• Elastomers and Composites
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• 제50권1호
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• pp.13-17
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• 2015

A study of the effects of MWCNT as a nucleating agent on the formation reactions of the rigid polyurethane foams (RPUFs) was carried out. Sample PUFs, formulated with grease-type master batch of MWCNT/surfactant, were fabricated by free-rising method. Temperature changes with time during foaming process were measured using a digital thermometer. RPUF foaming process was observed to undergo 2-step processes with temperature inflection around 60 sec after the start of reaction, and then reached slowly the max. temperature. While the max. temperature of neat PUF was measured as ca. $120^{\circ}C$, that of the samples with MWCNT were as higher value as ca. $130^{\circ}C$, and, even the time to reach that temperature was reduced by about 15 sec. Average cell size of PUF samples decreased from 185.1 for the neat PUF to $162.9{\mu}m$ for the sample of 0.01 phr of MWCNT. As the result, it was considered that MWCNT in RPUF foaming process could play a roll both as a nucleating agent and as a catalyst.

• 한국자기공명학회논문지
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• 제19권3호
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• pp.143-148
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• 2015

In some pathogenic bacteria, there are RNA thermometers, which regulate the production of virulence associated factors or heat shock proteins depending on temperature changes. Like a riboswitches, RNA thermometers are located in the 5'-untranslated region and involved translational gene regulatory mechanism. RNA thermometers block the ribosome-binding site and start codon area under the $37^{\circ}C$ within their secondary structure. After bacterial infection, increased the temperature in the host causes conformations changes of RNA, and the ribosome-binding site is exposed for translational initiation. Because structural differences between open and closed forms of RNA thermometers are mainly mediated by base pairing changes, NMR spectroscopy is a very useful method to study these thermodynamically changing RNA structure. In this review, we briefly provide a fundamental function of RNA thermometers, and also suggest a proper NMR experiments for studying RNA thermometers.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1996년도 춘계학술대회 논문집
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• pp.224-227
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• 1996

Platinum thin films were deposited on Si-wafer by DC magnetron sputtering for RTD (Resistance Thermometer Devices). We investigated the physical and electrical characteristics of these films under various conditions, the input power, working vacuum, temperature of substrate and also after annealing these films. The deposition rate was increased with increasing the input power but decreased with increasing Ar gas pressure. The resistivity were decreased wish increasing the temperature of substrate and the annealing time at 1000$^{\circ}C$. At substrate temperature 300$^{\circ}C$, input power 7(w/$\textrm{cm}^2$), working vacuum 5mtorr and annealing conditions 1000$^{\circ}C$, 240 min we obtained 10.65${\mu}$Ω$.$cm, resistivity of Pt thin film closed to the bulk value.

• 한국전기전자재료학회논문지
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• 제14권3호
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• pp.228-233
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• 2001

This paper presents the optimized design, fabrication and thermal characteristics of micro-heaters for thermal MEMS (micro elelctro mechanical system) applications usign SOI (Si-on-insulator) and trench structures. The micro-heater is based on a thermal measurement principle and contains for thermal isolation regions a 10㎛ thick Si membrane with oxide-filled trenches in the SOI membrane rim. The micro-heater was fabricated with Pt-RTD (resistance thermometer device) on the same substrate by suing MgO as medium layer. The thermal characteristics of the micro-heater wit the SOI membrane is 280$\^{C}$ at input power 0.9W; for the SOI membrane with 10 trenches, it is 580$\^{C}$ due to reduction of the external thermal loss. Therefore, the micro-heater with trenches in SOI membrane rim provides a powerful and versatile alternative technology for improving the performance of micro-thermal sensors and actuators.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 합동 추계학술대회 논문집 정보 및 제어부문
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• pp.609-612
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• 2002

In this paper, a 12-bit 100-MHz CMOS current steering digital-to-analog converter is designed. In the D/A converter, a driver circuit using a dynamic latch is implemented to obtain low glitch and thermometer decoder is used for low DNL errors, guaranteed monotonicity, reduced stitching noise. And a threshold voltage-compensated current source. The D/A converter is designed with 0.35-$\mu m$ CMOS technology at 3.3 V power supply and simulated with HSPICE. The maximum power dissipation of the designed DAC is 143 mW.

