• 제목/요약/키워드: 90 degree

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열선 유속계에 의한 정사각형 단면의 270도 곡관에서의 난류유동 특성에 관한 연구 (Measurement of Turbulent Flows in a Square Sectioned $270^{\circ}$ Bend)

  • 조석휴;최영돈;이건휘
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2000년도 추계학술대회논문집B
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    • pp.467-472
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    • 2000
  • Most of the past experimental or analytical studies were performed for the curved bend with a square cross-section. Velocity profiles and Reynolds stresses of the turbulence flow in the 270 degree bend with circular cross-section were measured by a hot-wire anemometer. The mean velocity of primary flowing direction effected by the downstream of bend in the entry region of the bend. The flow in the inner part of the bend slowed the distribution velocity relatively large and unsymmetric phenomenon. In the strong secondary flow occurred when the flow passed in the region of 45 degree to 90 degree. The secondary flow appeared very large value in the neighbor region of inner wall.

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다중벽 탄소 나노튜브의 멀티스케일 모델링 (Multi-scale Modeling of Multi wall Carbon Nanotube)

  • 박종연;조영삼;김성엽;이영민;전석기;임세영
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2004년도 춘계학술대회
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    • pp.542-546
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    • 2004
  • Fully non-local Quasicontinuum method using sub-divided region with Hermite interpolation function is proposed for simulation of carbon nanotube. Tersoff-Brenner potential is adopted for interaction of bonded atoms and also van der Waals force for non-bonded interaction. Bending of single wall carbon nanotube with chirality (20,0) and 15nm length is simulated up to 90 degree. Bending of double wall carbon nanotube with chirality (20,0) and (12,0) is simulated up to 65 degree. Bending of four wall carbon nanotube is simulated up to 45 degree.

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Effect of Low-Intensity Cardiac Rehabilitation on Cardiac Function and Degree of Fibrosis in a White Rat Acute Myocardial Infarction Model

  • Ji, Sung Ha;Kim, Ki Jong
    • 국제물리치료학회지
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    • 제7권2호
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    • pp.999-1005
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    • 2016
  • The purpose of this study was to investigate the effects of low-intensity cardiac rehabilitation exercise on the cardiac function and the degree of fibrosis in an older white rat model. This study used male Sprague-Dawley white rats that were 50 weeks old. After the acute myocardial infarction induction, Twenty of the rats were randomly allocated into an experimental group and a control group, and each of the groups consisted of 8 rats. In the experimental group, the exercise was conducted for six weeks, 30 minutes a day, five days a week, using a Rotarod treadmill for animals. The degree of myocardial fibrosis was significantly repressed in the experimental group($13.69{\pm}1.90%$) and in the control group($15.67{\pm}1.54%$)(p<0.05). However, fractional shortening and ejection fraction did not show a significant difference. The results of this study suggest that cardiac rehabilitation with low intensity treadmill exercise repress the myocardial fibrosis.

대학생의 광고에 반영된 성상품화에 대한 사회적 인식과 소비주의 성향과의 관계 (The Relationship Between Social Perception Reflected in Product Advertisement and Consumerism Toward Commodification of Sex Among College Students)

  • 박충선;정영숙
    • 대한가정학회지
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    • 제42권3호
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    • pp.79-90
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    • 2004
  • The purpose of this study was to investigate the relationship between social perception reflected in product advertisement and consumerism toward commodification of sex among college students. Subjects of this study were 1,100 college students in the Daegu metropolitan areas. Social perceptions were assessed by questions such as attitudes toward beauty contests, degree of commodification of sex in product advertisements and buying patterns. Consumerism was assessed by the Korean Featherstone version of consumer culture. Major findings of this study were as follows: a significant difference in the social perception of commodification of sex was found between male and female college students, showing that female students were more negative toward commodification of sex than male students. Higher scores were found for consumerism when subjects had higher perceptions for commodification of sex. Hence, the degree of commodification of sex was positively related to the degree of consumerism. In conclusion, consumerism enforced commodification of sex among college students, resulting negative effects on the sex culture in general.

Parametric study on flexible footing resting on partially saturated soil

  • Singh, Mandeep;Sawant, V.A.
    • Coupled systems mechanics
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    • 제3권2호
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    • pp.233-245
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    • 2014
  • Coupled finite element analysis is carried out to study the effect of degree of saturation on the vertical displacements and pore water pressures simultaneously by developing a FORTRAN90 code. The finite element formulation adopted in the present study is based upon Biot's consolidation theory to include partially saturated soils. Numerical methods are applied to a two-dimensional plane strain strip footing (flexible) problem and the effect of variable degree of saturation on the response of excess pore water pressure dissipation and settlement of the footing is studied. The immediate settlement in the case of partly saturated soils is larger than that of a fully saturated soil, the reason being the presence of pore air in partially saturated soils. On the other hand, the excess pore water pressure for partially saturated soil are smaller than those for fully saturated soil.

