• 한국도로학회논문집
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• 제16권4호
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• pp.87-95
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• 2014

PURPOSES: Evaluation of thermal conductivity and convection properties of asphalt mixture by using thermodynamics. METHODS: In this research, temperature prediction model based on thermodynamics is derived for asphalt mixture in transient state and it is verified with laboratory test results. RESULTS: The derived temperature prediction model shows good agreement with laboratory test results. CONCLUSIONS: It is concluded that the derived model based on thermodynamics and thermal properties in the literature are good enough to capture temperature variation in laboratory test. The approach based on thermodynamics can be applied to more complex temperature simulations.

• 공학교육연구
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• 제25권6호
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• pp.69-80
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• 2022

In this study, the application of flipped learning methodology to thermodynamics in mechanical engineering was examined, and how university students view flipped learning and the effects of flipped learning were analyzed. To analyze the effects of flipped learning, pre-class survey, assessment on learning in pre-class, team activities during class, and post-class survey were conducted. The analysis was also conducted on 33 students who took the thermodynamics course in mechanical engineering, and the PARTNER flipped learning model was applied to the class. The results of this study are as follows; In the preliminary survey, the students expected that the flip-learning class with team activities and teaching between team members would be helpful in improving their learning. In addition, students recognized that cooperative learning through a team was helpful for learning. The case reflecting the result of pre-learning evaluation to the subject grades showed higher pre-learning evaluation results than the case not reflecting the result of the pre-learning evaluation to the subject grades, and it was found that the pre-learning evaluation was acting as a factor to promote learning in pre-class. In post-class survey, the satisfaction with the flipped learning class was high, indicating that the effectiveness of the flipped learning class applied to the thermodynamics class was excellent.

• 공학교육연구
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• 제21권2호
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• pp.3-6
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• 2018

A few thermodynamics texts are commonly found to have unrealistic example problems in which the process violates the second law of thermodynamics. This error would result from presentation order in the text which introduces first the first law for cycles, systems, and control volumes and then the second law later. In the presentation order, the example problems deal only with the first law without telling whether the process violates the second law. To correct this erroneous situation, it could be recommended to present the first law and the second law successively so that both laws could be applied simultaneously to the given example problems.

• 대한기계학회논문집B
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• 제28권12호
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• pp.1573-1581
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• 2004

Thermodynamic principles are described with a new point of view. In present study, the interaction between two systems is focused instead of the behavior of a system in conventional thermodynamics. The state change of a system cannot occur by itself but it is the result of the interaction between systems. However, the interaction itself is also the result of another kind of interaction, the interaction between two interactions. To reconstruct thermodynamics with such a point of view, the reversible world is imagined, in which conservations and measurements are discussed. There exists a conserved quantity for each mode of reversible interaction. The conserved transferring quantity in the interaction between interactions is the effective work, which is supposed to be measurable and conserved in reversible world. Effective work is the primary concepts of energy. It is the key factor to explain measurements, energy conservation and energy dissipation. The concepts developed in reversible world are applied to the real world in which irreversible phenomena may occur. Irreversibility is the result of effective energy dissipation, in which effective work irreversibly changes into entropy. A quantitative relation between the disappearing effective work and the generated entropy is dissipation equation which is given by experiments. A special temperature scale to give a very simple type of the dissipation equation is the absolute temperature scale, which gives the conventional conservation of energy.

• 공학교육연구
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• 제26권6호
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• pp.51-61
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• 2023

In this study, the effects of pre-learning attitude on learning participation and academic achievement was analyzed when applying the flipped learning methodology to engineering subject education. The modified PARTN teaching and learning model was applied, and pre-class survey, assessment on learning in pre-class, and post-class survey were conducted to analyze the effectiveness of flipped learning. The results were analyzed for 24 students who took the applied thermodynamics lecture. They were asked to take the course with the videos provided in the pre-class stage, and a pre-learning assessment was conducted to measure the completeness and understanding of the learning. As a result of the study, it was found that students with relatively excellent learning ability had excellent pre-learning evaluation results and excellent final academic achievement. In addition, the lower the pre-learning completion rate within the pre-learning period or the higher the learning rate using mobile devices, the more difficult it was to faithfully complete pre-learning, leading to poor pre-learning evaluation results. Meanwhile, the survey revealed that conducting pre-learning assessments were helpful in encouraging individual learning. In addition, cases reflecting pre-learning evaluation results to course grades showed higher pre-learning evaluation results than cases not reflecting pre-learning evaluation results to course grades, and in flipped learning classes, pre-learning evaluations act as a factor that promotes pre-class learning.

