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Effect of reaction temperature on the particle size and crystal shape of precipitated calcium carbonate (반응온도가 침강성탄산칼슘의 입도 및 형상에 미치는 영향)

  • 송영준;박찬훈;조동성
    • Resources Recycling
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    • v.4 no.1
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    • pp.38-45
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    • 1995
  • The objective of this study was to investigate the effect of temperature on the formation of CaCO, polymorphs(i.e.,calcite, aragonite, vaterite) and on the crystal shape of CaCO,.The reaction systems were rnvestigated at the temperature range of 2.0%-85.3r, at the fixed cmditions ofconcentration and pressure, 2X10-' M, atomospheric pressure, respectively.The reaction systems studied include a Ca(HCO.,),-Air bubble, O Ca(OH)s-CO,, @ Ca(OH),-H,CO, ,Ca(OH1,-Na>CO,, O Ca(OH),-K,CO,, @ Ca(OH),-(NH,),CO,, D CaC1,-Na,CO,, CaC1,-K3C03, 8 CaC1,-(NH,,),CO,, 0 Ca(N0,X-Na,CO,, 03 Ca(N0,X-QCO,. 0 Ca(NO,),-(NH,XCO,. The results obtained are summarizedas follows:Calcite is formed at the temperature range of 2t-80"C and the highest calcite yield was obtained at 30%.Aragonite begins to be formed at the temperature range of 41.0%-53.0%. and the higher temperature is thehigher yield is obtained. pH of the reaction system affect the yield of aragonite, and the yield reaches the highestpercentage at the pH range of 10.0-11.0, and at the conditions of pH 12.3 or over, aragonite is scarcely formed.Vaterlle is fnrmed at the temperature range of 40.0% or less, and transites utterly to calcite within 10-60mmutes in the case of bemg residenced in mother liqmd which C1 is not contained, and within 140hours inthe case of containing CI-.s in the case of containing CI-.

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Effect of the Particle Size and Unburned Carbon Content on the Separation Efficiency of Fly ash in the Countercurrent Column Flotation (向流컬럼浮選機에서 石炭灰의 크기 및 未燃炭素 含量이 分離特性에 미치는 영향)

  • 이정은;이재근
    • Resources Recycling
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    • v.9 no.6
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    • pp.36-44
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    • 2000
  • Fly ash was composed of the unburned carbon and mineral particles. The former was able to attach on the bubbles, while the latter was not. Therefore, it was possible to separate the unburned carbon and the mineral from fly ash using the froth flotation process. This study was carried out to evaluate the separation efficiency as a function of the ny ash particle properties in the column flotation. Separation efficiency was analyzed for various size fraction of -38 fm,38~125 fm and 1125 W, and for various fly ash samples containing 7, 11, and 20 wt% unburned carbon. For the size fractions of -38 fm containing 7 wt% unburned carbon, separation efficiency was 86ft, whereas separation efficiency was found to be 74% for the size fraction of +125$\mu\textrm{m}$ containing 20 wt% unburned carbon. The results indicated that separation efficiency increased with the decrease in the particle size and the unburned carbon content of the fly ash.

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A Study on Primigravida's Antenatal Self-Care Behavior and Maternal Knowledge (초임부의 산전 자가간호 행위와 모성관련 지식에 관한 연구)

