• 제목/요약/키워드: ratios and proportions

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아토마이징 제강 환원슬래그를 골재로 사용한 폴리머 콘크리트 복합재료의 특성(II) (폴리스티렌 수축저감재 사용) (Characteristics of Concrete Polymer Composite Using Atomizing Reduction Steel Slag as an Aggregate (II) (Use of Polystyrene as a Shrinkage Reducing Agent))

  • 황의환;김진만
    • 공업화학
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    • 제25권4호
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    • pp.380-385
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    • 2014
  • 철강산업에서 발생되는 제강 환원슬래그(Ladle furnace slag, LFS)를 사용하여 아토마이징 공법을 통하여 구형의 아토마이징 제강 환원슬래그를 제조하였다. 아토마이징 제강 환원슬래그의 대량 재활용 기술을 개발하기 위하여 구형의 아토마이징 제강 환원슬래그를 입도에 따라 잔골재(강모래)와 굵은 골재(쇄석)를 대체 사용하여 폴리머 콘크리트 복합재료를 제조하였다. 폴리머 콘크리트 복합재료의 특성을 조사하기 위하여 폴리머 결합재의 첨가율과 아토마이징 제강 환원슬래그의 대체율에 따라 다양한 배합의 폴리머 콘크리트 공시체를 제조하였다. 시험결과, 아토마이징 제강 환원슬래그의 대체율 증가에 따라 공시체의 압축강도는 감소되었으나 휨강도는 50%의 대체율에서 최대 강도를 나타내었다. 아토마이징 제강 환원슬래그를 사용함으로서 작업성이 향상되어 폴리머 콘크리트 복합재료의 생산원가에 가장 큰 영향을 미치는 폴리머 결합재의 사용량을 최대 18.2 vol% 절감할 수 있었다. 그러나 내열수성시험에서 아토마이징 제강 환원슬래그를 사용한 공시체의 기계적 강도가 현저히 감소되기 때문에 더 많은 연구가 요구된다.

한국인 지방간 환자의 영양상태에 관한 연구 (A Study on the Nutritional Status of Korean Fatty Liver Patients)

  • 김미경
    • Journal of Nutrition and Health
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    • 제26권6호
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    • pp.715-727
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    • 1993
  • This study was performed to see the effect of nutritional status on fatty liver. Subjects were 219(male : 174, female : 45) fatty liver patients living in cities, and 10-60yrs old. Nutrient and alcohol intakes, health state and medical history were investigated by individual interview, and blood sample was taken. Results were as follow; Most subjects were obese an overweighing and suffering from hepatitis. Calorie and carbohydrate intakes of male and females patients were lower than mean intakes of normal citizens. Protein and fat intakes of male patients were higher than mean intakes of normal citizens. Proportions of protein and fat to total calorie intake in patients were higher than those of normal citizens. Alcohol intake was markedly higher in patients than normal group, and increased with increasing body weight. Serum total cholesterol, HDL-cholesterol, total lipid, total protein and albumin conc.s and Hb and Hct levels were in normal ranges, But serum TG level of patients was higher than normal level. Serum total fatty acid level, $\omega$-3/$\omega$-6 and P/S FA ratios were higher in patients than normals. Serum total EAAs, NEAAs and all AAs levels of patients were higher than normals. It is plausible that high animal food and alcohol intakes, excess body fat and hepatitis were associated with fatty liver.

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굵은골재 최대치수 40 mm 투수 콘크리트의 물리적 특성과 질소산화물 제거에 관한 연구 (An Experimental Study on NOx Degradation Efficiency and Physical Characteristics of Maximum Size 40 mm Porous Concrete)

  • 홍종현;김문훈;류성필;정광옥
    • 한국환경과학회지
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    • 제15권5호
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    • pp.431-438
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    • 2006
  • The strength, water permeability, and photo-degradation efficiency of NOx of porous concrete with a new concept were studied in this paper. The porous concrete was comprised of coarse aggregate of maximum size 40 mm, cement, silica fume, water and air-entraining(AE) water reducing agent. The strength of porous concrete was strongly related to its matrix proportion and compaction energy. An experimental test was carried out to study the parameters of cement proportions and silica fume content for pavement applications of porous concrete which were paving a footpath, a bikeway, a parking lot, and a driveway. The regressed equations of relation-ships between compressive strength and flexural strength, and coefficient permeability and void ratios were indicated as y=7.69x+71.74 and $y=0.42e^{0.28x}$. A method of making an air purification-functioning road, which was spraying a mixture of a photocatalyst, cement, and water onto the surface of the road, was suggested.

