• International Journal of Highway Engineering
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• v.12 no.1
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• pp.47-54
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• 2010

This study had a focus on investigating technical validity of Two-Lift Concrete Pavements which had never been constructed in Korea in order to olve the problem of existing concrete pavements. This study found out the application of Steel Fiber Reinforced Concrete (SFRC) which was one of ew techniques. Also, optimal steel fiber contents and pavement thickness were determined. This study also measured compressive strengths, lexural strengths, toughness indexes, tensile strengths and fatigue strengths to estimate the performance of SFRC of according to results of aboratory experiments, slumps and air contents of concrete specimens the standards satisfied and compressive strengths to open traffic. At bending ests, Toughness Index of SFRC increased but flexural strength didn’'t increase as compared with non-steel fiber concretes. And, energy absorption of SFRC was very good and SFRC showed improvement in freezing and thawing resistances. To complete this research, we will evaluate the pplication methods and performance of SFRC at field section.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.12 no.4
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• pp.95-106
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• 1992

This paper presents a comparative evaluation of five different types of steel fibers used as reinforcing material in concrete beams. Two types of plain and RC beams were prepared to compare the relative flexural behavior. The fibers used were dog bone (paddled), both ends hooked. コ-type straight. crimped and wavy type with aspect ratio of 43 to 75. Fiber volume fraction of 1 to 2% were used while shear span to depth ratio (aid) and steel ratio p were fixed. Fiber reinforcement effect index Ef and effective toughness index Te were adopted to evaluate fiber reinforcing effects. The effect of fiber reinforcement on flexural strength is higher in plain beams than in RC beams. Hooked and dog bone type fibers were found to be more effective than the other type ones in enhancing the flexural strength and post-peak energy absorption capacity of concrete beams.

• The Korean Journal of Community Living Science
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• v.28 no.1
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• pp.5-16
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• 2017

This study was conducted to compare the nutritional status, nutrient intakes, and chronic disease risks of Chinese elderly people. MNA (Mini Nutritional Assessment) developed for elderly people was used to determine their nutritional status. In this study, participants consisted of 148 urban residents aged 65 years and over residing in three cities in Shandong Province, China. Participants were 67 (45.3%) men and 81 (54.7%) women, and average age was 72.8 years. According to MNA score, 77.7% of participants were 'well nourished', 22.3% were 'at risk of malnutrition', and 2% were 'malnourished'. Nutritional status was divided into two groups by MNA score as 'well nourished' and 'malnourished', which was formed with the combination of 'at risk of malnutrition' and 'malnourished'. Compared with the well nourished group, the malnourished group was older, and physical status indicators such as weight, BMI (Body Mass Index), and calf circumference of the malnourished group were much smaller. The malnourished group had higher prevalence rates of heart disease and stomach disorders while the well nourished group had a higher rate of hypertension. There was no significant difference between the malnourished group and well nourished group in nutritional intake below Chinese DRIs (Dietary Reference Intakes) among elder males. A higher proportion of elder females showed insufficient intakes of energy, protein, vitamin A, vitamin E, and zinc in the malnourished group compared to the well nourished group. The INQ (Index of Nutrition Quality) of calcium, magnesium, zinc, iodine, and most vitamins was less than 1 in both the malnourished and well nourished groups.

• Korean Journal of Community Nutrition
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• v.19 no.1
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• pp.84-94
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• 2014

Periodontal disease is one of the most common chronic inflammatory diseases in the oral cavity, and this is the leading cause of loss of teeth. Studies on the association between diet and periodontal diseases are very limited. The purpose of this study was to investigate the association between food and nutrient intakes and the prevalence of periodontitis. Subjects were 13,391 adults participating in the 2008-2010 Korea Health and Nutrition Examination Survey. Periodontitis was diagnosed by dentists using the Community Periodontal Index. Nutrient intakes were estimated by the 24-hour dietary recall. Consumption frequencies of foods were from the food frequency questionnaire. Subjects were categorized into 'smoking' or 'non-smoking' groups. Multiple logistic regression analysis was applied to determine the association between diet and periodontitis. The proportions of subjects having periodontitis were 26% in the non-smoking group and 37.5% in the smoking group. In the nonsmoking group, intakes of fruits, dairy products, green tea, energy and vitamin C were inversely associated with the prevalence of periodontitis, but fish and coffee intakes were positively associated with the prevalence of periodontitis after adjusting for covariates. In the smoking group, protein and retinol intakes were inversely associated with the prevalence of periodontitis after adjusting for covariates. These results suggest that certain food and nutrient intakes such as fruits, dairy products, green tea, vitamin C, protein, or retinol intakes may affect the prevalence of periodontitis among Korean adults. Further studies are required to confirm these findings in other research settings.

