• Geomechanics and Engineering
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• v.19 no.1
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• pp.1-9
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• 2019

Shallow failures occur frequently in both engineered and natural slopes in expansive soils. Rainfall infiltration is the most predominant triggering factor that contributes to slope failures in both expansive soils and clayey soils. However, slope failures in expansive soils have some distinct characteristics in comparison to slopes in conventional clayey soils. They typically undergo shallow failures with gentle sliding retrogression characteristics. The shallow sliding mass near the slope surface is typically in a state of unsaturated condition and will exhibit significant volume changes with increasing water content during rainfall periods. Many other properties or characteristics change such as the shear strength, matric suction including stress distribution change with respect to depth and time. All these parameters have a significant contribution to the expansive soil slopes instability and are difficult to take into consideration in slope stability analysis using traditional slope stability analysis methods based on principles of saturated soil mechanics. In this paper, commercial software VADOSE/W that can account for climatic factors is used to predict variation of matric suction with respect to time for an expansive soil cut slope in China, which is reported in the literature. The variation of factor of safety with respect to time for this slope is computed using SLOPE/W by taking account of shear strength reduction associated with loss of matric suction extending state-of-the art understanding of the mechanics of unsaturated soils.

• Journal of the Korean Recycled Construction Resources Institute
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• v.9 no.4
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• pp.433-442
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• 2021

In this study, the properties of no-fines polymer concrete with different polymer binder contents were evaluated. The polymer concrete was formulated using a polymeric binder (unsaturated polyester resin), fly ash, and recycled coarse aggregate (60%) and crushed coarse aggregate (40%). The polymeric binder content (4.0-6.0wt.%) was used as an experimental variable because it dramatically affects both the cost-effectiveness and material properties. The results showed that the density, compressive strength, flexural strength both before and after exposure to freezing and thawing increased as the polymer binder content increased, while the absorption, void ratio, permeable voids, coefficient of permeability, and acid resistance (mass loss by acid attack) decreased as the polymeric binder content increased. In particular, even though the void ratio was 18.4% and the water permeability coefficient was 7.3mm/sec, the compressive strength and flexural strength were as high as 38.0MPa and 10.0MPa, respectively, much more significant than those of previous studies. Other properties such as absorption and acid resistance were also found to be excellent. The results appear to be rooted in the increased adhesion of the binder by adding a cross-linking agent and the surface hydrophobicity of the polymer.

• Journal of the Korean Recycled Construction Resources Institute
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• v.8 no.1
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• pp.33-40
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• 2013

The cement industry brought very severe environment problems with massive carbon dioxide during its production. To solve this problem, attempts on Alkali-Activated Slag (AAS) concrete that perfectly substitutes industrial by-products such as ground granulated blast furnace slag (GGBFS) for cement are being actively made. AAS concrete is possible to have high strength development at room temperature, however, it is difficult to ensure the working time due to the fast setting time and the loss of workabillity because of the alkali reaction. In this study, the early age properties of alkali activated slag mortar are investigated to obtain the fundamental data for AAS concrete application to structural members. The water-binder ratio (W/B) was fixed at 0.35 and sodium hydroxide and waterglass as alkali activator was used. The compressive strength, the flow and the ultrasonic pulse velocity were measured according to the type of superplasticisers, which were naphthalene(N), lignin(L), melamine(M) and PC(P), up to a maximum of 2 percent by the mass of GGBFS. The results showed that adding melamine type of superplasticizer improved the fluidity of AAS mortar without decreasing the compressive strength, while naphthalene and polycarbonate type of superplasticizer had little effect on the fluidity of AAS mortar.

• Journal of Korean Medicine Rehabilitation
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• v.15 no.1
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• pp.109-126
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• 2005

Objectives : This study is to examine the influence of exorcise program to body shape and body composition of women. Exercise program is composed muscular resistance exercise and aerobic exorcise with 70min/time, 5day/week for 4weeks and designed for the reinforcement of muscular strength and the decease the decrease of obesity. Methods : The subjects of this study are 26 females who are from twenty until thirty-nine years old and are divided into two groups according to Obese Rate. normal weight group is 18 females under a BMI of 23 and overweight group is 8 females over a BMI of 23. we measured body compositon and body shape with body composition analyzer(inbody 3.0) measured body compositions are body weight, Lean body mass, base metabolic rate, body fat, %body fat, waist hip ratio, body mass index. measured 6body shade are upper arm circumference, chest circumference, waist circumference, hip circumference, thigh circumference. the measurements had been taken before exercise of each group, after 4 weeks, after 8 weeks, after 12 weeks. Body compositon and body shape of the measured data were analyzed by two-way repeated ANOVA followed by Dunnett's Post hoc test using SPSS. Differences were considered significant at p<0.05. Results and Conclusions : The weight was reduced at a significant level in overweight group after 4 weeks. Body fat percent was reduced at a significant level in normal group alter 4 weeks and overweight group after 8 weeks. Waist-hip ratio was reduced at a significant level in normal and overweight group after 4 weeks. Lean body mass and body metabolic rate were reduced but did not satisfy statistical significance. Circumference of all body parts showed an decrease after 12 weeks exercise program. Upper Arm, Chest, Waist, Hip Circumference were reduced at a significant level in overweight group after 4 weeks, but In normal group only Waist Circumference was reduced at a significant level after 4 weeks. Aerobic and Circuit weight training for 12 weeks reduced body weight and body fat percent, waist circumstance statistically significant without loss of lean body mass and body metabolic rate. Also these change was more effective in overweight group than in normal group.

