• Title/Summary/Keyword: existence of solutions

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Preparation and Characteristics of Anti-Corrosive Coatings for Steel Structures using Polyaniline (폴리아닐린을 이용한 강 구조물용 방청도료의 제조 및 특성)

  • Kim, Tae-Ok;Kong, Seung-Dae;Park, Jin-U;Hahm, Hyun-Sik
    • Journal of the Korean Applied Science and Technology
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    • v.23 no.3
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    • pp.230-237
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    • 2006
  • Anti-corrosive coatings for steel structures with an alternative anti-corrosive pigment, polyaniline was prepared and anti-corrosive characteristics of the prepared coatings were investigated. The structure of the polyaniline was identified by using FT-IR, UV/Vis. and TGA analysis, and the anti-corrosive properties were analyzed from the results of the salt spray experiment. We found that the anti-corrosion properties of the prepared coatings varied in accordance with the types of primer coating resins as well as with the existence and nonexistence of the top coating. In this condition, the properties of adhesion, chemical resistance, and water resistance were found to be very satisfactory when using the single-packaged urethane resin as the primer coating resin and the urethane resin as the top coating resin.

Preparation of Conductive Leather Gloves for Operating Capacitive Touch Screen Displays (정전용량방식 터치스크린에 작동하는 전도성 가죽장갑 소재의 제조)

  • Hong, Kyung Hwa
    • Fashion & Textile Research Journal
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    • v.14 no.6
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    • pp.1018-1023
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    • 2012
  • Smartphone is integrated into the daily lives of all types of people not even young generation. A touch screen display is a primary input device of a smart phone, a tablet computer, etc. While there are many tough technologies in existence, resistive and capacitive are dominant and currently lead the touch screen panel industry. And a capacitive touch screen panel widely used in smart phones is coated with a material that stores electrical charges. In this study, we tried to manufacture gloves produced with electro-conducting leather as a tool to operate a touch panel screen. Therefore, electrically conductive materials, Polyaniline(PANI), Poly(3,4-ethylenedioxythiophene) (PEDOT), and Carbon nanotubes (CNT) were applied to the surface of leather to be used as a touching operator for capacitive touch screen panel. The leather samples were treated by simple painting method; firstly, they were painted with aqueous solution containing each of the electrically conductive materials and then dried. This cycle was repeated three times. Consequently, the treated leather samples showed electrical conductivity and reasonable working performance to the capacitive touch screen. And, PANI showed the best performance and highest electrical conductivity, and then PEDOT and, CNT in decreasing order. This is because the solubilities of PANI and PEDOT show higher than dispersibility of CNT. Thus, the concentration of conducting polymers was greater than that of CNT in the treating solutions.

Preparation and Application of Functional Carbon Whisker Membrane for Separation Process

  • Bae, Sang-Dae;Son, Hee-Jong;Jung, Chul-Woo
    • Journal of Environmental Science International
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    • v.17 no.11
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    • pp.1235-1241
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    • 2008
  • Membrane separation is extensively used for water/wastewater treatment because of its efficiency separation processes. However, particles in the feed water can deposit and accumulate on the membrane surface to created cake layer. As a consequence, the selectivity of the membrane and flux through the membrane are decreased, which is called fouling/blocking phenomenon. In order to solve fouling problem, we developed a novel membrane named Carbon Whisker Membrane (CWM) which contains vapor-grown carbon fibers/whiskers on the surface of the membrane and a layer of carbon film coated on the ceramic substrate. We firstly employed polymethyl methacrylate (PMMA) as a testing material to investigate the fouling mechanism. The results suggested that Carbon Whiskers on the surface of the membrane can prevent the directly contact between the membrane body and particles so that the fouling/blocking could not occurred easily compared to the membrane without carbon whiskers. We also researched the relationship with the diameter, density of carbon whisker on the membrane surface and total flux of solutions. Finally, we will be able to control the diameter and density of carbon whiskers on the membrane and existence of carbon whiskers on the membrane, it is important factor, might be prevent fouling/blocking in the water treatment.