• Economic and Environmental Geology
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• v.23 no.1
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• pp.87-104
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• 1990

Foliated granites between Damyang and Jinan are subdivided into Daegang foliated granite, Foliated hornblende biotite granodiorite, Sunchang foliated granodiorite, Foliated two mica granite and Samori foliated granite by mineral and texture. From EPMA data of the foliated granites following results are achieved. Composition of plagioclase are correspond to andesine, oligoclase and albite in Foliated hornblende biotite granodiorite, Sunchang foliated granodiorite and other foliated granites, respectively. And amphiboles are calcic hornblende in Foliated hornblende biotite granodiorite, and riebeckite in Daegang foliated granite. In differentiation index(D. I.) and Larsen index(L. I.), Daegang foliated granite, Foliated two mica granite and Samori foliated granite which belong to granite are 83.12-95.54 and 25.86-29.05 and Foliated hornblende biotite granodiorite and Sunchang foliated granodiorite of diorite to granodiorite are 54.99-78.54(D. I.) and 6.48-21.01(L. I.). Harker and AMF diagrams plotted from foliated granites show that the granites are product of calc alkali rock series orignated from co-magma. Characteristic foliation of foliated granites fromed by ductile deformation at deep zone of dextral strike slip fault. Foliated granites are considered as a series of differentiated product of Triassic Igneous activity of Songrim disturbance. According to REE, (La/Lu) and Eu/Sm, Foliated hornblende biotite granodiorite and Sunchang foliated granodiorite are correspond to granodiorite, and other foliated granites are monzo-and syeno-granite. Foliated granites having 0.20-0.01 of Em/Sm ratio are plutons emplaced by the tectonic setting in continents and continental margin.

• Environmental Engineering Research
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• v.23 no.2
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• pp.143-149
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• 2018

Air quality conditions and pollution status have been evaluated in the industrial area between Sharjah and Ajman border in UAE. Daily concentrations of $O_3$, CO, $NO_2$, $SO_2$, $PM_{2.5}$, $PM_{10}$, Total Volatile Organic Compounds (TVOC) and Total Suspended Particulate (TSP) have been monitored from Sept. 2015 to April 2016. The monthly average concentrations of $O_3$, CO, $NO_2$, $SO_2$, TVOC were within the UAE ambient air quality standards during the survey period. However, $PM_{10}$ and TSP levels exceeded the recommended limits in Sept. 2015, Oct. 2015 and March 2016. Temporal variations in air quality parameters showed highest levels in March 2016 for $PM_{2.5}$, $PM_{10}$, $NO_2$, TVOC and TSP, whereas $O_3$, $SO_2$ and CO showed relatively low values in this month. $PM_{2.5}$ levels in ambient air were above the EPA guideline of $35{\mu}g/m^3$ in all months. $PM_{2.5}$ was the critical ambient air pollutant with Index for Pollutant ($I_p$) values varying from 103-209, indicating Air Quality Index categories of unhealthy for sensitive groups (62.5%) to unhealthy (25%) to very unhealthy (12.5%). The $I_p$ average values of $PM_{2.5}$ decreased from Sept. 2015 to reach lowest value in Dec. 2015 before increasing gradually, peaking in March 2016. These results suggest the potential health risks associated with $PM_{2.5}$ is low in winter, where the prevailing meteorological conditions of lower temperatures, higher humidity, higher wind speed reduced particulate matter. The results revealed the industrial area is impacted by anthropogenic and natural sources of particulate matter.