• International Journal of Highway Engineering
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• v.7 no.3 s.25
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• pp.31-42
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• 2005

This study evaluates the physical mechanical properties, durability and sound absorbtion of porous concrete for pavement according to content of silica fume and steel fiber to elicit the presentation of data and the way to enhance its function for the practical field application of porous concrete as a material of pavement. The results of the test indicate that in every condition, the void ratio and the coefficient of water permeability of porous concrete for pavement satisfy both the domestic standards and proposition values. Among the properties of strength, the compressive strength satisfies the standards in the specification of Korea National Housing Corporation as for every factor of mixture but in the case of the flexural strength, more than 0.6vol.% of steel fiber satisfied the Japan Concrete Institute proposition values. The mixture of silica fume and steel fiber presents the excellent intensity, though. The case when silica fume and steel fiber are used simultaneously presents the strongest durability because the durability shows the similar tendency to the dynamic characteristics. The case when 10wt.% of silica fume and 0.6vol.% of steel fiber are used at the same time shows that the loss rate of mass by Cantabro test became 27% better and freeze-thaw resistance became 60% better. As for the characteristics of sound absorption of porous concrete for pavement, Noise Reduction Coefficient is 0.48 to prove that it possesses almost 50% sound absorption.

• Journal of Plant Biotechnology
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• v.34 no.4
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• pp.285-291
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• 2007

This study describes conditions for the mass production of activation-tagged mutant hairy root lines of ginseng by cocultivation with Agrobacterium rhizogenes. Because it is not currently possible to produce progeny from transgenic ginseng, a loss-of-function approach for functional genomics cannot be appliable to this species. A gain-of-function approach is alternatively the choice and hairy root production by cocultivation of A. rhizogenes would be most practical to obtain a large number of mutants. Various sources of explants were subjected to genetic transformation with various strains of A. rhizogenes harboring the activation-tagging vector pKH01 to determine optimum conditions for the highest frequency of hairy root formation on explants. Petiole explants cocultivated with A. rhizogenes R1000 produced hairy roots at a frequency of 85.9% after 4 weeks of culture. Conditions for maximum growth or branching rate of hairy roots were also investigated by using various culture media. Petiole explants cultured on half strength Schenk and Hildebrandt medium produced vigorously growing branched roots at a rate of 2.6 after 4 weeks of culture. A total of 1,989 lines of hairy root mutants were established in this study. These hairy root lines will be useful to determine functions of genes for biosynthesis of ginsenosides.

• Annals of Geriatric Medicine and Research
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• v.22 no.4
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• pp.167-175
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• 2018

Sarcopenia, a common clinical syndrome in older adults, is defined as decreased muscle mass, strength, and physical performance. Since sarcopenia is associated with the incidence of functional decline, falls, and even mortality in older adults, researchers and health care providers have been keen to accumulate clinical evidence to advocate the screening and prevention of sarcopenia progression in older adults. The factors that may accelerate the loss of muscle mass and function include chronic diseases, inactivity, and deficiency in appropriate nutritional support. Among these, nutritional support is considered an initial step to delay the progression of muscle wasting and improve physical performance in community-dwelling older adults. However, a nationwide study suggested that most Korean older adults do not consume sufficient dietary protein to maintain their muscle mass. Furthermore, considering age-associated anabolic resistance to dietary protein, higher protein intake should be emphasized in older adults than in younger people. To develop a dietary protein recommendation for older adults in Korea, we reviewed the relevant literature, including interventional studies from Korea. From these, we recommend that older adults consume at least 1.2 g of protein per kg of body weight per day (g/kg/day) to delay the progression of muscle wasting. The amount we recommend (1.2 g/kg/day) is 31.4% higher than the previously suggested recommended daily allowance (i.e., 0.91 g/kg/day) for the general population of Korea. Also, evidence to date suggests that the combination of exercise and nutritional support may enhance the beneficial effects of protein intake in older adults in Korea. We found that the current studies are insufficient to build population-based guidelines for older adults, and we call for further researches in Korea.