• 산업기술연구
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• 제18권
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• pp.267-275
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• 1998

Continuous thermodynamics has been applied for modeling of phase equilibria in multicomponent mixtures, to avoid disadvantages of the pseudo-component and key-component method. In this paper continuous thermodynamic relations formulated by using the Pate-Teja equation of state were adopted for calculations of phase equilibria in natural gas mixtures, crude oil mixtures and mixtures extracted by supercritical $CO_2$ fluids. Calculations of phase equilibria were performed by two procedures ; a moment method coupled with the beta distribution function and a quadrature method combined with Gaussian-Legendre polynomials. Calculated results were compared with experimental data. It was showed that continuous thermodynamic frameworks considered in this paper were well-matched to experimental data.

• 한국응용과학기술학회지
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• 제8권1호
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• pp.85-89
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• 1991

The thermodynamics of micellization of a new series of ionic surface-active agents, dimethyl alkyl-2-deoxy-2-epi-inosityi-ammonium chlorides, has been examined, A minimum in the critical micelle concentration versus temperature has been observed at $25^{\circ}C$ It has been found that the standard entropy of micellization is always positive showing that miceliization is governed by the gain in entropy associated with the removal of the monomer from an aqueous environment to the micelle over a $15^{\circ}C$ to $45^{\circ}C$ temperature while governed by enthalpy directed process below $25^C{\circ}$.

• 한국막학회:학술대회논문집
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• 한국막학회 2005년도 추계 총회 및 학술발표회
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• pp.96-101
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• 2005

A theory for the material transports through ion exchange membrane has been developed on the basis of nonequilibrium thermodynamics by removing the assumption of solvent flow in the previous paper and applied to a detailed study of the ionic transport properties of new charged mosaic membrane(CMM) system. The CMM having two different fixed charges in the polymer membrane indicated unique selective transport behavior then ion-exchange membrane. The separation behavior of ion transport across the CMM with a parallel array of positive and negative functional charges were investigated. It was well-known the analysis of the volume flux and solute flux based on nonequilibrium thermodynamics. Our suggests preferential salt transport across the charged mosaic membranes. Transport properties of heavy metal ions, $Mg^{2+}$, $Mn^{2+}$and sucrose system across the charged mosaic membrane were estimated. As a result, we were known metal salts transport depended largely on the CMM. The reflection coefficient indicated the negative value that suggested preferential material transport and was independent of charged mosaic membrane thickness.

• 한국자기학회:학술대회 개요집
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• 한국자기학회 2008년도 Asian Magnetics Conference
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• pp.273.2-273.2
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• 2008

• Korean Chemical Engineering Research
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• 제53권6호
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• pp.770-775
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• 2015

Adsorption of Congo Red (CR) from dye-containing effluents using modified bentonite (MB) has been investigated here. Isothermal studies were conducted to ascertain maximum adsorption capacity of the adsorbent. MB exhibited superior adsorption capacity compared to other low-cost adsorbents. Experimental data fitted the Langmuir isotherm better, indicating monolayer coverage of CR on MB. The feasibility of the process was measured in terms of separation factor $R_L$. The values of Gibbs free energy, entropy and enthalpy were calculated from the thermodynamics of the process. Adsorption was feasible and spontaneous, being endothermic. Analytical techniques including SEM, EDS, FTIR and XRD were applied to characterize MB and also to provide conclusive proof of the accumulation of CR on to MB.