• Journal of Biosystems Engineering
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• v.35 no.5
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• pp.357-365
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• 2010

Workers in the agricultural industry have been exposed to many work-related musculoskeletal disorders. So, our objectives in this study were to measure and analyze worker's physiological bio-information to reduce musculoskeletal disorders in relation to agricultural works. We investigated worker's bio-information of physiological signals during the repeated lifting work such as body temperature, heart rate, blood pressure, physical activity, and heart rate variability. Moreover, we analyzed the workloads of lumbar spine during the repeated lifting work using the 3-axis acceleration and angular velocity sensors. The changes of body temperature was not significant, but the mean heart rate increased from 90/min to 116/min significantly during 30 min of repeated lifting work (p<0.05). The average worker's physical activity(energy consumption rate) was 206 kcal/70kg/h during the repeated lifting work. The workers' acute stress index was more than 80, which indicated a stressful work. Also, the maximum shear force on the disk (L5/S1) of a worker's lumbar spine in static state was 500N, and the maximum inertia moment was 139 $N{\cdot}m$ in dynamic state.

• Structural Engineering and Mechanics
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• v.74 no.6
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• pp.723-735
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• 2020

This study is reported the adhesion failure in adhesive bonded composite and specifically for the T-joint structure. Three-dimensional finite element analysis has been performed using a commercial tool and the necessary outcomes are obtained via an eight noded solid element (Solid 185-element) from the library of ANSYS. The structural analysis input has been incurred through ANSYS parametric design language (APDL) code. The normal and shear stress distributions along different layers of the joint structure have been evaluated as the final outcomes. Based on the stress distributions, failure location in the composite joint structure has been identified by using the Tsai-Wu stress failure criterion. It has been found that the failure index is maximum at the interface between flange and web part of the joint (top layer) which indicates the probable location of failure initiation. This kind of failures are considered as adhesion failure and the failure propagation is governed by strain energy release rate (SERR) of fracture mechanics. The different adhesion failure lengths are also considered at the failure location to calculate the SERR values i.e. mode I fracture (opening), mode II fracture (sliding) and mode III fracture (tearing) along the failure front. Also, virtual crack closure technique (VCCT) principle of fracture mechanics steps is used to calculate the above said SERRs. It is found that the mode I SERR is more dominating compared to other two modes of failure for the joint considered. Finally, the influences of various parametric (geometrical and material) effect on SERR of the joint structure are evaluated and discussed in details.

• Nutrition Research and Practice
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• v.7 no.2
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• pp.77-81
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• 2013

The hypothesis of this study was that greater sugar consumption at breakfast promotes a stronger sensation of hunger and a later increase in energy consumption. The objective was to assess the relation between sugar consumption in a meal and the subsequent sensations of hunger and ad libitum food consumption. Sixteen women consumed a breakfast accompanied by 2 drinks sweetened ad libitum with sugar. After 3 h, a lunch was offered to evaluate ad libitum food consumption. During the period from breakfast to lunch, hunger sensations were evaluated at 30 min intervals. Women were divided according to the median amount of sugar used to sweeten the breakfast drinks (20 g). The group who consumed sugar above the median showed a greater hunger sensation in the preprandial period, and a greater ad libitum intake at lunch ($390{\pm}130g{\times}256{\pm}67g$, P = 0.002), compared to the group who had a lower sugar consumption. The amount of sugar consumed at breakfast was correlated positively with the sensation of preprandial hunger and food intake at lunch. We concluded that foods with a high glycemic index can modulate the appetite within a short period of time.

• Smart Structures and Systems
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• v.15 no.4
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• pp.1085-1101
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• 2015

Changes in substructure conditions, such as ballast fouling and subgrade settlement may cause the railway quality deterioration, including the differential geometry of the rails. The objective of this study is to develop and apply a hybrid cone penetrometer (HCP) to characterize the railway substructure. The HCP consists of an outer rod and an inner mini cone, which can dynamically and statically penetrate the ballast and the subgrade, respectively. An accelerometer and four strain gauges are installed at the head of the outer rod and four strain gauges are attached at the tip of the inner mini cone. In the ballast, the outer rod provides a dynamic cone penetration index (DCPI) and the corrected DCPI (CDCPI) with the energy transferred into the rod head. Then, the inner mini cone is pushed to estimate the strength of the subgrade from the cone tip resistance. Laboratory application tests are performed on the specimen, which is prepared with gravel and sandy soil. In addition, the HCP is applied in the field and compared with the standard dynamic cone penetration test. The results from the laboratory and the field tests show that the cone tip resistance is inversely proportional to the CDCPI. Furthermore, in the subgrade, the HCP produces a high-resolution profile of the cone tip resistance and a profile of the CDCPI in the ballast. This study suggests that the dynamic and static penetration tests using the HCP may be useful for characterizing the railway substructure.