• Corrosion Science and Technology
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• 제6권3호
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• pp.128-132
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• 2007

For a quantitative inspection on the performance of weathering steel bridges, we have investigated the relationship between the corrosion rate and the composition of the rust layers formed on weathering steel bridges located in various environments in Japan and applied a protective ability index (PAI) to the bridges. The corrosion rates were clearly classified by the PAI, ${\alpha}/{\gamma}*$ and sub index of $({\beta}+s)/{\gamma}*$, where $\alpha$, \gamma*, $\beta$ and s are the mass ratio of crystalline $\alpha-FeOOH$, the total of $\gamma$-FeOOH+ $\beta$-FeOOH + the spinel-type iron oxide (mainly $Fe_3O_4$), $\beta-FeOOH$ and spinel-type iron oxide, analyzed by powder X-ray diffraction, respectively. In the case of ${\alpha}/{\gamma}$*>1, the rust layer works protective enough to reduce the corrosion rate less than 0.01 mm/y. The sub index $({\beta}+s)/{\gamma}*$<0.5 or >0.5 classifies the corrosion rate of the non-protective rust layers, therefore the former state of the rust layer terms inactive and the latter terms active. The quantitative inspection of a weathering steel bridge requires a performance-inspection (PI) and periodical deteriorationinspections (DI). The PI can be completed by checking of the PAI, ${\alpha}/{\gamma}*$. The DI on the weathering steel bridges where deicing salt is sprinkled can be performed by checking the PAI, $({\beta}+s)/{\gamma}*$.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2000년도 제18회 학술발표회 논문개요집
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• pp.173-173
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• 2000

Multilayered films (MLF) consisting of transition metals and semiconductors have drawn a great deal of interest because of their unique properties and potential technological applications. Fe/Si MLF are a particular topic of research due to their interesting antiferromagnetic coupling behavior. although a number of experimental works have been done to understand the mechanism of the interlayer coupling in this system, the results are controversial and it is not yet well understood how the formation of an iron silicide in the spacer layers affects the coupling. The interpretation of the coupling data had been hampered by the lack of knowledge about the intermixed iron silicide layer which has been variously hypothesized to be a metallic compound in the B2 structure or a semiconductor in the more complex B20 structure. It is well known that both magneto-optical (MO0 and optical properties of a metal depend strongly on their electronic structure that is also correlated with the atomic and chemical ordering. In order to understand the structure and physical properties of the interfacial regions, Fe/Si multilayers with very thin sublayers were investigated by the MO and optical spectroscopies. The Fe/si MLF were prepared by rf-sputtering onto glass substrates at room temperature with a totall thickness of about 100nm. The thicknesses of Fe and Si sublayers were varied from 0.3 to 0.8 nm. In order to understand the fully intermixed state, the MLF were also annealed at various temperatures. The structure and magnetic properties of Fe/Si MLF were investigated by x-ray diffraction and vibrating sample magnertometer, respectively. The MO and optical properties were measured at toom temperature in the 1.0-4.7 eV energy range. The results were analyzed in connection with the MO and optical properties of bulk and thin-film silicides with various structures and stoichiometries.

• 복식문화연구
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• 제6권2호
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• pp.109-126
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• 1998

The purpose of this study was to analyze the expressional characteristics of the machine aesthetics in the fashion design. First, this study was started from analyzing mechanical beauty represented on the early 20th century art style. Machine aesthetics has influenced on the art and fashion design from modern to now. Futurism was grounded in the complete renewal of human sensibility brought about by the great discoveries of science. Especially, Russia avant-garde was inspired by the Futurism, that is Rayonism, Constructivism, Suprematism. Kasimir Malevich moved on immediately to purely abstract paintings of which the first was a black square on a white canvas. He had begun the art he called 'Suprematism'. Malevich's geometry was funded on the straight line, the supremely elemental form which symbolized man's ascendancy over the chaos of nature. The square was the basic suprematist element and was a repudiation of the world of appearances, and of past art. He repudiated any marriage of convenience between the artist and the engineer. Vladimir Tatlin made some of the most revolutionary works of modern art, these were the first works to be called 'construction'. Constructivists believed that the essential conditions of the machine and the consciousness of man inevitably create an aesthetic which would reflect their time. They eulogized simple shapes. That believed that buildings and objects should be freed from the ornamental excrescences and the accumulated barnacles of past art. Consequently, under the theoretical background, the result is as follows. First, The functional formativeness of machine aesthetics was expressed as a geometrical silhouette, construction line, non-ornamental construction, simple color in the 20th century design. Second, The mechanical formativeness of machine aesthetics was expressed as a construction of new material-iron, aluminium, plastic, glass-, geometrical form of material in he 20th century design. That is, machine beauty has more concerned with the expressional ideology of the art style and the formativeness of fashion design by silhouette, construction line, material, form.

