• 펄프종이기술
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• 제44권1호
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• pp.1-9
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• 2012

In this study, 5 solvent soluble polymers were treated on Hanji. Mechanical properties, morphology and oxidation index with thermal aging were measured on the aged Hanji, dewaxed Hanji and polymer treated Hanji. Synthetic polymers(such as polylactic acid, polybutylene succinate, polystyrene) treated Hanji had higher strength and thermal stability than cellulose derivatives(such as cellulose nitrate and cellulose acetate) treated Hanji. Polymer treated Hanji showed a little bit of color change. The oxidation index of PS treated Hanji did not increase with thermal aging because it did not have a carboxyl group in chemical structure. Finally, polystyrene was found to be the most efficient method for strengthening the dewaxed Hanji. The best aging safety and thermal stability were obtained at the polystyrene 3% solution.

• 동의생리병리학회지
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• 제19권4호
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• pp.897-902
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• 2005

Internal deficiency of vital Qi is origination of cancer and root cause of its development from the viewpoint of traditional Chinese medicine(TCM). For about 40 years, China has developed a combined system of TCM and Western medical system in treatment of cancers, laying stress on the therapeutic principle of strengthening the body resistance and restoring normal functioning of the body to consolidate the constitution (Fu Zheng Pei Ben). According to the results of the latest clinical and experimental studies, Chinese medicine not only increases curative effectiveness, but also reduces the side effect caused by the toxic, radio and chemical treatment of cancer cases in the western medical system as well as various complications. Long-term taking Chinese herbal medicine prevents recurrence and metastasis of tumor, and heightens long-term curative effectiveness after western medical treatments. It also helps to relieve symptoms, improve the quality of life, and prolong life of terminal cancer patients who have already lost opportunities of western medical treatments. In addition, it can prevent and cure premonitory symptoms of cancer.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2006년도 춘계 학술발표회 논문집(II)
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• pp.333-336
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• 2006

In general, polymer materials undergo degradation when exposed to ultraviolet radiation, which can cause dissociation of chemical bonds. FRP composites which are used in strengthening existing structure are usually adhered on the concrete surface, its mechanical properties as well as appearance such as color, surface conditions are affected by sunlight and expecially ultraviolet light. In this study, variations of tensile strength after exposure for certain period of time through accelerated exposure by Xe arc methods specified in KS F 2274 are measured in order to examine strength degradation characteristics of FRP composite. As a result of ultraviolet light test for FRP composite after accelerated exposure for 0, 500, 1000, 1500 hour, discoloration of FRP composite occurs according to the passage of time. But, few strength degradations of FRP composite are observed due to exposure of ultraviolet ray with an small variation of tensile strength.

• 한국안전학회지
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• 제28권4호
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• pp.97-102
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• 2013

This paper presents a new strengthening method of underground box structures against seismic loads for anti-seismic capacity improvement. A threaded steel member with pressure devices(so called 'I-bracing pressure system') is used to improve seismic capacity of the RC box structure. The I-bracing pressure system is fixed the corner of opening after chemical anchor was installed by drilling hole on the box structure. The structural performance was evaluated analytically. Two bracing types of strengthening methods were used; conventional bracing method and improved I-bracing pressure system. For the performance evaluation, seismic analyses were performed on moment and shear resisting structures with and without I-bracing pressure system. Numerical results confirmed that the proposed I-bracing pressure system can enhance the seismic capacity of the underground RC box structures.

• Journal of Information Display
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• 제4권3호
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• pp.12-16
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• 2003

In connection with the ion exchange strengthening on soda-lime-silicate, substrate glass for display use was investigated. In the processing, the temperature was varied during the ion exchange in order to make stress profile and to determine optimum condition. In the present work, we found that the maximum value of strength was 617.8 MPa after an ion exchange process at 470 $^{\circ}C$ for 1h, and then, at 450 $^{\circ}C$ for 24h. Also, the effect of residual stress placed on the near surface was measured by analyzing the number of crack branches and brittleness. This approach allowed us the residual stress profile to be engineered to improve mechanical reliability.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1991년도 가을 학술발표회 논문집
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• pp.158-161
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• 1991

By applying the newly developed techniques of polymer impregnated concrete (PIC) severely deteriorated and low quality concrete can be restored to an adequate structural material. Early deterioration of concrete causes severe problems for bridge deck concrete, pavement concrete for highways and airports, hydraulic structures and buiilding structures. Deterioration has its orgin in cracks on concrete surface, scaling of spalling due to freezing and thawing, neutralization of concrete, penetrations of water, salt, and calcium chloride. The objective of this study is to develope the new surface impregnants and strengthening techniques for them. It is found that the new impregnants and strengthening techniques developed in this study can retian the charecteristics of the existing concrete and decrease deterioration, and also increase durability, chemical resistance, strength, stiffness and ductility of the existing concrete.

