• Title/Summary/Keyword: SIF

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Effects of soaking on a lime stabilized clay and implications for pavement design

  • Bozbey, Ilknur;Kelesoglu, M. Kubilay;Oztoprak, Sadik;Komut, Muhammet;Comez, Senol;Ozturk, Tugba;Mert, Aykan;Ocal, Kivilcim
    • Geomechanics and Engineering
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    • v.24 no.2
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    • pp.115-127
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    • 2021
  • This paper investigates the effects of soaking on a lime stabilized high plasticity clay and evaluates the implications for pavement design. In this context, the soil was stabilized by 4%, 6% and 9% hydrated lime. The soil was pulverized in two different gradations so that representative field gradations could be simulated. Both soil pulverization levels passed the relevant field gradation criteria. Curing durations were chosen as 7 days, 28 days and 56 days. Two groups of samples were prepared and were tested in unconfined compression test apparatus to measure the strength and secant modulus at failure values. One of the groups was tested immediately after curing. The other group of samples were first cured and then subjected to soaking for ten days before testing. Visual observations were made on the samples during the soaking period. The results showed the superiority of fine soil pulverization over coarse soil pulverization for unsoaked conditions in terms of strength and modulus values. Soaking of the samples affected the unconfined compressive strength and modulus values based on lime content, curing duration and soil pulverization level. In soaked samples, fine soil pulverization resulted in higher strength and modulus values compared to coarse soil pulverization. However, even with fine soil pulverization, effects of soaking on modulus values were more significant. A new term named as "Soaking Influence Factor (SIF)" was defined to compare the reduction in strength and modulus due to soaking. The data was compared with the relevant design guidelines and an attempt was made to include Soaking Influence Factors for strength and modulus (SIFS and SIFM) into pavement design processes. Two equations which correlated secant modulus at failure to unconfined compressive strength were proposed based on the samples subjected to soaking. The results of this study showed that in order to decrease the diverse effects of soaking for lime stabilized soils, soil pulverization level should be kept as fine as possible in the field. Importance of proper drainage precautions in the pavements is highlighted for better performance of the pavements.

Risk Factors in Relation to Blood Pressure in Schoolchildren (국민학교 학동의 혈압에 관련된 요인분석)

  • Lee, Dong-Soo;Lee, Kyeong-Soo;Kang, Pock-Soo
    • Journal of Yeungnam Medical Science
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    • v.10 no.2
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    • pp.345-359
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    • 1993
  • This study was conducted to identify the factors related to the blood pressure in school children. The study subjects were 144 boys and 140 girls aged 10 years old, 4th grade student of one elementary school in Taegu City. Blood pressure and 18 variables for 284 school children were measured in May 1992. A weight-for-height index, R$\ddot{o}$hrer index(weight/$height^3$) was calculated for each individual as a measure of obesity. Body fat percent, fat weight, and lean body mass were measured by impedance fat meter(Model SIF-891). Serum total cholesterol, high-density lipoprotein, triglyceride, uric acid, total protein, and electrolyte were measured by automated clinical chemistry analyzer(Hitachi 4020). Low-density lipoprotein and atherogenic index were calculated by the equation. The variables assessed were sex, systolic blood pressure, diastolic blood pressure. R$\ddot{o}$hrer index, body fat percent, body fat weight, lean body mass, total cholesterol, high-density lipoprotein, low-density lipoprotein, uric acid, total protein, serum electrolyte and blood glucose. The mean systolic and diastolic blood pressures for boys were 104.1mmHg and 66.6mmHg and those for girls were 102.9mmHg and 67.5mmHg. Systolic blood pressure of boys was positively correlated with height, weight, R$\ddot{o}$hrer index, fat weight, lean body mass, and triglyceride. Systolic blood pressure of girls was positively correlated with height, weight, lean body mass, and uric acid. Diastolic blood pressure of boys was positively correlated with weight. R$\ddot{o}$hrer index, and lean body mass. Diastolic blood pressure of girls was positively correlated with height, weight, fat weight, and lean body mass and negatively with total serum protein. In multiple regression analysis for the systolic blood pressure, the significant independent variables were R$\ddot{o}$hrer index and serum sodium in boys, and serum uric acid, fat percent, and R$\ddot{o}$hrer index in girls. In multiple regression analysis of the diastolic blood pressure, the significant independent variables were R$\ddot{o}$hrer index in boys and total serum protein in girls. This study indicated that important factors influencing blood pressure in school children were R$\ddot{o}$hrer index, fat percent, serum sodium, uric acid, and total protein. R$\ddot{o}$hrer index was most important among these. It is recommended to enforce the nutritional education for diet control of obesity to prevent hypertention in children and to adopt healthy life-styles that promote good health and prevent development of cardiovascular risk factors.

