• 한국생산제조학회지
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• 제9권1호
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• pp.24-29
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• 2000

This paper is experimental study of machining characteristics about martensitic heat resisting steel STR11. Machining characteristics are different according to internal quality(chemical compositions, microscopic structure and nonmetallic inclusion) mechanical properties(tensile strength value impact value and hardness) and dynamic cutting force. Following are the results : 1. In analyzing internal quality test materials have typical martensite structure and a minute needle-shaped structure. 2. Tensile strength and reduction of area and hardness are larger. But values of elongation and impact values are smaller. Fracture surface of tensile specimen is ductile. 3, Cutting force is decreasing with cutting speed increasing 4. Cutting force is increasing with feed speed increasing.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2000년도 제21회 KOSCO SYMPOSIUM 논문집
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• pp.140-147
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• 2000

Using lobed burner, flame visualization and measurements of NOx and CO concentration in the combustor exit were carried out to evaluate the relation between the lobed structure in a burner and pollutant emission characteristics. The flame stability is enhanced by the lobed burner compared to conventional circular one. The correlation on fuel discharge velocity for flame blowout should be included on a variable related to the wall effect of the burner, because the flame blowout is observed at the burner having large perimeter. The burner having lobed structure in fuel discharge side compared to conventional burner reduces by 5% NOx emission due to lower flame intensity through flame elongation. Meanwhile the burner having lobed structure in air discharge side and both fuel and air discharge side increase the NOx emission.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 하계학술대회 논문집 D
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• pp.1401-1403
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• 1998

The composition, weight decrease, DTA, and surface structure of vinyl insulated wire with thermal treatment conditions have been investigated. The composition of Cu by EDX analysis indicates Cu, Cl, and O lines, and oxidation reaction results from thermal treatment. Thermal treated IV and HIV appeared chemical reaction at $269^{\circ}C$ and $265^{\circ}C$, respectively. SEM of thermal treated Cu at $250^{\circ}C$ disappears an elongation structure, and appears an original structure.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1997년도 춘계학술대회 논문집
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• pp.1073-1077
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• 1997

In this paper, we have studied internal quality including chemical compositions, microscopic structure and nonmetalic inclusion of test materials. We have analyzed machining characteristics including tensile strength value, impact value, hardness value etcs. Test materials are usd martensitic heat resisting steel, STR11 and STS420J2. The obtined results are as follows : 1. In analyzing internal quality, STR11 and STR420J2 have typical martensite structure and a minute needle-shaped structure. 2. Tensile strength and reduction of area and hardness value are large STR11 than STS420J2. But elongation impact are smaller STR11 than STS420J2. 3. Fracture surface of tensile speciman is ductile in STR11 and STS420J2.

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part2
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• pp.1269-1270
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• 2006

Mg-Zn-RE alloys had a novel lond period stacking ordered (LPO) structure. Their rapidly solidified powder metallurgy (RS P/M) alloys exhibited a combination of high strength and god ductility (tensile yield strength above 550 MPa and elongation above 5%). The LPO Mg-Zn-RE RS P/M alloys had high elevated temperature strength (tensile yield strength above 380 MPa at 473 K) and exhibited a high-strain-rate superplasticity at higher temperatures. In Japan, a national project for developing high strength LPO Mg-Zn-RE RS P/M alloys has started at 2003 for 5 years, which is founded by the Ministry of Economy, Trade and Industry (METI) of Japan. In the national project, project targets in materials performances have been achieved. The developed LPO Mg-Zn-RE RS P/M alloys exhibited higher tensile yield strength, fatigue strength and corrosion resistance than high strength aluminum alloys of extra-super-duralumin (7075-T6).

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 1996년도 춘계학술대회 논문집
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• pp.143-148
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• 1996

In this paper, we have studied internal quality including chemical compositions, microscopic structure and nonmetalic inclusion of test materials. We have analyzed dynamic characteristics of cutting force of milling including tensile strength value hardness etcs. Test materials are used the tempered carbon steel and the non-tempered carbon steel. The obtained results are as follows: 1.In analyzing internal quality, the tempered carbon steel have typical martensite structure and the non-tempered carbon steel have ferrite+pearlite structure. 2.Yield strength, tensile strength and hardness value are in the non-tempered carbon steel but elongation is maximum value in the tempered carbon steel. 3.Cutting force is smaller non-tempered carbon steel than tempered carbon steel when feed speed and depth of cut is constant. 4.Cutting force is smaller to the tempered carbon steel and smaller non-tempered carbon steel than tempered carbon steel when cutting conditions

• 환경위생공학
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• 제12권1호
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• pp.77-83
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• 1997

An experimental research was conducted in order to study the treatment of waste reuse system using the membrane. Cell tester which supplied by Amicon was used to compare the fluxes of various membranes. Specially investigated items in the experiment were carried out by using 5 species of microfiltration membranes as to various MLSS concentrations. From the results, it is recognized from the cell test that 0.2 $\mu $m pore-sized membrane have the most effective performance at 2000mg/L of MLSS, and physical properties of membranes such as strength, deflection, elongation, structure of pore are more important than chemical properties in microfiltration membrane.

