• Title/Summary/Keyword: low density

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Rearing Temperature and Density Effects on the Number of Bacterial and Fungal Colonies in Metamorphosed Dybowski's Frogs (Rana dybowskii)

  • Kim, Jong-Sun;Choi, Woo-Jin;Park, Il-Kook;Koo, Kyo-Soung;Kang, Hui-Beom;Kwon, Oh-Sung;Lee, Seung-Hyeon;Choi, Hye-Ji;Lee, Jung-Hyun;Lee, Jin-Gu;Park, Dae-Sik
    • Journal of Forest and Environmental Science
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    • v.34 no.1
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    • pp.61-65
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    • 2018
  • To know if small changes in rearing water temperature and density affect the number of bacterial and fungal colonies in metamorphosed frogs, Dybowski's frog tadpoles were reared from Gosner 25-26 stages at either low ($1^{\circ}C$ low to ambient water temperature), ambient, or high ($1^{\circ}C$ high) water temperature (each 15 tadpoles in 20 L water) condition and at either low (10 tadpoles/20 L water), medium (20 tadpoles), or high (30 tadpoles) density condition. Immediately after metamorphosis, we sampled bacteria and fungi from skin, liver, and heart of six metamorphosed frogs, randomly selected for each treatment group. After separate incubation of bacteria and fungi on 3M Petrifilm plates, we counted the number of bacterial and fungal colonies appeared on the plates and compared the numbers among the temperature and density treatment groups. For temperature treatment, high-temperature group had fewer bacterial colonies, while low-temperature group had more fungal colonies than the other two groups. For density treatment, low-density group had fewer bacterial colonies than the other two groups, but the number of fungal colonies were not different among the groups. Our results suggest that small increased rearing water temperature and lowered rearing density could potentially reduce pathogens in farming frogs.

A Spray Characteristics of Dual Orifice Injector with Different Fuel Properties (연료 종류에 따른 이중 오리피스 노즐의 분무 특성 연구)

  • Lee, D.H.;Choi, S.M.;Park, J.B.
    • Journal of ILASS-Korea
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    • v.8 no.2
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    • pp.7-15
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    • 2003
  • The effects of fuel density and fuel viscosity on spray characteristics were investigated under two different gas turbine fuels and various fuel supply pressure conditions through measurement of SMD, number density and volume flux by using PDPA system in dual orifice injector for gas turbine engines. In this study, we found out that the droplet size and spray structure are strongly depend on fuel density for dual orifice injector. The spray characteristics of high density fuel in dual orifice injector are similar with the characteristics of low density fuel in single orifice injector. The shear region between primary main fuel stream and secondary main fuel stream is examined in low density fuel condition but not exist in high density fuel condition, then this shear region is very important in quality of gas turbine spray. There are worth consideration for the effect of fuel density on spray characteristics in frontal device design to improve combustion efficiency.

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Studies on the Effect of Panax ginseng on the Interactions of Human Plasma Lipoproteins and Lecithin Dispersions with Dextran Sulfate (인삼(人蔘) Saponin이 혈장(血漿) Lipoproteins 및 Lecithin Dispersion과 Dextran Sulfate의 상호작용(相互作用)에 미치는 영향(影響))

  • Kim, Young-Choong;Jeon, Mee-Hee
    • Korean Journal of Pharmacognosy
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    • v.15 no.4
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    • pp.206-212
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    • 1984
  • The effect of saponin fractions of Panax ginseng root on the interactions of human plasma lipoproteins and lecithin dispersions with dextran sulfate were studied in order to examine the effect of Panax ginseng on the lipid accumulation in the aorta. The total saponin fraction and protopanaxadiol glycosides of Panax ginseng root seemed to slightly enhance the interaction of low density lipoproteins with dextran sulfate in the absence of divalent metal ions. Protopanaxatriol glycosides remarkably inhibited the interaction of low density lipoproteins with dextran sulfate. However, all of these three saponin fractions of Panax ginseng root showed the tendency of inhibition to the interaction of high density lipoproteins with dextran sulfate in the presence of divalent metal ions by the order of protopanxatriol glycosides, protopanaxadiol glycosides and total saponin. Three saponin fractions of Panax ginseng exerted almost same tendency to the interaction of lecithin dispersions with dextran sulfate in the presence of divalent metal ions as the interaction of low density lipoproteins with dextran sulfate absence of divalent metal ions.

