• 제목/요약/키워드: Antifatigue

검색결과 50건 처리시간 0.026초

SAE 5155강의 컴퓨터부식피로 균열에 미치는 압축잔류응력의 영향 (The Effect of Compressive Residual Stress on Computer Corrosion Fatigue Crack of SAE 5155)

  • 박성모;문광석;박경동
    • 한국기계가공학회지
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    • 제6권2호
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    • pp.34-40
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    • 2007
  • Antifatigue failure technology take an important part of current industries. Currently, the shot peening is used for removing the defect from the surface of steel and improving the fatigue strength on surface. Therefore, this paper the effect of compressive residual stress and corrosion of spring steel(SAE 5155)by shot-peening on fatigue crack growth characteristics in stress ratio(R=0.05)was investigated with considering fracture mechanics. By using the methods mentioned above, We arrived at the following conclusions. The fatigue crack growth rate(da/dN) of the shot-peening material was lower than that of the un-peening material. And in stage I, ${\Delta}Kth$, the threshold stress intensity factor, of the shot-peen processed material is high in critical parts unlike the un-peening material. Also m, fatigue crack growth exponent and number of cycle of the shot-peening material was higher than that of the un-peening material. That is concluded from effect of da/dN. Finally fracture of shot-peening material and un-peening material was identified and discussed in this study.

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한약재와 탕액(쌍화탕)중 내분비계 장애물질로서의 개별 중금속의 함량 연구( I ) (Monitoring Research for Heavy Metals as Endocrine Disruptors in Herbal Medicines and Ssangwha-Tang)

  • 김진숙;황성원;김종문;마진열
    • 한국한의학연구원논문집
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    • 제6권1호
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    • pp.117-122
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    • 2000
  • The purpose of this study is to compare the contents of heavy metals of boiled ssangwhatang with those of herbal ingredients which are composed of ssangwhatang. Ssangwhatang is used for antifatigue, tonic and so on. With industrial development, our environment has been very polluted. Herbal medicines also are seriously contaminated by heavy metals and pesticides. The herbal medicines of ssangwhatang were bought at 10 defferent markets. The contents of 14 heavy metals(Ag, As, Ba, Cd, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Sb, Sn, Zn) were analysed using ICP. It was found out that 7 heavy metals(Pb, As, Ba, Cd, Hg, Sb, Sn) were not detected at all in boiled ssangwhatangs. But they were detectable in all ssangwhatangingredients before boiling. For example, the content of Pb in one pack of ssangwhatang before boiling was $0.039^{\circ}{\pm}0.005mg$ and Pb in boiled one was not detected. Herbal medicine itself is seriously contaminated by heavy metals. These results suggest that boiled ssangwhatang which we take is safe from the contamination of heavy metals.

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한방방제의 제제학적 연구(1) - 추출방법에 따른 녹용사군자탕의 비교 - (Studies on Pharmaceutical Quality of Oriental Medicinal Preparations (I) - Studies on Decoction of Nokyong-Sagunja-Tang -)

  • 최혁재;김은진;김성수;김남재
    • 생약학회지
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    • 제37권3호
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    • pp.143-150
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    • 2006
  • Decoction of oriental medicinal preparation is prepared in various manners, and changes of chemical constituents might be occurred depending on the processing techniques. The present study was undertaken to investigate the phγsio-chemical and pharmacological equivalence between two extraction methods of Nokyong-sagunja-Tang. Samples were Prepared as follows ; Sample-I was prepared by simultaneously extracting Sagunja-Tang and velvet antler in one vessel. Sample-lI was prepared by adding velvet antler exact to the water extract of Sagunja-Tang. Both sanples showed similar results of physiochemical parameters such as pH, yield, TLC and HPLC chromatogram, and contents of ginsenoside $Rb_1$ and glycyrrhizin. Also, there were little different between two samples in pharmacological effects such as DPPH free radical scavenging effect, and inhibitory effects on xanthine oxidase, hyaluronidase, trypsin, TBA-Rs formation and hemolysis in vitro. And both samples showed no significant difference in antifatigue activities in mice. These results suggest that there might be little difference between two extraction process when velvet antler added to Sagunia-Tang.

