• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.1
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• pp.78-82
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• 2004

Effects of the extract of oriental herbal composition, Jang Baek Union (JBU), on hangover and liver function were studied in rats. To investigate anti-hangover effect, alcohol concentration and acetaldehyde concentration of blood were measured after oral ethanol treatment. Blood alcohol concentration was significantly reduced by pre-treatment of JBU extract. The effect of JBU extract on the blood acetaldehyde concentration was more significant than commercial product used as a positive control. To investigate hepato-protective effect, serum GOT and GPT levels and histological changes of liver tissue were analyzed in $CCl_4$-treated rats. JBU extract adminstration significantly inhibited the increase of serum GPT and GOT levels induced by $CCl_4$-treatment. Moreover, histological injuries of liver tissue such as fatty changes and sinusoidal leukocytosis were inhibited by JBU extract.

• Polymer(Korea)
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• v.28 no.4
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• pp.285-290
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• 2004

Nondestructive damage sensitivity of carbon nanotube(CNT) and nanofiber (CNF)/epoxy composites with their adding contents was investigated using electro-micromechanical technique. Carbon black (CB) was used only for the comparison with CNT and CNF. The fracture of carbon fiber was detected by acoustic emission (AE), which was correlated to the change in electrical resistance, ΔR under double-matrix composites (DMC) test. Stress sensing on carbon nanocomposites was performed by electro-pullout test under uniform cyclic loading. At the same volume fraction, the damage sensitivity for fiber fracture, matrix deformation and stress sensing were highest for CNT/epoxy composite, whereas for CB/epoxy composite they were the lowest among three carbon nanomaterials (CNMs). Damage sensitivity was correlated with morphological observation of carbon nanocomposites. Homogeneous dispersion among CNMs could be keying parameters for better damage monitoring. In this study, damage sensing of carbon nanocomposites could be evaluated well nondestructively by the electrical resistance measurement with AE.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.1D
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• pp.35-43
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• 2008

This paper mainly deals with the performance evaluation of 33 asphalt sections of Korea Expressway Corporation Test Road (KECTR) during the past four years. Since the construction of the KECTR in December 2002, key performance indicators of asphalt pavements have been collected five times with an Automatic Road Analyzer (ARAN), and have been analyzed for permanent deformation, surface distress, and road roughness. Linear viscoelastic characteristics of four dense graded HMAs used in KECTR were investigated with a series of complex modulus test. The effect of air void in HMAs on dynamic modulus was investigate at two air void contents for a surface course HMA (19 mm Nominal Maximum Size of Aggregate). Layer densification due to traffic was estimated from air void contents of field cored samples, and was correlated with pavement distresses and performances. One of findings of this study was that both permanent deformation and cracking were suspectible to pavement temperatures, rather than traffic. However, it was found that road roughness was mostly affected by traffic loading.

• The Journal of the Convergence on Culture Technology
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• v.10 no.3
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• pp.845-849
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• 2024

Currently, rail surface defects are increasing due to the aging of urban railway rails, but in the detailed guidelines for track performance evaluation established by the country, rail surface damage is inspected with the naked eye of an engineer and with simple measuring tools. It is very important to discover defects in the rail surface through periodic track tours and visual inspection. However, evaluating the severity of defects on the rail surface based on the subjective judgment of the inspector has significant limitations in predicting damage inside the rail. In this study, the characteristics of cracks inside the rail due to rail surface damage were studied. In field measurements, rail surface damage was selected, old rail samples were collected in the acceleration and braking sections, and a scanning electron microscope (SEM) was used to evaluate the rail surface damage was used to analyze the crack characteristics. As a result of the analysis, the crack mechanism caused by the running train and the crack characteristics of the acceleration section where cracks occur at an angle rising toward the rail surface were experimentally proven.

• The Journal of Korean Orthopaedic Ultrasound Society
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• v.1 no.2
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• pp.73-77
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• 2008

Purpose: The purpose of this study was to describe the method of dynamic sonographic measurements in the evaluation of the MCL injury of the knee joint while applying valgus and varus stress. Materials and Methods: Seven cases of MCL injury from January to April of 2008 was used for the study. For the evaluation of the medial instability, sonography was used immediately after injury, 6 weeks and 12 weeks after conservative treatment with limited motion brace. The length between the foot of the medial femoral epicondyle and the most proximal point of the tibial cortex was measured in 30 degrees flexion with valgus and varus stress of the knee joint. Results: The foot of the medial epicondyle and the starting point of the proximal tibial cortex underneath the round portion of the articular cartilage were always able to be seen on ultrasonography, even in varus and valgus stress with gravity in 30 degrees flexion of the knee joint. The results of measurements were always constant. Conclusion: Sonography can be used in evaluation of medial instability under the dynamic valgus and varus stress of the knee joint without further injury.