  • Park, Mi-Sook;Kim, Hae-Won
    • Women's Health Nursing
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    • v.6 no.1
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    • pp.153-165
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    • 2000
  • The antenatal self-care, one of antenatal management, was almost done by a pregnant woman herself. But It's especially difficult for primigravidas to cope with the change of being pregnant, and they also had insufficient knowledge of pregnancy, The purpose of this study was to serve as a basis for antenatal management, by grasping how much primigravidas performed antenatal self-care, how much they had maternity-related knowledge, and what factors affected those two factors. The subjects of this study were the primigravidas, selected from among visitors to a general hospital and a hospital for obstetrics and gynecology located in the city of K. A questionnaire survey was carried out over them from July 16 to August 19, 1998, to collect data. The test instrument used in this study for antenatal self-care behavior was one that modified the measurement instrument employed in studies by Kim Hae Won(1996), Lee Mi La(1984), and Yoon Young Mi(1994). Another one for maternity-related knowledge was Kim, Hae Won(1996)'s instrument. The collected data were statistically analyzed by SAS PC+. Frequency and percentage were calculated to find out the primigravidas' general characteristics, and the mean and standard deviation, rank were estimated to determine the degrees of antenatal self-care behavior and maternity-related knowledge, t-test and ANOVA were carried out to identify the general characteristic that affected antenatal self-care and maternity-related knowledge. and the relationship of antenatal self-care behavior to maternity-related knowledge was tested by Pearson correlation coefficient. The findings of this study were as follows; First, the age of the subjects ranged from 18 to 37, and their mean age was 26.43. Their mean gestational period was 24.87 weeks. 45% of the subjects were in the third-term pregnancy. Second, their total mean score in antenatal self-care behavior ranged from 94, the highest, to 36, the lowest. Its average score was 63.81(SD 9.98). The total mean score in maternity-related knowledge ranged from 20, the highest, to 1, the lowest, and its average score was 10.91(SD 4.59, 54.55 percent). Third, the general characteristics that gave impact on the primigravidas' antenatal self-care behavior were age, educational background, gestational period, experience of natural miscarriage, and experience of infertility test. A higher score in antenatal self-care behavior was gained by the primigravida group who had better educational background(F=3.29, p=.02), who was in the late stage of pregnancy(F=4.31, p=.01), who experienced a natural miscarriage(t=2.06, p=.04), and who went through a infertility test(t=-2.19, p=.04). Fourth, the general characteristics that had an influence on maternity-related knowledge were identified as the religion, the term of marriage, and the gestational period. A higher score in maternity-related knowledge was got by the primigravida group who had a religion(t=-2.02, p=.04), and who was in the late stage of pregnancy(F=5.77, p=.003). The term of marriage also made a significant difference(F=3.46, p=.02). Fifth, the relationship of the total mean score between antenatal self-care behavior and maternity-related knowledge was found to be at r=.37(p=.0001). In this study, an attempt was made to affirm the subjects' characteristics, the degree of their antenatal self-care behavior, and the extent of their maternity-related knowledge, to confirm what characteristics affected significantly primigravida's antenatal self-care behavior and maternity-related knowledge, and to verify that there was a relationship between the two variables. The meaning of this study might be backed up by the fact that its findings would serve as a basis for primigravida's efficient antenatal management in the future.

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Earthquake impacts on hydrology: a case study from the Canterbury, New Zealand earthquakes of 2010 and 2011

