• 한국식품영양과학회지
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• 제41권12호
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• pp.1842-1846
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• 2012

된장과 고추장에 대하여 Bacillus cereus 포자를 $10^5$ spore/g 접종하고 이의 저감화에 적용 가능한 허들로서 additive(95% ethanol 3%, 1% oregano 추출물 0.3%), Joule 가열($95^{\circ}C$, 5분) 및 초고압처리(500 MPa, $45^{\circ}C$, 5분)를 적용하여 Bacillus cereus 포자의 살균효과와 저장성을 분석하였다. 된장에 있어 AJ(additive+Joule 가열) 및 AJP(additive+Joule 가열+초고압) 처리구는 각각 2.80 log 및 3.74 log 감소효과를 보였고 고추장의 경우에는 각각 4.71 log 및 5.60 log 감소를 보여 Joule 가열처리구는 된장과 고추장에 있어서 additive 처리구와 함께 Bacillus cereus 포자의 살균에 상당한 시너지 효과를 나타내는 것으로 판단되었다. 한편 $30^{\circ}C$ 저장시험에서 additive, Joule 가열 및 초고압 병행 처리는 된장 및 고추장에서 낮은 수준의 포자를 유지하는 데에도 유효한 효과를 보여 AJ(additive+Joule 가열) 및 AJP(additive+Joule 가열+초고압) 처리기법은 된장 및 고추장의 Bacillus cereus 포자에 대한 효율적인 살균방법으로서 적용이 가능할 것으로 보였다.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회A
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• pp.1623-1628
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• 2008

A temperature gradient focusing (TGF) via Joule heating phenomenon was numerically studied. The governing transport equations are implemented into a quasi-1D numerical model to predict the resulting temperature, velocity, and concentration profiles along a microchannel of varying width under an applied electric field. The model is used to analyze the effects of varying certain geometrical parameters of a microchannel on the focusing performance of the device. We show the effects of varying width of the microchannel having a fixed length, and propose the optimal geometry of the device. This method can be easily implemented into lab-on-a-chip (LOC) applications where focusing is required based on its simple design.

• 한국기계가공학회지
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• 제19권8호
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• pp.104-109
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• 2020

Recently, vibration and noise have become an important issue in the auto industry. Asphalt vibration damping pads are used to reduce the noise and vibration of automobile bodies, and asphalt is used for many mass-produced parts due to its simple attachment process and low processing costs. In this study, the self-adhesion of asphalt pads using Joule heating was evaluated. To create the asphalt pad for the experiment, the asphalt pad was molded into a specific thickness by using SGACC material and rubber used in the vehicle body as a main component and a modified resin and filler. The SGACC material was 200 mm in length, 200 mm in width, and 0.7 mm in thickness. The asphalt pad was 200 mm in length, 100 mm in width, and 3 mm in thickness. The equipment was composed of a TR (Transformer) DC254kVA and a TC (Time controller) for a current of up to 20,000 A. The current for the Joule heating was set to 7.0 kA and a 3/1 cycle, for which the adhesion of the asphalt pad over the current flow time was evaluated.

• 한국재료학회지
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• 제17권2호
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• pp.91-95
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• 2007

Electromigration characteristics of Sn-3.5Ag flip chip solder bump were analyzed using flip chip packages which consisted of Si chip substrate and electroplated Cu under bump metallurgy. Electromigration test temperatures and current densities peformed were $140{\sim}175^{\circ}C\;and\;6{\sim}9{\times}10^4A/cm^2$ respectively. Mean time to failure of solder bump decreased as the temperature and current density increased. The activation energy and current density exponent were found to be 1.63 eV and 4.6, respectively. The activation energy and current density exponent have very high value because of high Joule heating. Evolution of Cu-Sn intermetallic compound was also investigated with respect to current density conditions.

• 한국세라믹학회지
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• 제55권5호
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• pp.440-445
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• 2018

To control the electrical properties of a SiC heating element, we sintered $SiC-ZrB_2$composites by using the spark plasma sintering method. The addition of $ZrB_2$ particles with lower electrical conductivity to the SiC matrices with comparatively higher electrical resistivity lowers the electrical resistivities of the composite material. The $ZrB_2$ particles aggregate to form large particles and 3-1, 3-2, and 3-3 networks, i.e., conduction paths. In our study, about $1-{\mu}m$-sized $ZrB_2$ powders start to form the conduction path at about 10 vol.% of addition, namely the threshold volume. The Joule heating experiment shows that 20 vol.% $ZrB_2$-added SiC heating element has outstanding heating efficiency.