• Journal of the Korea Concrete Institute
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• v.24 no.2
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• pp.173-183
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• 2012

Recently, experimental studies to prevent explosive spalling based on spalling mechanism and addition of Polypropylene fiber in high strength concrete (HSC) are performed actively. However, with respect to ultra high strength concrete (UHSC), its compact internal structure is more difficult release vapor pressure at rapid rising temperature compared to HSC. Therefore, in this study, an experiment was conducted to evaluate spalling properties of UHSC using ${\Box}$ $100mm{\times}100{\times}H200mm$ rectangular specimen according to ISO-834 standard fire curve. With respect melting point of fiber, three fiber types of Polyethylene, Polypropylene, and Nylon fibers with melting temperature of $110^{\circ}C$, $165^{\circ}C$, and $225^{\circ}C$, respectively, were considered. Mixed fiber of 0.15% and 0.25% of concrete volume was used to consider spalling properties based on water vapor pressure release. Then, TGDTA test on fiber and FEM analysis were performed. The results showed that it is difficult to prevent initial spalling without loss of fiber mass even if fiber melting temperature is low. Also, in preventing thermal spalling, fiber that melts to rapidly create porosity within 10 minutes of fire is more effective than that of low melting temperature property of fiber.

• Culinary science and hospitality research
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• v.23 no.1
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• pp.66-78
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• 2017

"Sarcopenia", sarcopenia is an old age syndrome, and used to describe the reduction of skeletal muscle. Initially, it was thought that sarcopenia was only a senile disease characterized by degeneration of muscle tissue. However, its cause is widely regarded as multifactorial, with neurological decline, hormonal changes, inflammatory pathway activation, declines in activity, chronic illness, fatty infiltration, and poor nutrition, all shown to be contributing factors. Skeletal muscle mass can be measured by a variety of methods, currently, the commonly used methods are dual-energy X-ray scanning (DXA), computer tomography (CT), magnetic resonance imaging (MRI), etc. Muscular skeletal disorders can also be assessed by measuring appendicular skeletal muscle (ASM), particularly muscle tissue content. At the same time, sarcopenia refers to skeletal muscle cell denervation, mitochondrial dysfunction, inflammation, hormone synthesis and secretion changes and a series of consequences caused by the above process and is a progressive loss of skeletal muscle syndrome, which can lead to the decrease of muscle strength, physical and functional disorders, and increase the risk of death. Sarcopenia is mainly associated with the aging process, but also related to other causes such as severe malnutrition, neurodegenerative diseases, and disuse and endocrine diseases associated with muscular dystrophy, and it is the comprehensive results of multi-factors, so it is difficult to define that sarcopenia is caused by a specific disease. With the aging problem of the population, the incidence of this disease is increasingly common, and seriously affects the quality of the life of the elderly. This paper reviews the etiology and pathogenesis of myopathy, screening methods and diagnosis, the influence of eating habits, etc, and hopes to provide reference for the diagnosis and treatment of this disease. At present, adequate nutrition and targeted exercise remain the gold standard for the therapy of sarcopenia.

• Herbal Formula Science
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• v.24 no.3
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• pp.153-161
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• 2016

Chronic alcoholic myopathy is one of the most common skeletal muscle disorders. It is characterized by a reduction in the entire skeletal musculature, skeletal muscle weakness, and difficulties in gait. Patients with alcoholic hepatitis and cirrhosis have severe muscle loss that contributes to worsening outcome. Although the myopathy selectively affects Type II (fast twitch, glycolytic, anaerobic) skeletal muscle fibers, total skeletal musculature is reduced. The severity of the muscle atrophy is proportional to the duration and amount of alcohol consumed and leads to decreased muscle strength. The mechanisms for the myopathy are generally unknown but it is not due to overt nutritional deficiency, nor due to either neuropathy or severe liver disease. Skeletal muscle mass and protein content are maintained by a balance between protein synthesis and breakdown and in vivo animal models studies have shown that ethanol inhibits skeletal muscle protein synthesis. Daekumeumja is a traditional Korean medicine that is widely employed to treat various alcohol-induced diseases. Muscle diseases are often related to liver diseases and conditions. The main objective of this study was to assess that Daekumeumja extract could have protective effect against alcoholic myopathy in a Sprague-Dawley rat model. Rats were orally given 25% ethanol (5ml/kg, body weight) for 8 weeks. After 30 minutes, rats were administrated with Daekumeumja extract. Controls were similarly administrated with the vehicle alone. The weights of gastrocnemius, soleus and plantaris muscles were assessed and the morphologic changes of gastrocnemius and plantaris muscles were also assessed by hematoxylin and eosin staining. In results, The muscles from ethanol treated rats displayed a significant reduction in muscle weight and average cross section area compared to Normal group. Daekumeumja extract treated group showed increased muscle weight and muscle fiber compared to the ethanol treated group. It was concluded that Daekumeumja extract showed ameliorating effects on chronic alcohol myopathy in skeletal muscle.