• 대한소아치과학회지
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• 제27권3호
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• pp.410-418
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• 2000

치아수복시 마무리 과정에서의 연마는 수복물의 수명 및 심미성을 결정하는 중요한 과정으로서 연마시 마찰열의 발생으로 인하여 치수에 위해작용을 줄 수 있으므로 주의를 하여야 한다. 여러 가지 수복 재료를 연마하는 동안 치수내에서 발생하는 열의 변화를 수복물 종류, 이장재 종류, 잔존 상아질의 두께, 연마 시간의 차이에 따라 조사하고자 발치된 구치에 수복물을 충전한 후 aluminum-oxide coated disc를 이용하여 연마하는 과정에서 thermocouple을 이용하여 치수내 온도값을 측정하였으며, 이에 대한 통계적 분석을 시행하여 다음과 같은 결과를 얻었다. 모든 경우에서 연마 시간이 증가함에 따라 치수내 온도가 증가하였으며, 아말감 연마시 다른 수복 재료에 비해 큰 온도 증가치를 보였으나 composite resin, glass ionomer cement, 그리고 compomer에서는 연마에 따른 온도 변화차가 관찰되지 않았다. 아말감 하방에 이장재를 사용한 경우에 이장재를 사용하지 않았을 경우에 비해 온도 증가량이 적었으며, 다른 수복재에서는 이장재 사용여부에 따른 온도 증가량의 차이는 존재하지 않았다. 본 실험에서 사용된 이장재 중 glass ionomer cement와 zinc phosphate cement에 비해 zinc oxide eugenol cement의 열 차단 효과가 가장 작았다. 수복물에 간헐적인 연마를 시행한 경우, 지속적인 연마를 시행한 경우에 비해 온도 증가량이 작았으며, 아말감 하방의 잔존 상아질의 두께가 감소하면 온도 증가량이 더 커졌으나, 다른 세 종류의 수복재에서는 잔존 상아질의 두께에 따른 차이가 발생하지 않았다.

• 국제초고층학회논문집
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• 제2권4호
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• pp.315-321
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• 2013

This building is a first-class super-high office building. This article briefly introduces energy-saving technique and measures adopted in HVAC system, such as cooling and heat sources, water and air system etc.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2003년도 추계학술발표대회 개요집
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• pp.179-181
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• 2003

The present study focuses on the effect of geometrical discontinuity, strength mismatch, which can elevate plastic constraint due to heterogeneous plastic straining, and loading rate on the ductile crack initiation using two-parameter criterion. Fracture initiation testing has been conducted under static and dynamic loading using circumferentially notched round-bar specimens. In order to evaluate the stress/strain state in the specimens, especially under dynamic loading, a thermal elastic-plastic dynamic finite element (FE) analysis considering the temperature rise due to plastic deformation has been carried out.

• 한국환경과학회지
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• 제20권5호
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• pp.667-672
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• 2011

The purpose of this work is to present the experiment results by a dynamic adsorption of water vapor on pelletized zeolites (ADZ300, ADZ400, and ADZ500) in fixed bed. The breakthrough curves of water vapor with several different concentrations and temperature in the range of 25~45 $^{\circ}C$ on zeolite bed were investigated. In the same conditions, the breakthrough time on ADZ400 and ADZ500 were little longer than ADZ300, and the equilibrium adsorption capacity on ADZ500 was highest. The higher the concentration of water vapor was, the faster the breakthrough time was, and the slope of breakthrough curves showed a tendency to increase. The faster the flow rate of water vapor was, the faster the breakthrough time was relatively, but variations between flow rate and breakthrough time did not have a proportional relationship. The breakthrough curve maintained constant gradient in spite of variation of flow rate in the same concentration. The temperature rise in zeolite bed by adsorption heat was occurred in the early stage of adsorption. After water molecule layers were formed on the surface of zeolite, the temperature was slowly cooled by water vapors continuously flowed in as constant temperature. The greater the concentration of water vapor and adsorption temperature were, the temperature difference in zeolite bed was increased.

