• 대한토목학회논문집
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• 제28권2A호
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• pp.179-186
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• 2008

강성비를 이용한 합성형교 외측강성 영향 평가의 타당성을 평가하기 위하여 동일 강성비에서 거더 간격 변화에 따른 수정계수를 해석적으로 분석하였으며, 강성비, 하중 형태, 거더 간격이 수정계수에 미치는 영향을 평가하였다. 현장재하시험 및 기존 설계법의 수정계수와 본 연구에서 분석된 수정계수를 비교한 결과 강성비를 이용한 외측강성 영향 평가가 가능한 것으로 판단된다.

• 한국주조공학회지
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• 제35권6호
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• pp.147-154
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• 2015

The effects of Sc and Sr elements on the modification of the eutectic $Mg_2Si$ phase and the castability were investigated in the Al-4wt%Mg-0.9wt%Si-0.3wt%Mn-0.15wt%Fe alloy. Measurements of the cooling curve and microstructure observations were performed to analyze the additional effects of Sc and Sr minor elements during the solidification process. A prominent effect found on the modification of the eutectic $Mg_2Si$ phase with additions of the Sr and Sc elements. Here, a fine eutectic $Mg_2Si$ phase and a decrease in the growth temperature of the eutectic $Mg_2Si$ phase were evident with an addition of Sc element up to 0.2 wt%. The growth temperature of the eutectic $Mg_2Si$ phase decreased and the effect on the modification of the eutectic $Mg_2Si$ phase increased with the addition of Sr element up to 0.02 wt%. The addition of 0.02wt%Sr had the strongest effect on the modification of the eutectic $Mg_2Si$ phase, and the resulting microstructure of the eutectic $Mg_2Si$ phase was found to have a fibrous morphology with a decreased aspect ratio and an increased modification ratio. Fluidity and shrinkage tests were conducted to evaluate the castability of the alloy. The addition of 0.02wt%Sr effectively increased the fluidity of the alloy, while an addition of Sc did not show any effect compared to when nothing was added. The maximum filling length was recorded for 0.01wt%TiB-0.02wt%Sr owing to the effect of the fine ${\alpha}$-Al grains. The macro-shrinkage ratio decreased, while the micro-shrinkage ratio increased with the addition of various eutectic modifiers. The highest ratio of micro-shrinkage was recorded for the 0.02wt%Sr condition. However, the total shrinkage ratio was nearly identical regardless of the amounts added in this study.

• 기본간호학회지
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• 제8권2호
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• pp.234-243
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• 2001

Purpose : To investigate the effects of exercise combined with behavior modification therapy on the degree of obesity. blood lipid level and self-esteem in obese middle aged women. Method : 18 obese middle-aged women volunteers with a BMI over 30% were assigned to exercise combined with behavior modification therapy (n=9) or to a control group(n=9). For the intervention the experiment group used walking outdoors as excercise and behavior modification therapy for 12 weeks. Result Body weight, BMI, TC, TG, LDL-C, and % TC/HDL-C were significantly decreased in experimental group. Changes in HDL-C and self-esteem were significantly increased in the experimental group. Conclusion : This study provides evidence that regular exercise combined with behavior modification is effective in changing the degree of obesity, blood lipid level and self esteem in obese middle-aged women over 12 weeks.

• 소음진동
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• 제10권5호
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• pp.859-864
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• 2000

An effective and new method of reducing the noise of a HDD by structural modification of cover was investigated in this study. The correlation between the noise characteristics of the HDD and the vibration characteristics of the cover, which is the main source of the HDD noise, is found from experiments. A theoretical analysis is performed to find the modification method of the cover, and this modification method is applied the real cover of the HDD. The modification reduces the vibration of the cover transferred from driving motor. The effect of the modification is verified through noise tests.

• BMB Reports
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• 제52권2호
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• pp.113-118
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• 2019

The small ubiquitin-related modification molecule (SUMO), one of the post-translational modification molecules, is involved in a variety of cellular functions where it regulates protein activity and stability, transcription, and cell cycling. Modulation of protein SUMOylation or deSUMOylation modification has been associated with regulation of carcinogenesis in breast cancer. In the dynamic processes of SUMOylation and deSUMOylation in a variety of cancers, SUMO proteases (SENPs), reverse SUMOylation by isopeptidase activity and SENPs are mostly elevated, and are related to poor patient prognosis. Although underlying mechanisms have been suggested for how SENPs participate in breast cancer tumorigenesis, such as through regulation of target protein transactivation, cancer cell survival, cell cycle, or other post-translational modification-related machinery recruitment, the effect of SENP isoform-specific inhibitors on the progression of breast cancer have not been well evaluated. This review will introduce the functions of SENP1 and SENP2 and the underlying signaling pathways in breast cancer for use in discovery of new biomarkers for diagnosis or therapeutic targets for treatment.