Growth Performance, Carcass Characteristics and Meat Yield of Boer Goats Fed Diets Containing Leaves or Whole Parts of Andrographis paniculata

  • Yusuf, A.L.;Goh, Y.M.;Samsudin, A.A.;Alimon, A.R.;Sazili, A.Q.
    • Asian-Australasian Journal of Animal Sciences
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    • 제27권4호
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    • pp.503-510
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    • 2014
  • The study was conducted to determine the effect of feeding diets containing Andrographis paniculata leaves (APL), whole Andrographis paniculata plant (APWP) and a control without Andrographis paniculata (AP0), on growth performance, carcass characteristics and meat yield of 24 intact Boer bucks. The results obtained indicated that inclusion of Andrographis paniculata significantly improved feed intake, weight gain, feed efficiency and live weight. The ratios of carcass to fat, lean to bone, lean to fat, and composition of meat were also improved. In addition, there were significant differences (p<0.05) between the dietary treatments in dressing percentage and chilling loss. Goats fed on AP0 (control) had significantly higher proportions of fat and bone, as well as thicker back fat than the supplemented animals (APL and APWP). Higher gut fill in animals fed Andrographis paniculata suggested slow rate of digestion, which could have improved utilization and absorption of nutrients by the animals. Goats fed Andrographis paniculata also produced higher meat yield and relatively lower fat contents (p<0.05).

The Bacterial Community of Southern Lake Baikal in Winter

  • Ahn, Tae-Seok;Hong, Sung-Hee;Kim, Dong-Joo;Suck, Jung-Hyun;Valentin V. Drucker
    • Journal of Microbiology
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    • 제37권1호
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    • pp.10-13
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    • 1999
  • The bacterial abundance, proportion of respiring bacteria, and bacterial community of southern Lake Baikal were analyzed at 1 m and 400m depths during winter. The total bacterial numbers were 5.1${\times}$105 cells ml-1 at 1 m and 2.5${\times}$105 cells ml-1 at 400 m depth, which are about half and quarter of the numbers of other lakes. The proportion of respiring bacteria was as low as 2.5% at 1 m and 1.4% at 400 m depth. Considering the amount of organic carbon which need to be degraded and low proportion of respiring bacteria, the bacteria could be assumed to have high activities. The EUB/DAPI ratios were 77 and 89% at 1 m and 400 m depths, respectively. Of the bacterial community, the other group was dominant at both depths, and gamma group of protebacteria followed next. But the beta group of proteobacteria and Cytophaga-Flavobacterium groups occupied very small proportions.

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사상체질 진단 도구(SCAT)와 전문가에 의해 판정된 사상체질별 신체적 특성 (Physical characteristics according to Sasang constitution typology determined by Sasang Constitution Analysis Tool(SCAT) and a specialist)

  • 김순미
    • 한국융합학회논문지
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    • 제11권12호
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    • pp.363-371
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    • 2020
  • 사상체질별 체형 특성을 살펴보기 위하여 대상자들의 체질을 사상 체질 진단 도구인 SCAT와 민간인 전문가에 의해 판정하고 결과가 일치하는 대상자의 8개 부위 신체둘레와 이들의 비율을 분석하였다. SCAT와 전문가의 체질 판정 일치율은 남녀 각각 33.0 %, 41.5 %이었으며, 소양인의 일치 비율이 가장 낮았다. 사상체질에 따른 신체둘레 비율 특성은 남성보다 여성에서 더 뚜렷하게 나타났다. 여성의 이마/목, 가슴/장골, 늑골/장골, 늑골/곡골 둘레 비율은 SCAT, 전문가 모두에서 동일한 결과를 나타내었다. 체질 판정에 있어서 둘레를 측정하는 것 보다 특정 둘레 사이의 비율을 측정하는 것이 더 의미 있는 기준이 될 수 있음을 확인하였다.

Impacts of Household Income and Economic Recession on Participation in Colorectal Cancer Screening in Korea

  • Myong, Jun-Pyo;Kim, Hyoung-Ryoul
    • Asian Pacific Journal of Cancer Prevention
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    • 제13권5호
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    • pp.1857-1862
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    • 2012
  • To assess the impact of household income and economic recession on participation in CRC screening, we estimated annual participating proportions from 2007 to 2009 for different CRC screening modalities according to household income levels. A total of 8,042 subjects were derived from the fourth Korean National Health and Nutrition Examination Survey (KNHANES IV). Multivariate logistic regression analysis was used to estimate odds ratios and 95% confidence intervals for CRC screening with household income quartiles by gender in each year. People were less likely to attend a high-cost CRC screening such as a sigmoidoscopy or colonoscopy independent of the income quartile during the economic recession. Income disparities for participating in opportunistic cancer screening appear to have existed among both males and females during the three years (2007-2009), but were most distinctive in 2009. An increase in mortality of CRC can therefore be expected due to late detection in periods of economic crisis. Accordingly, the government should expand the coverage of CRC screening to prevent excess deaths by reducing related direct and indirect costs during the economic recession.

