• Korean Journal of Exercise Nutrition
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• v.25 no.4
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• pp.38-44
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• 2021

[Purpose] Exercise can prevent conditions such as atrophy and degenerative brain diseases. However, owing to individual differences in athletic ability, exercise supplements can be used to improve a person's exercise capacity. Schisandra chinensis (SC) is a natural product with various physiologically active effects. In this study, we analyzed SC using a pharmacological network and determined whether it could be used as an exercise supplement. [Methods] The active compounds of SC and target genes were identified using the Traditional Chinese Medicine Database and Analysis Platform (TCMSP). The active compound and target genes were selected based on pharmacokinetic (PK) conditions (oral bioavailability (OB) ≥ 30%, Caco-2 permeability (Caco-2) ≥ -0.4, and drug-likeness (DL) ≥ 0.18). Gene ontology (GO) was analyzed using the Cytoscape software. [Results] Eight active compounds were identified according to the PK conditions. Twenty-one target genes were identified after excluding duplicates in the eight active compounds. The top 10 GOs were analyzed using GO-biological process analysis. GO was subsequently divided into three representative categories: postsynaptic neurotransmitter receptor activity (53.85%), an intracellular steroid hormone receptor signaling pathway (36.46%), and endopeptidase activity (10%). SC is related to immune function. [Conclusion] According to the GO analysis, SC plays a role in immunity and inflammation, promotes liver metabolism, improves fatigue, and regulates the function of steroid receptors. Therefore, we suggest SC as an exercise supplement with nutritional and anti-fatigue benefits.

• Korean Journal of Medicinal Crop Science
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• v.26 no.4
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• pp.271-280
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• 2018

Background: Astragalus membranaceus is a well known oriental medicinal herb. The polysaccharides of the aboveground parts (AMA) and the radix (AMR) of A. membranaceus are the most important functional constituents. Methods and Results: The aim of this study was to determine the effects of AMA and AMR on the oxidative damage induced in the skeletal muscle of rats subjected to exhaustive exercise. Sprague-Dawley rats were randomly divided into exercise and non-exercise groups; in the groups receiving the test compounds, AMA and AMR were administered orally for 30 days. Skeletal muscle samples were collected from each rat after running to exhaustion on a treadmill to determine the activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and catalase (CAT) and the concentation of malondialdehyde (MDA). The antioxidant enzyme activities of SOD and GSH-Px of skeletal muscle of AMA- and AMR-treated groups were significantly higher than those of the control and commercial sports drink (SPD)-treated groups in exhaustive exercise rats. In addition, MDA concentrations in the skeletal muscle of the AMA- and AMR-treated groups were significantly lower than those of the control and SPD-treated groups. In the present study, the effects of AMA and AMR on exercise endurance capacity were also evaluated in mice subjected to a swimming exercise test. AMA and AMR supplementation prolonged the swimming time of mice and enhanced exercise endurance capacity. AMA and AMR possess the ability to retard and lower the production of blood lactate, and prevent the decrease of serum blood glucose. Conclusions: These results showed that, AMR and AMA exerted beneficial effect in mice, increasing the activity of the antioxidant systems and inhibiting oxidative stress induced by exhaustive exercise. The compounds improved exercise performance and showed anti-fatigue effects against exhaustive exercise.

• Journal of Korean Society of Steel Construction
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• v.27 no.1
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• pp.53-61
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• 2015

The tension type joint is a mechanically very efficient connection method, as it directly uses the load capacity of base metal or high tension bolt, the reduction of the number of drilling hole and fastening and the fatigue resistance. It is applied to the joint of girder and cross beam, horizontal joints of towers, beam to column joints, the secondary member joints of deck floor ends, and brackets. In this paper, static load tests for the T-type tension joint were conducted to investigate the structural behavior of the joint. The parameters were bolt diameter, flange thickness, and the reduction of clamping force of the joint. The failure modes and load capacity of joints and the effects of flange thickness, bolt diameter and clamping force were investigated.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.12
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• pp.1937-1941
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• 2014