• 대한물리치료과학회지
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• 제1권1호
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• pp.121-127
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• 1994

The purpose of this study was to determine whether vasodilation occurs when interferential current is applied to the cervical sympathetic chain and peripheral sympathetic nerves. A digital thermometer was used to record skin temperature change. The protocols used for interferential stimulation were 90-100 Hz, applied for 20 minutes via two pairs of electrodes 1) to the throat and 2) to the forearm. Forty subjects were stimulated at each of the two sites. There was no significant correlation between inital skin temperature, sex or age and temperature change. Even though there was a statistically significant temperature increase with cervical sympathetic chain stimulation, this had no clinical vasodilatory effect. More research on interferential current stimulation is needed so that the potential benefits to normal subjects and patients is better understood.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2006년도 제32회 KOSCO SYMPOSIUM 논문집
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• pp.13-18
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• 2006

Radiant burners are applicable to drying, preheating and curing in materials manufacturing processes. High radiation efficiency is one of the most important performance criteria for these burners. The wide variation in reported radiation efficiencies are partly due to the differences in the measurement techniques. In the present work, water cooled radiant heat flux meter was used to measure radiant heat flux from a metal fiber mat burner. Non-contact type thermometer was also utilized to measure the surface temperature of the burner. Combustion gas was measured by gas analyzers. According to the thermal loads and stoichiometric ratios, radiant heat transfer ratio and combustion performance were discussed here in.

• 센서학회지
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• 제18권4호
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• pp.322-326
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• 2009

To estimate the measurement uncertainty for industrial platinum resistance thermometers(IPRTs) made with 3-wire connection, the immersion temperature profile was investigated using a liquid bath. Two types of IPRTs having lead wires made of silver and nickel were constructed and the immersion profiles were measured at temperatures from -50 $^{\circ}C$ to 250 $^{\circ}C$ using 3-wire and 4-wire method. As immersion depth and temperature increased, the resistances measured by 3-wire method increased linearly but not for 4-wire method. To calibrate a 3-wire IPRT, the immersion effect must be accounted for. We propose a linear equation to assess correctly the measurement uncertainty.

• Progress in Superconductivity
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• 제4권1호
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• pp.80-85
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• 2002

In order to disseminate the IEC international standard of RRR measurement of Cu／Nb／-Ti composite superconductors, a measuring system was developed at KRISS. The system consisted of helium reservoir, base plate, thermometer, voltmeter and current source. The helium reservoir and base plate provided a stable temperature of a range from 4.2 K to 300 K and the voltmeter measured several order of $mutextrm{V}$ on specimen for obtaining RRR of the Cu／Nb-Ti composite superconductor. Three specimens of the Cu／Nb-Ti composite superconductors were measured using this system for characterizing their RRR. The resistance-temperature curves ortho specimens showed 10／sup -6／ to 10／sup -5／ Ohms near transition temperature and 10／sup -4／ to 10／sup -3／ Ohms at 293 K. The RRR values of the specimens were 145, 71 and 140, respectively.

• 한국전문물리치료학회지
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• 제5권3호
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• pp.56-62
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• 1998

The nature of entrainment between the locomotor and the respiratory rhythm was investigated while normal human subjects were walked or running on a treadmill. The purpose of this study was to analyze the incidence and type of coordination between the locomotor and the respiratory rhythm during running at different work load. The experiments were carried out on 12 untrained volunteers exercising at 3 work loads (2 METs, 3 METs, 4 METs in randomized order). The gait cycle was measured by electromyography (EMG) signal of gastrocnemius firing and the respiratory cycle was measured by a thermometer. We found that the ratio between the locomotor and the respiratory rhythm existed and 2:1 ratio between the locomotor-respiratory coupling was dominant at 2 METs and 3 METs.