• Journal of the Korean Applied Science and Technology
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• v.38 no.3
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• pp.700-707
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• 2021

This study aimed to understand the effects of apricot kernel oil on the improvement of hair texture by producing a hair texture improvement agent added with apricot kernel oil and then applying it to damaged hair. In the test method and measurement, the agent was produced by putting different contents of apricot kernel oil like 0 g, 1 g 2 g, and 3 g. After applying the produced agent to bleached sample hair, it was heat treated and then left as it was. The comparative analysis was conducted by measuring each sample before and after application. To understand its effects on the improvement of hair texture, the tensile strength, absorbance with the use of methylene blue, and gloss were measured. In the results of this study, the tensile strength was increased in every sample except for healthy hair after application. In the results of analyzing the absorbance with the use of methylene blue, it was decreased in samples like 7L(1), 7L(2), 7L(3), and 9L(3) after application. In the results of measuring the gloss, it was increased in the samples like 7L(1), 7L(2), 7L(3), and 9L(3). Such changes in the tensile strength, absorbance, and gloss showed the effects of apricot kernel oil on the texture improvement of damaged hair. In the future, it would be necessary to have researches on various methods of measurement and treatment.

• Journal of Conservation Science
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• v.30 no.4
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• pp.427-438
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• 2014

To measure the depth and extension on the surface cracks of the stone monument, ultrasonic pulse velocity targeted at the Mulgyeseowon Stele in Changnyeong was used in this research. Additionally, to establish a long-term countermeasure of management and conservation for this stele, we have investigated the material properties and damage on it and have conducted a precise diagnosis by a variety of non-destructive techniques. Our research has revealed that stones of the stele are composed mainly of three rock types according to the parts of it, alkali-feldspar granite, gabbro and diorite. The result of the deterioration evaluation has occurred that cracks, which are observed from every direction in the body of the stele, are the significant factors to reduce structural stability. The ultrasonic velocity for an evaluation on the properties of the stele has revealed that the speed was high in the order of body, pedestal and crown. Furthermore, to understand the present condition and occurrences of the cracks which have measured in many different forms on the stele quantitatively, we have estimated from 0.6 to 24.1cm deep of the cracks by To-Tc method using ultrasonic velocity.

• Journal of Life Science
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• v.17 no.12
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• pp.1723-1728
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• 2007

Rubus coreanus Miquel (RCM), a type of red raspberry, grows wild in Korea and China and its unripe fruit is used as a folk medicine for the treatment of impotence and as a diuretic. RCM was extracted with methanol and then further fractionated it into for different types. In this study, we investigated the antioxidant activity of a RCM extract (ext.) and its fraction (fr.). DPPH free radical scavenging activity assay, total polyphenols contents, total flavonoids contents assay were used to analyze antioxidant activity. The DPPH free radical scavenging activity $(RC_{50}:1.67{\mu}g/ml)$ and total polyphenols contents $(546.25{\mu}g/mg)$ were higher in butanol fraction than in other fr. And total flavonoids contents was higher in ethylacetate fr. $(141.78{\mu}g/mg)$. We applied comet assay to measure the DNA damage in the individual cells and exposed time course at $IC_{50}$. Comet assay is a rapid and sensitive fluorescent microscopic method to examine DNA damage and repair at individual cell level. The butanol fro from RCM significantly induced 54.12%, 57.95% of DNA damage after treated RCM for 8 hr. In conclus

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.37 no.8
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• pp.780-788
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• 2009

AE technique was applied to the static structural test of the composite wing structure to evaluate the structural integrity and damage. During the test, strain and displacements measurement technique were used to figure out for static structural strength. AE parameter analysis and source location technique were used to evaluate the internal damage and find out damage source location. Design limit load test, the 1st and 2nd design ultimate load tests and fracture test were performed. Main AE source was detected by an sensor attached on skin near by front lug. Especially, at the 1st design ultimate test, strain and displacements results didn't show internal damage but AE signal presented a phenomenon that the internal damage was formed. At the fracture test, AE activities were very lively, and strain and displacements results showed a tendency that the load path was changed by severe damage. The internal damage initiation load and location were accurately evaluated during the static structural test using AE technique. It is certified from this paper that AE technique is useful technique for evaluation of internal damage at static structural strength test.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.32 no.4
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• pp.233-240
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• 2019

Open-hole tensile tests are usually performed to measure the tensile strengths of composites as they are an essential parameter for designing composite structures. However, correctly modeling the tensile test is extremely challenging as it involves various damages such as fiber and matrix damage, delamination, and debonding damage between the fiber and matrix. Therefore, a progressive damage model was developed in this study to estimate the in-plane failure and delamination between the fiber and matrix. The Hashin damage model and cohesive zone approach were used to model ply and delamination failures. The results of the present model were compared with previously published experimental and numerical findings. It was observed that neglecting delamination during finite element analysis led to overestimation of tensile strength.