• 제목/요약/키워드: Effective normal stress

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The Effect of Planar Anisotropy in Plane-Stress Bore Expanding (평면 응력 Bore Expanding 에 있어서의 평면이방성 의 영향)

  • 주진원;이중홍;양동열
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.8 no.5
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    • pp.435-441
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    • 1984
  • The matrix method, as an effective FEM formulation for the analysis of rigid-plastic deformation, was applied to the bore expanding of anisotropic sheet metal. The effect of planar anisotropy on sheet metal deformation was studied for bore expanding process under the uniform radial stretching condition, and the results were compared with isotropic and normal anisotropic solutions. Experiments were carried out using a flat punch for cold-rolled sheet metal. The experimental results were compared with computations from the matrix method with the boundary conditions corresponding to actual experiment. Both in theory and experiment, it is found that the maximum thinning which results in necking occurs in the direction of the minimum R-value. The results also suggest that the matrix method is efficient for analyzing planar anisotropic sheet metal. The comparison between theory and experiment suggests that Hill's theory of planar anisotropy is somewhat exaggerated. However, the theoretical predictions are in qualitative agreement with the experimental results.

Effects of Purslane Extract on Obesity and Diabetes in High-Fat Diet-Induced Obese Mice

  • Kang, Kwang-Soon
    • Journal of the Korea Society of Computer and Information
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    • v.21 no.7
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    • pp.61-66
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    • 2016
  • The frequency of obesity has risen dramatically in recent years but only few safe and effective drugs are currently available. In addition, obesity can induce type 2 diabetes (T2DM), hyperlipidemia and fatty liver disease. Recently, protective effect of purslane extract (PE) on obesity has been reported, but little is known about the role and mechanism of PE in obesity. This study aimed to evaluate the effect of PE on obesity and diabetes in obese mice. In addition, the effect of PE was compared with anti-obesity and diabetes drugs. High-fat diet (HFD)-induced obese mice were treated for 8 weeks with drugs as follows: PE, orlistat, metformin, voglibose or pioglitazone. While PE mixed with normal diet did not have any effects on BW in non-obese mice, PE mixed with HFD significantly reduced BW gain, insulin resistance, and glucose intolerance, without affecting food intake and appetite in obese mice. The effect was comparable to the effects of anti-obesity and diabetes drugs. Furthermore, PE significantly increased the activity of hepatocellular anti-oxidant enzymes, leading to protection of liver from oxidative stress in obese mice. These results suggest that PE treatment may be a useful tool for preventing obesity and complication of obesity.

PSE (pale, soft, exudative) Pork : The Causes and Solutions - Review -

  • Lee, Y.B.;Choi, Y.I.
    • Asian-Australasian Journal of Animal Sciences
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    • v.12 no.2
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    • pp.244-252
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    • 1999
  • Intensive selection for muscle development and against fat deposition in pigs during the last 50 years has contributed to the increased incidence of porcine stress syndrome (PSS) and pale soft exudative pork (PSE). Genetics, nutrition and management, preslaughter animal handling, stunning, dehairing and carcass chilling influence the incidence and magnitude of the PSE condition. The normal incidence of PSE has been reported to range from 10 to 30%, but in some isolated instances is up to 60%. The elimination of halothane-positive pigs in breeding programs has reduced PSS and PSE. Further improvements in meat quality by terminal sire evaluation and selection can be achieved within halothane-negative populations because around 20% of the variation in meat color and water binding capacity seems to be genetically related. Pre-slaughter handling on the farm, during transit to the packing plant and at the packing plant can greatly influence the meat quality, contributing 10 to 25% of the variation. An effective stunning method, skinning instead of scalding/dehairing and rapid post-slaughter chilling further reduce the incidence of PSE pork. In addition to proper care and handling a carcass-merit based marketing system, that reflected the value differential between desirable and undesirable meat quality in the pricing system for pigs, would provide a great incentive to change pork production systems in order to improve meat quality, thus improving the image and usefulness of pork as food.

