• Title/Summary/Keyword: stress intensity

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The Effect of Aerobic Exercise and Allium Tuberosum Intake on Blood Lipids, MDA and Antioxidant Enzyme in Rats (유산소 운동과 부추섭취가 혈중지질, 지질과산화 및 항산화효소에 미치는 영향)

  • Baek, Yeong-Ho;Lee, Sang-Ho
    • Journal of Life Science
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    • v.20 no.2
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    • pp.245-252
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    • 2010
  • The purpose of this study was to investigate the effects of aerobic exercise and Allium tuberosum intake on blood lipids, MDA and antioxidant enzyme in rats. Twenty four male Sprague-Dawley rats, 4 weeks old, were used. Experimental groups were aerobic exercise with Allium tuberosum intake group (A, n=6), aerobic exercise group (B, n=6), Allium tuberosum intake group (C, n=6), and the control group (D, n=6). Aerobic exercise was administered through a treadmill running program (14~15 m/min, $0^{\circ}$ grade, 25~30 min/day, 5 day/wk) and these rats were given 5% Allium tuberosum for 2 wk. The results of this study are as follows: TC and TG didn't show change; groups A, B, C showed a significant increase in HDL-C compared to the D group; groups A, B, and C showed a significant decrease in LDL-C compared to the D group; groups B and C showed a significant decrease in MDA level compared to the D group; groups B and C showed a significant increase in SOD activity compared to the D group; and the A group showed a significant increase in CAT activity compared to the D group. In conclusion, low intensity aerobic exercise and intake of the natural antioxidant Allium tuberosum seem to have the health promoting effect of retarding oxidative stress by decreasing lipid peroxidation.

A Geographical Study on the Spiritual Therapeutic Landscape: From a Perspective of Catholic Sacred Places in Korea (영적 치유의 경관에 관한 지리학적 고찰: 한국 천주교 순례지를 중심으로)

  • Park, Sookyung
    • Journal of the Korean Geographical Society
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    • v.51 no.1
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    • pp.143-166
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    • 2016
  • This study aims to consider spiritual therapeutic landscapes thought the case of catholic sacred places in Korea. The catholic sacred places, which have been a series of persecution, are distributed in 300 all over the country and can be divided into a formational type, a selective type, and a participatory type. In the formational type, the catholic sculptures are scattered here and there; but it seems that there are limits somewhat to feel the emotional stability and the experience of caring by God. Because the formational type is deserted or is built up in unnoticeable urban areas. The religious factors, for example, museums, special pray, Station of the Cross, Rosary way, statues of the Virgin Mary, catholic sculptures, etc. in the selective type are placed in the corners of the catholic sacred places to provide the opportunity of holy experience to pilgrims. But the level and the intensity of healing depends on the matter as to how much pilgrims experience religious factors voluntarily. Lastly, the participatory type means the experience of various religious factors following scheduled programs. The experience is for the group of pilgrims, not a person; and the human relationship via the religious experience spiritualizes the network of interest towards other participants. Furthermore, the spiritualized open mind towards other people becomes the power that can arrive at the emotional stability, the relief of stress, and the in-depth and authentic healing. Ultimately, the spiritual healing through religious factors is to realize human finitude and dedicate one's own self to God; in addition, the spiritual therapeutic landscapes are the place that can carry out such a spiritual ritual without any restraint.

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The Effects of Vitamin C Supplementation and Yoga on the Improvement of Serum Lipid Peroxidation in Middle-aged Women (비타민 C 보충과 요가가 중년여성의 혈청 지질과산화물가 개선에 미치는 영향)