• 대한기계학회논문집
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• 제3권2호
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• pp.43-47
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• 1979

This paper presents the effect of stress relief annealing on mechanical properties in single Vee-groove welding joint. In this experiment, the investigation of annealing effect on mechanical properties of test material carried out by changing the annealing temperature from $600^{\circ}C$ to $900^{\circ}C$ under the given conditions. The results pbtained by this study are as follows: (1) Under the constant welding conditions, the tensile strength of test welded joint decrease in accordance with the increase of annealing temperature. The experimental results show that the reduction rate of tensile strength is about 35.09% of base metal strength. (2) Microhafdness distribution of welded joint bring about the maximum hardness near the bended line of welding joint. (3) Izod impact energy of welded joint in increase in according to the rise of annealing temperature and the peak energy of impact test occurs at $800^{\circ}C$

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2006년도 추계 학술발표회 논문집
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• pp.849-852
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• 2006

The lightweight foamed concrete is superior to properties of insulation and light-weight because it is included in many inner pore. So, lightweight foamed concrete used to construction field that need to property of insulation. The property of insulation of lightweight foamed concrete is varied with density. Also, Density is varied with hardening matrix and pore rate. The purpose of the experiment is to know thermal properties of specimen according to the change of density when heating the specimen. As a result of this experiment, the higher density, the lower temperature of mold. this tendency isn't same as ordinary lightweight foamed concrete, and then density 0.9 is expressed most low temperature result also the discontinuity of shape of mold was efficient for the prevention of the temperature rise.

• Interaction and multiscale mechanics
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• 제4권2호
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• pp.139-153
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• 2011

In this paper we develop a fully anisotropic pressure and temperature dependent model to investigate the effect of the microstructure on the shock response of ${\beta}$-HMX molecular single and polycrystals. This micromechanics-based model can account for crystal orientation as well as crystallographic twinning and slip during deformation and has been calibrated using existing gas gun data. We observe that due to the high degree of anisotropy of these polycrystals, certain orientations are more favorable for plastic deformation - and therefore defect and dislocation generation - than others. Loading along these directions results in highly localized deformation and temperature fields. This observation confirms that most of the temperature rise during high rates of loading is due to plastic deformation or dislocation pile up at microscale and not due to volumetric changes.

• 한국추진공학회지
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• 제7권3호
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• pp.8-14
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• 2003

KSR-III 축소형 엔진을 원형으로 하는 8채널형 칼로리미터의 냉각성능해석을 수행하였다. 축대칭 압축성 해석을 통해서 연소실 벽으로의 열유속을 예측하였으며 이를 이용하여 3차원 냉각유로 내부의 열전달 해석을 수행하였다. 연소실 벽으로의 열유속은 문헌에서 제시하는 수준으로 확인되었으며 열전달 해석을 통하여 칼로리미터 개발과 운용에 필요한 냉각수의 압력강하, 온도상승 및 연소실벽의 최고온도를 제시하였다. 연소실 압력증가에 따른 냉각요구량을 결정하였으며 냉각수의 물성변화에 의한 냉각성능 변화를 예측하였다.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2002년도 추계 학술대회논문집
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• pp.109-113
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• 2002

Numerical analysis of aerodynamic heating for KPSAM is performed using aerodynamic heating model suitable to KPSAM, which has complex flow field resulting from the spike attached to the dome, such as large separation area and the strong shock/boundary layer interaction region around reattachment point on the dome. The aerodynamic heating model is validated and modified through the comparison between the flight test measurement and the thermal analysis results. TFD temperature sensors are installed on the dome to measure surface temperature during the flight. Computation results, obtained from the heat transfer analysis on the sensors, agree well with flight test data. The aerodynamic heating model provides heat transfer rate into surface as a boundary condition of unsteady 1D/axisymmetric thermal analysis on the missile structure. The axisymmetric thermal analysis using FLUENT is more versatile than the 1D analysis and can be applied to the heating problem related with complex structures and multi-dimensional heat transfer problems such as prediction of temperature rise at contact surface of different materials.

• Membrane and Water Treatment
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• 제10권2호
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• pp.179-189
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• 2019

This study aimed to investigate the effect of temperature and solid retention time (SRT) on membrane fouling in a membrane bioreactors (MBRs). For this purpose, a lab-scale submerged MBR system was used. This system operated at two SRTs of 15 and 5 days, three various temperatures (20, 25 and $30^{\circ}C$) and hydraulic retention time (HRT) of 8 h. The results indicated that decreased the cake layer resistance and increased particles size of foulant due to increasing temperature and SRT. Fourier transform infrared (FTIR) analysis show that the cake layer formed on the membrane surface, contained high levels of proteins and especially polysaccharides in extracellular polymeric substances (EPS) but absorbance intensity of EPS functional groups decreased with temperature and SRT. EEM analysis showed that the peak on the range of Ex/Em=220-240/350-400 in SRT of 15 and temperature of $30^{\circ}C$ indicates the presence of fulvic acid in the cake. In addition, as the temperature rise from 20 to $30^{\circ}C$, concentration of soluble microbial products (SMP) increased and COD removal reached 89%. Furthermore, the rate of membrane fouling was found to increase with decreasing temperature and SRT.