The effects of Tabebuia avellanedae (Taheebo) on exercise endurance capacity were investigated using mice in an adjustable-current water pool. Compared to the control group, a 1.8~2.0 fold increase in swimming time was observed in mice administered hot water extract (TAW) and 80% ethanol extract (TAE) of inner bark from T. avellanedae. Blood lactate level, an important fatigue relevance factor, was significantly lower in the TAW and TAE groups than in the control group. The total phenolic contents of TAW and TAE were $93.3{\pm}1.6$ and $115.7{\pm}1.5mgGAE/g$, respectively. The levels of flavonoids in the extracts were $77.3{\pm}1.3$ and $95.9{\pm}1.7mgCE/g$, respectively. Higher antioxidant activities of TAE were observed in each assay at the same concentration as compared to TAW. Correlation between antioxidant activities of TAE with total polyphenol contents was observed. These results suggest that extracts of Taheebo increase exercise endurance capacity by elevating antioxidative potentials.

• Earthquakes and Structures
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• v.17 no.2
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• pp.221-232
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• 2019

Material non-linearity of Reinforced Concrete (RC) framed structures is studied by modelling concrete using the Concrete Damage Plasticity (CDP) theory. The stress-strain data of concrete in compression is modelled using the Hsu model. The structures are analyzed using a finite element approach by modelling them in ABAQUS / CAE. Single bay single storey RC frames, designed according to Indian Standard (IS):456:2000 and IS:13920:2016 are considered for assessing their maximum load carrying capacity and failure behavior under the influence of gravity loads and lateral loads. It is found that the CDP model is effective in predicting the failure behaviors of RC frame structures. Under the influence of the lateral load, the structure designed according to IS:13920 had a higher load carrying capacity when compared with the structure designed according to IS:456. Ultra High Performance Fiber Reinforced Concrete (UHPFRC) strip is used for strengthening the columns and beam column joints of the RC frame individually against lateral loads. 10mm and 20mm thick strips are adopted for the numerical simulation of RC column and beam-column joint. Results obtained from the study indicated that UHPFRC with two different thickness strips acts as a very good strengthening material in increasing the load carrying capacity of columns and beam-column joint by more than 5%. UHPFRC also improved the performance of the RC frames against lateral loads with an increase of more than 3.5% with the two different strips adopted. 20 mm thick strip is found to be an ideal size to enhance the load carrying capacity of the columns and beam-column joints. Among the strengthening locations adopted in the study, column strengthening is found to be more efficient when compared with the beam column joint strengthening.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.12
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• pp.1700-1707
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• 2011

This study evaluated the effect of multigrain supplementation on exercise-related changes in running time and glycogen storage capacity of male SD rats engaged in treadmill exercise. Thirty-six 6-week-old rats were divided into six groups: normal (Nor) fed normal feed, control (Con) fed with 20% normal feed and 80% milled rice, test group one (GI) fed with multigrain feed I, test group two (GII) fed with multigrain feed II, test group three (GIII) fed with multigrain feed III, and test group four (GIV) fed with multigrain feed IV. Endurance tests by treadmill machine were administered after 24 days of multigrain feed supplementation and adaptive training. Running time was extended and glycogen storage capacity increased in the multigrain-treated group compared to the non-treated group. Also, the fatigue indicators of inorganic phosphorous, CPK, and lactate concentration were all reduced in the multigrain feed group compared to the control group after 25 min and/or exhausted exercise. But there was no difference in GOP, GTP, lactate, or LDH concentrations between the groups. Our results demonstrated that endurance improved with multigrain feed in rats. Specifically, running time, glycogen storage capacity, inorganic phosphorous, CPK, and lactate serum concentration increased. Importantly, the improvements in endurance brought about in the GII group fed with waxy barley was the greatest among the experimental groups.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.6C
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• pp.251-258
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• 2011

