5. In the case of H/W=3.5, the smaller primary vortex was presented with the secondary reverse vortex.

Comparison of Dissolved Air and Micro-Bubble Concentration by a Micro-Bubble Generating Pump (미세기포 발생 펌프에서 생성되는 기포농도와 용존공기농도의 비교)

  • Lee, Chang-Han;Ahn, Kab-Hwan
    • Journal of Environmental Science International
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    • v.23 no.11
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    • pp.1835-1842
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    • 2014
  • The goal of this study was to evaluate micro-bubble concentration ($C_{air}$) in water by air/water ratio (A/W ratio) with a micro-bubble generating pump. The estimation of micro-bubble concentration is based on the balance of inlet/outlet air and water flow rate. On net A/W ratio to be generated micro-bubble, we found that the obtained the $C_{air}$ are shown as a function of discharge pressure ($P_g$) of the micro-bubble generating pump. The correlation of the $C_{air}$ and the $P_g$ ($C_{air}=3.261P_g-1.754$) was adequately described by the least square methods with a high correlation coefficient (r = 0.9459) and calculated values fit the experimental data quite well. The $C_{air}$ was lower than theoretical dissolved air concentration ($C_{aq}$) calculated by Henry's law. The $C_{air}$ for being operated the micro-bubble generating pump was 6.75 - 39.53 mL/L, however, we found that the optimum of the $C_{air}$ to generate micro-bubble was the range from 10 to 12 mL/L.

Mung Bean (Phaseolus aureus L.) Improves Lipid Composition Protein Concentration in Hyperlipidemic Rats (녹두(Phaseolus aureus L.) 첨가 식이가 고지혈증 흰쥐의 지질성분 개선 및 단백질 농도에 미치는 영향)

  • Kim, Han-Soo;Kang, Dong-Soo
    • Journal of Environmental Science International
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    • v.30 no.7
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    • pp.537-545
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    • 2021
  • This study aimed to investigate the improvement effect of 5% (w/w) mung bean (Phaseolus aureus L.) on lipid composition and protein concentration in hyperlipidemic rats. Seven-week-old male (Sprague-Dawley) rats were divided into four groups (n=6, each), and fed experimental diets containing mung bean meal [basal diet+5% (w/w) mung bean (BM), basal-hyperlipidemic diet+5% (w/w) mung bean (BHM)], basal-hyperlipidemic diet (BH), and control (basal diet, BD). Lipid composition in the mung bean diet groups (BM and BHM) evidenced significant reductions in serum total cholesterol, low-density lipoprotein cholesterol, atherosclerotic index, cardiac risk factor, triglyceride, phospholipid, free cholesterol, cholesteryl ester, blood glucose, nonesterified fatty acid, and an elevation in high-density lipoprotein cholesterol. The serum albumin/globulin ratio was increased in mung bean diet-supplemented rats compared to that in hyperlipidemic rats (p < 0.05). Total calcium, phosphorus and potassium concentrations in sera were higher in the BM, BHM and BD groups than in the BH group. Concentrations of sodium and chlorine in sera were lower in the mung bean diet-supplemented groups than in the hyperlipidemic group. The in vivo experiments showed that ingestion of mung bean was effective in improving lipid composition, protein concentration, and blood glucose.

Effect of Oligosaccharides on Quality Characteristics and Antioxidant Activities of Prunus persica Batsch var. davidiana Max. preserved in Sugar (올리고당을 활용한 당절임 야생 복숭아의 품질특성과 항산화 효과에 미치는 영향)

  • Jung, Kyung-Mi;Choi, Mi-Ae;Park, Sun-Ill
    • Culinary science and hospitality research
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    • v.23 no.8
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    • pp.163-172
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    • 2017
  • In order to investigate the quality characteristics of Prunus persica Batsch var. davidiana Max. preserved in sugar, the quality characteristics were examined by dividing them into four groups: PS-A (P. persica preserved in sugar mixed with sucrose and oligosaccharides at a ratio of 100:0, w/w), PS-B (P. persica preserved in sugar mixed with sucrose and oligosaccharides at a ratio of 60:40, w/w), PS-C (P. persica preserved in sugar mixed with sucrose and oligosaccharides at a ratio of 40:60, w/w) and PS-D (P. persica preserved in sugar mixed with sucrose and oligosaccharides at a ratio of 0:100, w/w). The results were as follows: pH levels and soluble solid contents of PS-D sample were lower than those of the others, however total acidity value were higher. In case of Hunter's value, the 'L', 'a' and 'b' values of all samples were affected by addition of oligosaccharides. No great difference occurred among samples in reducing sugar contents. Organic acid content was significantly decreased with the lower addition of sucrose. The predominating organic acid components analyzed in all samples were lactic acid 156.15 g/100 g, tartaric acid 72.75 g/100 g and citric acid 32.90 g/100 g. The highest contents of total phenol and flavonoid, and DPPH and ABTS radical scavenging activity were $10.79{\pm}0.55mg\;GAE/mL$, $8.71{\pm}0.06mg\;CE/mL$ and 71.8%, 71.0% for PS-D, respectively. The results of this study indicated the use of oligosaccharides could increase the quality and antioxidant potentials of P. persica preserved in sugar.

