• Title/Summary/Keyword: water-reducing

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Increase of strength and freezing-thawing resistance of porous concrete by Silica-fume (실리카흄을 사용(使用)한 투수(透水)콘크리트의 강도(强度) 및 동결융해저항성(凍結融解抵抗性))

  • Hong, Chang-Woo
    • Resources Recycling
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    • v.19 no.4
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    • pp.35-40
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    • 2010
  • Existing porous concrete has problems with reduction of strength due to freezing and thawing and exfoliation of aggregate at joints. In this study, a method for increasing strength and durability of porous concrete by using fine aggregate, silica-fume and high-range water-reducing agent was proposed by laboratory tests. Mixing ratio between silica-fume (10%) and fine aggregate (0%, 7%, 15%) was selected as a major test factor, and laboratory tests for compressive strength, flexural strength, permeability coefficient, porosity, freezing and thawing were conducted. Compressive strength and flexural strength were increased as the mixing ratio of fine aggregate was increased. However, permeability and freezing-thawing resistance were decreased due to reduction of porosity. Therefore, the ratio of fine aggregate should be limited to increase strength and durability of the porous concrete, while the mixing ratio of silica-fume should be over 10%.

Factors stimulating the Growth of Lactic acid Bacteria in Cucumber Juice (오이에 대(對)한 유산균(乳酸菌) 생육촉진(生育促進) 인자(因子)에 관(關)하여)

  • Kim, H.S.;Chun, J.K.
    • Applied Biological Chemistry
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    • v.9
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    • pp.35-39
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    • 1968
  • Addition of one percent cucumber, as a Kimchi component, showed the stimulation of lactic acid fermentation, by reducing the lagphase, and resulted the early matured Kimchi. Alcohol-soluble fraction from cucumber serum accerelated the growth of Lactobacillus plantarum, p-1, p-2 newly isolated strains from cucumber pickle, but had no effect on the growth rate of Streptococus faecalis. The growth promoting activity was inactivated by dialysis against water and heat treatment at $120^{\circ}C$ for 10 minutes. Softness of cucumber tissues enables to extract easily out a substance, which is thought one of the important factors for the stimulation of me growth of Lactic acid bacteria.

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The Investigation of literature of Driental and western medicine about relation of 'Su-Chun'( ), 'Hwa-Chun'( ) and cardiac rapid respiration (수천(水喘) 및 화천(火喘)과 심장성(心臟性) 천식(喘息)에 관(關)한 동서의학적(東西醫學的) 문헌(文獻) 고찰(考察) -(원인(原因).증상(症狀) 중심(中心)으로)-)

  • Kim, Yung-Tae;Lee, Hyung-Gu;Jung, Sung-Gi
    • The Journal of Internal Korean Medicine
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    • v.11 no.1
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    • pp.53-60
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    • 1990
  • The results are as follows through the investigation of literature. 1. The cause of shortness of breath due to fluid retention is abnormal rising of water-evil and it srepregentative symptom are as follows'Cough or dyspnea, shortness of breath-sleeplessness, rapid respiration accused by having rest, edemd on the body and leg' 2. Dyspnea caused by fire-evil is It repregentative symptom are 'getting better or getting worse, reducing by eating rapid respiration accused by eating If having rest the ditalenergy (gui) is made a peace At moving, the vital energy is abrupt or irregalar and acused rapid respiration' 3. From the point of view, the rapid respiration accused by heart usually bring about imperfect left heart Its repregentetive symptom are cyspnea, acute dyspnea at night, bronchial wheezing edema on the leg, and the thing which bring about at moving is mildcase but what bring about at rest is severe case 4. We have known that the symptom of shortness of breath due to fluid retention are similiar to cardiac rapid respiration, and the symptom of dyspnea acused by fire-evil alike 'dyspnea at moving' acused at mild case of cardiac rapid respiration.'

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Effect on Vessel Motion Caused by Mitigation of Sloshing Impact Loads using Floaters (플로터를 이용한 슬로싱 충격하중 저감효과가 선체운동에 미치는 영향)

  • Nam, Jung-Woo;Kim, Kyung-Sung;Hwang, Sung-Chul;Heo, Jae-Kyung;Park, Jong-Chun;Kim, Moo-Hyun
    • Journal of Ocean Engineering and Technology
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    • v.26 no.4
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    • pp.50-56
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    • 2012
  • When a liquid cargo tank is partially filled with fluid, internal impact loads can be occurred from the vessel's motions. In this study, liquid sloshing problems with a thin top layer of particles with a lighter density than water and the coupling effects of the liquid-sloshing/vessel-motion were investigated in order to reduce the sloshing-induced impact loads. The PNU-MPS (Pusan-National-University-modified Moving Particle Simulation) method for solving the liquid motion inside a tank and the CHARM3D BEM (Boundary Element Method) based time-domain ship motion analysis program for vessel-motion simulation were coupled. From the simulation results, we could see that the floaters seemed to be quite effective at reducing the sloshing impact loads in the case of tank-only sloshing problems, but not as much for the coupling problem with vessel motion.

