• KCI Concrete Journal
• /
• 제14권3호
• /
• pp.111-120
• /
• 2002

This study proposes a joint model consisting of different types of members as a new structural system, and then investigates the resulting structural behavior. The joint model consists of a concrete-filled steel tube column (CFT) together with a steel reinforced concrete at the end plus reinforced concrete beam at the center. For comparison, two other joint models were designed, that are, a CPT with a reinforced concrete beam, and a CFT with a steel reinforced concrete at the end plus steel concrete beam at the center, then their joint capacity and rigidity, energy absorption capacity, etc., were all investigated. From the results, the CFT column with a steel reinforced concrete at the end plus steel concrete beam at the center was outstanding in terms of its capacity and rigidity. The results of this analysis demonstrate that an adequate connection type and reinforcement method with different materials of increasing the rigidity, thereby producing a capacity improvement along with protection from pre-fractures.

• Journal of Advanced Marine Engineering and Technology
• /
• 제15권3호
• /
• pp.31-38
• /
• 1991

Due to the structural complexity and the mutual interference of "water columns", the estimations of absorption power for a large wave energy conversion devices of flosting type in ocean could not achieve the desired results. Thus, in this paper the authors will propose a new methodology based on the three dimensional source ditribution method. We distributed the source to the device and the thin & light plate in "water column", And from the behaviour of this plated, the power and the pressure in water column are calculated. But, yet method should be proved to be valid by experiment.

• 한국구조물진단유지관리공학회지
• /
• 제19권2호
• /
• pp.32-38
• /
• 2015

• Bulletin of the Korean Chemical Society
• /
• 제23권4호
• /
• pp.545-549
• /
• 2002

A simple and rapid technique for the separation and preconcentration of lead in water and biological samples has been devised. Preconcentrationis based on the depositionof analyte onto a column packed with dithizone immobilized on sodium dodecyl sulfate coated alumina at pH $\geq$ 3. The trapped lead is eluted with 5 mL of 4 M nitric acid and determined by flame atomic absorption spectroscopy. A sample of 1 L, results in a preconcentration factor of 200 and the precision at 20${\mu}g$ $L^{-1}$ is 1.3%(n=8). The procedure is applied to tap water, well water, river water, vegetable extract and milk samples, and accuracy is assessed through recovery experiments and by independent analysis by furnace atomic absorption.

• 천문학회보
• /
• 제44권1호
• /
• pp.67.4-67.4
• /
• 2019

We present preliminary results of our long-term (2009-2017) observing campaign using the NASA IRTF at Mauna Kea, to obtain $2-5{\mu}m$ spectroscopy of ~200 red point sources in the line of sight to the Galactic center. Point sources in our sample were selected from the mid-infrared images of the Spitzer Space telescope, and include candidate massive young stellar objects, which have previously been identified from our Spitzer/IRS spectroscopy. We show high foreground extinction of these sources from deep $3.1{\mu}m$ H2O ice and aliphatic hydrocarbon absorption features, suggesting that they are likely located in the central 300 pc region of the Galactic center. While many sources reveal photospheric $2.3{\mu}m$ gas CO absorption, few of them clearly indicate $3.54{\mu}m$ CH3OH ice absorption, possibly indicating a large dust column density intrinsic to a massive young stellar object.

• 한국식품과학회지
• /
• 제30권2호
• /
• pp.319-323
• /
• 1998

치자의 황색소를 L. plantalium, V. vulinficus, P. aeruginosa, S. mutans, B. subtilis, S. epidermidis, S. typhimurium, S. aureus 등 8종의 균주의 배지에 첨가하고 배양하면 청녹색계 색소로 변환된다. 미생물에 의해 변환된 색소의 분광학적 성질을 경시적으로 추적하면 색소의 변환형태는 3군으로 나뉘어지며, 색차계로 측정된 ${\Delta}E$ 값의 변환형태도 그러하였다. 청녹색계색소로의 변환속도는 균주에 따라 차이를 보였는데 8종의 미생물중 S. epidermidis는 가장 빨라 배양 16시간에 색소변환이 완성되었다. 치자황색소와 변환된색소는 $H_2O-MeOH$ 용매계에 의한 Amberlite XAD-4 column chromatography에 의해 완전히 분리되었으며, 광과 열에 대한 저장안정성은 치자황색소보다 변환된 색소가 보다 안정함을 나타냈다.

