• Advances in Computational Design
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• 제4권3호
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• pp.239-250
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• 2019

The insertion of femoral implants is the most important phase for surgeons, given the characteristics of the cement during its mixing phase, generating residual stresses of thermal origin that increase the different stresses induced in the bone cement. The aim of our study is to determine the different stresses that affect the cement and more particularly at the cement-implant interface for different temperatures, and to make a comparison with the cement at ambient temperature. It was concluded that, there are a large concentration of stresses in the proximal part of the cement. For normal stresses, the bone cement is affected by stresses of tension and compression due to the effect of polymerization and the contraction of the cement.

• 한국화재소방학회논문지
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• 제11권2호
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• pp.11-17
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• 1997

화재시 실내의 경계면 선정에 관한 연구를 하기 위하여 쓰레기통, 의자, 카패트 및 소파의 화재실험 을 실제건물에서 수행하였다. 경계변의 선정을 하기위해서 화재실의 온도변화가 큰 지점은 여러 곳 온 도를 측정하고, 각 측정점의 온도를 시간과 높이별로 평균온도를 구한다. 또한 기본 측정점을 기준으로 화재실 전체구역에 대한 평변의 온도분포를 구하여 용도변화가 가장 큰 지점을 경계면의 높이로 정한 다. 이결과 어느 화재의 경우나 경계면이 뚜렷이 나타났고, 경계면 높이는 1[m] 근처에서 일정한 상태 값을 유지하였다. 다만, 최대온도를 나타내는 시간에는 경계면 높이가 O.25[m]내지 O.75[m]까지도 내 려왔다.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2003년도 춘계학술대회논문집
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• pp.299-302
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• 2003

The interface heat transfer coefficient was measured for non-isothermal bulk forming of Ti-6Al-4V. FE analysis and experiments were conducted. Equipment consisting of AISI H13 die was instrumented with thermocouples located at sub-surface of the bottom die. Die temperature changes were investigated in related to the process variables such as reduction, lubricant and initial die temperature. The calibration approach based on heat conduction and FE analysis using an inverse algorithm were used to evaluate the interface heat transfer between graphite-lubricated die and glass-coated workpiece. The coefficients determined determined were affected mainly by the contact pressure. The validation of the coefficients was made by the comparison between experimental data and FE analysis results.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 추계학술대회 논문집 학회본부 C
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• pp.938-940
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• 1998

In order to improve insulating character and ability of insulating system of power apparatus, the interfacial and complex structure is widely used. However, the interface or complex structure of insulation materials is reported as a weak point which causes breakdown. As the interface of insulation system degrades its electrical property and eventually causes a failure, the datailed phenomenon analysis is reported. The object of this paper is to evaluate dielectric property of PET film with the interface. The $tan{\delta}$ increased with the existence of semiconducting layer and showed prominent decrease as a function of temperature. Also, the $tan{\delta}$ showed prominent increase as a function of frequency. The dielectric properties of interfacial were affected by the interface characteristics.

• 소성∙가공
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• 제12권4호
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• pp.370-375
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• 2003

Determination of the interface heat transfer coefficient was investigated in non-isothermal bulk forming of glass-coated Ti-6Al-4V. FE analysis and experiments were conducted. Equipment consisting of AISI Hl3 die was instrumented with thermocouples located at sub-surface of the bottom die. Die temperature changes were investigated in related to the process variables such as reduction, lubricant and initial die temperature. The calibration approach based on heat conduction and FE analysis using an inverse algorithm were used to evaluate the interface heat transfer between graphite-lubricated die and glass-coated workpiece. The coefficients determined were affected mainly by the contact pressure. The validation of the coefficients was made by the comparison between experimental data and FE analysis results.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1988년도 추계학술대회 논문집
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• pp.1-4
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• 1988

The high frequency and quasi-state C-V curves were measured to determine the interface state density in MNOS devices. Berglund method was appropriate for determination of energy distribution of interface state density all over the energy gap. Applying Vg vs Øs relation by Berlund method to comparison-analysis method of the high-frequency and quasi-static C-V curves, we were able to determine the energy distribution by only measured C-V curves without theoretical C-V curves. The interface state density near the conduction band was high at lower temperature than room temperature.