Perception of sugar reduction, nutrition education, and frequency of snacking in children by the self-perceived sweet dietary habits of mothers in Busan

  • Yeon, Jee-Young;Lee, Soon-Kyu
    • Nutrition Research and Practice
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    • v.10 no.5
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    • pp.546-554
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    • 2016
  • BACKGROUND/OBJECTIVES: The aim of this study was to investigate the perception of sugar reduction, nutrition education, and frequency of snacking in children according to the self-perceived dietary preferences for sweet taste by mothers in Busan. SUBJECTS/METHODS: A total of 277 mothers were surveyed, and their perceptions of sugar reduction and the frequency of snacking in children were assessed using a questionnaire. The subjects were classified into either a sweet (n = 91) or an unsweet (n = 186) group according to their self-perceived preferences for a sweet taste. RESULTS: In the sweet group, the results for sweet products were sweetened ice (86.8%), confectionery (74.7%), processed milk (73.6%), carbonated beverages (71.4%), and fermented milk (53.9%). In the unsweet group, the results were sweetened ice (88.7%), carbonated beverages (78.5%), processed milk (75.8%), confectionery (69.4%), and fermented milk (50.5%). The necessity of sugar intake reduction was high in both groups (sweet = 89.0%, unsweet = 82.8%). Beverage purchases after identifying the nutrition labeling was significantly lower in the sweet group than in the unsweet group (P < 0.05). The reasons for the beverage purchases instead of water were "habitually" (50.5%) and "like sweet taste" (25.3%) in the sweet group (P < 0.01). Snacking in children was significantly higher in the sweet group based on the increased frequencies of carbonated drinks (P < 0.01), fast food (P < 0.001), candy and chocolate (P < 0.05), crackers (P < 0.01), ramen (P < 0.01), and fish paste/hotdogs (P < 0.01). The frequency of purchase education after identifying the nutrition labeling was significantly lower in the sweet group than in the unsweet group (P < 0.01). CONCLUSIONS: These findings suggest that a perception of sugar reduction and practical nutrition education aimed at reducing the sugar intake are necessary to improve dietary habits.

The Effective Control of Hot Weather Concreting by Optimum Mineral and Chemical Admixtures (혼화재 및 혼화제의 조절에 의한 서중 콘크리트의 효과적 관리)

  • Lee, Dongyule;Ham, Suyun;Oh, Taekeun
    • Journal of the Korean Society of Safety
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    • v.30 no.3
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    • pp.59-66
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    • 2015
  • The undesirable effects of elevated external temperatures at placement on the properties of the fresh and hardened concrete are discussed briefly, and the possible use of the mineral admixtures to mitigate them and the association with water-reducing and retarding admixtures in terms of the mix design which are critical for minimizing slump loss and entrained air loss are examined in this study. To investigate the effects of such the mineral and chemical admixtures on the fresh and hardened properties of concrete exposed to high temperature, a series of concrete mixtures subjected to the high temperature were carried out and then fresh and hardened properties of the mixtures were analyzed and evaluated. Based on the results, new guide lines concerning the appropriate admixtures for hot weather are suggested.

Changes in Plant Species on a Grass Roof over Time (초지지붕에서의 시간경과에 따른 식생변화)

  • Lee, Young-Moo
    • Journal of the Korean Institute of Landscape Architecture
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    • v.34 no.6 s.119
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    • pp.39-53
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    • 2007
  • Unlike conventional roof landscaping, where various kinds of plants and structures are employed, a grass roof is a roof on which herbaceous plants are grown in planting medium and which is not accessed or maintained, mainly because it doesn't have sufficient load capacity to support a regular roof garden. They are mostly built on existing roofs, whether flat slab or gabled. Planting on roofs has numerous advantages, such as creating a biotope, purifying urban air, adding moisture to the atmosphere, storing rain water, preventing flash floods, reducing energy use for heating and air conditioning, enhancing the urban landscape and providing relaxation to the city dwellers, not to mention the alleviation of global warming by absorbing $CO_2$. In addition to the general merits of roof planting, the grass roof has its own unique qualities. Only herbaceous species are planted on the roof, resulting in light weight which allows roofs of existing buildings to be planted without structural reinforcement. The species chosen are mostly short, tough perennials that don't need to be maintained. These conditions provide an ideal situation where massive planting can be done in urban areas where roofs are often the only and definitely the largest space available to be planted. If roofs are planted on a massive scale they can play a significant role in alleviating global warming, heat island effects and energy shortages. Despite the advantages of grass roofs, there are some problems. The most significant problem is the invasion of neighboring plants. They may be brought in with the planting medium, by birds or by wind. These plants have little aesthetic value comparing to the chosen species and are usually taller. Eventually they dominate and prevail over the original species. The intended planting design disappears and the roof comes to look wild. Since the primary value of a grass roof is ecological, a change in attitude towards what constitutes beauty on the roofscape is necessary. Instead of keeping the roof neat through constant maintenance, people must learn that the wild grass with bird's nests on their roof is more beautiful as it is.

