• 한국세라믹학회지
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• 제45권3호
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• pp.146-149
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• 2008

Strontium-substituted $Sr_{1-x}Ba_xAl_2O_4:Eu^{2+},\;Dy^{3+}$ compositions were prepared by the solid state synthesis method. These compositions were characterized for their phase, crystallinity and morphology using powder x-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques. Photoluminescence properties were investigated by measuring excitation spectra, emission spectra and decay time for varying Ba/Sr concentrations. Photoluminescence results show higher luminescence and long decay time for $Sr_{1-x}Ba_xAl_2O_4:Eu^{2+},\;Dy^{3+}$(x=0). This is probably due to the influence of the 5d electron states of $Eu^{2+}$ in the crystal field. Long persistence was observed for these compositions due to $Dy^{3+}$ co-doping.

• 한국식품영양과학회지
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• 제25권3호
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• pp.513-518
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• 1996

In order to investigate the characteristics of alcohol fermentation by Saccharomyces cerevisiae, compositions and free sugar content of dried riped pumpkin powder were determined. The proximate compositions of ripe pumpkin powder were as follows: moisture 11.98%, total sugar 62.18%(dried weight basis 70.64%), protein 13.38%, lipid 0.85%, fiber 7.07% and ash 4.54%. The compositions of free sugar in well ripe pumpkin were: glucese 85.36mg/g, fructose 40.68mg/g, sucrose 68.25mg/g, lactose 18.60mg/g and maltose 3.82mg/g. The optimum conditions for alcohol fermentation by S. cerevisiae were as follows; incubation temperature of 3$0^{\circ}C$, initial pH of 6.0, ripe pumpkin powder concentration of 10% and cells inoculation of 1.3$\times$$10^{6}$ cells/ml liquid medium. Ethanol production under the optimum conditions was 5.95g/100g in liquid medium containing 10% ripe pumpkin powder after 4 days incubation.

• 환경위생공학
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• 제17권1호
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• pp.28-35
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• 2002

본 연구 목적은 계측저항이 없는 열선유속계를 이용하여 매립지 가스의 유량을 산정할 때 가스조성에 의해 발생되는 계측오차를 최소화할 수 있는 방안을 제시하고자하였다. Rotor meter와 가스조성 밀도를 이용하여 산정한 관 중심유속을 계측저항이 없는 열선유속계를 이용하여 구한 관 중심유속을 비교함으로서 계측오차를 측정하였다. 실험결과 열선 유속계와 rotor meter를 이용한 매립지 가스유속 계측오차의 최소화 방안을 통하여 매립지 가스유량의 오차 범위를 10% 이내로 최소화 할 수 있는 것으로 조사되었다.

• Journal of the korean society of oceanography
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• 제32권3호
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• pp.138-144
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• 1997

The tidal deposits in the Haenam Bay, southwest coast of Korea, are stratigraphically divided at least into two units (Unit I of Holocene and Unit II of late Pleistocene) based on the obtained vibracoring sediments. In Unit I, clay minerals of illite, chlorite, kaolinite and smectite are observed as similar to those of the other modern tidal deposits. Of note, however, is the absence of smectite and chlorite in the upper part of Unit II compared with the clay mineral compositions of Unit I. It is concluded that the subaerial weathering and diagenetic effects rather than depositional processes are responsible for the positive and characteristic differences in clay mineral compositions between two units, that is, the upper part of Unit II was exposed subaerially and weathered diagenetically prior to the late Holocene transgression. Therefore, the bounding relationship between Unit I and Unit II is unconformable.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2005년도 총회 및 춘계학술발표회
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• pp.405-407
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• 2005

To evaluate the main hydrogeochemical characteristics, river waters are investigated using element리 and isotopic compositions in South Korea. In this area, the chemical compositions are mostly classified into three groups; $Ca^{2+}-{HCO_3}^-$ type, $Ca^{2+}-Cl^{-}-{NO_3}^-$ type and $Ca^{2+}-{HCO_3}^{-}-Cl^{-}-{NO_3}^-$ type. These types are affected by two major factors: water-rock interaction and anthropogenic inputs such as sewage and fertilizers. Based on the values of ${\delta}^{18}O$ and ${\delta}D$, most of waters are originated from precipitation except two samples contaminated. The lithology and geography of basins mainly control the water chemistry. Elemental and isotopic compositions show that water chemistry are mainly controlled by three end members, especially by carbonate dissolution, and suggest that anthropogenic input affect the water chemistry. Also, three weathering sources are identified: silicates, dolomite and limestone.