도로유실 복구를 위한 골재 충전 고흐름도 모르타르의 기초 배합 연구 (Fundamental Study of Mix Proportions of High-Flow Cement-Based Mortar for Gravel-Fill Used in Restoration of Collapsed Roads)

  • 조현명;전상표;김승원;윤경구;박철우
    • 한국도로학회논문집
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    • 제17권2호
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    • pp.63-70
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    • 2015
  • PURPOSES: As a part of our research into repair techniques for roads that have collapsed as a result of a natural disaster, this study set out to find the optimum mix proportion for gravels to be used to restore a damaged area. METHODS: This study considered flow and strength-development characteristics. The experimental variables were the W/C ratio, the usage of the admixture, the types of cement, and the quantity of fine aggregate over three different experimental stages. The compressive strength was measured at 12 hours, one day, three days, and seven days. RESULTS : The flow varied with the amount of fine aggregate and the use of a high-range water-reducing (HRWR) admixture. The compressive strength also varied with respect to the type of cement and the W/C ratios. The strength satisfied the expected requirement of 21 MPa after one day, provided the mix proportion was appropriate. CONCLUSIONS: A gravel-filling high-flow cement-based mortar exhibited strength and consistency with a W/C ratio in the range of 0.40 to 0.45, assuming the use of HRWR at 0.5 to 0.7% and a fine aggregate/cement ratio of 1.0 to 1.5.

Development of slag based Shirasu geopolymer

  • Katpady, Dhruva Narayana;Takewaka, Koji;Yamaguchi, Toshinobu
    • Computers and Concrete
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    • 제20권1호
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    • pp.77-84
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    • 2017
  • Shirasu, a pyroclastic flow deposit, showed considerable performance as aluminosilicate source in geopolymer, based on past research. However, the polymerization reactivity was somewhat lower compared to the traditional fly ash based geopolymer even though the long-term strength was fairly good. The present study concentrates on the development of higher initial strength performance of Shirasu based geopolymer by utilizing ground granulated blast furnace slag as an admixture. Mortars with various mix proportions were adopted to study the effect of parametric changes on strength development along with the addition of slag in different percentages. A combination of sodium hydroxide and sodium silicate was used as alkaline activators considering parameters like molar ratios of alkali to geopolymer water and silica to alkali molar ratio. The mortars were cured at elevated temperatures under different curing conditions to analyze the effect on strength development. Compressive strength test, mercury intrusion porosimetry and X-ray powder diffraction were carried out to assess the strength performance and microstructure of slag-Shirasu based geopolymer. Based on the experimental study, it was observed that the initial and long-term strength development of Slag-Shirasu geopolymer were improved by the addition of slag.

축인장하(軸引張下)의 평판(平板)의 단부(段部) Fillet 근처(近處)의 Relieving Groove가 응력집중(應力集中)에 미치는 영향(影響) (Effect of the Semi-circular Relieving Groove on the Stress Concentration at the Fillet of the Stepped Bar under Axial Tension)

  • 김효철
    • 대한조선학회지
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    • 제6권2호
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    • pp.5-10
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    • 1969
  • A stepped bar with seimi-circular stress relieving groove near the fillet was subjected by axial tension in a polarized light field. On the stress concentration factor, the effect of the ratios of the fillet radius, the distance between two relieving grooves and the groove radius to the breath of the narrower portion of the stepped bar have been investigate. Observing the stress concentration in 48 models with various proportions, the conclusion arrived at were as follow: 1) If the fillet radius of the stepped bar is larger than half breadth of the narrower portion, the reduction of the stress concentrations can not be expected. 2) If the fillet radius is smaller than half breadth of the narrower portion of the stepped bar, the stress concentration can be droped to the reasonable range. 3) When the groove radius is larger than a quarter of the difference between the distance of two relieving grooves and the breadth of the stepped bar and smaller than a half of that, the stress concentration factors can have their possible minimum value. 4) When the sun of the breadth of the narrower portion of the stepped bar and twice of the relieving groove radius is smaller than the distance between two relieving grooves, minimum stress concentration can be obtained.

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