  • Davie, Tim;Smith, Jeff;Scott, David;Ezzy, Tim;Cox, Simon;Rutter, Helen
    • Proceedings of the Korea Water Resources Association Conference
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    • 2011.05a
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    • pp.8-9
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    • 2011
  • On 4 September 2010 an earthquake of magnitude 7.1 on the Richter scale occurred on the Canterbury Plains in the South Island of New Zealand. The Canterbury Plains are an area of extensive groundwater and spring fed surface water systems. Since the September earthquake there have been several thousand aftershocks (Fig. 1), the largest being a 6.3 magnitude quake which occurred close to the centre of Christchurch on 22February 2011. This second quake caused extensive damage to the city of Christchurch including the deaths of 189 people. Both of these quakes had marked hydrological impacts. Water is a vital natural resource for Canterburywith groundwater being extracted for potable supply and both ground and surface water being used extensively for agricultural and horticultural irrigation.The groundwater is of very high quality so that the city of Christchurch (population approx. 400,000) supplies untreated artesian water to the majority of households and businesses. Both earthquakes caused immediate hydrological effects, the most dramatic of which was the liquefaction of sediments and the release of shallow groundwater containing a fine grey silt-sand material. The liquefaction that occurred fitted within the empirical relationship between distance from epicentre and magnitude of quake described by Montgomery et al. (2003). . It appears that liquefaction resulted in development of discontinuities in confining layers. In some cases these appear to have been maintained by artesian pressure and continuing flow, and the springs are continuing to flow even now. In spring-fed streams there was an increase in flow that lasted for several days and in some cases flows remained high for several months afterwards although this could be linked to a very wet winter prior to the September earthquake. Analysis of the slope of baseflow recession for a spring-fed stream before and after the September earthquake shows no change, indicating no substantial change in the aquifer structure that feeds this stream.A complicating factor for consideration of river flows was that in some places the liquefaction of shallow sediments led to lateral spreading of river banks. The lateral spread lessened the channel cross section so water levels rose although the flow might not have risen accordingly. Groundwater level peaks moved both up and down, depending on the location of wells. Groundwater level changes for the two earthquakes were strongly related to the proximity to the epicentre. The February 2011 earthquake resulted in significantly larger groundwater level changes in eastern Christchurch than occurred in September 2010. In a well of similar distance from both epicentres the two events resulted in a similar sized increase in water level but the slightly slower rate of increase and the markedly slower recession recorded in the February event suggests that the well may have been partially blocked by sediment flowing into the well at depth. The effects of the February earthquake were more localised and in the area to the west of Christchurch it was the earlier earthquake that had greater impact. Many of the recorded responses have been compromised, or complicated, by damage or clogging and further inspections will need to be carried out to allow a more definitive interpretation. Nevertheless, it is reasonable to provisionally conclude that there is no clear evidence of significant change in aquifer pressures or properties. The different response of groundwater to earthquakes across the Canterbury Plains is the subject of a new research project about to start that uses the information to improve groundwater characterisation for the region. Montgomery D.R., Greenberg H.M., Smith D.T. (2003) Stream flow response to the Nisqually earthquake. Earth & Planetary Science Letters 209 19-28.

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Influence of Ultrasonification on Extraction Yield and Chemical Property of Green Tea Infusion (초음파 처리가 녹차 침출액의 추출 수율 및 화학적 특성에 미치는 영향)

  • Kim, Byung-Chul;Kang, Sung-Won;Chung, Chang-Ho;Heo, Ho-Jin;Lee, Seung-Cheol;Cho, Sung-Hwan;Choi, Sung-Gil
    • Journal of agriculture & life science
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    • v.44 no.5
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    • pp.91-99
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    • 2010
  • The objective of this work was to investigate the influence of ultrasonification on extraction yield and chemical properties of green tea infusion. Changes in total soluble matter(TSM), vitamin C, total phenolic compounds, flavonols, catechins, caffeine, free amino acids contents in green tea infusion(GTI) influenced by ultrasonification at $60^{\circ}C$ of extraction temperature for 1, 5, 30, and 60 min were investigated. The amount of infused TSM increased about 5.3% by ultrasonification for 60min. Vitamin C contents also increased 0.21, 0.16, 0.31 mg/g from 1 to 30 min by ultrasonification. However, vitamin C decreased from 2.47 to 2.22 mg/g at 60min. Total phenol compounds contents increased about 10~13 mg/g on all extraction times by ultrasonification. Flavonols such as, myricetin, quercetin, kaempferol were increased to doubled contents as an influence of ultrasonification. Catechins such as, EGCG, EGC, ECG, EC, (+)-C and caffeine contents showed same tendency as the results of vitamin C. On the other hand, result of free amino acids showed different tendency. All amounts of free amino acids did not increase by ultrasonification. Consequently, content of bioactive compounds such as, vitamin C, total phenolic, flavonols and catechins in green tea infusion were influenced by ultrasonification.

