• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2008.11a
• /
• pp.187-191
• /
• 2008

It is necessary to develop a technology for effectively controling explosive spalling of high strength concrete caused increasing construction of high rise building and putting up the fireproof standard of high strength concrete by MLTM (Ministry of Land, Transport and Maritime Affairs). Accordingly, it was investigated basic properties such as slump, air content and compressive strength, and fire resistance properties of high strength concrete using polypropylene fiber for field application as a countermeasure for explosive spalling of concrete on fire in this study, As a test result, it was confirmed that PP fiber is available as fire resistance method of high strength concrete.

• Multiscale and Multiphysics Mechanics
• /
• v.1 no.4
• /
• pp.327-340
• /
• 2016

Poly(${\epsilon}$-caprolactone) (PCL) diol, with good biodegradation and biocompatibility, is one of the widely used soft segments (SSs) in composing bio-polyester-urethanes (Bio-PUs), which show great potential in both biomedical and tissue engineering applications. Properties of Bio-PUs are tunable by combining SS monomers with different molecular weights, structures, modifications, and ratio of components. Although numbers of research have reported many Bio-PUs properties, few studies have been done at the molecular scale. In this study, we use molecular dynamic (MD) simulation to construct atomistic models for two commonly used PCL diol SSs with different molecular weights 1247.58 Da and 1932.42 Da. We compare the simulation results by using two widely used classical force fields for organic molecules: Consistent Valence Force Field (CVFF) and CHARMM General Force Field (CGenFF), and discuss the validity and accuracy. Melt density, volume, polymer conformations, transition temperature, and mechanical properties of PCL diols are calculated and compared with experiments. Our results show that both force fields provide accurate predictions on the properties of PCL diol system at the molecular scale and could help the design of future Bio-PUs.

• Korean Journal of Mathematics
• /
• v.21 no.1
• /
• pp.91-100
• /
• 2013

This paper is a direct continuation of [1] and [2]. In this paper we investigate some properties of ES-curvature tensor and contracted ES-curvature tensor of g - $ESX_n$. Also, we study the field equations in the n-dimensional ES manifold g - $ESX_n$.

• Communications of the Korean Mathematical Society
• /
• v.20 no.2
• /
• pp.231-238
• /
• 2005

In this paper, we study the arithmetic properties of orders in a quaternion algebra over a dyadic local field and we find the mass formula of orders.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2007.11a
• /
• pp.450-451
• /
• 2007

Dot-patterned carbon nanotube (CNT) emitters with excellent field emission properties were fabricated using photosensitive CNT paste. We carried out a parametric study on the compositions and the fabrication processes of the paste, in particular, by ball milling CNTs, which were optimized in terms of dot shapes and their field emission characteristics. The ball milling process improved the field emission current of the dot-patterned CNT emitters several times higher than that of the non-milled paste.

• International Journal of Highway Engineering
• /
• v.19 no.2
• /
• pp.45-53
• /
• 2017

PURPOSES: The objectives of this study are to develop a new cold-applied crack sealant and to evaluate its properties and field applicability by comparing with other conventionally used crack sealants. METHODS : A new cold-applied crack sealant was developed by using neoprene latex to improve material properties. The fundamental properties such as viscosity, residue %, penetration, and softening point of the developed crack sealant were tested by TxDOT criteria to evaluate crack sealing capability. Moreover, the performance of the developed cold-applied crack sealant was evaluated under both laboratory and field conditions. In the laboratory, the bond property was evaluated using the developed cold-applied crack sealant and conventional hot-applied crack sealant by the bond-properties test standardized under ASTM D 6690. In the field, test sections were constructed on three areas: a trunk road, bus-only lane, and motorway, with the developed crack sealant and three conventional crack sealants. After construction, early field-inspection was performed on the test sections. RESULTS AND CONCLUSIONS : Overall, the developed cold-applied crack sealant demonstrates reasonable storage stability, durability, and bond property compared to conventional hot-applied crack sealants. From the test sections, it was established that the developed cold-applied crack sealant does not pose construction issues. Moreover, the early performance was verified through field inspection. However, as the field inspection was conducted a week after the construction, it is necessary to conduct an inspection of performance from a long-term point of view.