Onion Supplementation Inhibits Lipid Peroxidation and Leukocyte DNA Damage due to Oxidative Stress in High Fat-cholesterol Fed Male Rats

  • Park, Jae-Hee;Seo, Bo-Young;Lee, Kyung-Hea;Park, Eun-Ju
    • Food Science and Biotechnology
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    • v.18 no.1
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    • pp.179-184
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    • 2009
  • The aim of this study was to investigate effects of onion, red onion, or quercetin on plasma antioxidant vitamin, lipid peroxidation, and leukocyte DNA damage in rats fed a high fat-cholesterol diet. Forty SD male rats were assigned to normal control, high fat-cholesterol diet (HF), or HF+5% onion powder, HF+5% red onion powder, or HF+0.0l% quercetin. The HF diet resulted in significantly higher plasma lipid peroxidation which decreased with onion, red onion, or quercetin supplementation. Leukocyte DNA damage induced by HF diet decreased significantly in rats fed onion and red onion, while quercetin supplementation had no effect on preventing leukocyte DNA damage. $H_2O_2$ induced leukocyte DNA damage exhibited a highly significant negative correlation with plasma retinol and tocopherols. These results suggest that onion or red onion powder exerts a protective effect with regard to DNA damage in rats fed HF diet. However, 0.01% quercetin in pure form might not be effective at preventing DNA damage.

Verification of Effectiveness of Wearing Compression Pants in Wearable Robot Based on Bio-signals (생체신호에 기반한 웨어러블 로봇 내 부분 압박 바지 착용 시 효과 검증)

  • Park, Soyoung;Lee, Yejin
    • Journal of the Korean Society of Clothing and Textiles
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    • v.45 no.2
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    • pp.305-316
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    • 2021
  • In this study, the effect of wearing functional compression pants is verified using a lower-limb wearable robot through a bio-signal analysis and subjective fit evaluation. First, the compression area to be applied to the functional compression pants is derived using the quad method for nine men in their 20s. Subsequently, functional compression pants are prepared, and changes in Electroencephalogram (EEG) and Electrocardiogram (ECG) signals when wearing the functional compression and normal regular pants inside a wearable robot are measured. The EEG and ECG signals are measured with eyes closed and open. Results indicate that the Relative alpha (RA) and Relative gamma wave (RG) of the EEG signal differ significantly, resulting in increased stability and reduced anxiety and stress when wearing the functional compression pants. Furthermore, the ECG analysis results indicate statistically significant differences in the Low frequency (LF)/High frequency (HF) index, which reflect the overall balance of the autonomic nervous system and can be interpreted as feeling comfortable and balanced when wearing the functional compression pants. Moreover, subjective sense is discovered to be effective in assessing wear fit, ease of movement, skin friction, and wear comfort when wearing the functional compression pants.

Aerobic Exercise Ameliorated High Fat Diet-induced Endoplasmic Reticulum Stress More Than Polyphenol Supplementation in Skeletal Muscle of Obese Mice (비만에 의해 유도된 근형질세망 스트레스에서 유산소 운동에 의한 감소효과)

