• Title/Summary/Keyword: material area

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Detergency Performance Evaluation of Organic Adherent Pollutant by Modified Silicate-Based Antifouling Coating Material (변성 실리케이트계 방오성 코팅재의 유기성 피착 오염물질 세정성능 평가)

  • Chae, Woo-Byung;Seong, Dong-Yun;Kim, Cheun-Soo;Seo, Sang-Kyo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2012.05a
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    • pp.275-278
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    • 2012
  • This study try to finding the self-detergency performance of adherent pollutant on the mortar surface by using the developed silicate based antifouling coating material. Developed coating material coated on the surface of mortar test piece and after 30 minutes, over layed already coated mortar surface. After 7 days, the surface is polluted with crayons and oily magic marker. After 24 hours, contaminated area was wiped out the water. From the result of self-detergency performance test, it is concluded the developed material could be used as a detergent the contaminated concrete surface.

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Effects of Resistivity of Gate Line Material on TFT-LCD Pixel Operations (게이트 라인 물질의 저항률이 TFT-LCD 화소의 동작에 미치는 영향)

  • 이영삼;최종선
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1998.06a
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    • pp.321-324
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    • 1998
  • Pixel-Design Array Simulation Tool(PDAST) was used to profoundly the gate signal distortion and pixel changing capability, which are the most critical limiting factors for high-quality TFT-LCDs. Since PDAST can simulate the gate, data and pixel voltages of a certain pixel on TFT array at any time and at any location on an array, the effect of the resistivity of gate line material on the pixel operations can be effectively analyzed. The gate signal delay, pixel charging ratio, level-shift of the pixel voltage were simulated with varying the resis5tivity of the gate line material. The information obtained from this study could be utilized to design the larger area and finer image quality panel.

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A Study on the Economic Justification of a Material Handling System using AHP (AHP기버을 이요한 물류시스템의 경제성평가에 관한 연구)

  • 장원호;함효준;이광수
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.18 no.35
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    • pp.139-155
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    • 1995
  • This study is concerned with the economic analysis of implementing a material handling system using automated guided vehicle(AGV)s in order to improve the productivity of the production process of chinawares. Analytic hierarchy process(AHP) method for selecting the facilities of material handling systems is presented. Subsequently, as an example, a chinaware production line is analyzed for the economic analysis. The result shows that seven manpowers can be reduced. However the introduction of the new material handling system is turn out to be undesirable due to high initial cost of AGV system, Nevertheless, in the long term, automatic material handling system such as AGV system are expected to play major roles in the modern manufacturing area.

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Disposal Characteristics of Dredged Material from the Hopper Dredger (호퍼준설선의 투기특성)

  • Jeong, D.D.;Lee, J.W.
    • Journal of Korean Port Research
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    • v.11 no.2
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    • pp.203-214
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    • 1997
  • Hydraulic dredgers(Hopper dredger) are the most important piece of equipment in the entire harbor engineering field, and most suitable for the removal of sand and weakly consloidated sediment such as silt. In maintenance dredging, specially confined harbor or congested passage area, Hopper dredger is user most popularly because less obstruction and danger to navigation than other mostly stationary dredgers. Investigation of the physical behave of dredged material disposal in coastal water from the Hopper dredger includes estimations of pattern as well as thickness of material on the bottom. Calculation based on vertical settling and horizontal advection of single particles ignore the effects of bulk properties of the disposed marterial, vertical and horizontal diffusion. and material dilution due to the entrainment of ambient water during descent. This paper focuses on the analysis of dredging and dumping characteristics and the spatial and temporal changes in the dumping fields for the water column and bottom at a hypothetically confined coastal water. This model accounts the behavior of material after release from the hopper dredger. It is shown that the model describes the qualitative feature of prototype dumping process and its response.