• 청정기술
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• 제12권1호
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• pp.19-25
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• 2006

본 연구에서는 폴리에테르 계열의 폴리올과 이소시아네이트 (2,4-toluene diisocyanate) 그리고 하이드록시 아크릴레이트 (hydroxypropyl methacrylae)를 이용하여 광경화가 가능한 우레탄 메타아크릴레이트 계열의 올리고머를 합성하였다. 합성된 우레탄 메타아크릴레이트의 색상, 점도, 굴절율과 같은 기본적인 물성과 광경화후 필름에 대한 인장 강도, 신율, 영율 등을 측정하였다. 광경화 속도는 Photo-DSC를 이용하여 측정하였다. 유사한 폴리올 구조 내에서는 폴리올의 분자량이 증가하면 인장 강도, 영율, 광경화 속도는 감소하고 연신율은 증가하는 결과를 얻었다. 우레탄 메타아크릴레이트 올리고머의 관능기 숫자가 증가하면 인장 강도, 영율, 광경화 속도는 증가하고 반대로 연신율은 감소하는 결과를 얻게 되었다.

• 한국환경복원기술학회지
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• 제9권6호
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• pp.23-37
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• 2006

The purposes of this study are (1) carrying out the case study for the urban park planning in point of landscape ecology, (2) analyzing and evaluating the indicator character of the landscape ecological view on the basis of the case study and (3) proposing the urban park planning in point of landscape ecology. The results of this study are as follows. As a result of the elongation analysis among the shape indicators, especially, Dalsung Park has the highest score 0.85 and Chimsan Park has the lowest score 0.34. In case of green shape index, Bummul Park has 1.70 and Chimsan Park has 1.40 respectively. As a result of the buffer analysis, Chimsan Park turned out to be the highest, Bummul Park turned out the lowest. Chimsan Park gets I grade in two indicators but Bummul Park gets III grade in four indicators contrastively. As a result of the possibility analysis of the urban park planning, increasing elongation index and the number of major lobes can be an improvement method. Also by changing multilayer structure, micro-multiformity and curvature are increased and buffer of edge is improved.In this study, the basic data of landscape ecology can be obtained by the character analysis of landscape ecology. This study has a significant meaning of possibility in planning of the urban park which reflects the character of landscape ecology. This research was only performed in Chimsan Park, so additional researches for various cases will be needed.

• 패션비즈니스
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• 제12권6호
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• pp.11-22
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• 2008

The goal of this study is to provide beauticians with the fundamental material to use effectively heat permanent wave in beauty industry as well as their customer's satisfaction. It carried out an experiment with damaged hair of a woman in her late twenties to investigate the change of physical and morphological characteristics by its water content when performing heat permanent wave. After spreading 0g, 1g, 2g, 3g, and 4g of water on damaged hair respectively, heat permanent wave was treated and the change of hair was observed. The change of physical characteristic was compared through permanent wave form of hair, tensile strength and elongation. The change of morphological characteristic was observed through Scanning Electron Microscope(SEM) and Transmission Electron Microscope(TEM). The result of experiment on the physical specificity revealed that permanent wave form was the most ideal when the water content was 2g, also 3g. Though the materials with much moisture content formed the results were not satisfied. The material with 0g of water content didn't make the wave. In terms of tensile strength and elongation, tensile strength was generally reduced as per the damaged degree of hair. On the contrary, elongation was increased. It observed the changes of morphological characteristic that the damage on hair cuticle was deepen, as its moisture content was decreased, and cuticle's surface was worn away. The observation of fine structure on hair section by transmission electronic microscope also certainly showed the result that damaged hair having experience with chemical treatment had got much damaged to hair cuticle as well as hair cortex. Generally chemical treatment makes hair damaged. Under consideration of this aspect, the ultimate goal of this thesis is to minimize the damage of hair caused by chemical treatment and get the satisfaction on the hair style. According to the result of experiment, the damaged hair whose moisture content was 3g showed the best permanent wave form.