Effects of Food Deprivation and Feeding Ratio on the Growth, Feed Utilization and Body Composition of Juvenile Olive Flounder Paralichthys olivaceus

  • Cho, Sung Hwoan
    • Fisheries and Aquatic Sciences
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    • v.17 no.4
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    • pp.449-454
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    • 2014
  • The effects of food deprivation and feeding ratio on the growth, feed utilization and body composition of juvenile olive flounder Paralichthys olivaceus were investigated in 810 juvenile fish averaging 6.4 g in weight randomly distributed in 27 400-L flow-through tanks. A 3 [food deprivation: 8-week feeding without food deprivation (8W), 7-week feeding after 1-week food deprivation (7W) and 6-week feeding after 2-week food deprivation (6W)]${\time}3$ (feeding ratio: 100%, 95% and 90% of satiation, hereafter denoted by 100, 95 and 90, respectively) factorial design was applied. The weight gain of the fish was significantly affected by both food deprivation and feeding ratio. The weight gain of the fish under the 8W-100 treatment was higher than that of those under the 7W-95, 7W-90, 6W-100, 6W-95 and 6W-90 treatments, but did not differ from those of fish under the 8W-95, 8W-90 and 7W-100 treatments. The specific growth rate (SGR) and the feed intake of the fish were affected by both food deprivation and feeding ratio. However, the feed conversion ratio (FCR) was unaffected by both food deprivation and feeding ratio. The protein efficiency ratio (PER) was affected by the feeding ratio, but not by food deprivation. The protein retention (PR) was affected by food deprivation, but not by feeding ratio. Juvenile olive flounder subjected to 1-week food deprivation at 100% satiation (7W-100 treatment) achieved full compensatory growth.

Optimization of Betacyanin Production by Red Beet (Beta vulgaris L.) Hairy Root Cultures. (Red Beet의 모상근 배양을 이용한 천연색소인 Betacyanin 생산의 최적화)

  • Kim, Sun-Hee;Kim, Sung-Hoon;Lee, Jo-No;An, Sang-Wook;Kim, Kwang-Soo;Hwnag, Baik;Lee, Hyeong-Yong
    • Microbiology and Biotechnology Letters
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    • v.26 no.5
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    • pp.435-441
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    • 1998
  • Optimal conditions for the production of natural color, betacyanin were investigated by varying light intensity, C/N ratio, concentrations of phosphate and kinds of elicitors. Batch cultivation was employed to characterize cell growth and betacyanin production of 32 days. The maximum specific growth rate, ${\mu}$$\sub$max/, was 0.3 (1/day) for batch cultivation. The maximum specific production rate, q$\^$max/$\sub$p/, was enhanced 0.11 (mg/g-cell/day) at 3 klux. A light intensity of 3 klux was shown to the best for both cell growth and betacyanin production. The maximum specific production rate was 0.125 (mg/g-cell/day) at 0.242 (1/day), the maximum specific growth rate. The dependence of specific growth rate on the light lintensity is fit to the photoinhibition model. The correlation between ${\mu}$ and q$\sub$p/ showed that the product formation parameters, ${\alpha}$ and ${\beta}$$\sub$p/ were 0.3756 (mg/cell) and 0.001 (mg/g-cell/day), respectively. The betacyanin production was partially cell growth related process, which is different from the production of a typical product in plant cell cultures. In C/N ratio experiment, high carbon concentration, 42.1 (w/w) improved cell growth rate while lower concentration, 31.6 (w/w) increased the betacyanin production rate. The ${\mu}$$\sub$max/ and q$\^$max/$\sub$p/ were 0.26 (1/day) and 0.075 (mg/g-cell/day), respectively. Beta vulgaris L. cells under 1.25 mM phosphate concentration produced 10.15 mg/L betacyanin with 13.46 (g-dry wt./L) of maximum cell density. The production of betacyanin was elongated by adding 0.1 ${\mu}$M of kinetin. This also increased the cell growth. Optimum culture conditions of light intensity, C/N, phosphate concentration were obtained as 5.5 klux, 27 (w/w), 1.25 mM, respectively by the response surface methodology. The maximum cell density, X$\sub$max/, and maximum production, P$\sub$max/, in optimized conditions were 16 (g-dry wt./L), 12.5 (mg/L) which were higher than 8 (g-dry wt./L), 4.48 (mg/L) in normal conditions. The ${\mu}$$\sub$max/ and q$\^$max/$\sub$p/ were 0.376 (1/day) and 0.134 (mg/g-cell/day) at the optimal condition. The overall results may be useful in scaling up hairy root cell culture system for commercial production of betacyanin.