A Study on the Geometrical Features of Soil Doundaries and Mapping Units for Consolidation Works of Arable Land (농경지(農耕地)의 기반조성(基盤造成)을 위한 작도단위(作圖單位) 및 배계(培界)의 기하학적(幾何學的) 형태(形態)에 관한 조사(調査))

  • Yoon, Eul-Soo;Jung, Yeun-Tae;Kim, Jung-Kon;Son, Il-Soo
    • Korean Journal of Soil Science and Fertilizer
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    • v.22 no.1
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    • pp.6-11
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    • 1989
  • This investigation was conducted to get basic informations on land consolidation works and soil management for arable land. The characteristics of geometrical features of mapping units in the detailed soil maps of Korea were measured from 70 soil series (565 soil phases) by using a picture analysis system. The results obtained were as follows: 1. The mean values of the mapping units in extent, periphery, diameter of long axis and short axis, roundness and number of acute angles were 22.0ha, 2.267m, 911m, 0.104, and 3.5, respectively. It was suggested that "Simplicity Index of Mapping Unit", $=\frac{Extent\;in\;ara}{Length\;of\;boundary\;periphery\;in\;meter}{\times}\frac{1}{number\;of\;acute\;angle}$ be valuable to judge the complexity degrees of mapping units. 2. The size of mapping unit among physiographyic position was shown in order of Alluvial plains > Fluviomarine plains > Terraces > Hills > Fans > Mt. foot slopes > Valleys, and the simplicity index of mapping units also showed similar order of the extent. 3. The size and the simplicity index of the soils developed on plains with silty textured imperfectly drained were higher than the soils developed on sloped land with loamy textured. As the slopes getting steeper or relatively better in soil drainage, the size and the simplicity index became smaller. 4. The relationship between the simplicity index and the size of the farm unit divides by the land consolidation works was positively correlated. And it was concluded that the parcelling of the farm unit divides by the planning of land consolidation should be based on the soil boundaries of the detailed soil maps for mechanized or collaborated farming.

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Studies on the Various Utilization of Microbial Formulation for the Production of Vegetable Crops (원예작물(園藝作物) 생산성(生産性)에 미치는 미생물(微生物) 제제(製劑)의 복합적(複合的) 이용연구(利用硏究))

  • Kim, Kwang-Sik;Kim, Young-Woong;Choi, Young-Soo
    • Korean Journal of Soil Science and Fertilizer
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    • v.28 no.2
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    • pp.191-205
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    • 1995
  • The carrier materials used for the development of bacterial inoculants to be effective in field were made with various carrier materials of two major forms, alginate bead and powder inoculants. Inoculants were prepared after mixing those carrier materials with Pseudomonas fluorescens SSL3 and Bacillus subtilis B5, and the treatment effects of each inoculants was investigated on cucumber, tomato, pepper and potato. Survival density of SSL3 and B5 in various carrier materials for duration of storage and the bead inoculants were better than the powder. In the powders, survival rate increased in carrier materials treated 5% skimilk. The growth condition of microorganisms in carrier materials is good at powder. When they were preserved in the long period, contamination is problem. Scanning(200 to 600nm) of the P. fluorescens SSL3 supernatant in centrifuged MKB broth incubated for 48h had two main peaks, pyochelin(300nm) and pyoverdin(400nm). The potato yield in field experiments of spring, treated with bead formulas showed increase of 22~29% in whole potato breeds as compared with control, because the bead formulas degraded, and released the antibiotic microorganisms in slow and constant rate. In the pot experiment, there were significant difference in soil, wheatbran, and bead formed wheatbran.