• 상하수도학회지
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• 제22권4호
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• pp.429-436
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• 2008

Membrane system has been increasingly considered as a safe and cost-effective water treatment process especially in case of small scale water works. This research is a basis of membrane application in water works through a long period test with obtaining operation skills and evaluation of water quality and cost competitiveness. For the research, the UF membrane system was installed in small water treatment plant that uses river-bed water as raw water. The system was consisted of 2 stage membrane and operated in constant flow mode (Flux: 1.5, 1.0, 0.9, 0.6). In each different flux condition, TMP trends were showed better results at lower flux condition. And through the high flux condition test, it is certified that membrane system could deal with breakdown of one stage. Water quality of permeate was satisfied the water quality standards especially turbidity. To know what mainly causes fouling on membrane, the test by membrane with several cleaning agents and EDX analysis have done in lab. Through the tests, ferrous concentration in raw water, backwashing water and membrane surface etc. was high and it causes fouling inside and outside of membrane. So acid cleaning using organic acid such as oxalic acid is necessary in Chemical in Place (CIP). At the economical aspect the electrical cost of membrane system is higher than that of slow sand filtration but labor cost can be reduced by automation. However, the use of labor should be determined considering effectiveness and stability of operation. Because during the operation, there are several breakdown such as electrical shock by lightning, water drop in summer, etc.

• 대한영양사협회학술지
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• 제9권4호
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• pp.326-335
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• 2003

This study was carried out to collect information to establish a framework for meal management and nutritional service for prevention of chronic degenerative disease in the industrial workers. We investigated the health concerned life-style, nutrient intakes, anthropometry and biochemical parameters in the male workers in Korea by work condition. Anthropometric parameters of height, weight, waist, hip and triceps skinfold thickness were measured and biochemical parameters including Urine pH, hemoglobin, blood glucose, total cholesterol, GOT, GPT, $\gamma$-GPT and blood pressure were determined for 101 subjects(50 office workers : 33.9yr, 51 laborers : 34.4yr). To assess the nutrient intakes and diet quality of workers, dietary intake was measured by one day 24-hour recall method. Result of anthropometric parameters of height(p<0.01), weight(p<0.05), hip(p<0.05), TSF(p<0.01) were significantly higher in office workers than in laborers. Biochemical parameters were not significantly difference in both of them. Average daily nutrient intakes of both groups was higher than the Korean RDA and report on 2001 National Health & Nutrition Survey. The calcium(p<0.01), iron(p<0.05), vitamin A(p<0.01), vitamin B1(p<0.01) and niacin(p<0.05) intakes in laborers were significantly higher than in office workers. Nutrition adequacy ratio(NAR), mean adequacy ratio(MAR) and index of nutritional quality(INQ) of laborers were higher than those of office workers. This results indicated that the onset possibility of chronic degenerative disease appeared higher in office workers. Therefore, meal menagement and nutritional service for prevention of chronic degenerative disease of industrial works needs to be more variant guidelines.

• 한국재료학회지
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• 제9권12호
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• pp.1252-1262
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• 1999

자동차 휠, 멤버 등의 소재로 사용되는 인장강도 580MPa급 열연강판의 버링성형성을 향상시키기 위하여 강판의 신장 플랜지성(stretch-flangeability)에 대한 미세조직 및 열간압연후 냉각인자의 영향에 대하여 검토하였다. 열간압연후 3단 냉각제어 및 권취온도의 극저온화에 의하여 신장플랜지성이 우수한 페라이트-베이나이트 복합조직강의 제조가 가능하며, 3단 제어냉각에서 강판의 온도를 $Ar_3$ 직하의 페라이트변태역에서 일정 시간 유지하면 페라이트 변태 및 NbC의 석출이 조장됨을 확인하였다. 페라이트-베이나이트 복합조직 열연강판의 우수한 신장플랜지성은 3단 냉각 및 극저온 권취에 의한 등축 페라이트 분율의 증가, 입계 세멘타이트의 미세화 및 구성 상간의 경도차 저하에 의하여 타발공정에서의 미소균열 생성 및 전파가 억제되기 때문인 것으로 판단되었다. 아울러 0.08wt%C-1.5wt%Mn-0.04wt%Nb 성분계를 이용하여 제조된 인장강도 580MPa급 페라이트-베이나이트 복합조직 열연강판은 연신율 22% 이상, 구멍확장율 (신장플랜지성) 90% 이상의 재질특성을 가지며, 버링비 60% 이상의 자동차 휠 디스크에 적용 가능한 것으로 판명되었다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1994년도 봄 학술발표회 논문집
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• pp.148-151
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• 1994