  • Kang, Yeong-Soo;Lee, Sang-Ho;Baek, Yeong-Ho
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.38 no.1
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    • pp.47-51
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    • 2009
  • The purpose of this study was to investigate the effects of vitamin C supplementation and yoga practice on total antioxidant status (TEAC), lipid peroxidation, and blood lipid profiles of middle-aged women. Thirty two women ($53.34{\pm}5.08$ years old) in B city volunteered and the signed consents were received before the study. Experimental groups were normal (n=8), vitamin C intake group (n=8), yoga group (n=8), and vitamin C intake with yoga group (n=8). Total experimental period was 12 weeks. Yoga group practiced yoga 3 times a week for 12 weeks with intensity of RPE $13{\sim}15$. Each practice was 60 minutes. Vt. C group was instructed to take 1 g of Vt. C every day after dinner meal. Changes in TEAC after 12 weeks were 28.23% for the normal group, 30% for Vt. C group, 26.58% for yoga group, and 43.66% for Vt. C with yoga group; the increases in TEAC among groups were not significantly different. Serum malondialehyde (MDA) concentration of the normal group increased by 10% during 12 weeks of experiment while that for the Vt. C, yoga, and Vt. C with yoga group were significantly decreased by 25%, 32.14%, and 33.87%, respectively (p<0.05) compared with the normal group. Neither yoga, Vt. C supplementation nor combined program for 12 weeks were effective enough to change the serum lipid profiles compared with the normal group. In conclusion, Vitamin C supplementation or regular yoga practice seems to have health promoting effects of retarding the oxidative stress by decreasing lipid peroxidation in middle-aged woman.

Rearing Black Bengal Goat under Semi-Intensive Management 1. Physiological and Reproductive Performances

  • Chowdhury, S.A.;Bhuiyan, M.S.A.;Faruk, S.
    • Asian-Australasian Journal of Animal Sciences
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    • v.15 no.4
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    • pp.477-484
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    • 2002
  • Ninety pre-puberal (6-7 months) female and 15 pre-puberal male Black Bengal goats were collected on the basis of their phenotypic characteristics from different parts of Bangladesh. Goats were reared under semi-intensive management, in permanent house. The animals were vaccinated against Peste Des Petits Ruminants (PPR), drenched with anthelmentics and deeped in 0.5% Melathion solution. They were allowed to graze 6-7 h along with supplemental concentrate and green forages. Concentrates were supplied either 200-300 g/d (low level feeding) or quantity that supply NRC (1981) recommended nutrient (high level of feeding). Different physiological, productive and reproductive characteristics of the breed were recorded. At noon (temperature=$95^{\circ}F$ and light intensity=60480 LUX) rectal temperature and respiration rate of adult male and female increased from 100.8 to $104.8^{\circ}F$ and 35 to 115 breath/min, indicated a heat stress situation. Young female attain puberty at an average age and weight of 7.2$\pm$0.18 months and 8.89$\pm$0.33 kg respectively. Mean age and weight at 1st kidding were 13.5$\pm$0.49 months and 15.3$\pm$0.44 kg respectively. It required 1.24-1.68 services per conception with an average gestation length of 146 days. At low level of feeding the postpartum estrus interval was 37$\pm$2.6 days, which reduced (p<0.05) with high feeding level to 21$\pm$6.9 days. Kidding interval also reduced (p<0.05) from 192 d at low feeding level to 177 d at high feeding level. On an average there were two kiddings/doe/year. Average litter sizes in the 1st, 2nd, 3rd and 4th parity were 1.29, 1.71, 1.87 and 2.17 respectively. Birth weights of male and female kids were 1.24 and 1.20 kg respectively, which increased (p<0.05) with better feeding. Although kid mortality was affected (p<0.05) by dam's weight at kidding, birth weight of kid, milk yield of dam, parity of kidding, season of birth, but pre-netal dam's nutrition found to be the most important factor. Kid mortality reduced from 35% at low level of feeding to 6.5% at high level of feeding of dam during gestation. Apparently, this was due to high (p<0.05) average daily milk yield (334 vs. 556 g/d) and heavier and stronger kid at birth at high feeding level.

Effect of Cationic Initiator Content on Electron-beam Curing of Difunctional Epoxy Resin (양이온 개시제 함량이 2관능성 에폭시 수지의 Electron-beam 경화에 미치는 효과)

  • Soo-Jin Park;Gun-Young Heo;Jae-Rock Lee;Dong Hack Suh
    • Journal of the Korean Chemical Society
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    • v.47 no.3
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    • pp.250-256
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    • 2003
  • In this work, the effect of cationic initiator content on the electron-beam (EB) curing process of diglycidylether of bisphenol-A (DGEBA) resin was studied using near-infrared spectroscopy (NIRS), thermogravimetric analysis (TGA), and critical stress intensity factor $(K_{IC})$. Benzylquinoxalinium hexafluoroantimonate (BQH) were used as an initiator and its content was varied from 0.5 to 3 phr. NIRS measurements showed that the hydroxyl group of EB-cured epoxy resin was increased with increasing the BQH content. Thermal stability and $K_{IC}$ value of EB-cured epoxy resin were increased with increasing the BQH content but were decreased above 2 phr content. These results could be attributed to the decrease of the conversion and degree of crosslinking. In another word, the conversion and degree of crosslinking were restricted by the incomplete network structure from high reactivity at the BQH content above 2 phr, resulting in decreasings of thermal stability and $K_{IC}$.

