• Title/Summary/Keyword: interface temperature

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Effects of temperature on the evolution of stresses at the stem cement interface

  • Kaci, Djafar Ait;Moulgada, Abdelmadjid;Achache, Habib;Bounoua, Noureddine
    • Advances in Computational Design
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    • v.4 no.3
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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.

A Study on the Decision of the Interface Height in Compartment Fire (건물화재시 경계면 선정에 관한 연구)

  • 허만성
    • Fire Science and Engineering
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    • v.11 no.2
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    • pp.11-17
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    • 1997
  • The objective of this research is to study on the decision of the interface height in a room in case of trashcan, chair, carpet and sofa as a fire starter in a residential room by performing the experimental studies. For the decision of the interface height, the temperatures of various positions in fire room are measured and the averaged temperatures are calculated from these measured temperatures every time and height. The temperatures of all positions in fire room are obtained as the basis of the measured temperatures and the middle point of the highest temperature slope is decided as the interface point. The interface heights were distinct and were around 1[m] maintaining constant state. However, at the time of the maximum temperature, the interface height was lowered to 0.25[m]-0.75[m] from the floor.

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Determination of the interface heat transfer coefficient for hot-forming process of Ti-6Al-4V (Ti-6Al-4V 합금의 열간성형공정에 대한 계면열전달계수의 결정)

  • 염종택;임정숙;나영상;박노광;신태진;황상무;심인옥
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2003.05a
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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.

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Dependencies of Dielectric Properties on Temperature and Frequency in PET films with interfaces (계면을 갖는 PET 필름의 유전특성의 온도 및 주파수 의존성)

  • Lee, Chang-Hoon;Lee, Jong-Bok;Lee, Dong-Young;Kang, Moo-Sung;Park, Dae-Hee
    • Proceedings of the KIEE Conference
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    • 1998.11c
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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.

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Determination and Analysis of Interface Heat Transfer Coefficients in Hot Forming of Ti-6Al-4V (Ti-6Al-4V 합금의 열간성형에 대한 계면열전달계수의 결정 및 분석)

  • 염종택;임정숙;박노광;신태진;황상무;홍성석
    • Transactions of Materials Processing
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    • v.12 no.4
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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.

Determination of Energy Distribution of Interface State Density in the MNOS Memory Device (MNOS 기억소자의 계면상태밀도의 에너지 분포의 결정)

  • 한태현;강창수;박종하;서광열
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1988.10a
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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.

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Factors Predicting the Interface Pressure Related to Pressure Injury in Intensive Care Unit Patients (중환자실 환자의 욕창 관련 경계압력 예측요인)

  • Shine, Ji Seon;Kim, Soo Jin;Lee, Ji Hyun;Yu, Mi
    • Journal of Korean Academy of Nursing
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    • v.47 no.6
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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.

Quantum Hall Effect of CVD Graphene

  • Kim, Young-Soo;Park, Su-Beom;Bae, Su-Kang;Choi, Kyoung-Jun;Park, Myung-Jin;Son, Su-Yeon;Lee, Bo-Ra;Kim, Dong-Sung;Hong, Byung-Hee
    • Proceedings of the Korean Vacuum Society Conference
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    • 2011.02a
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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.

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Effects of the Furnace Temperature on the Growth Behavior of Directionally Solidified Al-Cu-Mg Alloy (Al-Cu-Mg합금의 일방향응고시 로온도에 따른 응고거동변화)

  • Moon, Cheol-Hee
    • Journal of Korea Foundry Society
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    • v.17 no.6
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    • pp.545-551
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    • 1997
  • 14 cm length Al-15Cu-1Mg alloys have been directionally solidified in 3 mm diameter alumina tubes in a furnace moved with a constant velocity V=12 cm/hr under various furnace temperatures of 660, 710 and $760^{\circ}C$. By analysing the evolution of the temperature profiles along the alloy length during the solidification, the growth characteristics such as the position of the solid/liquid interface, the local growth velocity (R) and the temperature gradient at the solid/liquid interface (G) have been determined. The effects of the furnace temperature on the growth behavior have been investigated by the comparison of R and G values for each temperature. Under the furnace temperature of $760^{\circ}C$, steady state growth region was observed for the latter half of the growth period.

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A study on the characteristic of adhesion on the low temperature concrete of self adhesive waterproofing sheet using interface leakage test. (계면 누수를 통한 자착형 방수시트의 저온 부착 특성에 관한 연구)

  • Choi, Su-Young;Kim, Meong-Ji;Lee, Jung-Hoon;Choi, Sung-Min;Oh, Sang-Keun
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2014.05a
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    • pp.234-235
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    • 2014
  • Recently, waterproof construction used to self adhesive waterproofing sheet in the actual field in winter for reduce cost and term. However self adhesive waterproofing sheet's quality is declined in low temperature condition. So, this study was to confirm on the low temperature condition of concrete substrate effecting the adhesion of self adhesion waterproofing sheet using interface leakage test. As a result of this study, self adhesion waterproofing sheet must not be used at temperature below 5℃. Also, adhesion between waterproofing sheet and concrete is declined in low temperature.

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