Development of constant current device for using in the water treatment controller with Ni-Tl-P alloy deposits (Ni-Tl-P합금피막을 이용한 수처리장치용 정전류소자의 개발)

  • Ryu, Il-Kwang
    • Journal of environmental and Sanitary engineering
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    • v.18 no.3 s.49
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    • pp.35-42
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    • 2003
  • The electric resistance and constant current were investigated on the nickel-thallium-phosphorus alloy deposits by electroless-plating. The Ni-Tl-P alloy deposits were achieved with a bath using sodium hypophosphit as the reducing agent and sodium citrate as the comlexing agent. The basic plating solution is composed of 0.1M NiSO$_4$, 0.005${\sim}$0.0IM Tl$_2$S0$_4$, 0.1${\sim}$O.2M sodium hypophosphite and 0.02${\sim}$O.IM sodium citrate and the plating condition were pH 5${\sim}$6, temperrature 80$_4$90${\circ}$C. The results obtained are summarized as follows: 1) The crystal structure of deposit was amorphous structure as deposited state, became microcrystallized centering on Ni(111) plane by heat treatment at 200${\circ}$C, and grew as polycrystalline Ni, Ni$_3$P, Ni$_5$p$_2$,Tl, etc. by heat treatment higher than 350${\circ}$C. The grain size of plated deposits was grown up to 28.3~42.0nm by heat treatment for 1hour at 500${\circ}$C. 2) The electrical resistivity showed a comparatively high value of 192.5$_4$208.3 ${\mu}$${\Omega}$Cm and its thermal stability was great with resistivity value less than 0.22% in the thermal surroundings of 200${\circ}$C. 3) Ni-Tl-P alloy deposit showed such good constant current-making-effect in the variation of electric voltage, heat treatment temperature, and the composition of the deposit that it can be put to practical use as the matter of constant current device.

Effect of Torilis Fructus on Procollagen Biosynthesis and Activity of Matrix Metalloproteinase-I(MMP-1) in Human Dermal Fibroblast (사상자(Torilis Fructus)가 섬유아세포의 Procollagen 생합성과 Matrix metalloproteinase-I(MMP-1)의 활성에 미치는 영향)

  • Koo, Bon-Suk;Hwang, Eui-Il;So, Seung-Ho;Lee, Seong-Kye;Han, Gyeong-Ho;Kim, Na-Mi
    • Korean Journal of Pharmacognosy
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    • v.38 no.4
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    • pp.349-353
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    • 2007
  • Skin wrinkle formations are associated with collagen synthesis and matrix metalloproteinase-I(MMP-1) activity. This study was carried out to find out skin wrinkle reducing components in Torilis Fructus. Torilis Fructus were extracted with 70% ethanol and the ethanol extracts were systematically fractionated with n-hexane, ethylacetate, n-butanol and distilled water. Among them, antiwrinkle component from n-hexane fraction was purified by several column chromatographies and HPLC, which identified as torilin by $^1H-NMR,\;^{13}C-NMR$ and ESI-MS. To determine cell viability, collagen biosynthesis and MMP-1 activity, human dermal fibroblast was treated with 1-5 ppm concentrations of Torilis Fructus extract fraction and torilin. Cell viability was showed 84-102% at all group treated with 1-5 ppm. Collagen synthesis was increased in all group, especially torilin-treated group was highest amount. Active forms of MMP-1 were decreased in all group. From these results, we consider that Torilis Fructus have several antiwrinkle components and torilin may be one of the effective components.

Comparative Study of Antioxidant abilities on Prunus yedoensis and Betula platyphylla var. japonica (산화적 손상에 대한 화피(樺皮)의 효능 - 왕벚나무와 자작나무 수피의 항산화능 비교 평가-)

  • Hong, Sang Cheol;Jun, Ji Ae;Kim, Dong Hee
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.27 no.4
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    • pp.391-399
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    • 2013
  • The aim of the present study was to investigate the antioxidant efficacies between extracts of Prunus yedoensis(PY) and Betulae platyphyllae var. japonica(BP). HPLC pattern was different between barks and extract solvents. Content of total phenolic compound was the highest in ethanol extract of BP(382.201 mg/g ext.) and its content was 1.9 times higher than that from the water extract of PY. Total antioxidant efficacy also was the highest in ethanol extract of BP (292 copper reducing equivalents). Nitric oxide scavenging activity was almost 70% in ethanol extract of BP treated 200 ug/ml and it was higher than positive control(ascorbic acid). DPPH radical scavenging ability was up by 80% in all samples. ABTS cation decolorization from each barks was activated over 85% in all samples at 100 ug/ml concentration, especially, the activity was the highest (94.4%) in ethanol extract of BP. Hydrogen peroxide scavenging activities were also highest (45%) in ethanol extract of BP at 200 ug/ml concentration and were as high as positive control. Stimulation of the macrophages RAW 264.7 cells with lipopolysaccharide (LPS) increased intracellular ROS levels and ethanol extract of BP at 200 ug/ml concentration reduced ROS levels up to 41 %. The results indicated that the barks of PY and BP has potent antioxidant activities and ethanol extract of BP of them has the highest antioxidant activities.