90 MPa의 수소 압력에 의한 HDPE의 수소 열화 연구 (A Study on the Hydrogen Degradation of HDPE by Hydrogen Pressure of 90 MPa)

  • 김민아;이창훈
    • 한국수소및신에너지학회논문집
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    • 제34권3호
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    • pp.307-315
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    • 2023
  • The physical and chemical changes exhibited by high density polyethylene (HDPE) after treatment with hydrogen at a pressure of 90 MPa followed by rapid release of the hydrogen were studied. X-ray diffraction, differential scanning calorimetry, thermo gravimetric analysis, and attenuated total reflectance (ATR)-fourier transform infrared (FTIR) were used for this purpose. As a result, it was found that the degree of crystallinity of HDPE decreased after hydrogen pressure treatment, while the average thickness of lamellae that constitute the crystals and the melting temperature of the crystalline region actually increased. The decomposition temperature also increased by about 3℃. In addition, it was found that the hydrogen bonding network between -OH groups in the HDPE sample was strengthened and partial chain scission occurred. These cut chains were found to be terminated by oxidative degradation such as cross-linking between chains, -C=O, -C-O, and -CHO, or by the formation of -CH3 at the chain ends, as confirmed by ATR-FTIR.

행동수정프로그램과 에어로빅운동이 비만여중생의 비만도, 식이행동, 우울 및 자아존중감에 미치는 효과 (Effects of Behavior Modification and Aerobic Exercise on the Degree of Obesity, Eating Behavior, Depression and Self Esteem in Obese Adolescent Girls)

  • 정승교
    • 기본간호학회지
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    • 제4권1호
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    • pp.103-117
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    • 1997
  • This study was designed to investigate the effects of behavior medication and aerobic exercise on the degree of obesity, eating behavior, depression and self esteem among adolescent girls who were overweight and obese. Forty seven subjects were selected from one girl's middle school located in Seoul. Seventeen girls received the behavior modification program by joining 60-90 minute group session weekly. Behavior modification, in this study, consisted of self-monitoring, changing patterns of life style and attitudes, teaching nutrition and physical activities, and asking personal help. The aerobic exercise program was given to 16 girls 3 times per week with 60 minutes each time. Forteen girls received both behavior modification and aerobic exercise. These interventions continued for 8 weeks. Changes after intervention were examined twice after 4 weeks and 8 weeks for degree of obesity and once after 8 weeks only for eating behavior, depression and self esteem. The results were as follows ; 1. Degree of obesity was significantly decreased after 4 weeks and 8 weeks in 3 groups. Degree of obesity after 4 weeks and 8 weeks were not significantly different among 3 groups. 2. The mean score of eating behavior related to obesity decresed significantly after intervention in the behavior modification group only. There was significant difference in eating behavior among 3 groups after intervention. 3. The behavior modification group showed no significant changes in depression and self esteem after intervention. In the aerobic exercise group and group who participated in both behavior modification and aerobic exercise, the level of depression decreased significantly and the level of self esteem increased significantly. There were no significant differences in the level of depression and self esteem among 3 groups after intervention. These findings indicate that behavior modification might be effective in decreasing degree of obesity and eating behavior related to obesity, aerobic exercise be effective in decreasing degree of obesity and the level of depression, and also in increasing the level of self esteem.

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치매환자 부양자의 스트레스와 소진경험 (Stress and Burn-Out Experience in Caregivers of Patients with Senile Dementia)

  • 손계순
    • 한국농촌간호학회지
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    • 제1권1호
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    • pp.40-48
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    • 2006
  • Purpose: This study was done to identify the experience of stress and burn-out in caregivers of patients with senile dementia. Method: To evaluate the degree of stress and burn-out in caregivers of patients with senile dementia, 64 caregivers and matched to 64 patients with senile dementia at a Primary Health Care Post in South Kyung Sung Province were selected. The study was carried out from March 6 to March 30, 2001. Data on the degree of dementia in the patients was measured by the MMSE-K (Mini-Mental State Examination-Korea) and caregiver characteristics such as, sex, age, marital status, educational level, job, socioeconomic status, religion, number in family, relationship with patient, duration of care, and chronic disease in caregiver were collected by direct interview with a questionnaire. Results: Of 64 patients with senile dementia, 15.6% were classified as mild dementia (MMSE score 20-24) and 84.4%, as severe dementia. There were no significant characteristics of caregivers associated with the degree of stress and burn-out experience. The degree of burn-out in these caregivers of patients with severe dementia (mean value 94.3) was significantly higher than the 81.4 for those caring for patients with mild dementia (p<0.05). However, the degree of stress was not significantly related with the degree of dementia. The proportion experiencing severe burn-out (above score 4) was 54.7% in the physical domain, 90.6% in the emotional domain, and 73.4% in psychiatric domain, respectively. Conclusion: The above findings suggest that the degree of stress and burn-out experienced by caregivers of patients with senile dementia are high. Also the degree of burn-out experienced by in caregivers of patients with severe dementia was higher than for those caring for patients with mild dementia.