현가장치용 SUP-9강의 피로파괴에 미치는 압축잔류응력의 영향 (The Effect of Compressive Residual Stress on Fatigue Fracture of the Spring steel)

  • 박경동;진영범
    • 한국기계가공학회지
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    • 제3권3호
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    • pp.79-85
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    • 2004
  • The lightness of components required in automobile and machinery industry is requiring high strength of components. In particular, fatigue failure phenomena, which happen in metal, bring on danger in human life and property. Therefore, antifatigue failure technology takes an important part of current industries. Currently, the shot peening is used for removing the defects from the surface of steel and improving the fatigue strength on surface. Therefore, in this paper the effect of compressive residual stress of spring steel(JISG SUP-9)by shot peening on fatigue crack growth characteristics in stress ratio(R=0 1, R=0 3, R=0 6)was investigated considering fracture mechanics. By using the methods mentioned above, I arrived at the following conclusions: (1) The fatigue crack growth rate(da/dN) of the shot peening material was lower than the unpeening material And in stage I, ${\Delta}K_{th}$, the threshold stress intensity factor, of the shot peening material is high in critical parts unlike the unpeening material. (2) Fatigue life shows more Improvement in the shot peening material than in the unpeening material. And compressive residual stress of surface on the shot peening processed operate the resistance of fatigue crack propagation.

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구조용강의 용접가공에 따른 피로균열진전에 미치는 응력비의 영향 (Effect of Stress Ratio on Fatigue Crack Propagation Processing of Structural Steel)

  • 박경동;신영진;이주영
    • 한국기계가공학회지
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    • 제5권4호
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    • pp.65-71
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    • 2006
  • The lightness of components required on marine and shipbuilding industry is requiring high strength of components. In particular, fatigue failure phenomena, which happen in metal, bring on danger in human life and property. Therefore, antifatigue failure technology takes an important part on current industries. In this study, it is investigated about endurance and fatigue crack propagation rate of according to welding methods such as SMAW, FCAW and SAW commonly used for welding structures in present. Endurance limits carried out highly in the order of SMAW, FCAW, SAW and fatigue crack propagation rate out lowly in the order of SMAW, FCAW, SAW. By these results, it is needed to use SMAW welding method for welding structures with small welding capacity and FCAW, SAW methods for large welding structures after consideration about economic gains and operation efficiency of welding. Fatigue crack propagation rate is more affected by strength of welding materials than endurance limit of welding materials according to welding methods.

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쌍화탕의 중추억제 및 항염증작용에 관한 연구 (Studies on CNS-Depression and Antiinflammatory Action of Ssangwhatang)

  • 정지창;박대규
    • Journal of Pharmaceutical Investigation
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    • 제16권1호
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    • pp.24-30
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    • 1986
  • Ssangwhatang which has been known to have antipyretic, analgesic and antifatigue effects are composed of Paeoniae Radix, Angelicae gigantis Radix, Astragali Radix, Rehmaniae Radix, Cnidii Rhizoma, Cassiae Cortex, Glycyrrhizae Radix and Puerariae Radix. Effects of some formulations of Ssangwhatang were studied with respect to the analgesic, antipyretic, hypothermic, anticonvulsive and antiinflammatory actions in experimental animals. The results obtained were as follows: 1) Prescription A, B, C and D of Ssangwhatang were showed significant analgesic effect by the acetic acid stimulating method in mice. 2) All Ssangwhatang-prescriptions used in this studies had hypothermic effect in normal mice. 3) Significant antipyretic effect in febrile rabbits were recognized in prescription A and C of Ssangwhatang, while not in prescription B and D of Ssangwhatang. 4) Prescription A, B, C and D of Ssangwhatang showed marked antiinflammatory effect against the edema induced by carrageenin in rats. 5) Prescriptions of Ssangwhatang did not show significant anticonvulsive effect against the convulsion induced by picrotoxin and strychnine in mice. From the above results, analgesic, hypothermic, antipyretic and antiinflammatory effects were recognized in Ssangwhatang. Ssangwhatang A- and C- prescriptions added with Pueraiae Radix showed better effects than prescription B and C of Ssangwhatang.

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Ginseng-derived compounds as potential anticancer agents targeting cancer stem cells

  • Ji-Sun Lee;Ho-Young Lee
    • Journal of Ginseng Research
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    • 제48권3호
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    • pp.266-275
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    • 2024
  • Cancer stem cells (CSCs) are a rare subpopulation of cancer cells that exhibit stem cell-like characteristics, including self-renewal and differentiation in a multi-stage lineage state via symmetric or asymmetric division, causing tumor initiation, heterogeneity, progression, and recurrence and posing a major challenge to current anticancer therapy. Despite the importance of CSCs in carcinogenesis and cancer progression, currently available anticancer therapeutics have limitations for eradicating CSCs. Moreover, the efficacy and therapeutic windows of currently available anti-CSC agents are limited, suggesting the necessity to optimize and develop a novel anticancer agent targeting CSCs. Ginseng has been traditionally used for enhancing immunity and relieving fatigue. As ginseng's long history of use has demonstrated its safety, it has gained attention for its potential pharmacological properties, including anticancer effects. Several studies have identified the bioactive principles of ginseng, such as ginseng saponin (ginsenosides) and non-saponin compounds (e.g., polysaccharides, polyacetylenes, and phenolic compounds), and their pharmacological activities, including antioxidant, anticancer, antidiabetic, antifatigue, and neuroprotective effects. Notably, recent reports have shown the potential of ginseng-derived compounds as anti-CSC agents. This review investigates the biology of CSCs and efforts to utilize ginseng-derived components for cancer treatment targeting CSCs, highlighting their role in overcoming current therapeutic limitations.