• 대한간호학회지
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• 제47권6호
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• pp.794-805
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• 2017

Purpose: Interface pressure is a factor that contributes to the occurrence of pressure injuries. This study aimed to investigate interface pressure at common sites of pressure injury (occipital, gluteal and peritrochanteric areas), to explore the relationships among risk factors, skin condition and interface pressure, and to identify risk factors influencing interface pressure. Methods: A total of 100 patients admitted to the intensive care unit were enrolled at a tertiary teaching hospital in Korea. Interface pressure was recorded by a scanning aid device (PalmQ). Patient data regarding age, pulmonary disease, Braden Scale score, body mass index, serum albumin, hemoglobin, mean blood pressure, body temperature, and oxygen saturation were included as risk factors. Data collected from July to September 2016 were analyzed using binary logistic regression. Results: The mean interface pressure of the occipital, gluteal, and right and left peritrochanteric areas were 37.96 (${\pm}14.90$), 41.15 (${\pm}16.04$), 53.44(${\pm}24.67$), and 54.33 (${\pm}22.80$) mmHg, respectively. Predictive factors for pressure injuries in the occipital area were age ${\geq}70$ years (OR 3.45, 95% confidence interval [CI]: 1.19~9.98), serum albumin deficit (OR 2.88, 95% CI: 1.00~8.26) and body temperature ${\geq}36.5^{\circ}C$ (OR 3.12, 95% CI: 1.17~8.17); age ${\geq}70$ years (OR 2.81, 95% CI: 1.10~7.15) in the right peritrochanteric area; and body temperature ${\geq}36.5^{\circ}C$ (OR 2.86, 95% CI: 1.17~6.98) in the left peritrochanteric area. Conclusion: Our findings suggest that old age, hypoalbuminemia, and high body temperature may be contributory factors to increasing interface pressure; therefore, careful assessment and nursing care of these patients are needed to prevent pressure injury. Further studies are needed to establish cutoff values of interface pressure for patients with pressure ulcers.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2011년도 제40회 동계학술대회 초록집
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• pp.454-454
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• 2011

Graphene shows unusual electronic properties, such as carrier mobility as high as 10,000 $cm^2$/Vs at room temperature and quantum electronic transport, due to its electronic structure. Carrier mobility of graphene is ten times higher than that of Silicon device. On the one hand, quantum mechanical studies have continued on graphene. One of them is quantum Hall effect which is observed in graphene when high magnetic field is applied under low temperature. This is why two dimension electron gases can be formed on Graphene surface. Moreover, quantum Hall effect can be observed in room temperature under high magnetic field and shows fractional quantization values. Quantum Hall effect is important because quantized Hall resistances always have fundamental value of h/$e^2$ ~ 25,812 Ohm and it can confirm the quantum mechanical behaviors. The value of the quantized Hall resistance is extremely stable and reproducible. Therefore, it can be used for SI unit. We study to measure quantum Hall effect in CVD graphene. Graphene devices are made by using conventional E-beam lithography and RIE. We measure quantum Hall effect under high magnetic field at low temperature by using He4 gas closed loop cryostat.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2009년도 춘계학술대회 논문집
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• pp.172-175
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• 2009

n-type crystalline silicon wafers were passivated with intrinsic a-Si:H thin films on both sides using HWCVD. Minority carrier lifetime measurement was used to verify interface passivation properties between a-Si:H thin film and crystalline Si wafer. Thin film interface characteristics were investigated depending on $H_2/SiH_4$ ratio and hot wire deposition temperature. Vacuum annealing were processed after deposition a-Si:H thin films on both sides to investigate thermal effects from post process steps. We noticed the effect of interface passivation properties according to $H_2/SiH_4$ ratio and hot wire deposition temperature, and we had maximum point of minority carrier lifetime at H2/SiH4 10 ratio and $1600^{\circ}C$ wire temperature.

• 한국세라믹학회지
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• 제34권8호
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• pp.825-833
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• 1997

Silicon carbide films were deposited by low pressure chemical vapor deposition(LPCVD) using MTS(CH3SICl3) in hydrogen atmosphere on (100) Si substrate. To prevent the unstable interface from being formed on the substrate, the experiments were performed through three deposition processes which were the deposition on 1) as received Si, 2) low temperature grown SiC, and 3) carbonized Si by C2H2. The microstructure of the interface between Si substrates and SiC films was observed by SEM and the adhesion between Si substrates and SiC films was measured through scratch test. The SiC films deposited on the low temperature grown SiC thin films, showed the stable interfacial structures. The interface of the SiC films deposited on carbonized Si, however, was more stable and showed better adhesion than the others. In the case of the low temperature growth process, the optimum condition was 120$0^{\circ}C$ on carbonized Si by 3% C2H2, at 105$0^{\circ}C$, 5 torr, 10 min, showed the most stable interface. As a result of XRD analysis, it was observed that the preferred orientation of (200) plane was increased with Si carbonization. On the basis of the experimental results, the models of defect formation in the process of each deposition were compared.