Studies on the Decomposition of CN ion in the electroplating waste Water and COD Variation of photodeveloping Waste-water (오존에 의한 폐수처리에 관한 연구 -도금폐액의 CN이온 분해와 사진 폐수의 COD 처리-)

  • 김덕묵;이치종
    • Journal of the Korean Professional Engineers Association
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    • v.14 no.1
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    • pp.22-29
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    • 1981
  • This study concernes the decomposition of cyanide ion in electroplating plant wastewater and COD variation of photodeveloping wastewater under various conditions. Determinations of CN- concentration were carried out by AgNO$_3$ titration method. The sample solutions were pretreated by passing ozone and decompositions were checked as a function of time for ozone treatment. Analysis of film developing wastewater was carried out by KMnO$_4$ method. Electroplating plant wastewater was also examined at various pH; decomposition rate of cyanide ion was found to increase at higher pH. Time required for the decomposition could be shortened by removing the heavy metal ions under alkaline condition. The effect of temperature on decomposition was studied at 40$^{\circ}$ and 60$^{\circ}C$. The result was better at 40$^{\circ}C$ although time for decomposition was almost same at both temperatures. Analysis of film developing wastewater revealed that COD decrease was faster during the first 1 to 2 hours. However, further decrease could not be effected. The existence of unknown special organics resistant to the decomposition was believed to be the reason.

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Conjoined Towers for Livable and Sustainable Vertical Urbanism

  • Moon, Kyoung Sun;de Oliveira Miranda, Miguel Darcy
    • International Journal of High-Rise Buildings
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    • v.9 no.4
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    • pp.387-396
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    • 2020
  • While tall buildings are an essential building type to accommodate an ever-growing urban population, as buildings become taller and taller, many design challenges arise. As floor spaces are repeated vertically, the occupants' natural horizontal circulation-based social interactions are limited. As buildings become ever taller, safe evacuation to the ground level becomes more challenging in emergencies. With respect to safety as well as serviceability, one of the most fundamental design challenges of exceedingly tall buildings is their structural systems that make the physical existence of tall buildings possible. While many different design solutions can be sought to resolve these issues as well as other design challenges of extremely tall buildings, this paper investigates the potential of conjoined towers to create more livable and sustainable vertical environments. Emphasis is placed on the social and structural capabilities of conjoined towers in providing enhanced social interactions and more efficient ultra-tall structures. The related brief history of conjoined towers is presented. To understand their current status, contemporary design practices of conjoined towers are discussed. Lastly, a new concept of superframed conjoined towers developed for exceedingly tall building complexes is introduced through design studies. Though envisioning future tall buildings is challenging, conjoined towers can be among the strong candidates toward more livable and sustainable vertical urbanism.

The Ethical Obligations of Humankind towards Animals and Its Implications for Korean Religions: Focusing on Korean Buddhism and Daesoon Thought

  • Dominik RUTANA
    • Journal of Daesoon Thought and the Religions of East Asia
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    • v.3 no.2
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    • pp.55-70
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    • 2024
  • This study presents and examines various ethical theories that could offer potential solutions to the issue of discrimination against non-human animals in contemporary society, and traces its implications for Korean religions. The article focuses on two normative ethical theories - virtue ethics and the ethics of care - and through an analysis of existing research, argues that both theories may serve as foundational principles guiding our behavior, not only in our interactions with other humans but also in our treatment of non-human animals. Furthermore, the examples presented in this study demonstrate that similar ethical theories have already been adopted as frameworks for human behavior towards other living beings within two religious traditions, Buddhism and Daesoon Jinrihoe. In both belief systems, animals are acknowledged as integral components of the world in which we live. Additionally, both religions endorse the idea that the well-being of non-human animals and our attitudes toward them can also have a direct impact on our present lives, as well as on our future existence. Consequently, promoting morally upright conduct towards other living creatures should be viewed as a necessary measure, beneficial not only for the animals themselves but also for the collective well-being of humanity.