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Geochemistry of Precambrian Metamorphic Rocks from Yongin-Anseong Area, the Southernmost Part of Central Gyeonggi Massif (경기육괴 중부 남단(용인-안성지역)에 분포하는 선캠브리아기 변성암류의 지구화학적 특징)

  • 이승구;송용선;증전창정
    • The Journal of the Petrological Society of Korea
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    • v.13 no.3
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    • pp.142-151
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    • 2004
  • The metamorphic rocks of Yongin-Anseong area in Gyeonggi massif are composed of high-grade gneisses and schists which are considered as Precambrian basement, and Jurassic granite which intruded the metamorphic rocks. In this paper, we discuss the geochemical characteristics of metamorphic rocks and granites in this area based on REE and Nd isotope geochemistry. And we also discuss the petrogenetic relationship between metamorphic rocks and granites in this area. Most of Nd model ages (T$\_$DM/$\^$Nd/) from the metamorphic rocks range ca. 2.6Ga~2.9Ga which are correspond to the main crustal formation stage in Gyeonggi massif by Lee et. al. (2003). And Nd model ages show that the source material of quartzofeldspathic gneiss is slightly older than that of biotite banded gneiss. In chondrite-normalized rare earth element pattern, the range of (La/Yb)$\_$N/ value from biotite banded gneiss is 37~136, which shows sharp gradient and suggests that biotite banded gneiss was originated from a strongly fractionated source material. However, that of amphibolite is 4.65~6.64, which shows nearly flattened pattern. Particularly, the chondrite normalized REE patterns from the high-grade metamorphic rocks show the REE geochemisoy of original source material before metamorphism. In addition, the values of (La/Yb)$\_$N/ and Nd model ages of granite are 32~40 and 1.69Ga~2.08Ga, respectively, which suggest that the source material of granite is different from that of Precambrian basement such as biotite banded gneiss and quartzofeldspthic gneiss in the area.

Effect of Structural Geometry of Jointed Concrete Pavement on Backcalculation using AREA Method (줄눈콘크리트 포장의 구조적 형상이 AREA법을 이용한 역해석에 미치는 영향)

  • Yoo, Tae-Seok;Sim, Jong-Sung
    • International Journal of Highway Engineering
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    • v.9 no.1 s.31
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    • pp.39-46
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    • 2007
  • Different backcalculation results for the same material properties are caused by different structural geometry. In this paper, based on real simulation results for typical pavement systems using 3-dimensional FE models, modified AREA graphs are proposed to graphically backcalculate modulus of elasticity of slab and subgrade based on center deflection and AREA. In modified graph for single infinity slab models, deflection and AREA are increased in deeper depth to bedrock. But, effects of depth to bedrock more than 4.0 meters on backcalculation results are negligible. And, center deflection and AREA generated from multifinite slab models are larger than those of single infinity slab models with same depth to bedrock.

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Effects of Combination of the Load and the Apparent Area of Contact on Sliding Wear behavior of Mild Steel in a Pin-on-disc Type Apparatus (Pin-on-Disc식 미끄럼마모시험 시 마모 거동에 미치는 접촉면적 및 하중 조합의 영향)

  • Lee, Han-Young
    • Tribology and Lubricants
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    • v.29 no.2
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    • pp.85-90
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    • 2013
  • The effects of contact pressure on the sliding wear behavior of mild steel in a pin-on-disc type apparatus were investigated. Sliding wear tests were conducted with various combinations of the load and apparent area of contact. The wear behavior of mild steel as a function of sliding speed was independent of contact pressure. However, the wear rate at different sliding speeds was influenced by the load regardless of the apparent area of contact. This was attributed to the fact that there may be no difference in the real area of contact for any combination of the load and apparent area of contact.

