• Title/Summary/Keyword: polar force

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Effect of Temperature on the Surface Tensions in the Detergency System(I) -Change of Surface Tension Components of Washing Liquids- (온도가 세척계의 표면장력에 미치는 영향(제1보) -세액의 표면장력 성분변화를 중심으로-)

  • Chae, Chung-Hee;Kim, Sung-Reon
    • Journal of the Korean Society of Clothing and Textiles
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    • v.17 no.4
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    • pp.511-517
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    • 1993
  • Changes of the surface and interface tension with temperature for washing liquids and alkanes were measured by FACE surface tensiometer. Using the extended Fowkes' equation, the dispersion and polar force components of the surface tension were estimated. The results were as follows : 1. The surface tensions of washing liquids and alkanes decreased almost linearly with the increase of temperature. 2. The interface tensions of 0.25% DBS/alkane increased slowly with the increase of temperature. In the case of nonionic surfactant solutions, however, the interface tensions with alkanes varied with the number of hydrophilic ethylene oxide(EO) groups. 3. Of the surface tension of water at $20^{\circ}C$, the dispersion force component was 25.3 dyn/cm and the polar force component was 47.8 dyn/cm. As the temperature increased, both the polar and dispersion force components decreased in a similar fashion. 4. The dispersion force component of surface tension of 0.25% DBS solution was 30.0 dyn/cm, and the polar force component was 2.2 dyn/cm at $20^{\circ}C$. The two components decreased with the increase of temperature. 5. As the temperature increased, the dispersion force component of surface tension decreased and the polar force component increased significantly for 0.25% NPPG-7.5EO solution. In the case of 025% NPPG-10EO, both the dispersion and polar force components decreased slowly, but the polar force component is expected to increase from $60^{\circ}C$. However, the polar force component of surface tension decreased with the increase of temperature for 025% NPPG-15EO solution, and at the temperature higher than $60^{\circ}C$ the surface tension is expected to be composed of only dispersion force component.

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Large deflection behavior of a flexible circular cantilever arc device subjected to inward or outward polar force

  • Al-Sadder, Samir Z.
    • Structural Engineering and Mechanics
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    • v.22 no.4
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    • pp.433-447
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    • 2006
  • The problem of very large deflection of a circular cantilever arc device subjected to inward or outward polar force is studied. An exact elliptic integral solution is derived for the two cases and the results are checked using large displacement finite element analysis via the ANSYS package by performing a new novel modeling simulation technique for this problem. Excellent agreements have been obtained between the exact analytical solution and the numerical approach. From this study, a design chart for engineers is developed to predict the required value for the inward polar force for the device to switch on for a given angle forming the circular arc (${\theta}_o$). This study has several interesting applications in mechanical engineering, integrated circuit technology, nanotechnology and especially in microelectromechanical systems (MEMs) such as a MEM circular device switch subjected to attractive or repulsive magnetic forces due to the attachments of two magnetic poles at the fixed and at the free end of the circular cantilever arc switch device.

Introduction to IMO Polar Code - From the perspective of class

  • Suk, Ji-Hoon
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2015.10a
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    • pp.130-132
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    • 2015
  • The IMO Polar Code was adopted by Res.MSC.385(94) and Res.MEPC.264(68) and will enter into force on 1 January 2017. The Polar Code will affect design and equipment of ships intending to operate in polar areas. In this study, the requirements in the Polar Code are analysed from the perspective of class.

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Performance Analysis of Brushless DC Motor According to Polar Magnetizing Characteristic of Ferrite Bonded Permanent Magnet (페라이트 본드 영구자석의 극이방 자화특성에 따른 BLDC 모터의 특성해석)

  • Baek, Soo-Hyun
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.59 no.12
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    • pp.2173-2178
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    • 2010
  • The magnetization directions of a polar magnetized ferrite bonded magnet are analyzed by finite element method (FEM). The influence of the width of SmCo magnets for magnetic field generation is investigated. The surface flux densities of the polar anisotropic magnets are analyzed and compared according to the pole number and thickness of the magnets. And the electromotive force (EMF) values of brushless DC motors with the magnets are investigated. The validity of the analysis method is verified by comparing the analyzed results with measured ones.