The Bridge Suspended by Cables and the History of Investigation of the Equation Induced from It (케이블에 의하여 매달려 있는 현수교 방정식의 발견과 연구의 흐름)

  • Nam Hyewon;Choi Q-Heung
    • Journal for History of Mathematics
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    • v.18 no.2
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    • pp.107-116
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    • 2005
  • A suspension bridge is an example of a nonlinear dynamical system, especially systems with the so called jumping nonlinearity. The fact that we deal with a serious and topical problem is demonstrated for example by the collapse of the Tacoma Narrow suspension bridge. So it would be very contributive to determine under what conditions a similar situation cannot occur and find out safe parameters of the bridge construction. In this paper, we show various possibilities how to model the behaviour of suspension bridge. Then we introduce our own results concerning existence and uniqueness of time-periodic solutions.

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Attachment Behavior of Fission Products to Solution Aerosol

  • Takamiya, Koichi;Tanaka, Toru;Nitta, Shinnosuke;Itosu, Satoshi;Sekimoto, Shun;Oki, Yuichi;Ohtsuki, Tsutomu
    • Journal of Radiation Protection and Research
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    • v.41 no.4
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    • pp.350-353
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    • 2016
  • Background: Various characteristics such as size distribution, chemical component and radio-activity have been analyzed for radioactive aerosols released from Fukushima Daiichi Nuclear Power Plant. Measured results for radioactive aerosols suggest that the potential transport medium for radioactive cesium was non-sea-salt sulfate. This result indicates that cesium isotopes would preferentially attach with sulfate compounds. In the present work the attachment behavior of fission products to aqueous solution aerosols of sodium salts has been studied using a generation system of solution aerosols and spontaneous fission source of $^{248}Cm$. Materials and Methods: Attachment ratios of fission products to the solution aerosols were compared among the aerosols generated by different solutions of sodium salt. Results and Discussion: A significant difference according as a solute of solution aerosols was found in the attachment behavior. Conclusion: The present results suggest the existence of chemical effects in the attachment behavior of fission products to solution aerosols.

Efficient Shear-warp Volume Rendering using Spacial Locality of Memory Access (메모리 참조 공간 연관성을 이용한 효율적인 쉬어-왑 분해 볼륨렌더링)

  • 계희원;신영길
    • Journal of KIISE:Computer Systems and Theory
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    • v.31 no.3_4
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    • pp.187-194
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    • 2004
  • Shear-Warp volume rendering has many advantages such as good image Quality and fast rendering speed. However in the interactive classification environment it has low efficiency of memory access since preprocessed classification is unavailable. In this paper we present an algorithm using the spacial locality of memory access in the interactive classification environment. We propose an extension model appending a rotation matrix to the factorization of viewing transformation, it thus performs a scanline-based rendering in the object and image space. We also show causes and solutions of three problems of the proposed algorithm such as inaccurate front-to-back composition, existence of hole, increasing computational cost. This model is efficient due to the spacial locality of memory access.

Coastally Trapped Waves over a Double Shelf Topography(I) : Free Waves with Exponential Topography (양향성 대륙붕의 대륙붕파(I): 지수함수적 해저지형에서의 자유파)

  • PANG Ig-Chan
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.24 no.6
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    • pp.428-436
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    • 1991
  • Double shelf topography allows the existence of two sets of waves propagating in opposite directons. In the case that two shelves are apart sufficiently enough, the solutions show two independent sets of waves which recover the single shelf waves. However, if the distance between two shelves is less than the Rossby deformation radius, the waves become dependent on the geometry of both shelves. Even over a double shelf topography, shelf waves propagate with the shallow water to the right in the Northern Hemisphere. The group velocity of shelf wave has the same direction as phase velocity in the long wave case, but the opposite direction in the short wave case. Each shelf mode has a zero group velocity at some intermediate value of wave length.

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