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Screening of Antioxidative Compounds toward Human Low Density Lipoprotein (LDL) from Useful Plants (유용식물로부터 Human Low Density Lipoprotein(LDL)에 대한 항산화제의 탐색)

  • 임복규;류병호
    • The Korean Journal of Food And Nutrition
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    • v.17 no.2
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    • pp.138-146
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    • 2004
  • This study was designed to investigate antioxidative activity of substances isolated from 25 kinds of useful plants resources toward free radical and human low density lipoprotein(LDL). Methanol extracts of Oenothers odorate had the highest antioxidative activity similar with ${\alpha}$-tocopherol. Methanol extracts of Oenothers odorate was extracted again by the ethylacetate. The ethylacetate soluble acidic fraction obtained from methanol extract of Oenothers odorate showed highest activity toward human LDL. Each fraction was purified through Sepadex LH-20 chromatography by elution of chloroform-methanol mixture (90:10 v/v). Fraction, F-2 obtained from Oenothers odorate showed at highest levels of electron donating activity. Fraction, F-2 was identified as 3,4-dihydroxybenzoic acid and 3-hydroxycinnamic acid.

Crystallization Characteristics of Metallocene Low Density Polyethylene/Low Density Polyethylene Blends (메탈로센 선형 저밀도 폴리에틸렌/선형 저밀도 폴리에틸렌 블렌드의 결정화 거동)

  • 김경룡;한정우;강호종
    • Polymer(Korea)
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    • v.25 no.6
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    • pp.840-847
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    • 2001
  • The crystallization characteristics of metallocene linear low density polyethylene (m-LLDPE)/linear low density polyethylene (LLDPE) blends were investigated. The effect of blending on the induction time for crystallization, spherulites growth rate, and maximum size of spherulites was mainly considered in this study. The formation of separate crystal which is well known crystallization behavior in LLDPE/LDPE blend was not found in m-LLDPE/LLDPE blends. The blending m-LLDPE to LLDPE caused the dramatic decrease in the induction time of m-LLDPE/LLDPE blends but it seems that the blend composition shows less effect on the induction time. Lower branching number in m-LLDPE resulted in the increasing of spherulites growth rate and the maximum size of spherulites is depend upon both the induction time and spherulites growth rate of LLDPE component affected by m-LLDPE.

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Progressive Edge-Growth Algorithm for Low-Density MIMO Codes

  • Jiang, Xueqin;Yang, Yi;Lee, Moon Ho;Zhu, Minda
    • Journal of Communications and Networks
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    • v.16 no.6
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    • pp.639-644
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    • 2014
  • In low-density parity-check (LDPC) coded multiple-input multiple-output (MIMO) communication systems, probabilistic information are exchanged between an LDPC decoder and a MIMO detector. TheMIMO detector has to calculate probabilistic values for each bit which can be very complex. In [1], the authors presented a class of linear block codes named low-density MIMO codes (LDMC) which can reduce the complexity of MIMO detector. However, this code only supports the outer-iterations between the MIMO detector and decoder, but does not support the inner-iterations inside the LDPC decoder. In this paper, a new approach to construct LDMC codes is introduced. The new LDMC codes can be encoded efficiently at the transmitter side and support both of the inner-iterations and outer-iterations at the receiver side. Furthermore they can achieve the design rates and perform very well over MIMO channels.

Discovery of Antioxidant on Human Low Density Lipoprotein (LDL) by Bacillus sp. RH-5 Isolated from Marine Origin (해양에서 분리한 Bacillus sp. RH-5에 의한 사람 Low Density Lipoprotein(LDL) 산화에 대한 항산화제의 개발)

  • 류병호;박종옥;김동석
    • Journal of Life Science
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    • v.9 no.1
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    • pp.99-105
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    • 1999
  • The aims of this studies were carried out to investigate the antioxidant activity on low density lipoprotein(LDL) using substances extracted from Bacillus sp. RH-5. The antioxidative substances produced extracellular in the culture broth by Bacillius sp. RH-S was obtained by elution of chloroform : methanol from silicagel column (80cm x100cm) chromatography. Band 4 eluted from fraction 3 by TLC was appeared at highest level of antioxidative activity using thiocyanate methed. Band 4 at a concentration of 100 or 200$\mu$g/$m\ell$ inhibited oxidation of LDL induced by the mouse transformed macrophage. According to IR. NMR or GC/MASS, the antioxidant substance was identified as 5-hydroxyindole.

