• Journal of Nutrition and Health
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• v.46 no.2
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• pp.156-165
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• 2013

This study examined how achievement of session goals contributes to outcomes of subjects after participation in a 12-week lifestyle intervention program in men with metabolic syndrome (MetS). Thirty office workers with MetS, aged $47.2{\pm}6.6$ years, participated in this study, from March to July, 2011. The intervention program included face-to-face counseling five times during the 12-week period. Counselors and subjects designed session goals for each round. The average of the goal achievement rate was calculated based on compliance for each round. The subjects were divided into three groups according to their tertiles of achievement rate: Low-compliance group (LC, < 59%), medium-compliance group (MC, 59-70%), and high-compliance group (HC, > 70%). Anthropometry, biochemical index, and nutrient intake were examined at baseline and at the end of the 12-week intervention program. After the intervention, diastolic blood pressure (DBP) showed a significant decrease in the LC group, and waist circumference (WC) showed a significant decrease in the MC group. Systolic blood pressure (SBP), DBP, and low-density lipoprotein cholesterol (LDL) showed a significant decrease in the HI group. Changes in SBP and DBP were significantly lower in the HC group than in the MC group (p < 0.05, p < 0.01). Changes in LDL were significantly lower in the HC group than in the MC group (p < 0.05). Results for intake of total energy, protein, fat, and sodium, as well as rates of carbohydrate and fat intake, showed a significant decrease in all participants (p < 0.05). The change in fiber was significantly higher in the HC group than in the MC group (p < 0.05). The change of fruit serving size showed a significant increase in the HC group (p < 0.01). The number of risk factors for MetS showed a significant decrease in the LC and HC groups (p < 0.05), however, no significant mean differences were observed among the three groups. In conclusion, participation in this intervention program resulted in positive effects on risk factors for MetS, nutrient intake, and dietary habits, especially in the High-compliance group.

• Korean Journal of Materials Research
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• v.13 no.12
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• pp.850-854
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• 2003

The abrasion wear behavior on the hardfacing weld was investigated by performing abrasion wear, hardness, and microstructural tests. The gas metal arc(GMA) weld was produced by using the cored wire which was filled with the hard metal, i.e., the recycled tungsten carbide (WC) reinforced metal matrix composite. For 30% addition of the hard metal, the abrasion wear resistance was significantly improved comparing with that for 20% addition of the hard metal. Above 30% addition of the hard metal, however, there was no significant improvement of the wear resistance. The improvement of the wear resistance was due to the increased amount of eutectic carbides(W$_{6}$C) which was formed during GMA welding. For the weld in which the hard metal was added to 30-40%, an optimum level of abrasion wear resistance was performed.

• Proceedings of the KWS Conference
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• 2009.11a
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• pp.42-42
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• 2009

마찰교반접합 (Friction Stir Welding)은 1991년 영국 TWI에서 개발된 접합 법으로서 회전하는 툴이 재료내부에 삽입되면 툴과 재료사이에서 발생하는 마찰열에 의하여 온도가 상승하게 되어 재료는 연화되고, 이러한 재료 내부에서 회전하는 툴이 이동하게 되면 재료 내부는 기계적 교반에 의해 소성변형이 일어남과 동시에 접합이 이루어진다. 마찰교반접합은 동적 재결정에 의한 접합부의 미세한 결정립 형성으로 인하여 기계적 특성이 향상되며 보호 가스가 필요 없어 친환경적임과 동시에 용융 용접 법에 비해 접합 시 에너지 소모가 적으며 또한 접합 후 접합부에서의 변형이 상대적으로 적다는 장점이 있다. 이러한 장점을 가진 마찰교반접합은 알루미늄 합금, 마그네슘 합금 그리고 동 합금과 같은 저 융점 비철재료에 많은 연구와 적용 사례들이 있어왔다. 하지만 최근에는 일반 탄소강, 연강, 오스테나이트계 스테인리스강, 니켈 합금, 티타늄 합금과 같은 고융점 재료에도 연구 및 적용이 진행되고 있는 추세이다. 페라이트계 스테인리스강은 가격이 비싼 Ni을 함유하지 않아 오스테나이트계 스테인리스강에 비하여 강재의 가격은 낮으면서도 고온특성 및 내식성이 우수하여 건축용, 자동차 배기계용으로 널리 사용되고 있다. 하지만 이런 장점을 가진 페라이트계 스테인리스강을 기존의 용융 용접 법으로 접합 시 용접부 및 열영향부에서의 결정립의 조대화로 인한 인성 및 연성이 저하되며, 특히 예민화된 열영향부 입계 내에 Cr 탄화물이 석출되어 입계주변에 Cr 결핍 층을 형성되어 입계부식이 발생되는 문제점이 발생된다. 본 연구에서는 마찰교반접합을 이용하여 두께 3mm의 409 스테인리스강에 대해 맞대기 접합을 실시하였다. 접합 변수를 툴의 재료 (WC-12wt%Co, $Si_3N_4$)로 하여 접합을 실시하였고 접합 후 외관상태 점검, 광학 현미경과 주사 전자 현미경을 통하여 미세조직을 관찰하였으며 황산-황산동 부식 시험을 실시하여 접합부의 부식 특성을 평가하였다.

• Journal of The Korean Society of Integrative Medicine
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• v.4 no.2
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• pp.97-107
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• 2016

Purpose : Cardiovascular disease is major factor of mortality in worldwide. Previous studies shown that the socioeconomic factors, nutrition factors, health behavior factors, biological factors and co-morbidity are increasing a prevalence of cardiovascular disease. Method : This study examined the risk factors for cardiovascular disease among adults aged 30 years and older using the data from the 2012 to 2014 Korean National Health and Nutrition Examination Survey (KNHANES). The study participants were 7,555 Cardiovascular disease includes hypertension, stroke, angina pactoris, and myocardial infarction. Descriptive statistic and multivariates logistic regression were calculated. Result : The overall prevalence of cardiovascular disease was 31.16% in the participants. Cardiovascular disease was significantly associated with gender, age, income, education, marital status as socioeconomic factors in unadjusted model. After adjusting socioeconomic status variables, past smoker (OR 1.27, 95% CI 1.05-1.55), obesity (OR 7.14, 95% CI 4.21-12.11), skipping a meal (OR 2.79, 95% CI 2.46-3.16), HDL-C (OR 0.99, 95% CI 0.98-0.99) and WC (OR 1.06, 95% CI 1.05-1.07) were associated with cardiovascular disease. Conclusion : The results marked the importance of finding high risk groups and an early management of cardiovascular disease.

• Bulletin of the Korean Chemical Society
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• v.32 no.12
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• pp.4270-4274
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• 2011

A method is proposed for determining chromium content in the carbon steel pipes of a nuclear power plant (NPP) to evaluate wall thinning caused by flow-accelerated corrosion (FAC). A flat file was used to obtain filings samples. To assess sampling quality, a disk form of SRM 1227 was ground with the flat file, and the amount of Cr in the filings was determined by ICP-AES. The content of chromium in the filings of SRM 1227 was estimated as six times higher than the certified value due to the contamination of chromium in the file. To eliminate chromium contamination from the file, it was coated with WC-12Co using high-velocity oxygen-fuel (HVOF) spraying systems. After obtaining filings samples using the coated file, Cr content in four types of disk-form SRMs was determined by ICP-AES. The recoveries of Cr in the disk-form SRMs were in the range of 95.4-102.6%, with relative standard deviations from 0.43 to 3.0%. The Cr contents in the filings collected from the used outlet headers of the nuclear power plants using the flat file coated were in the range of 0.11-0.19%.