• 한국산업융합학회 논문집
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• 제16권3호
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• pp.75-83
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• 2013

The purpose of this study was to investigate its characteristics of the spatial compositions at several kindergartens in Daegu area. Through this, the study is intended to provide the basic data of the efficient building planning and facility operations in the kindergarten. The results of this study are as follows. 1) Recently, the spatial compositions of kindergarten was classified as education, educational aids, educational support, teacher / administration, and public service area. 2) The concept of special classroom space was set up in all the surveyed facilities. This space was used for small-scale events, meals, and game features. 3) Support staff, including teachers, are insufficient for the service space. 4) The size of total land area of the facility's public service area was affecting. 5) The Lobby and aisle space of the surveyed facilities was used as a multipurpose space. 6) In response to diverse educational content, the direction to plan should be seperated by multi-space.

• 동아시아식생활학회지
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• 제10권1호
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• pp.37-41
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• 2000

Physiocheical properties and chemical compositions of two plums(Oishiwase, Formosa ) produced in Kimcheon area were investigated . Chemical compositions of two plum cultivars were similar except nitrogen free extract(NFE) . NFE value of Formosa was higher than Oishiwase . Alcohol insoluble substance content, total soluble pectin, total sugar content and total organic acid content of Oishiwase were 2.08%, 14.16%, 5.07% and 949.16mg%, respectively. In case of Formosa cultivar, those were 50%, 15.42%, 5.91% and 985.91mg%, respectively. Fructose content among free sugars of two plum cultivars range from 3.97-3.45% and the other were glucose, sucrose and inositol, 1.83-1.53%, 0.08-0.05% and 0.04-0.03%, respectively. Malic acid content was 35-373mg% and others were levulinic acid, lactic acid, citric acid, succinic acid and fumaric acid in the decreasing order.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1988년도 추계학술대회 논문집
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• pp.47-49
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• 1988

This paper discusses dynamic properties of bubble garnet thin films. The dynamic properties considered are Gilbert damping parameters, saturation velocity, and wall mobility. The parameters are evaluated to facilitate the search for desirable garnet thin film compositions. Given bubble diameter and Q-value, the computer prints out all compositions which meet the desired requirements. The computer model determines magnetization, anisotropy, damping, velocity, mobility among others from the film compositions. The computer modeling program is described by an algorithm detailing its operation.

• 한국환경과학회지
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• 제7권2호
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• pp.157-164
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• 1998

preliminary study on the chemical compositions of forty seven precipitations from March 1994 to May 1995 In Yeoncheon-gun, which Is adjacent to the southern boundary of demilitarized zone (DMZ) in the northernmost tip of Kyunggi Province has been Performed. The metal cation and anion concentrations were measured by atomic absorption spectrometer and ion chromatography, respectively. pH/lon meter and direct nesslerization method were used for the concentration measurements of $H^+$ ion and $NH_46+$ ions, respectively Based on the data, the quantitative orders of the cation and anion average concentrations were $Ca^{2+}>NH_4^+>Na^+>K^+>Mg^{2+}>H^+ and SO_4^{2+}>Cl^-> NO_3^-$, respectively..The ratio of average total anion concentration to average total cation concentration was 0.97. The average pH value of the precipitations was 5.60. These results, correlation coefficients between the ion concentrations, and monthly variations of pH value and precipitation amount are used for chemical analysis on the environmental Pollution and Pollutant sources In Yeoncheon-gun of Kyunggi province near DMZ.

• 한국세라믹학회지
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• 제20권1호
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• pp.55-62
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• 1983

the preliminary work on the prepartion of fine hydroxyapatite powder and the synthesis of dense hydroxyapatite ceramic from the powder were investigated for the development of artificial bone and tooth materials for implants. The effects of the process variables such as compositions of the raw materials the initial pH of the solutions and sintering temperature on the physical properties were investigated in order to determine the optimum conditions for the fabrication of tooth implant material. As the initial pH of the solutions was increased in the range of 10-11.6 the initial particle size of precipitates was decreased thus the sinterability of precipitates was improved. It was found that the composition of calcium rich of 1.75 in Ca/P mole ratio exhibited better sinterability and mechanical strength of the apatite ceramics for example the highest value of Vicker's hardness obtained from the compositions of 1.75 in Ca/P mole ratio was 764±30 Kg/mm2 compared to the maximum value of 600 kg/mm2 obtained from the compositions of 1.67 in Ca/P mole ratio.