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THE HEALING EFFECTS OF LOW POWER DENSITY LASER TO THE EXPERIMENTAL PERIODONTITIS;HISTOPATHOLOGIC STUDY (저출력 레이저 조사가 성견의 실험적 치주질환 치유에 미치는 영향에 관한 조직병리학적 연구)

  • Kim, Dong-Woon;Lee, Jae-Hyun;Chung, Chin-Hyung
    • Journal of Periodontal and Implant Science
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    • v.23 no.1
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    • pp.16-26
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    • 1993
  • In order to investigate the healing effect on inflammation and bone regeneration of low power density laser radiation in dogs, experimental periodontitis was made in dog mandibular 3rd, 4th premolars. All teeth were classified with four groups of two experimental group and control groups. The second group were irradiated on periodontitis site and the first group were control. The fourth group were irradiated on periodontitis site flap operation and the third group were flap control. Experimental groups were irradiated with GaAs low power density laser of pulse wave and continuous wave of 904nm every day by five days respectively and then control group and experimental groups were evaluated by histo-pathological study. The results were as follows : 1. Experimental periodontits site of dog were irradiated with GaAs low power laser results in reducing of pseudoepitheliomatous proliferation and inflammation at light microscope. 2. After irradiation with low power density laser, experimental groups were revealed that PDL forming activity were increased and newly formed collagen deposition were observed. 3. Low power density lsaer irradiation on experimental periodontits site after flap operation showed that decreasing of inflammation, reducing of osteoclast activity. Capillary proliferation, reduction of pseudoepitheliomatous proliferation. 4. After irradiation with low power density laser on flap experimental site, experimental groups were revealed that newly formed collagen in periodontal ligament and alveolar bone were detected on MT staining.

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Low Cycle Fatigue Life Assessment of Alloy 617 Weldments at 900℃ by Coffin-Manson and Strain Energy Density-Based Models

  • Rando, Tungga Dewa;Kim, Seon-Jin
    • Journal of Power System Engineering
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    • v.21 no.1
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    • pp.43-49
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    • 2017
  • This work aims to investigate on the low cycle fatigue life assessment, which is adopted on the strain-life relationship, or better known as the Coffin-Manson relationship, and also the strain energy density-based model. The low cycle fatigue test results of Alloy 617 weldments under $900^{\circ}C$ have been statistically estimated through the Coffin-Manson relationship according to the provided strain profile. In addition, the strain energy density-based model is proposed to represent the energy dissipated per cycle as fatigue damage parameter. Based on the results, Alloy 617 weldments followed the Coffin-Manson relationship and strain energy density-based model well, and they were compatible with the experimental data. The predicted lives based on these two proposed models were examined with the experimental data to select a proper life prediction parameter.

Planning of low-rise high-density small-scaled urban housing complex (국내 도시지역에 적용가능한 저층고밀 소형 공동주택 계획안)

  • An, Jae-Min;Mo, Jeong-Hyun
    • Proceeding of Spring/Autumn Annual Conference of KHA
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    • 2009.11a
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    • pp.263-267
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    • 2009
  • Recently, we have seen the change of population and family structure, population growth has slowed and family differentiation was constantly done. A rapidly increase of single and couple household. So small-scaled house demand will be increased. Therefore this study planned to solve recent collective housing problem and to satisfy new housing demand. The purpose of planning was that low-rise high-density small-scaled of urban housing complex. This study used for two methods. First methods were literature analysis for domestic collective houses's present conditions and issues. Other purpose was to confirm change of household. Second method is case studies. It went through two phases to select the cases. The cases selected domestic and foreign each eight, total sixteen. The cases analyzed to twelve elements characteristic of housing complex, unit and community facilities. This study applied one area of Seoul to the low-rise high-density small-scaled housing complex.

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