Up to now, sea sand without complete removal of salt is being used in the construction works because there is little satisfactory counterplan for the substitute aggregate. In the case that such sea sand is used in the reinforced concrete, the residual salt gives rise to deterioration phenmenon and iron corrosion, reducing durability of the ferro-concrete structures. The paper, an experimental study on the effect of corrosion protection by tighting concrete used SF and FA, is to investigate general steel bar's corrosion and to develop concrete using sea sand economically after it is analyzed and examinated ratio of the corrosion area affected by the autoclave cycle. As a test results, as for corrosion area ratio, it is very effective to use admixrutes such as SF and FA which decrease corrosion area remarkably with increasing the amounts of admixtures. Accordingly the use of admixtures is advantageous for tightening concrete and has an effect of salt damage prevention and rust protection in concrete used sea sand.

• 한국환경과학회지
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• 제19권2호
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• pp.157-170
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• 2010

Air mass recirculation is a common characteristic in the coastal area as a result of the land-sea breeze circulation. This study simulates the recirculation of air mass over the Gwangyang Bay using WRF-FLEXPART and offers a basic information about the effective domain size that can reflect recirculation. For this purpose, WRF is set up four nested domains and three cases are selected. Subsequently FLEXPART is operated on the basis of WRF output. During the clear summer days with weak wind speed, particles that emitted from Yeosu national industrial complex and Gwangyang iron works flow into emission sources because of the land-sea breeze. When land-sea breeze is strengthen, the recirculation phenomena appears clearly. However particles aren't recirculated under weak synoptic condition. Also plume trajectory is analyzed and as a consequence, the smallest domain area have to be multiplied by 1.3 to understand recirculated dispersion pattern of particles.

• 한국실내디자인학회논문집
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• 제13권6호
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• pp.12-19
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• 2004

Mies van der Rohe is still known as the architect whose influence is the largest among modem architects. As his work is typical of modern architecture, the architecture of Mies shows an interest in materials and techniques, even though It established the new architectural world by glass and iron, and only transparency is emphasized with glass. So it is blame for the loss of peculiarity a result of thinking In the way of sachlich with expression and structure of material and hierarchical relation. Vincent Scully has insist on that an appearance of modem architecture be occur not by simply a technical request of a technician but by reflection of the times and times' spirit. In this means, the works of Mies is the trial to express the new times' spirit that the new times order and an understanding of material properties about glass with new material of modern. For that, this study tries to consider that Mies'work is the new trial through reflection of material to express about the bstraction beyond the limit of sachlich expression, on the point of expresslonal characteristics of material shown in plan of the Barcelona Pavilion and skyscraper and on the basis of the theory of Gottfried Semper and Karl Boetticher that architectural surface Is a medium which can define space and also express mass.

• 한국농공학회지
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• 제27권2호
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• pp.47-56
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• 1985

Wasting fiberous residues from the cutting processes of steel materials at an iron-Works were mixed with concrete. The strength and toughness of steel fiber concrete with different steel contents were tested in a laboratory. The test results showed that the steel fiber residues can be used for the reinforcement of concrete. The potential applications of such product include floor constructions for facilities like dairy barns, grain storages, and machinery shops. The test results are as follows. 1. The compressive strengths of steel fiber concrete with one percent steel content by volume were 20 percent greater than that of plain concrete. The treatments also increased the concrete toughness by 96 percent. 2. When applied to tensile forces, the steel fiber concrete showed the increased strengths by 20 percent, and the toughness by 48 percent. 3. The steel content levels greater than or equal to 1.5 percent by volume resulted in the decreases of the compressive and tensile strengths of steel fiber concrete by 10 percent as compared to plain concrete. The concrete toughness increased with the steel contents. 4. The reinforcement effects of steel fiber depend on the quality of fiber material being used. Good steel fiber for concrete reinforcement appears to be uniform in shape and component, fine and long, and round-shaped.