• 한국수자원학회논문집
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• 제53권11호
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• pp.999-1013
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• 2020

전세계적으로 기상조절 연구가 활발히 수행되어져 왔으나 연구 효과를 보다 정량적으로 검증할 수 있는 기술이 필요하다. 본 연구에서는 기상조절 실험에 대한 강수 증가 효율인 시딩효과(seeding effect)를 레이더 자료를 이용하여 검증하였다. 또한, 시딩물질이 대기수상체 변화에 미치는 영향을 분석하였다. 이를 위해 레이더 자료, 기상조건, 확산 수치모의 자료가 사용되었다. 먼저, 시딩전, 시딩중, 시딩후의 세 단계로 시딩효과를 분석할 수 있는 방법을 제안하였다. 제안한 방법을 강원도와 서해 지역을 대상으로 수행된 세 개의 기상조절 실험 사례에 적용하였다. 그 결과, 자연강수가 없을 때는 강수 변화가 예측된 구역에서 감지된 레이더 반사도가 시딩효과로 판단되었다. 자연강수가 발생하면 관측된 최대 반사도에서 자연강수의 영향을 제외하여 시딩효과를 결정하였다. 적용사례에 대해 시딩효과로 강수강도가 0.1 mm/h 증가한 것으로 나타났다. 아울러 시딩 구름에 빙정이나 과냉각 수적, 혼합상의 수상체가 분포한 것으로 나타났다. 이러한 기상조절 연구 결과는 수자원 확보와 구름 물리 연구에 활용할 수 있을 것으로 판단된다.

• Carbon letters
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• 제6권1호
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• pp.25-30
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• 2005

The electrosorption of U(VI) from waste water was carried out by using an activated carbon fiber (ACF) felt electrode in a continuous electrosorption cell. In order to enhance the electrosorption capacity at a lower potential, the ACF was electrochemically modified in an acidic and a basic solution. Pore structure and functional groups of the electrochemically modified ACF were examined, and the effects of the modification conditions were studied for the adsorption of U(VI). Specific surface area of all the ACFs was decreased by this modification. The amount of the acidic functional groups decreased with a basic modification, while the amount increased a lot with an acidic modification. The electrosorption capacity of U(VI) decreased on the acid modified electrode due to the shielding effect of the acidic functional groups. The base modified electrode enhanced the capacity due to a reduction of the acidic functional groups. The electrosorption amount of U(VI) on the base modified electrode at .0.3 V corresponds to that of the as-received ACF electrode at .0.9 V. Such a good adsorption capacity was due to a reduction of the shielding effect and an increase of the hydroxyl ions in the electric double layer on the ACF surface by the application of negative potential.

• 한국정밀공학회지
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• 제27권12호
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• pp.113-118
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• 2010

For a present study, woven type carbon fibers were surface-modified by oxygen plasma to improve adhesive strength between carbon fibers and epoxy. The change of hydrophilic properties by the plasma modification was investigated through the contact angle measurement and the calculation of surface energy of carbon fiber due to the oxygen plasma modification. FESEM and XPS analyses were performed to study the chemical and physical changes on the surface of carbon fibers due to the oxygen plasma modification. Pin-on-disk wear tests were conducted under dry condition using unmodified and plasma-modified carbon/epoxy composites to investigate the effect of plasma modification on the wear behavior of woven type carbon/epoxy composites. The results showed that the friction coefficient and the wear rate of plasma-modified carbon/epoxy composites were lower than those of unmodified carbon/epoxy composites, respectively. XPS analysis showed that new functional group of a carbonyl type was created on the carbon fibers by the $O_2$ plasma treatment, which enhanced adhesive strength between carbon fibers and epoxy, leading to improve wear properties

• Corrosion Science and Technology
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• 제18권5호
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• pp.196-205
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• 2019

Surface modification techniques are known to improve SCC by adding large compressive residual stresses to metal surfaces. This surface modification technology is attracting attention because it is an economical and practical technology compared to the maintenance method of existing nuclear power plants. Surface modification techniques include laser, water jet and ultrasonic peening, pinning and ultrasonic Nano-crystal surface modification (UNSM). The focus of this study was on the effect of ultrasonic amplitude in UNSM treatment on the corrosion properties of Alloy 600. A microstructure analysis was conducted using an optical microscope (OM), scanning electron microscope (SEM) and electron backscattering diffraction (EBSD). A cyclic polarization test and AC-impedance measurement were both used to analyze the corrosion properties. UNSM treatment influences the corrosion resistance of Alloy 600 depending on its amplitude. Below the critical amplitude value, the pitting corrosion properties are improved by grain refinement and compressive residual stress, but above the critical amplitude value, crevices are formed by the formation of overlapped waves. These crevices act as corrosion initiators, reducing pitting corrosion resistance.

• Bulletin of the Korean Chemical Society
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• 제34권9호
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• pp.2747-2752
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• 2013

Surface modification of colloidal silica nanoparticles without disrupting the electric double layer of nanoparticles is a major challenge. In the work, silane was employed to modify colloidal silica nanoparticles without inducing bridge flocculation obviously. The effect of pH value of the silica sol, the amount of silane in feed, and reaction temperature on the graft amount and the final size of modified particles was investigated. The increased weight loss by TG and the appearance of $T_2$ and $T_3$ except for $Q_2$ and $Q_3$ signals by CP/MAS $^{29}Si$ NMR of the modified samples verified the successful grafting of silane. The graft amount reached 0.57 mmol/g, which was slightly lower than theory value, and the particle size remained nearly the same as unmodified particles for acidic silica sol at the optimum condition. For alkaline silica sol after modification, aggregates composed of several nanoparticles connected together with silane moleculars as the bridge appeared.