• Structural Engineering and Mechanics
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• 제89권3호
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• pp.323-334
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• 2024

Physical and chemical factors can cause traditional timber constructions to lose structural integrity. Knowing the dynamic properties of the building components is vital to avoid damage to the buildings from dynamic effects, a subset of physical effects. In this work, spruce and scotch pine wooden beams that had been strengthened in three distinct ways with carbon fiber strengthened polymer (CFRP) were investigated for changes in their dynamic properties. For this, CFRP was used to strengthening unstrengthened wooden beams in the form of bottom confinement, U-shaped confinement, and full confinement after the dynamic parameters of the beams were determined. By using experimental modal analysis with both free-free and fixed-fixed boundary conditions, the beams'initial natural frequencies were identified.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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• pp.178-178
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• 2016

Every display is equipped with a cover glass to protect the underneath displaying devices from mechanical and environmental impact during its use. The strengthened glass such as Gorilla glass.$^{TM}$ has been exclusively adopted as a cover glass in many displays. Conventionally, the strengthened glass has been manufactured via ion-exchange process in wet salt bath at high temperature of around $500^{\circ}C$ for hours of treatment time. During ion-exchange process, Na ions with smaller diameter are substituted with larger-diameter K ions, resulting in high compressive stress in near-surface region and making the treated glass very resistant to scratch or impact during its use. In this study, PIIID (plasma immersion ion implantation and deposition) technique was used to implant metal ions into the glass surface for strengthening. In addition, due to the plasmonic effect of the implanted metal ions, the metal-ion implanted glass samples got colored. To implant metal ions, plasma immersion ion implantation technique combined with HiPIMS method was adopted. The HiPIMS pulse voltage of up to 1.4 kV was applied to the 3" magnetron sputtering targets (Cu, Ag, Au, Al). At the same time, the sample stage with glass samples was synchronously pulse-biased via -50 kV high voltage pulse modulator. The frequency and pulse width of 100 Hz and 15 usec, respectively, were used during metal ion implantation. In addition, nitrogen ions were implanted to study the strengthening effect of gas ion implantation. The mechanical and optical properties of implanted glass samples were investigated using micro-hardness tester and UV-Vis spectrometer. The implanted ion distribution and the chemical states along depth was studied with XPS (X-ray photo-electron spectroscopy). A cross-sectional TEM study was also conducted to investigate the nature of implanted metal ions. The ion-implanted glass samples showed increased hardness of ~1.5 times at short implantation times. However, with increasing the implantation time, the surface hardness was decreased due to the accumulation of implantation damage.

• 산업공학
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• 제12권3호
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• pp.406-413
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• 1999

In this study, we analyzed the innovation pattern of product and process between Korean, Japanese and German chemical firms. To do this study, a mail survey was chosen as the data collection method. For the empirical study, 36 Korean, 35 Japanese and 50 German chemical firms were analyzed. The major results are indicated as follows: (1) The Korean and Japanese firms have focused more on the process innovation, while the German firm have focused more on the product innovation. (2) The Korean and Japanese firms have oriented more to cost saving, while the German firms have oriented more market share. Based on these findings, the Korean firms have no purse simultaneously product and process innovation for strengthening of international. competitiveness, but the direction of the innovation patterns depends on the situations of the nation, industry and company.

• 한국가스학회지
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• 제21권4호
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• pp.62-69
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• 2017

화학사고는 화학물질관리법으로 체계적으로 관리되고 있다. 하지만 유해화학물질 폭력사건은 용어 정의, 사례에 대한 연구 등이 전반적으로 부족한 실정이다. 이에 본 연구에서는 현 법령의 문제점을 고찰하고 국내 외 사례를 통해서 개선사항을 도출하여 유해화학물질 폭력사건 예방을 위한 법적, 제도상의 개선방향을 제시하는데 연구의 중점을 두었다. 제안한 개선방향은 1) 법령의 개정을 통한 예방 강화로 (1) 주관 부처의 선정 등; 2) 온 오프라인 상거래에 대한 규제 강화에서는 (1) 개인 구매량 설정 등; 3) 환경부 중심의 예방, 관리 체계의 강화로 (1) 화학물질평가위원회를 통한 지속적인 제도의 개선 등 3가지 방향에 대해서 제시하였다.