• 한국의류학회지
• /
• 제23권1호
• /
• pp.140-146
• /
• 1999

Colorants in green tea were extracted freeze-dried and analyzed to investigate the possibility of using as a natural dye. Fractionation of the colorants was carried out by column chromatograpy. Colorants in green tea were eluted into five fractions. All the fractions except fraction F2 showed absorption peakat 280nm. Fraction f2 showed absorption peak at 270nm and broad peak at 350nm, From the IR analysis it is speculated that fractions F2-F5 having similar stucture but different molecular weight are catechis. Silk fabrics dyes with fractions F1-F4 showed yellowish red color while sample dyed with fraction F5 showed red color. The colorants from green tea infusion was applied to silk wool nylon cotton and rayon fabrices. It showed relatively good affinity to protein and polyamide fibers bur low affinity to cellulose and regenerated cellulose fibers.

• 상하수도학회지
• /
• 제22권4호
• /
• pp.413-420
• /
• 2008

In order to utilize cinder melting slag as a filter media to control the quality of early rainwater, its environmental stability was verified by heavy metal elution experiment and improved by pre-treatment. Possibilities of improving its function as an absorbent was considered. Absorption characteristics of melting slag before and after the pre-treatment were analyzed by heavy metal equilibrium and stationary-phase column experiments, which in turn were analyzed by comparison experiment with activated carbon. As a result of heavy metal elution experiment, every metal item existed in a much lower amount than the criteria or was not detected, implying that there is no problem recycling it. Absorption equilibrium experiment showed that the time for pre-treatment melting slag to reach the equilibrium was reduced, while the absorbed amount was greatly increased. Stationary-phase column experiment assures us that the elimination rate was not changed much by influx rate, pH and the change in packing volume rate, indicating that this melting slag can be used not only as a filter media to control the quality of early rainwater but also in many areas of water-processing.

• 한국공간구조학회논문집
• /
• 제10권1호
• /
• pp.85-93
• /
• 2010

공간구조의 지붕을 지지하는 기둥상단부에 탄소성기구를 설치하여 설계 하중을 초과하는 지진동이 가해졌을 때 이 기구의 탄소성 이력거동을 통하여 지진에너지가 흡수되는 효과를 검토한다. 이 효과로 지붕트러스로 전달되는 지진에너지가 저감되는 것을 입증하고 이러한 원리를 공간구조물의 제진설계에 활용할 수 있음을 입증한다. 트러스 형식의 지붕구조에 설계하중 이상의 외력이 가해지는 경우에는 구성부재의 좌굴파괴로 인한 건물전체의 취성붕괴가 예상되기 때문에 이러한 상황에서 구조안전성을 확보하는 설계법이 요망되며, 이 논문은 트러스 지붕에 전달되는 지진에너지를 감소시키는 설계방법을 제안하고 있다.

• Computers and Concrete
• /
• 제33권1호
• /
• pp.41-53
• /
• 2024

Under constant and cyclic axial compression, square composite short columns reinforced with Self Compacting Concrete (SCC) added with scrap rubber infilled inside steel tubes and with different types of concrete were cast and tested. The test is carried out to find the effectiveness of utilizing an aggregate manufactured from industrial waste and to address the problems associated with the need for alternative reinforcements along with waste management. The main testing parameters are the type of concrete, the effect of fiber inclusion, and the significance of rubber-infilled steel tubes. The failure modes of the columns and axial load-displacement curves of the steel tube-reinforced columns were all thoroughly investigated. According to the test results, all specimens failed due to compression failure with a longitudinal crack along the loading axis. The fiber-reinforced column specimens demonstrated improved ductility and energy absorption. In comparison to the normal-weight concrete columns, the lightweight concrete columns significantly improved the axial load-carrying capacity. The addition of basalt fiber to the columns significantly increased the yield stress and ultimate stress to 9.21%. The corresponding displacement at yield load and ultimate load was reduced to 10.36% and 28.79%, respectively. The precision of volumetric information regarding the obtained crack quantification, aggregates, and the fiber in concrete is studied in detail through image processing using MATLAB environment.