Fracture Toughness Evaluation and Influence Parameter Analysis by Numerical Simulation of Brazilian Test (Brazilian시험의 수치해석 시뮬레이션을 통한 파괴인성 산정 및 영향변수 분석)

  • Synn, Joong-Ho;Park, Chan;Shin, Hee-Soon;Chung, Yong-Bok;Lee, Hi-Keun
    • Proceedings of the Korean Society for Rock Mechanics Conference
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    • 2000.09a
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    • pp.67-75
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    • 2000
  • The numerical simulation of Brazilian fracture toughness test is carried out using PFC code and the influence parameters are analyzed such as shape of loading plane, size of Brazilian disc and unit panicle of model, loading angle and loading rate. The flattened Brazilian disc is adopted for applying uniform load. The range of loading angle(2$\alpha$) necessary to induce the tensile crack at disc center and to obtain the load-displacement curve giving the critical load for the stable crack propagation is shown as 20$^{\circ}$~40$^{\circ}$. In condition that the loading angle is 20$^{\circ}$, the mode-I fracture toughness is evaluated almost constant in the range of particle size less than I mm and loading rate less than 0.01 mm/s. This range of influence parameters seems appropriate condition for the tensile crack initiation at disc center and the control of stable crack propagation, which can give the reliance in evaluation of fracture toughness by Brazilian test.

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Fracture Toughness Evaluation and Influence Parameter Analysis by Numerical Simulation of Brazilian Test (Brazilian 시험의 수치해석 시뮬레이션을 통한 파괴인성 산정 및 영향변수 분석)

  • Synn, Joong-Ho;Park, Chan;Shin, Hee-Soon;Chung, Yong-Bok;Lee, Hi-Keun
    • Tunnel and Underground Space
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    • v.10 no.3
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    • pp.320-328
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    • 2000
  • The numerical simulation of Brazilian fracture toughness test is carried out using PFC code and the influence parameters are analyzed such as shape of loading plane, size of Brazilian disc and unit particle of model, loading angle and loading rate. The flattened Brazilian disc is adopted for applying uniform load. The range of loading angle(2$\alpha$) necessary to induce the tensile crack at disc center and to obtain the load-displacement curve giving the critical load for the stable crack propagation is shown as 20°∼40°. In condition that the loading angle is 20°, the mode-I fracture toughness is evaluated almost constant in the range of particle size less than 1 mm and loading rate less than 0.01㎜/s. This range of influence parameters seems appropriate condition for the tensile crack initiation at disc center and the control of stable crack propagation, which can give the reliance in evaluation of fracture toughness by Brazilian test.

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Flow Visualization of Acoustic Streaming Induced by Ultrasonic Vibration Using Particle Imaging Velocimetry (PIV를 이용한 초음파 진동에 의해 유도된 음향유동의 가시화)