  • Park, Jong-Gu;Kim, Yong-An;Park, Hee-Geun;Lee, Wang-Lok
    • Journal of Life Science
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    • v.28 no.10
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    • pp.1186-1192
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    • 2018
  • The purpose of this study was to compare the effects of either aerobic exercise or polyphenols supplementation on mRNA expression of endoplasmic reticulum stress in skeletal muscle of high fat diet-induced obese mice. In the study, mice were divided into five groups: (1) NC (normal diet for 16 weeks as a control, n=10), (2) HC (high fat diet for 16 weeks as a control, n=10), (3) H-Re (high fat diet with resveratrol 25 mg/kg supplementation for 16 weeks, n=10), (4) H-Ch (high fat diet with chrysin 50 mg/kg supplementation for 16 weeks, n=10), and (5) HE (high fat diet with aerobic exercise for 16 weeks, n=10). Aerobic exercise was performed on a treadmill for 40~60 min/day at 10~14 m/min, 0% grade, four days/week for 16 weeks. Endoplasmic reticulum stress related genes were measured by real-time polymerase chain reaction. ATF6, PERK, $IRE1{\alpha}$, and BIP/GRP78 mRNA were significantly decreased in HE compared with those in HC (p<0.05). Also, ATF6, $IRE1{\alpha}$, and BIP/GRP78 mRNA were significantly decreased in H-Re compared with those in HC (p<0.05). ATF6 mRNA was significantly decreased in H-Ch compared with that in HC (p<0.05). These findings suggest that aerobic exercise, resveratrol, and chrysin supplementation changed ER stress markers. However, aerobic exercise was most effective on ameliorating the high fat diet induced ER stress markers. Thus, it seems that aerobic exercise might have a more positive effect on skeletal muscle endoplasmic reticulum stress compared with polyphenol supplementation in high fat diet-induced obese mice.

A Case of Negative Symptoms of Schizophrenia (전증(癲證) 환자의 치험 1례)

  • Heo, Eun-Jung;Kim, Ji-Hyon;Lyu, Heui-Yeong
    • Journal of Oriental Neuropsychiatry
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    • v.21 no.2
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    • pp.215-227
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    • 2010
  • Objectives : Jeon-Jeung(癲證) is one of negative symptoms from schizophrenia in Western medecine, which causes flattening of affect, emotional bluntness, and avolition. Compared with positive symptoms of schizophrenia, there is no established treatments that have been proved to be effective for negative symptoms, and since negative symptoms are chronically processed, they finally lead to devastate the mental health. Since Jeon-Jeung(癲證) is usually in set in adolescent period and tends to become chronic through life time, it is important to start getting treatments in early stage by being distinguished from other diseases, such as anxiety disorder. A patient in this case was affective blunting, general weakness, and delusion when sixteen years old. However, he refused to get Western medicine treatment and wanted oriental medicine treatment. Methods : The patient in this case had been suffered from severe stress from his family since he was young and had kept having irregular and unhealthy eating habits. Therefore, he diagnosed stagnant qi transforming into fire(氣鬱化火), heart blood deficiency(心血虛), and spleen-stomach deficiency cold(脾胃虛寒) and since then he had received several treatments including herbal treatment, acupumcture treatment, supportive therapy, and family therapy. These treatments were successful and reduced the level of symptoms. After discharged from the hospital, he had continued receiving outpatient treatment with his family for 8 months and his progress had been still observed after the discharge. Results : The symptoms of patient had been almost reduced and eliminated after he received 29days of admission treatment and the patient got better and better and now lives a normal life 8 months outpatient treatment. Conclusions : This result suggests that our oriental medical treatments and family treatments was effective on schizophrenia.

Calibration of Borehole Roughness Measurement System for Large Diameter Drilled Shafts in Water (수중에서 적용가능한 대구경 현장타설말뚝의 굴착공 벽면거칠기 측정장치의 보정에 관한 연구)

  • Park, Bong-Geun;Nam, Moon-S.;Choi, Yong-Kyu
    • Journal of the Korean Geotechnical Society
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    • v.25 no.8
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    • pp.5-21
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    • 2009
  • Based on recent studies on rock socketed drilled shafts, it was found that the side resistance of rock socketed drilled shafts is affected by unconfined compressive strength of rock, socket roughness, rock types and joints, and initial normal stress. Especially, the socket roughness is affected by rock types and joints, drilling methods, and diameters. Since existing roughness measurement systems could be conducted only in the air, a new roughness measurement system, which can measure rock socket roughness in the air and also in the water, is needed. However, the development of new roughness measurement system fur civil engineers has been faced with difficulties of electrical applications. In this study, the laboratory verification system far BKS-LRPS (Backyoung-KyungSung Laser Roughness Profiling System) was developed, which can be applied both in the water and air. Based on the laboratory verification, it was found that the improved BKS-LRPS could define effective measurement distances for the conditions reflecting the apparatus and in-situ situations.