Molecular Interactions of Soaked Nonionic Dye in Ionomer Films (아이오노머 필름에 흡수된 비이온계 염료의 분자간 상호작용에 관한 연구)

  • ;;;;;;Forrest A. Landis;Robert B. Moore
    • Polymer(Korea)
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    • v.25 no.5
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    • pp.671-678
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    • 2001
  • Sodium and zinc salts of poly(ethyaene-co-methacrylic acid) ionomers consist of three phases, i.e. ionic aggregates, amorphous, and crystalline phases. Dye molecules after soaked from the methanol solution are located near the amorphous phase or ionic aggregates within ionomer films. Depending on the location of the molecules in the ionomer film, they are under influence of dispersion forces (ethylene parts), polar forces (acid parts). and ionic dipole (ionic aggregates) interactions. The UV/Vis absorption peak of Nile Red under the dispersion force is found at near 500 nm, for the dye under the polar force effect 525 nm, and 550 and 610 nm for the dyes under $Na^+$ and $Zn^{2+}$ ionization effects, respectively. Since the divalent $Zn^{2+}$ ion has larger ionic dipole than the monovalent $Na^+$ ion, the larger red-shift of the absorption band due to the ionic dipole interaction is observed for $Zn^{2+}$ counter ion.

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Experimental Study of Ice Friction and Abrasion Test Methods for Polar Paint (극지용 도료의 빙마찰 및 빙마모 시험기법 연구)

  • Cho, Seong-Rak;Oh, Eun-Jin;Kim, Cheol-Hee;Lee, Jae-Man;Kim, Sung-Pyo
    • Journal of the Society of Naval Architects of Korea
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    • v.56 no.6
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    • pp.532-540
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    • 2019
  • This study describes a test method for evaluating the ice friction and abrasion performance of polar coatings. The evaluation methods of physical properties of general coatings for ocean-going vessels and polar coatings for ice-going vessels were investigated and their limitations were analyzed. We have also reviewed previous researches related to the development of polar paints and confirmed the necessity of developing test techniques. A flat steel plate was coated with several types of commercial coating, and cold model ice was used to cause ice friction and abrasion events between coated surface and ice. For evaluation of ice friction and abrasion performances, test procedures such as measurement of coating surface roughness, measurement of frictional force using model ice, implementation of ice abrasion and drying of coating surface were developed. The friction and abrasion characteristics of each coating are analyzed and summarized through the change of friction force and roughness data according to the progress of ice abrasion.

A Study on the Development of Curriculum of Polar safety training (극지기초안전교육과정 개발에 관한 연구)

  • LEE, Jin-Woo;KIM, E-Wan;WOO, Young-Jin;LEE, Chang-Hee
    • Journal of Fisheries and Marine Sciences Education
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    • v.28 no.4
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    • pp.1031-1041
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    • 2016
  • Interests in the Polar Regions have been growing due to various factors such as depletion of natural resources and advanced resource development technologies, accelerated rate of polar ice melting as a result of global warming, etc. In particular, demand for the workforce related to vessel passage using the Northern Sea Route and polar studies is still expanding. The International Maritime Organization adopted the Polar Code in 2015 for the safety of ship operation in polar waters and it will enter into force from 2017. But education and training section in the code has been prescribed only for the safe navigation in the ice covered waters intended for navigational offices. There is no basic safety training requirement that applies commonly for all personnel exposed to the risk of the polar regions and the relevant study or discussion has not been made so far. Therefore, this study provides basic data for developing safety training courses for crew and other personnel by analyzing relevant regulations on polar safety training and the contents of relevant safety training in offshore industry required by the costal states adjacent to arctic ocean.

