• Journal of the Korean Applied Science and Technology
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• v.20 no.3
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• pp.204-211
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• 2003

Poly(oxypropylene-oxyethylene glycol) block copolymer(PBC) oil dispersant, which has low toxicity, high biodegradability, and an excellent dispersion efficiency to crude oils and weathered W/O emulsion was prepared by blending PBC, poly(oxyethylene) oleate, and sorbitan monooleate. The dispersing efficiency was measured by swirling flask method. The PBC oil dispersant had an excellent dispersing efficiency to weathered oil products formed as stable W/O emulsion, and the low toxicity, such as 4000 ppm to Oryzias Latipes(24 hr, TLM), Brine Shrimp Artemia(24 hr, TLM).

• Computers and Concrete
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• v.20 no.3
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• pp.257-262
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• 2017

This study aims to develop a signal processing scheme to accurately predict the thickness of concrete slab using air-coupled impact-echo. Air-coupled impact-echo has been applied to concrete non-destructive tests (NDT); however, it is often difficult to obtain thickness mode frequency due to noise components. Furthermore, apparent velocity in concrete is a usually unknown parameter in the field and the thickness of the concrete slab often cannot be accurately measured. This study proposes a signal processing scheme using guided wave analysis, wherein dispersion curves are drawn in both frequency-wave number (f-k) and phase velocity-frequency ($V_{cp}-f$) domains. The theoretical and experimental results demonstrate that thickness mode frequency and apparent velocity in concrete are clearly obtained from the f-k and $V_{cp}-f$ domains, respectively. The proposed method has great potential with regard to the application of air-coupled impact-echo in the field.

• Journal of Astronomy and Space Sciences
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• v.27 no.4
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• pp.309-318
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• 2010

We introduce a technical approach for reducing three-dimensional infrared (IR) spectroscopic data generated by integral field spectroscopy or slit-scanning observations. The first part of data reduction using IRAF presents a guideline for processing spectral images from long-slit IR spectroscopy. Multichannel image reconstruction, Image Analysis and Display (MIRIAD) is used in the later part to construct and analyze the data cubes which contain spatial and kinematic information of the objects. This technic has been applied to a sample data set of diffuse 2.1218 ${\mu}m$ $H_2$ 1-0 S(1) emission features observed by slit-scanning around Sgr A East in the Galactic center. Details of image processing for the high-dispersion infrared data are described to suggest a sequence of contamination cleaning and distortion correction. Practical solutions for handling data cubes are presented for survey observations with various configurations of slit positioning.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.07a
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• pp.467-469
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• 2001

KAM200 which can be used electroluminescence binder is cyano material. In this study, we have fabricated KAM200 thin film by Spin-Coating method. And we have studied the electical properties of KAM200 thin films. In the I-V characteristics, the current decreases as the voltage overflow definite voltage immediately. And that definite voltage depend on thickness of KAM200 material. In the case of thickness is 1.9[$\mu\textrm{m}$], definite voltage is 7[V]. And that's electrical field 3.86[MV/m]. The dielectric properties of KAM200 thin film is investigated by measuring dielectric dispersion and absorption. KAM200's Relative dielectric constant is 10.25, and it has high permittivity compared with different materials.

• Proceedings of the KIEE Conference
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• 1998.11c
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• pp.761-763
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• 1998

In this paper, Co-Cr thin films which are known for a excellent perpendicular magnetic recording media were prepared. Changing target- substrate distance, Ar gas pressure and arriving atoms, the incident angle and c-axis orientation properties by using the facing targets sputtering system. We evaluated the c-axis dispersion angle by measu ring half-height width with Micro area X-Ray Diffractometer, measured the thickness of thin film with Ellipsometer. The magnetic properties were compared measuring in-plane squareness and perpendicular coercivity with vibrating sample Magnetometer.

• Elastomers and Composites
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• v.24 no.2
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• pp.105-109
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• 1989

Liquid phase adsorption of organic compounds solution on the activated carbon fiber was measured by chromatographic method in a packed column. Adsorption equilibrium constant Ka of dextrose solution was found to be $72.5cm^3/g$ on ACF without bacteria growth, while in the bacterial ACF packed column Ka was $87.9cm^3/g$. It is suggested that for biological ACF there is a large contribution of bacterial activity to the adsorption equilibrium constant. Axial dispersion coefficient Ez was determined to be in proportional to flow rate and Pe=dpu/Ez independent or existence or bacteria.

• Proceedings of the Polymer Society of Korea Conference
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• 2006.10a
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• pp.279-279
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• 2006

We report a fabrication of carbon nanotube (CNT) monolayer thin film using liquid-liquid interface. The multiwalled carbon nanotube (MWCNT), which were synthesized by the alumina template method formed a monolayer at the liquid-liquid interface after sonicating the MWCNT water-oil dispersion. Moreover, with the addition of ethanol, the MWCNT monlayer was also formed at the liquid-liquid interface. The monolayer is transferable onto solid substrates and the transferred film was observed using atomic force microscopy (AFM)

• Smart Structures and Systems
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• v.13 no.1
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• pp.155-171
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• 2014

Various monitoring techniques are now available for structural health monitoring and Acoustic Emission (AE) is one of them. One of the major advantages of the AE technique is its capability to locate active cracks in structural members. AE crack locating approaches are affected by the signal attenuation and dispersion of elastic waves due to inhomogeneity and geometry of reinforced concrete (RC) members. In this paper, a novel technique is described based on signal processing and sensor arrangement to process multisensory AE data generated by the onset and propagation of cracks and is validated with experimental results from an in-situ load test. Considering the sources of uncertainty in the AE crack location process, a methodology is proposed to capture and locate events generated by cracks. In particular, the relationship between AE events and load is analyzed, and the feasibility of using the AE technique to evaluate the cracking behavior of two RC slab strips during loading to failure is studied.

• Journal of ILASS-Korea
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• v.5 no.4
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• pp.33-39
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• 2000

The behavior of the 2-stage spray was studied by using the schlieren method with the high pressure common-rail injection system. The spray injected 2 times with the interval of $0.3ms{\sim}1.5ms$ between the 1st and the 2nd spray in a modeled combustion chamber of constant volume bomb. In this case, the quantity of injected fuel of 1st and 2nd also changed. The schlieren photograph shows that the 2nd spray goes further away than the 1st spray when the quantity of the 1st spray is less than that of the 2nd spray. The dispersion of the vapour to the combustion chamber is not affect in a 10% of 1st spray quantity. When the 1st spray quantity is more than the 2nd spray, the vapour scattering of spray is good.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2001.04a
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• pp.381-384
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• 2001

The combined stirring method to uniform distribution of particle is consisted of two strring force both electro-magnetic stirring generated from induction heating and mechanical stirring with graphite stirrer. PMMC billets were fabricated with the volume fractions ranged from 0% to 20% and particle sizes ranged from 14$\mu\textrm{m}$ to 25$\mu\textrm{m}$. It is important to control the size of primary ${\alpha}$-AI solid particles because it could become the cause of the particle pushing or capture phenomena from the fact that secondary dendrite arm spacing size depends on the cooling rate during the solidification in hypoeutectic AI-Si alloy.