• Journal of the Korean housing association
• /
• v.16 no.5
• /
• pp.75-81
• /
• 2005

The purpose of this study is to shed light on the field dynamics of 'lived space' in the light of our intuitive experiential contents by way of investigating three properties of space. While finding inspirations in the field theory of modern physics, investigation of our intuitive responses to the physical and spatial environment leads us to a coherent view of matter and space. We find then that our lived world is more than a system of inert matter; it is a dynamic environment of life in which feeling and mood, spiritual meaning and value, are perpetually infused with matter. Any concept of space, if it is to be meaningful to lift has to somehow acknowledge this fact. Empty space and matter cannot be conceived as mutually exclusive and independent as in classical physics. Rather they should be seen as two different manifestations of an underlying dynamism which permeates the world. The 'properties' of space can only be understood in terms of the 'impact' of material presence. The object cannot be seen as an isolated entity, but the 'conditioning' of its surrounding space has to be understood as an integral part of its being. Lived space can thus be viewed as an emotionally charged field, or a field of emotional energy, whose properties may be described in terms of concentration, mobility and resonance.

• Journal of Sensor Science and Technology
• /
• v.26 no.3
• /
• pp.186-191
• /
• 2017

In this study, we investigated the simultaneous detection properties of organic vapor, pressure difference, and magnetic field using a single rugate-structured free-standing porous silicon (RFPS) thin film. Both the wavelength and the intensity of the rugate peaks were changed in the reflectivity spectrum measured at the thin film surface while the organic vapor was exposed to the RFPS thin film. However, when the pressure difference and the magnetic field were exposed to the film, only the rugate peak intensity was changed. Therefore, it is possible to distinguish whether or not the organic vapor is detected by simultaneously changing the rugate peak wavelength and intensity. In addition, a method of distinguishing between the pressure difference and the magnetic field detection signal has been derived by rapidly modulating the direction of the magnetic field. This study shows that it is possible to simultaneously detect and distinguish various objects using a single RFPS thin film, and it is found that porous silicon can be utilized as a sensor sufficiently.

• Proceedings of the Korean Magnestics Society Conference
• /
• 2011.06a
• /
• pp.93-95
• /
• 2011

In this study we tried to measure the effect of magnetic field on the dielectric properties of $BaTiO_3-MgFe_2O_4$ soft magnetic composite. Composites with different weight percents of ferroelectric and ferromagnetic phases were subjected to magnetic field in the order of 0 to 450 Oe and the variation of the dielectric properties was observed. The Variation of dielectric polarization was discussed in terms of Maxwell-Wagner type polarization in particulate composites.

• Korean Journal of Veterinary Service
• /
• v.15 no.1
• /
• pp.67-80
• /
• 1992

Avian reoviruses have been implicated in respiratory disease enteric conditions including Cloacal pasting in young thicks, pericarditis, hydropericardium, anaemia with swollen spleen and liver and petechiation of skeletal muscle and viral arthritis. This study was conducted to examine properties of reovirus field 3 strains isolated from affected broiler from several farms. An infectious agent was isolated from leg tendons and intestine of broiler with clinical tenosynovitis. The agent grew well on the chicken embryo kideny cells(CEK). One of them produced cytopathic effects(CPE) of round type and formed intranuclear inclusions, and the other was characterized by CPE of syncytical type and cytoplasmic inclusion. The properties and serological classification of field strains were examined by hemagglutin test, virus neutralization test, agar gel precipitin, electropherotype. They showed no hemagglutination reactions and not well neutralization and to possess common antigens detectable by AGP test. RNA electropherotype presented 10 segment band as the previous report. These data suggest that the field strains and standard strains (1133, 1733) may be the same group.