이온 보조 반응법을 이용한 상용 PVC의 친수성 증대

  • 한영건;조준식;최성창;고석근;김동환
    • Proceedings of the Korean Vacuum Society Conference
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    • 1999.07a
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    • pp.199-199
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    • 1999
  • 상용의 PVC가 갖는 소수 특성을 개선하기 위해 산소, 아르곤, 수소 이온의 이온 보조 반응법을 이용하여 표면의 친수성을 증대시키고 이때 친수성 증가의 직접적 원인인 표면에너지 증가를 각각의 이온조사에 따라서 비교하였다. 이온 소스는 직경 5-cm의 cold hollow cathod ion gun을 이용하였으며 산소, 아르곤, 수소이온을 이온 조사량 5$\times$1014~1$\times$1017ions/cm2까지 변화시키고 산소의 유량을 0~8sccm까지 변화시키면서 표면 에너지 변화를 관찰하였다. 표면 에너지는 두 가지의 극성 용매인 물과 포름아마이드의 접촉각을 정적 접촉각 측정기를 이용하여 측정한 후에 이로부터 dispersion force와 polar force를 계산하여 얻었다. 계산된 결과를 보면 처리 전과후의 dispersion force의 변화는 거의 없으나 polar force는 크게 증가하였다. 이때 표면 에너지의 증가는 표면 형상의 변화와 극성을 띠는 친수성기의 증가로 여겨지며 각각의 경우에 대한 분석을 위해 AFM과 XPS 분석을 시행하여 각각의 이온에 따르는 표면 형상의 변화와 친수성기의 형성 및 상대적인 양을 비교하였다.

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Sorption Characteristics of Butanol/Water and Isopropanol/Water Solutions on the FASs Coated Inorganic Membrane (FASs로 코팅한 무기막에 대한 부탄올/물, 이소프로판올/물 용액의 수착 특성)

  • Lee, Kwang-Rae
    • Membrane Journal
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    • v.28 no.5
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    • pp.320-325
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    • 2018
  • The sorption amounts of butanol/water and isopropanol/water solution on the surface modified with FASs (fluoroalkylsilanes) hydrophobic membrane were measured and analyzed using Hansen's solubility parameters. The difference of the solubility parameter of butanol (${\delta}_t=20.4$) and that of the surface modified with FASs hydrophobic membrane (${\delta}_t=16.9$) was greater than the case of isopropanol (${\delta}_t=24.6$), which might explain the result that the sorption amount of butanol was much higher than that of isopropanol. We might also explain the effect of the polar force (${\delta}_p$) on the sorption amount. The difference (${\Delta}$) between FASs polar force (${\delta}_p=4.6$) and butanol polar force (${\delta}_p=6.3$) was much smaller than that between FASs polar force (${\delta}_p=4.6$) and isopropanol polar force (${\delta}_p=9.0$), which meant that the interaction of butanol-FASs was much greater than that of isopropanol-FASs, and resulted in greater sorption amount of butanol on the FASs. This study showed Hansen's solubility parameters might be used for analysis of sorption characteristics of alcohol on membrane and solubility of solute in solvent.

Study on The Non-polar Optical Phonon Scattering According to The Mixture of Atoms in a $A_{1-x}B_{x}$ Alloy semiconductor ($A_{1-x}B_{x}$ 혼합물반도체에서 원자들의 혼합형태에 따른 비극성 Optical 포논산란에 대한 연구)

  • 박일수;전상국
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.14 no.8
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    • pp.611-617
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    • 2001
  • The non-polar optical phonon scattering in the valence band depends on the masses, ratios, and types of mixtures of constituent atoms. Therefore, the random distribution of atoms in alloy semiconductors should be considered in the analysis of scattering mechanisms. For this purpose, the force equations of n atoms in a unit cell are expressed in a n x n matrix form to obtain the angular frequencies due to the acoustic and non-polar optical phonons. And, n is then assumed to be infinity. When this work is compared with other results published elsewhere, it is concluded that the independence of atomic displacement or amplitude of oscillation as ell as the infinite number of atoms in a unit cell must be taken into account for the random distribution of atoms in alloy semiconductors.

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