• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.20 no.4
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• pp.419-426
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• 2011

In this study, an experimental and theoretical program were carried out to determine the cutting forces and chip formation at different cutting speeds using a 0.4mm nose radius ceramic insert and -7 rake angle for non heat-treated AISI 4140 (27HRc) and heat-treated AISI 4140 (45 HRc) steel. The results obtained were compared to show the hardness differences between the materials. The secondary deformation zone thicknesses when comparing the two materials show different physical structure but similar size. These results were also discussed in light of the heat treatment and the effects it had on the machining characteristics of the material. In addition, the Oxley Machining Theory was used to predict the cutting forces for these materials and a comparison made. The predicted cutting performances were verified experimentally and showed good agreement with experimental data.

• Explosives and Blasting
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• v.25 no.1
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• pp.79-84
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• 2007

This study was conducted to investigate suitable material properties for scaled model test. Unconfined compressive strength of each material was obtained through former studies. UCS calculated from scale factor and former studies results were compared. Two results had a similar tendency, cement mortar is better than plaster for scaled model test.

• Journal of the Korea Furniture Society
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• v.17 no.2
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• pp.1-7
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• 2006

A chinese wood species called China Hongmu, is an excellent wood to make high quality furniture owing to attracting color, beautiful grain, and durability. Hongmu is not a tree or wood species name. The general designation in Hongmu group is a similar to one of its density, structure, color and use. Hongmu considers more than 30 hardwood species of Pterocarpus, Dalbergia, Diospyros, Millettia, and Cassia. According to the macrostructural characteristics and properties, Hongmu group can be classified into 8 groups which are Zitanmulei, Hualimulei, Heisuanzhimulei, Hongsuanzhimulei, Xiangzhimulei, Wumulei, Tiaowenwumulei and Jichimulei. In this paper, the growing areas, scientific names and identifiable characteristics of these Hongmu group species were introduced for help to identify China Hongmu and its products in the market as well.

• Journal of Microbiology and Biotechnology
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• v.13 no.4
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• pp.483-486
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• 2003

3'-[S-Methyl-cysteinyl]-3'-amino-3'-deoxy-N,N- dimethyl adenosine, cystocin, is a biosynthesized antibiotic material newly identified from Streptomyces sp. GCA0001. Its structure was found to be similar to puromycin, where the terminal tyrosine is replaced by a methyl cysteine. NMR data prove that the 3-ammo ribose is connected to dimethylaminopurine through the anomeric carbon at 1'-carbon. The methyl cysteinyl unit is connected to the amino unit of ribose by peptide bond. The verification of the structure was performed by comparing the puromycin nucleosides resulted from the hydrolysis of cystocin and puromycin, respectively. Antibiotic activity of cystocin against Streptococcus was found to be two times more potent than that of puromycin.

• Journal of the Korean Society for Advanced Composite Structures
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• v.5 no.1
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• pp.16-21
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• 2014

In the study, tensile, compression and in-plane tests about longitudinal direction of glass fiber were performed. Also, to obtain the material properties of GFRP fabric composite, tensile test was performed. All test were performed by the test method of ASTM. Maximum compressive strength was smaller than the maximum tensile strength at the longitudinal direction test results. Elastic modulus of the tensile and compressive was almost similar at the compression test results in the longitudinal direction. Based on the GFRP fabric composite test results, GF91 was showed good performance at maximum compressive, maximum strain and elastic modulus.

• Proceedings of the KOSOMBE Conference
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• v.1997 no.05
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• pp.439-442
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• 1997

For the treatment of arteriovenous malformations (AVM), we developed a new liquid embolic material and named it Embol. The material was pre-tested in an in vitro AVM model and tested in rete mirabile of pigs that is similar in structure with the AVM in human. We report on the construction of the in vitro AVM model, the pre-test results of Embol in the AVM model, and the animal test result in pig rete mirabile.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.07a
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• pp.1036-1038
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• 2001

The sapphire orientation dependence of the crystallization of ZnO thin films has been studied using real-time synchrotron x-ray scattering. The amorphous ZnO thin films with a 2400-${\AA}$-thick were grown on sapphire(110) and sapphire(001) substrates by radio frequency magnetron sputtering at room temperature. The amorphous ZnO films were crystallization into epitaxial ZnO(002) grains both on the sapphire(110) and on the sapphire(001) substrates. The epitaxial quality, such as mosaic distribution and crystal domain size, of the ZnO grains on the sapphire(110) is high, similar to that of the ZnO grains on the sapphire(001). With increasing the annealing temperature to 600$^{\circ}C$, the mosaic distribution and the crystal domain size of ZnO(002) grains in the film normal direction was improved and decreased, respectively.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.07a
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• pp.1039-1042
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• 2001

A method for designing antireflection (AR) and antistatic (AS) films by the use of conducting polymer as an electrically conductive transparent layer is proposed. The conducting AR film is composed of four-layer with alternating high and low refractive index layer: silicon dioxide (n=1.44) and titanium dioxide (n=2.02) prepared at low temperature by sol-gel method are used as the low and high refractive index layer, respectively. The 3,4-polyethylenedioxythiophene (PEDOT) which has the sheet resistance of 10$^4$$\Omega$/$\square$ is used as a conductive layer. Optical constant of ARAS film was measured by the spectroscopic ellipsometer and from the measured optical constants the spectral properties such as reflectance and transmittance were simulated in the visible region. The reflectance of ARAS films on glass substrate was below 0.8 %R and the transmittance was higher than 95 % in the visible wavelength (400-700 nm). The measured AR spectral properties was very similar to its simulated results.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.07a
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• pp.503-506
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• 2001

This paper presents leakage magnetic field and leakage inductance calculations in current transformer by means of 3-D Integral methods. From the distribution diagram of leakage magnetic flux to be analyzed using program called TRACAL3, it confirms a parallel to the winding axis direction of the leakage flux lines in the air gap between the windings. The leakage inductances L$\sub$r1/ and L$\sub$R2/ of the primary and secondary windings were calculated, their values are 4.23 mH and 0.49 mH, respectively. They are also similar to the measured values of the leakage inductances for the experimental verification, 4.06 mH and 0.47 mH.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1995.11a
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• pp.118-121
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• 1995

Fabrication and a new analytical expression for the capacitance characteristics of hydrogenerated amorphous silicon thin film transistors(a-Si:H TFTs) is presented and experimentally verified. The results show that the experimental capacitance characteristics are easily measeured. Measured transfer and DC output characteristic curves of a-Si:H TFT are similar to those of the standard MOSFET-IC. The capacitances on bias voltages are in good agreement with experimental data. This capacitance characteristics is suitable for incorporation into a circuit simulator and can be used for computer-aided design of a-Si thin film transistor integrated circuits.