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Effect of antioxidation and antibacterial activity on crude extract and Characterization of American Cockroaches (Periplaneta americana L.) in Korea (국내 서식 미국바퀴(Periplaneta americana L.)의 특성 및 추출물의 항산화·항균 효과)

  • Kim, Jung-Eun;Kim, Seon-Gon;Kang, Sung-Ju;Kim, Chun-Sung;Choi, Yong-Soo
    • Journal of Sericultural and Entomological Science
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    • v.53 no.2
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    • pp.135-142
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    • 2015
  • The American cockroaches, Periplaneta americana L. was the most important worldwide pest species. It has been an public health problems. We were determinated life cycle and extraction of crude extracts by chemical reagents from cockraches (P. americana L.). The extracted crude solution has been antibacterial activity to gram negative bacteria (Pseudomonas aeruginosa, $6.44{\pm}1.03mm$), gram positive bacteria (Bacillus subtilis, $1.88{\pm}0.40mm$), and fungus (Candida albicans, $5.61{\pm}0.57mm$) using radial diffusion assay. We were analysed of up-regulation of Glutathione-S-transferases (GSTs) stimulation, indicating that antioxidantial protein from various classes are simultaneously expressed in a single insect upon infection or injury. The gene from Periplaneta americana L. were cloned, analysed sequence, and measured protein expression by Real Time PCR (Polymerase Chain Reaction).

Optimization of Extraction of Functional Components from Black Rice Bran (흑미 미강의 기능성 성분 추출 공정 최적화)

  • Jo, In-Hee;Choi, Yong-Hee
    • Food Engineering Progress
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    • v.15 no.4
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    • pp.388-397
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    • 2011
  • The purpose of this study was to determine the optimum ethanol extraction conditions for maximum extraction of functional components such as ferulic acid, oryzanol, and toopherol from black rice bran using Response Surface Methodology (RSM). A central composite design was applied to investigate the effects of the independent variables of solvent ratio ($X_{1}$), extraction temperature ($X_{2}$) and extraction time ($X_{3}$) on the dependent variables such as total phenol components ($Y_{1}$), total flavonoids compounds ($Y_{2}$), electron donating ability ($Y_{3}$), $\gamma$-oryzanol ($Y_{4}$), ferulic acid ($Y_{5}$) and $\alpha$-toopherol components ($Y_{6}$). ANOVA results showed that coefficients of determination (R-square) of estimated models for dependent variables ranged from 0.8939 to 0.9470. It was found that solvent ratio and extraction temperature were the main effective factors in this extraction proess. Particularly, the extraction efficiency of ferulic acid, $\gamma$-oryzanol and $\alpha$-toopherol components were significantly affected by extraction temperature. As a result, optimum extraction conditions were 20.35 mL/g of solvent ratio, 79.4$^{\circ}C$ of extraction temperature and 2.88 hr of extraction time. Predicted values at the optimized conditions were acceptable when compared with experimental values.

Assessment of Applicability of a Calcium Carbonate-Alginate Beads as Neutralizer for the High Cell Density Cultivation of Isolated Sourdough Lactic Acid Bacteria (Sourdough에서 분리된 유산균의 고농도 배양을 위한 중화제로서 Calcium Carbonate-Alginate Bead의 이용가능성 평가)

  • Jung, Seung-Won;Lee, Kwang-Geun;Kim, Cheol Woo;Lee, Su Han
    • Food Engineering Progress
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    • v.14 no.3
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    • pp.208-216
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    • 2010
  • Lab scale experiments were conducted in order to assess the applicability of $CaCO_{3}$-alginate beads as neutralizer for the high cell density cultivation and prepare the direct vat inoculation cultures of isolated sourdough lactic acid bacteria. With increasing the amount of bead and decreasing the diameter of bead in acidic solution, the neutralizing effect of $CaCO_{3}$-alginate bead became higher. In batch process with $CaCO_{3}$-alginate beads, Lactobacillus amylovorus DU-21 isolated from sourdough showed the highest viable cell counts and optical density in MRS broth. The values of viable cell counts and optical density were 9.996 log CFU/mL and 3.97, respectively. Experiments on the conditions which increase viability during lyophilization were carried out and the following results were obtained; 15% glycerol revealed the high cryoprotective effect on the concentrated cultures during lyophilization among the two cryoprotective agents. Consequently, $CaCO_{3}$-alginate beads and 15% glycerol were found to be useful not only to cultivate Lactobacillus amylovorus DU-21 but also to preserve strain.