  • 노병국;권기정;이장연;이동렬
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.14 no.6
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    • pp.528-535
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    • 2004
  • Ultrasonic Vibrator is designed to achieve the maximum vibration amplitude at 30 kHz by in-cluding a horn (diameter, 40 mm), mechanical vibration amplifier at the top of the ultrasonic vibrator in the system and making the complete system resonate. In addition, it is experimentally visualized by particle imaging velocimetry (PIV) that the acoustic streaming velocity in the gap is at maximum when the gap between the ultrasonic vibrator and stationary plate agrees with the multiples of half-wavelength of the ultrasonic wave. This fact results from the resonance of the sound wave and the theoretical analysis of that is also accomplished and verified by experiment. It is observed that the magnitude of the acoustic streaming dependent upon the gap between the ultrasonic vibrator and stationary plate possibly changes due to the measurement of the average velocity fields of the acoustic streaming induced by the ultrasonic vibration at resonance and non-resonance. There exists extremely small average velocity at non-resonant gaps while the relatively large average velocity exists at resonant gaps compared with non-resonant gaps. It also reveals that there should be larger axial turbulent intensity at the hub region of the vibrator and at the edge of it in the resonant gap where the air streaming velocity is maximized and the flow phenomena is conspicuous than that at the other region. Because the variation of the acoustic streaming velocity at resonant gap is more distinctive than that at non-resonant gap, shear stress increases more in the resonant gap and is also maximized at the center region of the vibrator except the local position of center (r〓0). At the non-resonant gap there should be low values of vorticity distribution, but in contrast to the non-resonant gap, high and negative values of it exist at the center region of the vibrator with respect to the radial direction and in the vicinity of the middle region with respect to the axial direction. Acoustic streaming is noise-free due to the ultrasonic vibration and maintenance-free because of the absence of moving parts. Moreover, the proposed method by acoustic streaming can be utilized to the nano and micro-electro mechanical systems as a driving mechanism in addition to the augmentation of the streaming velocity.

Adhesive Performance and Fracture Toughness Evaluation of FRP-Reinforced Laminated Plate (FRP 보강적층판의 접착성능 및 파괴인성평가)

  • Jung, Hong-Ju;Hong, Soon-Il
    • Journal of the Korean Wood Science and Technology
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    • v.43 no.6
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    • pp.868-875
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    • 2015
  • In order to replace existing slit type steel plate on the wooden structure joint, the FRP-reinforced laminated plates were produced. Four types of FRP-reinforced laminated plates were produced according to the type of reinforcement and adhesive, and before applying to the joint, the adhesion performance test according to KSF 3021 and KSF 2160 and the Compact Tension (CT) type fracture toughness test specified in ASTM D5045-99 were carried out. As a result of adhesion performance test, all GFRP textile, GFRP sheet, and GFRP Textile-Sheet type FRP-reinforced laminated plates satisfied the requirement of soaking delamination percentage with smaller than 5% based on KS standard. However, aramid type specimen satisfied the standard as the soaking delamination percentage of 4.8% but it did not satisfied the standard as the water proof soaking delamination percentage of 70%. As a result of fracture toughness test, the volume ratio of reinforcement to timber became 23% so that the strength of FRP-reinforced laminated plates increased by two to four times in comparison to the control specimen. It was confirmed that the GFRP Textile-Sheet type specimen was most resistant to the fracture most since the ratio of stress intensity factor compared with that of the control increased to 61% owing to the parallel arrangement of glass fiber to the load. As a result of tensile shear strength test using FRP-reinforced laminated plates and nonmetal dowels, it is about 12% lower than metal connectors.

A Fundamental Study on the Fracture Mechanism of Steel Plates under Completely Alternating Load (완전교번하중하(完全交番荷重下)에서의 강판(鋼板)의 파괴기구(破壞機構)에 관한 기차적(基磋的) 연구(研究))

  • Chang, Dong Il;Chung, Yeong Wha
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.2 no.3
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    • pp.1-13
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    • 1982
  • Transition process of plastic region. displacements, stresses and strains ahead the flaw tips were analysed by the finite element method on the steel plate with the circular hole and the one with the elliptical hole under completely alternating load (repetition of tensile loading, unloading and compressive loading). As the results, the followings were obtained. Transition process of elastic failure (yielding) region was estimated. From this the tendency was confirmed that the fracture would be initiated from ahead the flaw tip, and propagated along the $45^{\circ}$ direction. The fundamental data available in estimating the stress intensity factor that was considered as the core in analysing the fracture mechanism of steel plates were obtained. It was indicated that when unloading after tension the effect of compressive loading, and even the compressive reyield, was occured ahead the flaw tip. Similarly it was indicated that when unloading after compression the effect of tensile loading, and even the tensile reyield, was occured ahead the flaw tip. It was considered that these phenomena were occured because the unloading effect was constrained by the residual strains when unloading. It was considered that the fatigue phenomenon was occured ahead, the flaw tip by repetition of tensile yield, the above compressive reyield, compressive yeild and the above tensile reyield. In addition, the tendency was confirmed that the fracture ahead the flaw tip was occured as the flaw was changed from the circular hole to the elliptical hole and became to be the crack lastly.

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