Constitutive Characteristics of Decomposed Korean Granites(1) (구성식을 이용한 다짐화강토의 공학적 특성(1))

  • Kim, Yong-Jin;Lee, In-Mo;Lee, In-Geun
    • Geotechnical Engineering
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    • v.10 no.3
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    • pp.55-78
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    • 1994
  • Decomposed granite soil is a Granitic Gneiss, and it is a c Korean peninsula. It is known a changed significantly when it is aim of this study is to evaluat utility of the constitutive laws. Firstly, triaxial tests were pe sites prepared by the laborato scrutinized the characteristics results were analysed and the p evaluated. Finally, the predicted Even though the origins of slight difference in the angle of pression line( A) : both soils show In the effective mean normal uniqueness of the Normal Compr The relationships between the the decomposed granite soil tier OCR is larger than 2, the stress stress(MDS) or. even thous moved below the theoretical Ros was found to coincide with the (NC) soils, the pore pressure parameter, A,, increased up to 1.3. This phenomenon might be mainly due to the effect of the particle crushing during shearing, When the OCR value approaches 7, the negative pore pressure is developed in undrained tests and the dilatancy is observed in drained tests. The predicted and the observed behavior of drained tests showed relatively good fitting with the Cam-Clay model.

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Development of the Somatization Rating Scale (신체화 평가 척도의 개발)

  • Koh, Kyung-Bong;Park, Joong-Kyu
    • Korean Journal of Psychosomatic Medicine
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    • v.10 no.2
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    • pp.78-91
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    • 2002
  • Objective : The purpose of this study was to develop the somatization rating scale (SRS), and then to use the scale in clinical pracitice. Methods: First, a preliminary survey was conducted for 109 healthy adults to obtain 40 response items. Second, a preliminary questionnaire was completed by 215 healthy subjects. Third, a comparison was made regarding somatization responses among 242 patients (71 with anxiety disorder. 73 with depressive disorder, 47 with somatoform disorder, and 51 with psychosomatic disorder) and 215 healthy subjects. Results : Factor analysis yielded 5 subscales : cardiorespiratory and nervous responses, somatic sensitivity, gastrointestinal responses, general somatic responses, genitourinary, eye and muscular responses. Reliability was computed by administering the SRS to 62 healthy subjects during a 2-week interval. Test-retest reliability for 5 subscales and the total score was significantly high, ranging between .86-.94. Internal consistency was computed, and Cronbach's ${\alpha}$ for 5 subscales ranged between .72-.92, and .95 for the total score. Convergent validity was computed by correlating the 5 subscales and the total score with the total score of the global assessment of recent stress (GARS) scale, the perceived stress questionnaire (PSQ), and the symptom checklist-90-revised (SCL-90-R). The correlations were all at significant levels. Discriminant validity was computed by comparing the total score and the 5 subscale scores of the patient and control groups. Significant differences were found for 5 subscales and the total score. Only the depressive disorder group was siginificantly higher than control group in all the subscale scores and total scores of SRS among 4 patient groups. In somatic sensitivity, only depressive disorder patients were significantly higher than the normal controls, whereas in general somatic subscale, depressive disorder and somatoform disorder groups were significantly higher than the normal controls. In total scores of the SRS, female subjects were significantly higher than males. Conclusion : These results indicate that the SRS is highly reliable and valid, and that it can be utilized as an effective measure for research in stress- and somatization-related fields. The depressive disorder and somatoform disorder groups showed more widespread somatization than the anxiety and psychosomatic disorder groups.

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