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Forces and flow around three side-by-side square cylinders

  • Zheng, Qinmin;Alam, Md. Mahbub;Rehman, S.;Maiti, D.K.
    • Wind and Structures
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    • v.29 no.1
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    • pp.1-13
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    • 2019
  • A numerical investigation on forces and flow around three square cylinders in side-by-side arrangement is conducted at a Reynolds number Re = 150 with the cylinder center-to-center spacing ratio L/W = 1.1 ~ 9.0, where W is the cylinder side width. The flowat this Re is assumed to be two-dimensional, incompressible, and Newtonian. The flow simulation is conducted by using ANSYS-Fluent. The flow around the three side-by-side cylinders entails some novel flow physics, involving the interaction between the gap and free-stream side flows as well as that between the two gap flows. An increase in L/W from 1.1 to 9.0 leads to five distinct flow regimes, viz., base-bleed flow (L/W < 1.4), flip-flopping flow (1.4 < L/W < 2.1), symmetrically biased beat flow (2.1 < L/W < 2.6), non-biased beat flow (2.6 < L/W < 7.25) and weak interaction flow (7.25 < L/W < 9.0). The gap flow behaviors, time-averaged and fluctuating fluid forces, time-averaged pressure, recirculation bubble, formation length, and wake width in each flow regime are discussed in detail.

Improvement of Sedimentation Rate in the Settling Basin by Labyrinth Weir (래버린스 위어를 이용한 침사지 내 침전효율 개선)

  • Cho, Hun Sik;Yeo, Chang Geon;Im, Janghyuk;Lee, Seung Oh
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.32 no.3B
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    • pp.153-159
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    • 2012
  • In this study, we proposed modified settling basins transformed by substituting the downstream sill for low head weirs such as generic labyrinth weir and inclined crest labyrinth weir worked as internal baffles. Laboratory experiments were carried out to understand hydraulic characteristics inside of the settling basin to improve the efficiency of sedimentation rate. For a quantitative analysis, we suggested the headwater ratio($H_t/P$), the magnification ratio(L/W) and the inflow rate per total crest length($q_L$) as primary analysis indexes for sedimentation efficiency. Six different types of settling basin were used for labscaled pilot tests by distinguishing with internal structures. Based on results, the variation of headwater ratio with the change of magnification ratio would highly affect the deposition efficiency(%) and it was improved under specific condition that repeating arrange number(N) of labyrinth weir was between 2 and 4. Also, the regression analysis showed that initial condition and shape for improving sedimentation efficiency were plotted on the graph for both $q_L{\geq}3.5cm^2/s$ and $L/W{\leq}3.5$. It would be expected that the geometrically optimized labyrinth settling basin could be designed with proper deposition efficiency for inflow rates of influent and required area of settling basin utilizing the proposed analysis index in this study.

BIOLOGICAL STUDIES ON THE SAND-EEL, AMMODYTES PERSONATUS GIRARD (까나리, Ammedytes Personatus GIRARD의 생물학적 연구)

  • CHUN Chan-Il
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.7 no.4
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    • pp.215-220
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    • 1974
  • The sand-eel, Ammedytes Personatus is a commercially important fish abounantly found in west and east coast of Korea. Samples were collected from the Baegryeong Island (Yellow Sea), Geoje Island(southern coast) and Jumunjin (East Sea) from May 1973 to December 1974. In this paper the author dealt with some biological point of the fish, especially the relationship between total length ang body weight, and the major spawning season and sex ratio. 1. The major spawning season was confined to the end of November and the end of December at Jumunjin. 2. The sex ratio (male/female) is 0.75 before the main spawning season and increases up to 1.36 after spawning at Jumunjin in 1974. 3. The relationship between the total length (L) and body weight (In were represented as follows: $W=0.0001906L^{3.1998319}$ for the sample from Baegryeong Is. $W=0.0003419L^{3.0213438}$ for the sample from Geoje Is. $W=0.0002655L^{3.1408629}$ for the sample from Jumunjin.

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Light-susceptibility of Camptothecin Production from in Vitro Cultures of Camptotheca acuminata Decne

  • Park, Young-Goo;Park, Mee-Hee;Yang, Jae-Kyung;Chung, Young-Gwan;Park, Myung-Suk
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.8 no.1
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    • pp.32-36
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    • 2003
  • Production of camptothecin ((PT) from callus cultures of Camptotheca acuminata Decne was affected by light and culture conditions. Among the culture media tested, modified B5 medium containing 3% (w/v) sucrose, 2 mg/L B,4-D, 2 times of MS medium vitamins, 500 mg/L casein hydrolysate, 250 mg/L myo-inositol, 0.05% (w/v) activated charcoal, and 0.15% (w/v) gelite was used for callus induction . The highest cell growth and CPT production were obtained in dark and green light condition, respectively. Photoperiod has no effect on cell growth and CPT production. Both cell growth and CPT production were also influenced by combination ratio of red and blue light .Cell growth and CPT production were the highest in the ratio of red and blue light,90:10.