• Proceeding of EDISON Challenge
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• 2014.03a
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• pp.311-323
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• 2014

분자동역학 모의실험을 이용하여 간단한 van der Waals 상호작용하는 이성분 혼합물 계의 섞임 자유에너지 및 섞임 엔트로피 등 섞임과 관련된 열역학 함수들을 계산하는 방법을 소개한다. 각 혼합물의 과잉 자유에너지는 열역학 적분 (thermodynamic integration)방법을 이용하여 계산하고, 이성분 혼합물의 섞임 관련 열역학 함수들은 Hess의 법칙을 확장함으로써 구한다. 계산 결과로부터 온도가 증가할수록 계의 섞임 Helmholtz 자유에너지는 감소하며, 섞임 내부에너지도 감소함을 알 수 있다. 섞임 엔트로피는 온도가 증가할수록 이상기체의 섞임 엔트로피에 접근함을 알 수 있다. 섞임 Helmholtz 자유에너지에 대한 섞임 내부에너지와 섞임 엔트로피 기여도를 조사한 결과 이 계의 섞임 과정을 주도하는 추진력은 엔트로피에 의한 것임을 알 수 있다. 본 연구 방법과 결과를 이용함으로써 학부생들이 혼합물의 열역학 성질을 이해하는데 도움을 주리라 기대한다.

• Journal of Adhesion and Interface
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• v.4 no.4
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• pp.1-6
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• 2003

After atmospheric pressure plasma treatment of polypropylene(PP) film surface, we measured the contact angle of the surface by using polar solvent (water) and non-polar solvent (diiodomethane). We also calculated the surface free energy of PP film by using the measured values of contact angles. And then we analyzed contact angle and surface free energy with changing the condition of atmospheric pressure plasma treatment. Upon each condition of atmospheric plasma treatment, contact angle and surface free energy showed an optimum value or leveled off.

• The Korea Swine Journal
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• v.23 no.9 s.265
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• pp.123-126
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• 2001

돼지 성별 사료섭취량 및 체조성과 관련된 시험 결과를 보면 자유채식시 사료섭취량은 거세돈이 암퇘지와 비거세돈보다 많으며, 적육 축적률은 낮다. 체중 30$\~$60kg의 비육기에 자유채식과 제한급여구를 비교한 결과 증체율과 지방축적률은 자유채식에서 높았으며, 거세돈의 에너지 섭취 수준을 $8\%$ 제한시 암퇘지를 자유채식시킨 경우와 비슷한 성장률을 보였다. 또한 80$\~$140kg의 체중에서 최대 단백질 축적량은 수퇘지 42.5kg 암퇘지 40.0kg, 거세돈37.5kg이고, 1일 단백질 축적량은 수퇘지 180g, 암퇘지 160g, 거세돈 145g정도로 성별로 차이가 있다. 체지방축적은 에너지 수준과 거세실시 여부, 일당증체량은 에너지 수준에 큰 영향을 받는다.

• Polymer(Korea)
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• v.27 no.2
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• pp.98-105
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• 2003

The surface energy and the effect of functional groups on the surface of the ozone-treated low-density polyethylene (LDPE) film were studied. Treatment conditions were treatment time, total amount of transferred ozone, and ozone concentration. The introduction of polar groups on the surface of LDPE film after ozone treatment was confirmed by FTIR-ATR and XPS analyses. Surface fee energy of the LDPE film was examined by a contact angle method. The ozone treated-LDPE film showed a decreased water contact angles about 15$^{\circ}$ mainly due to the increased concentration of oxygen-containing functional groups, which was attributed to the increased surface free energy or $O_{IS}/C_{IS}$Also, the concentrations of the oxygen-containing functional groups on the surface of LDPE film increased with ozone treatment time and concentration, whereas no significant effects were found for the total amount of transferred ozone. From the dyeability test using Kubelka-Munk equation, it was found that the ozone treatment plays an important role in the growth of oxygen-containing functional groups of LDPE film, resulting in the improvement of dyeability for basic dyeing agent.

• Journal of the Korean Vacuum Society
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• v.15 no.5
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• pp.435-450
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• 2006

Free electron lasers (FELs) are promising sources of coherent radiation that can provide users with radiations having a wide-range frequency-tunability and good spectral characteristics for basic science and industrial applications. Especially in Terahertz or X-ray ranges of spectrum, FELs can generate much stronger radiations than conventional light sources. In this paper, we introduce the working principles and key technologies of FELs, the status and the prospects of FEL developments.

• Korea Petroleum Association Journal
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• no.10 s.20
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• pp.64-67
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• 1982

이 자료는 최근 미국의 Socal사가 작성 발표한 자유세계의 장기에너지 수급전망을 요약ㆍ정리한 것이다. (편집자주)

• Journal of the Korean Chemical Society
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• v.36 no.5
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• pp.632-637
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• 1992

Standard transfer free energies of sodium and cupric perchlorates in water-acetylacetone solvent system have been determined by electromotive force measurements of galvanic cell and these energies of sodium and cupric ions in this solvent system have been evaluated by the tetrabutylammonium tetraphenylborate assumption as the extrathermodynamic procedure. Standard transfer free energy values of sodium and cupric ions from water to acetylacetone solvent were 5.09 and 4.16 kcal/mol at 25${\circ}C$, respectively. These values mean that acetylacetone is much weaker donor solvent to sodium and cupric ions than water. The standard transfer free energy value of cupric ion from water to mixture solvents which contain small amount of acetylacetone is changed by an unusual form. This is because of the chelate formation effect of acetylacetone to cupric ion.

• Nuclear Engineering and Technology
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• v.3 no.1
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• pp.21-31
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• 1971

The part of the work of plastic deformation of metal goes into the changes in the total surface free energy. This contribution is dependent on the specific surface free energy, which is affected by the environment. Based on thermodynamical approach, volume constancy requirement and adsorption induced two distinct dislocation interaction mechanisms for strengthening or weakening of metals at surface, theoretical derivation has been made to show that the environmental contribution on the strain hardening, the stress and the energy required for plastic deformation can be expressed in terms of solid surface tension in vacuum (${\gamma}$$_{s}$), interfacial tension (${\gamma}$$_{se}$ ), surface dislocation density ($\rho$$_{s}$), internal dislocation density ($\rho$$_{i}$) and fraction of surface site uncoverage (f). On the basis of theoretical derivation, the various mechanical behaviours under different environments are predicted.d.d.

• Proceedings of the KSEEG Conference
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• 1999.04a
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• pp.273-275
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• 1999

• Elastomers and Composites
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• v.35 no.2
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• pp.98-105
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• 2000

Using FT-IR and contact angle measurements it is observed that the chemical surface treatments on virgin carbon blacks lead to a change of the surface properties, including surface functionality and surface free energy It is found that the developments of surface functional groups on acidically and basically treated (ACB and BCB in this study, respectively) carbon blacks are largely correlated with the specific component of surface free energy of the carbon blacks. However, a significant advantage of compounding composites is gained by BCB or NCB (nonpolar chemical treatment) specimens, resulting in improving the hardness, elongation at break, and tensile strength. Particularly, it is seen that the tensile strength of the composites are greatly depended on the London dispersive component of surface free energy determined from the contact angle measurements. It is then concluded that the London dispersion component of carbon blacks plays an important role in an organic rubbers-based compounding composite system.