Steel pipe piles have been used as various deep foundation materials for a long time. Recent increase in steel material cost has made engineers reluctant in using it even with its good quality and ease of construction. Therefore when constructing with steel pipe pile, the decision to reuse the excessive pile length that is cut off from the designed pile head elevation after pile driving can be cost saving. This has caused many constructors to reuse the pile leftovers with new piles, but the absence of quantitative structural capacity behaviors of steel pipe pile after pile driving or appropriate countermeasures and standards in reusing steel pipe pile has resulted in wrong applications, pile structural integrity problems, inappropriate limitation of reusable pile length, etc. The structural performance analysis between a new pile and a pile that has undergone working state and ultimate state stress level during pile driving was performed in this research by means of comparing the results between the dynamic pile load test, tensile load test, charpy energy test and fatigue test for high strength steel of $440N/mm^2$ yield strength. Test results show that under working load conditions the yield strength variation is less than 2% and for ultimate load conditions the variation is less than 5% for maximum total blow count of 3000. The results have been statistically analyzed to check the sensitivity of each factors involved. From the test results, reusability of steel pipe pile lies not in the main pipe yield strength deviation but in the reduction of absorb energy, strength changes and quality control at the welded section, shape deformation and local buckling during pile driving.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1994.10a
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• pp.160-166
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• 1994

In general, the problems of strengthening and repairing of deteriorated or damaged reinforced concrete members are usually worked out in situ by externally bounding steel plates using epoxy resins, which has been recognized to be one of effective and convenient methods. But the disadvantages of strengthening/repairing concrete members with externally bonded steel plates include ; (a) deterioration of the bond at the steel-concrete interface caused by the corrosion of steel ; (b) difficulty in manipulating the plate at the construction site ; (c) improper formation of joints, due to the limited delivery lengths of the steel plates ; and etc. Therefore these difficulties eventually have led to the concept of replacing the steel plates by fiber-reinforced composite sheets which are characterized by their light weight, extremely high stiffness, excellent fatigue properties, and outstanding corrosion resistance. In the paper, for the reliability assessment of reinforced concrete beams externally strengthened by carbon fiber plastic(CFRP) laminates, an attempt is made to suggest a limit state model based on the strain compatibility method and the concept of fracture mechanics. And the reliability of the proposed models is evaluated by using the AFOSM method. The load carrying capacity of the deteriorated and/or damaged RC beams is considerably increased. Thus, it may be stated that the post-strengthening of concrete beams with externally bonded CFRP materials may be one of very effective way of increasing the load carrying capacity and stiffeness characteristics of existing structures.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.8 no.1
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• pp.41-48
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• 1988

Fatigue phenomena usually occur in the structures such as bridges subjected to repeated loading with increasing service year. Especially, applied stresses happen to approach to design values due to rapid increase of traffic volume and vehicle weight, so it gives serious effects to the stability of bridges. Therefore, in this paper, the data for load carrying capacity of bridges obtained from field tests were analysed statistically to investigate bridge behaviour and a basic approach to estimate the impact factor was proposed after a comparison war made between field-test data and the calculated values obtained by using matrix structural analysis method.

• Journal of the Korean Society for Precision Engineering
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• v.27 no.2
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• pp.102-108
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• 2010

Recently, carbon fiber reinforced plastic(CFRP) composite materials have been widely used in various fields of engineering because of its advanced properties. Also, CFRP composite materials offer new design flexibilities, corrosion and wear resistance, low thermal conductivity and increased fatigue life. However CFRP composite materials are susceptible to impact damage due to their lack of through-thickness reinforcement and it causes large drops in the load-carrying capacity of a structure. Therefore, the impact damage behavior and subsequently load-carrying capacity of impacted composite materials deserve careful investigation. In this study, the residual strength and impact characteristics of plain-woven CFRP composites with impact damage are investigated under axial tensile test. By using obtained residual strength and Tan-Cheng failure criterion, residual strength of CFRP laminate with arbitrary fiber angle were evaluated.