• The Pure and Applied Mathematics
• /
• v.13 no.1 s.31
• /
• pp.1-10
• /
• 2006

The unsteady Hartmann flow of an electrically conducting, viscous, incompressible fluid bounded by two parallel non-conducting porous plates is studied with heat transfer. An external uniform magnetic field and a uniform suction and injection are applied perpendicular to the plates while the fluid motion is subjected to a constant pressure gradient. The two plates are kept at different but constant temperatures while the Joule and viscous dissipations are included in the energy equation. The effect of the magnetic field and the uniform suction and injection on both the velocity and temperature distributions is examined.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.28 no.7
• /
• pp.462-466
• /
• 2015

In this paper, we investigated the relations between dispersion of CNTs (carbon nanotubes) and electrical conductivity in the CNT/PVDF (polyvinylidene fluoride) composite film. By adding hydrophobic CNTs as filler into the PVDF matrix, we fabricated hydrophobic and electrically conducting polymer coating film. Dispersion of CNTs in the CNT/PVDF composite film plays a significant role in terms of electrical conductivity and wetting property. Spray coating method was used to form the CNT/PVDF composite films by injecting the dispersed CNTs in the PVDF solution with different weight ratios from 0.7 wt% to 7 wt%. We investigated the electrical properties and contact angles of the CNT/PVDF composite films with the CNT concentration. Finally we discussed the conducting mechanism and feasibility of the CNT/PVDF composite film for the conducting polymer films.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2001.07a
• /
• pp.1039-1042
• /
• 2001

A method for designing antireflection (AR) and antistatic (AS) films by the use of conducting polymer as an electrically conductive transparent layer is proposed. The conducting AR film is composed of four-layer with alternating high and low refractive index layer: silicon dioxide (n=1.44) and titanium dioxide (n=2.02) prepared at low temperature by sol-gel method are used as the low and high refractive index layer, respectively. The 3,4-polyethylenedioxythiophene (PEDOT) which has the sheet resistance of 10$^4$$\Omega$/$\square$ is used as a conductive layer. Optical constant of ARAS film was measured by the spectroscopic ellipsometer and from the measured optical constants the spectral properties such as reflectance and transmittance were simulated in the visible region. The reflectance of ARAS films on glass substrate was below 0.8 %R and the transmittance was higher than 95 % in the visible wavelength (400-700 nm). The measured AR spectral properties was very similar to its simulated results.

• 한국전산유체공학회:학술대회논문집
• /
• 2008.08a
• /
• pp.72.2-72.2
• /
• 2008

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2009.06a
• /
• pp.369-370
• /
• 2009

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2008.06a
• /
• pp.141-142
• /
• 2008

• Fashion & Textile Research Journal
• /
• v.14 no.6
• /
• pp.1018-1023
• /
• 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.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2004.07a
• /
• pp.445-448
• /
• 2004

Radio frequency and microwave dielectric heating are well-known electroheating methods, used in industrial applications where non electrically conducting materials are to be heated, dried or otherwise processed. The major reason for considering this technique for any process is based on its unique ability to transfer heat into the volume of an electrically non conducting material such as insulator directly, rather than, via a surface. Conventional heating must first bring heat to the product surface and there after it depends on the physical characteristics and condition of the material as to how effectively this heat is transmitted into the mass. The product would suffer surface damage before the main body is adequately processed. Dielectric heating is applied to enhance conventional heating methods and to drastically shorten the required processing duration. Although the use of dielectric heating has been a well proven technique for several years in some industries, its application in the preheating of FRP has been limited by the insufficient experience. In this paper a method is described for uniform radio frequency heating of preheating of FRP.

• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.25 no.5
• /
• pp.345-351
• /
• 2015

Sounds of electrically powered vehicle components such as window lift system, roller blind, etc., are required to be more comfortable and not to irritate the people emotionally. In this paper, a study was conducted to identify the significant sound quality metric and compose the luxuriousness sound quality index of electrically powered vehicle roller blind which is part of vehicle sunroof system. Before conducting subjective evaluation, sound characteristics of roller blind was analyzed and set the target operating sound for subjective evaluation. Thus, transfer sound of roller blind which has the characteristics of sound modulation was used for subjective evaluation. Multiple linear regression analysis was carried out by chosen Zwicker's metrics which are pointed by comments of jurors. Loudness and sharpness related metrics are prime metrics in luxuriousness sound quality index we composed. Also, effect of roller blind assay when it is attached to real vehicle was identified to evaluate the validity of index.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2005.05a
• /
• pp.423-423
• /
• 2005

A carbon nanotube-based nanoelectromechanical device in resonance is examined theoretically. Mechanical deflections are electrically induced and resonantly excited at the fundamental frequency in cantilevered carbon nanotube. The electrically conducting elastic beam with van der Waals interactions at the tip is used for the modeling of the carbon nanotube device. Due to the elastic, electrical, and van der Waals interactions, the total energy of the system shows the unsymmetric two-well potentials. The predictions can be made that the device exhibits its nonlinear dynamic features in the two-well potentials. Also it is predicted that the fundamental frequency of the carbon nanotube device was changed by the nonlinear interactions induced by electrical and van der Waals potentials between carbon nanotube and ground surface of the device.