A Study on the Wear comfort and the Wearing Effects of Maternity Girdles (시판 임산부용 거들의 착용감 및 착용효과에 관한 연구)

  • 최혜선
    • Journal of the Korean Home Economics Association
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    • v.29 no.3
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    • pp.11-21
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    • 1991
  • The study has been intended to find out meaningful information about the development of a prototype of enhanced maternity girdle. The girdles of three different models which were available in the market have been carried out by three six-month pregnant women and three nine-month pregnant women. The results of the study are as follows. 1. All three girdles showed improved wear effects in order of model A, model B, model C. Body surface area measurement and two body surface angles of abdomen are significantly dicreased by wearing and type of girdles. It is presumed that the reasons of good wear effect of model A is low expansion rate of the material and tight fitness of the model. Model B is made of material whose expansion rate is higher than model A. Also abdominal part of the model B is bias cut which is considered to result better stretch and consequently lower wear effect. 2. For wear comfort, subjects preferred in order of model B, model C, and model A. All subjects feel more comfortable after wearing girdles 30 minutes than after wearing girdles 1 day. Comparing 2 subject groups, 6-month pregnant group feel more comfortable about wearing girdles than 9-month pregnant group. 3. The girdles are expanded as a whole in order of model B, model C and model A. Considering the expansion rate of some specific area of the girdles, abdominal area expands more than hip area which expands more than thigh area. The expansion rates of girdles worn to 6-month pregnant group are very low at all area, while the expansion rates of girdles worn to 9-month pregnant group are very high.

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Investigation of Cutting Characteristics in the Sharp Edge for the Case of Cutting of a Low Carbon Steel Sheet using High-power CW Nd:YAG Laser (고출력 CW Nd:YAG 레이저를 이용한 저탄소 냉연강판 절단시 모서리부 절단 특성 분석)

  • Ahn, Dong-Gyu;Yoo, Young-Tae
    • Journal of Welding and Joining
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    • v.24 no.4
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    • pp.32-38
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    • 2006
  • The objective of present research works is to investigate the effects of process parameters, including the power of laser, cutting speed, material thickness, and the edge angle, on the melted area in the sharp edge of the cut material fur the case of cutting of a low carbon steel sheet using high-power CW Nd:YAG laser. In order to investigate the influence of edge angle and size of loop on the melted area in the sharp edge, angular cutting tests and loop cutting tests have been carried out. From the results of angular cutting tests, the relationship between the edge angle and the melted area has been obtained. The results of the experiments have been shown that the melted area is rapidly reduced from $120^{\circ}$ of the edge angle and the melted area is nearly zero at $150^{\circ}$ of the edge angle. Through the results of loop cutting experiments, the relationship between the cutting angle on the melted area in the edge according to the size of loop have been obtained. In addition, it has been shown that a proper size of loop is nearly 3 mm as the corner angle is greater than $90^{\circ}$ and 5 mm as the comer angle is less than $90^{\circ}$. The results of above experiments will be reflected on the knowledge base to generate optimal cutting path of the laser.

Improved Mesoporous Structure of High Surface Area Carbon Nanofiber for Electrical Double-Layer Capacitors

  • Lee, Young-Geun.;An, Geon-Hyoung;Ahn, Hyo-Jin
    • Korean Journal of Materials Research
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    • v.27 no.4
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    • pp.192-198
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    • 2017
  • Carbon nanofiber (CNF) is used as an electrode material for electrical double layer capacitors (EDLCs), and is being consistently researched to improve its electrochemical performance. However, CNF still faces important challenges due to the low mesopore volume, leading to a poor high-rate performance. In the present study, we prepared the unique architecture of the activated mesoporous CNF with a high specific surface area and high mesopore volume, which were successfully synthesized using PMMA as a pore-forming agent and the KOH activation. The activated mesoporous CNF was found to exhibit the high specific surface area of $703m^2g^{-1}$, total pore volume of $0.51cm^3g^{-1}$, average pore diameter of 2.9 nm, and high mesopore volume of 35.2 %. The activated mesoporous CNF also indicated the high specific capacitance of $143F\;g^{-1}$, high-rate performance, high energy density of $17.9-13.0W\;h\;kg^{-1}$, and excellent cycling stability. Therefore, this unique architecture with a high specific surface area and high mesopore volume provides profitable synergistic effects in terms of the increased electrical double-layer area and favorable ion diffusion at a high current density. Consequently, the activated mesoporous CNF is a promising candidate as an electrode material for high-performance EDLCs.