헛개나무열매 열수추출물 투여에 의한 흰쥐의 지구력 향상 효과 (Improvement in Exercise Endurance by Hovenia dulcis Fruit Hot Water Extract in Mice)

  • 권태형;한준희;이선엽;유근형
    • 한국식품영양학회지
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    • 제33권4호
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    • pp.363-371
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    • 2020
  • This study was designed to evaluate the improvement in exercise endurance by Hovenia dulcis fruit hot water extract (HDWE) for the potential application as a functional food material. The effect was based on the evaluation of the forced-swimming capacity and changes in biochemical parameters in mice. Six-week-old mice were classified into four groups based on a randomized block design: the negative control group, the HDWE 50 mg/kg body weight group, the HDWE 200 mg/kg body weight group, and the 1-octacosanol 50 mg/kg body weight group (n=8 mice per group). The swimming exercise time in the HDWE-50 group was increased at 545±43 sec compared to the control group at 263±28 sec. The HDWE-200 fatigue indicators, lactate acid and ammonia content, decreased to 4.99±0.33 mg/mL and 0.63±0.05 mg/mL, respectively. In addition, the content of glycogen in the liver and muscle tended to increase in the group administered HDWE but was not significant. Likewise, the LDH and glucose contents were increased compared to the control group. The muscle damage indicators ALT (52.7±2.6 U/L) and AST (42.5±5.2 U/L) tended to decrease compared to the control group (76.4±10.2 U/L).

눈꽃 동충하초의 약물활성 (Pharmacological Activities of Paecilomyces japonica, A New Type Cordyceps sp.)

  • 심진영;이연실;임순성;현진이;김성연;이은방;신국현
    • 생약학회지
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    • 제31권2호
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    • pp.163-167
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    • 2000
  • Cordyceps is reputed for its broad biological activities and as a tonic for replenishing vital function in Chinese traditional medicines. As an attempt to obtain fundamental data for the development of a new type Cordyceps, the effects of the fruiting bodies of cultivated fungus of Paecilomyces japonica grown on silkworm larvae on hyperglycemia induced by streptozotocin(STZ) and by epinephrine in rats and in mice as well as on immunological functions in mice were investigated. The 70% methanol extract of the fungus, when administered orally at 100 and 300 mg/kg in STZ-induced hyperglycemic rats, caused a significant decrease in blood glucose level 3hr after sample treatments. The methanol extract, when administered p.o. at the same dose levels in epinephrine-induced hyperglycemic mice, also caused a significant decrease in serum glucose levels as well as a significant reversal of the liver glycogen contents suggesting its hypoglycemic activity might be due to glycogen breakdown in the liver. Treatment of normoglycaemic mice with the methanol extract of the fungus exhibited a significant glucose tolerance up to 3hr after oral glucose load(2.0 g/kg). The methanol extract also showed immuno-stimulating activity as measured by carbon clearance in mice and a significant antifatigue effect as measured by weight loaded forced swimming performance in mice.

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쇼트피닝 가공된 해양구조용강의 피로파괴에 미치는 응력비의 영향 (Effect of Stress Ratio on Fatigue Fracture of a Shot Peening Marine Structural Steel)

  • 박경동;진영범;박형동
    • 한국해양공학회지
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    • 제18권5호
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    • pp.43-49
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    • 2004
  • The lightness of components required in the automobile and machine industry necessitates the use of high strength components. In particular, the fatigue failure phenomena, which occurs when using metal, increases the danger to human life and property. Therefore, antifatigue failure technology is an integral part of current industries. Currently, the shot peening is used for removing the defect from the surface of steel, while improving the fatigue strength on surface. Therefore, in this paper, the effect of compressive residual stress of spring steel(JISG SUP-9) by shot-peening on fatigue crack growth characteristics in a stress ratio(R=0.1, R=0.3, R=0.6) was investigated, giving consideration to fracture mechanics. By using the methods mentioned above, following conclusions are drawn: (1) The fatigue crack growth rate(da/dN) of the shot-peening material was lower than that of the un-peening material and in stage I, ΔKth, the threshold stress intensity factor of the shot-peen processed material is high in critical parts, unlike the un-peening material. Also m, fatigue crack growth exponent and number of cycle of the shot-peening material, was higher than that of the un-peening material, as concluded from effect of da/dN. (2) Fatigue life shows more improvement in the shot-peening material than in the un-peening material, and the compressive residual stress of surface on the shot-peen processed operate resistance of fatigue crack propagation.