• Journal of the Korean Chemical Society
• /
• v.22 no.1
• /
• pp.1-6
• /
• 1978

Feeling the potential field within a cell for various environments, every liquid molecule moves to minimize its potential energy. With this simple and fundamental concept, liquid molecules may be treated as a combination of three kinds of typical molecules characterized by Lennard-Jones and Devonshire's earlier work. We can get a partition function which has better functional from and less defects compared to the cell theory and the significant structure theory.

• Proceedings of the Korean Institute of Surface Engineering Conference
• /
• 2017.05a
• /
• pp.169-169
• /
• 2017

Due to key roles for the electrochemical stability and charge capacity the solid-electrolyte interphase (SEI) has been extensively studied in anodes of a Li-ion battery cell. There is, however, few of investigation for cathodes. Using first-principles based calculations we describe atomic-level process of the SEI layer formation at the interface of a carbonate electrolyte and $LiMn_2O_4$ spinel cathode. Furthermore, using beyond the conventional density functional theory (DFT+U) calculations we examine the work function of the cathode and frontier orbitals of the electrolyte. Based on the results we propose that proton transfer at the interface is an essential mechanism initiating the SEI layer formation in the $LiMn_2O_4$. Our results can guide a design concept for stable and high capacity Li-ion battery cell through screening an optimum electrolyte fine-tuned energy band alignment for a given cathode.

• Korean Journal of Organic Agriculture
• /
• v.18 no.1
• /
• pp.21-40
• /
• 2010

This work is described as an fresh effort to study environmental sustainable management in organic products retailing markets. Sustainable management means creating value for business, nature and society. The main point of this thesis is about the concept, the content and the target of environmental sustainable management, and the technical method and basis to achieve it. Also this thesis shows the strategy of sustainable management as well as the realization of sustainable development by carrying out organic agricultural production. The main content of sustainable management is that: - Rationalize the utilization of resource and energy. - Maximize economic benefit. - Minimize harm to humans and the environment. Examines business strategies that have successfully targeted markets, such as advertising, labeling, gaining consumer trust, partnerships, and diversifying operations. These included management skills, and marketing organic and other sustainably grown products to determine strategies for developing new markets for these products. Suggests that consumers are becoming more aware of the importance of environmentally sound methods for growing food, the health benefits of wholesome food, and are willing to pay more for these products.

• Journal of Korean Institute of Industrial Engineers
• /
• v.43 no.2
• /
• pp.83-89
• /
• 2017

This study aims to investigate the compatibility between 'quality' and 'R&D' and to ascertain what methodology can be applied. To consider the compatibility, this study discussed whether quality management can expand into R&D area in future and whether the quality management principles in ISO9000 can work well in R&D environment. Our conclusion is that the application of the quality management in R&D is valid and can serve as a new paradigm for improving R&D performance. In addition, this study divided the quality concept in R&D into several types from the viewpoints of quality definition and suggested quality methodologies for each type.

• Nuclear Engineering and Technology
• /
• v.29 no.1
• /
• pp.25-34
• /
• 1997

This study presents a new approach for expert opinion elicitation process to assess an uncertainty inherent in accident management. The need to work with rare event and limited data in accident management leads analysis to use expert opinions extensively. Unlike the conventional approach using point-valued probabilities, the study proposes the concept of fuzzy probability to represent expert opinion. The use of fuzzy probability has an advantage over the conventional approach when an expert's judgment is used under limited dat3 and imprecise knowledge. The study demonstrates a method of combining and propagating fuzzy probabilities. finally, the proposed methodology is applied to the evaluation of the probability of a bottom head failure for the flooded case in the Peach Bottom BWR nuclear power plant.

• Journal of Energy Engineering
• /
• v.18 no.3
• /
• pp.163-168
• /
• 2009

This paper describes the homogeneous charge compression ignition (HCCI) engine for a new concept. HCCI engines are being considered as a future alternative for diesel and gasoline engines. HCCI engines have the potential for high indicated thermal efficiency under part load and very low NOx emissions. The objective of this paper is to clear the effects of exhaust gas recirculation (EGR) rate on the HCCI. For this purpose, a 4-cylinder, compression ignition engine was converted into a HCCI engine This work has been run with propane and butane fuels at a constant speed.