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Relationship of Body Fat Percent with Serum Lipid Level and Blood Pressure in Adults (Impedance Fat Meter로 측정한 체지방 비율과 혈청 지질치 및 혈압과의 관련성)

  • Lee, Seock-Whan;Hwang, Tae-Yoon;Kim, Chang-Yoon
    • Journal of Preventive Medicine and Public Health
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    • v.28 no.4 s.51
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    • pp.783-794
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    • 1995
  • This study was conducted to clarify the relationship of body fat percent with serum lipid level and blood pressure in adults. The study subjects were 472 men and 189 women who visited Multiphasic Health Screening Center of Yeungnam University Hospital in Taegu from May 20 to September 30, 1994. The relationship of serum lipid and blood pressure with BMI, Katsura index, atherogenic index, which calculated from the health screening data and body fat percent measured by impedance fat meter(model SIF-819) were analyzed. Three groups were classified as Group I (men : body fat Percent $\geq$ 20, women : body fat percent $\geq$ 25), Group II (men : 15 $\leq$ body fat percent< 20, women : 20 $\leq$ body fat percent< 25), Group III(men : body fat percent < 15, women body fat percent <20). In this study, Group I accounted for 3.2% in men, 3.7% in women. Weight was significantly different among three groups in both sexes(p<0.01) and height was not significantly different among three groups. In men, serum total cholesterol, triglyceride, high density lipoprotein, low density lipoprotein, atherogenic index were significantly different(p<0.01). In women, serum total cholesterol and low density lipoprotein were significantly different(p<0.05) but there was no differences in triglyceride and high density lipoprotein among three groups. BMI and Katsura index were significantly different among three groups in both sexes(p<0.01). In men, body fat percent was positively correlated with weight, BMI, Katsura index, total cholesterol, triglyceride, low density lipoprotein, atherogenic index and systolic and diastolic blood pressures, and negatively correlated with high density lipoprotein. In women, body fat percent was positively correlated with age, height, weight, BMI, Katsura index, total cholesterol, triglyceride, low density lipoprotein and atherogenic index, and negatively correlated with high density lipoprotein. But there was no significant correlation between body fat percent and blood pressure in women. In multiple regression analysis for total cholesterol, fat percent, age and BMI were significant independent variables in men$(p<0.05,\;R^2=0.1286)$, and body fat percent and age in women$(p<0.05,\;R^2=0.3399)$. In case of LDL/HDL ratio, only BMI was a significant independent variable in menu$(p<0.01,\;R^2=0.0954)$, and body fat percent, age and BMI in women$(p<0.05,\;R^2=0.3164)$. In multiple regression analysis, age, low density lipoprotein and total cholesterol were significant independent variables on systolic blood pressure in men$(p<0.05,\;R^2=0.1297)$, age and total cholesterol in women$(p<0.05,\;R^2=0.1705)$. On diastolic blood pressure, only age was a significantly independent variable in men$(p<0.01,\;R^2=0.0972)$ and women$(p<0.01,\;R^2=0.1218)$. From the result of this study, it could concluded that body fat percent was significantly associated with other obesity indices and serum lipid, but had no significant association with blood pressure. To establish the relationship of body fat percent with blood pressure, further study which consider other variables that may have an effect on blood pressure should be performed.

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