• 한국주조공학회지
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• 제25권3호
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• pp.115-122
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• 2005

In the present study, an EMC (Electromagnetic Casting) process, using a segmented Cu cold crucible under a high frequency alternating magnetic field of 20 kHz, was practiced for the fabrication of poly-crystalline Si ingot of 50 mm diameter. The effects of Joule heating and electromagnetic pressure in molten Si were systematically investigated with various processing parameters such as electric current and crucible configuration. A preliminary experimental work was initiated with the pure Al system for the establishment of a stabilized non-contact working condition, and further adapted to the semiconductor-off-grade Si system. A commercialized software such as Opera-3D was utilized in order to simulate electromagnetic pressure and Joule heating. In order to evaluate the meniscus shape of the molten melts, shape parameter was used throughout the research. A segmented graphite crucible, which was attached at the upper part of the cold crucible, was introduced to enhance significantly the heating efficiency of Si melt keeping non-contact condition during continuous melting and casting processes.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2012년도 춘계학술대회 논문집
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• pp.935-936
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• 2012

• 대한기계학회논문집B
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• 제33권10호
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• pp.797-802
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• 2009

Large area crystallization of amorphous silicon thin-films on glass substrates is one of key technologies in manufacturing flat displays. Among various crystallization technologies, the Joule induced crystallization (JIC) is considered as the highly promising one in the OLED fabrication industries, since the amorphous silicon films on the glass can be crystallized within tens of microseconds, minimizing the thermally and structurally harmful influence on the glass. In the JIC process the metallic layers can be utilized to heat up the amorphous silicon thin films beyond the melting temperatures of silicon and can be fabricated as electrodes in OLED devices during the subsequent processes. This numerical study investigates the heating mechanisms during the JIC process and estimates the deformation of the glass substrate. Based on the thermal analysis, we can understand the temporal and spatial temperature fields of the backplane and its warping phenomena.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2008년도 제31회 추계학술대회논문집
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• pp.310-313
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• 2008

스크램젯 비행체에서 극초음속 순항미사일의 추진 특성을 향상시키고 항력을 적게 발생하면서 전력을 생산하는 장치로써 MHD 장치가 최근 들어 큰 관심을 받아왔다. 이전에 보였던 것보다 보다 완전한 물리적 모델을 바탕으로 하면, 경계층 박리 억제나 파워 바이패스를 통해 극초음속 추진 시스템의 성능 향상을 하는 MHD의 쓰임새를 논의하는 것은 불필요한 일이 된다. MHD 유동 제어를 하게 되면 엔진 성능에 상당한 역효과를 미치는 불가피한 Joule 가열이 크게 발생한다. 하지만, 예비 조사에 따르면 MHD는 약간의 항력만을 더 발생하면서 스크램젯 엔진을 장착한 무기에 메가와트 단위의 큰 전력을 생산해 낼 수 있을 것으로 여겨진다.

• Journal of the Korean Physical Society
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• 제73권9호
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• pp.1303-1309
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• 2018

In the present paper, we study the entropy analysis of boundary layer flow over a slender stretching sheet under the action of a non uniform magnetic field that is acting perpendicular to the flow direction. The effects of viscous dissipation and Joule heating are included in the energy equation. Using similarity transformation technique the momentum and thermal boundary layer equations to a system of nonlinear differential equations. Numerical solutions are obtained using the shooting and fourth-order Runge-Kutta method. The expressions for the entropy generation number and Bejan number are also obtained using a suggested similarity transformation. The main objective of this article is to investigate the effects of different governing parameters such as the magnetic parameter ($M^2$), Prandtl number (Pr), Eckert number (Ec), velocity index parameter (m), wall thickness parameter (${\alpha}$), temperature difference parameter (${\Omega}$), entropy generation number (Ns) and Bejan number (Be). All these effects are portrayed graphically and discussed in detail. The analysis reveals that entropy generation reduces with decreasing wall thickness parameter and increasing temperature difference between the stretching sheet and the fluid outside the boundary layer. The viscous and magnetic irreversibilities are dominant in the vicinity of the stretching surface.