• Steel and Composite Structures
• /
• v.26 no.4
• /
• pp.439-452
• /
• 2018

This paper presents experimental and numerical study on buckling behaviors and hysteretic performance of Class 1 H-shaped steel beam subjected to cyclic pure bending within the scope of ultra-low cycle fatigue (ULCF). A loading device was designed to achieve the pure bending loading condition and 4 H-shaped specimens with a small width-to-thickness ratio were tested under 4 different loading histories. The emphasis of this work is on the impacts induced by local buckling and subsequent ductile fracture. The experimental and numerical results indicate that the specimen failure is mainly induced by elasto-plastic local buckling, and is closely correlated with the plastic straining history. Compared with monotonic loading, the elasto-plastic local buckling can occur at a much smaller displacement amplitude due to a number of preceding plastic reversals with relative small strain amplitudes, which is mainly correlated with decreasing tangent modulus of the material under cyclic straining. Ductile fracture is found to be a secondary factor leading to deterioration of the load-carrying capacity. In addition, a new ULCF life evaluation method is proposed for the specimens using the concept of energy decomposition, where the cumulative plastic energy is classified into two categories as isotropic hardening and kinematic hardening correlated. A linear correlation between the two energies is found and formulated, which compares well with the experimental results.

• Computational Structural Engineering
• /
• v.10 no.4
• /
• pp.131-142
• /
• 1997

In this paper the kinematics of damage for finite elastoplastic deformations is introduced using the fourth-order damage effect tensor through the concept of the effective stress within the framework of continuum damage mechanics. Unlike the approach of strain equivalence or energy equivalence, which is applicable only to small strains, the proposed kinematic description provides a relation between the effective strain and the damage elastoplastic strain in finite deformation. This is accomplished by directly considering the kinematics of the deformation field both real configuration. The proposed approach shows that it is equivalent to the hypothesis of energy equivalence at finite strains. The damage effect tensor in this work is explicitly characterized in terms of a kinematic measure of damage in the elastoplastic domain through a second-order damage tensor.

• Advances in Energy Research
• /
• v.6 no.2
• /
• pp.161-172
• /
• 2019

The principal intention of this experimental work is to confer upon the exergy study of GSHP associated with horizontal earth heat exchanger for space heating. The exergy analysis recognizes the assessment of the tendency of various energy flows and quantifies the extensive impression of inefficiencies in the system and its components. Consequently, this study intends to provide the enlightenment for well interpretation of exergy concept for GSHP. This GSHP system is composed of heat pump cycle, earth heat exchanger cycle and fan coil cycle. All the required data were measured and recorded when the experimental set up run at steady state and average of the measured data were used for exergy investigation purpose. In this study the rate at which exergy destructed at all the subsystems and system has been estimated using the analytical expression. The overall rational exergetic efficiency of the GSHP system was evaluated for estimating its effectiveness. Hence, we draw the exergy flow diagram by using the various calculated results. The result shows that in the whole system the maximum exergy destruction rate component was compressor and minimum exergy flow component was earth heat exchanger. Consequently, compressor and earth heat exchanger need to be pay more attention.

• Journal of Hydrogen and New Energy
• /
• v.27 no.5
• /
• pp.604-611
• /
• 2016

This paper describes the characteristics of n-Butane fuel for the homogeneous charge compression ignition (HCCI) engine for a new concept. HCCI engines are being considered as a future alternative for diesel and gasoline engines. From the experimental observations, the effect of n-Butane fuel in HCCI engine on CO, HC and NOx are analysed. The objective of this paper is to clear the effects of equivalence ratio and inlet temperature with n-Butane on the HCCI. For this purpose, a 4-cylinder, compression ignition engine was converted into a HCCI engine This work has been run with n-butane fuel at a constant speed.