• Title/Summary/Keyword: reduction of pressure

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The Effect of Aging Treatment on the High Temperature Fatigue Fracture Behavior of Friction Welded Domestic Heat Resisting Steels (SUH3-SUS 303) (마찰용접된 국산내열 강 (SUH3-SUS303 )의 시효열처리가 고온피로강도 및 파괴거동에 미치는 영향에 관한 연구)

  • Lee, Kyu-Yong;Oh, Sae-Kyoo
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.17 no.2
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    • pp.93-103
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    • 1981
  • It is well-known that nowadays heat resisting and anti-corrosive materials have been widely used as the components materials of gas turbines, nuclear power plants and engines etc. In the fields of machine production industry. And materials for engine components, like as the exhaust valve of internal combustion engine, have been required to operate under the high temperature range of $700^{\circ}C$-$800^{\circ}C$ and high pressured gas with repeated mechanical load for the high performance of engines. For these components, friction welding for bonding of dissimilar steels can be applied for in order to obtain process shortening, production cost reduction and excellent bonding quality. And age hardening recently has been noticed to the heat resisting materials for further strengthening of high temperature strength, especially high temperature fatigue strength. However, it is difficult to find out any report concerning the effects of age hardening for strengthening high temperature fatigue strength to the Friction welded heat resisting and anti-corrosive materials. In this study the experiment was carried out as the high temperature rotary bending fatigue testing under the condition of $700^{\circ}C$ high temperature to the friction welded domestic heat resisting steels, SUH3-SUS303, which were 10hr., 100hr. aging heat treated at $700^{\circ}C$ after solution treatment 1hr. at $1, 060^{\circ}C$ for the purpose of observing the effects of the high temperature fatigue strength and fatigue fracture behaviors as well as with various mechanical properties of welded joints. The results obtained are summarized as follows: 1) Through mechanical tests and micro-structural examinations, the determined optimum welding conditions, rotating speed 2420 rpm, heating pressure 8kg/mm super(2), upsetting pressure 22kg/mm super(2), the amount of total upset 7mm (heating time 3 sec and upsetting time 2 sec) were satisfied. 2) The solution treated material SUH 3, SUS 303, have the highest inclination gradient on S-N curve due to the high temperature fatigue testing for long time at $700^{\circ}C$. 3) The optimum aging time of friction welded SUH3-SUS 303, has been recognized near the 10hr. at $700^{\circ}C$ after the solution treatment of 1hr. at $1, 060^{\circ}C$. 4) The high temperature fatigue limits of aging treated materials were compared with those of raw material according to the extender of aging time, on 10hr. aging, fatigue limits were increased by SUH 3 75.4%, SUS 303 28.5%, friction welded joints SUH 3-SUS 303 44.2% and 100hr. aging the rates were 64.9%, 30.4% and 36.6% respectively. 5) The fatigue fractures occurred at the side of the base matal SUS303 of the friction welded joints SUH 3-SUS 303 and it is difficult to find out fractures at the friction welding interfaces. 6) The cracking mode of SUS 303, SUH 3-303 is intergranular in any case, but SUH 3 is fractured by transgranular cracking.

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The Effect of Aroma Therapy on Lower Extremity Edema of Terminal Cancer Patients: A Controlled Trial (아로마 요법이 말기 암 환자의 하지부종에 미치는 영향 - 대조군 연구)

  • Kim, Sung-Ah;Kim, Sung-Ju;Chung, Ju-Hye;Lee, Soo-Young;Han, Myung-Suk;Oh, Seon-Hee;Kim, Se-Hong
    • Journal of Hospice and Palliative Care
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    • v.12 no.3
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    • pp.139-146
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    • 2009
  • This study was designed to examine the effect of aroma massage therapy on lower extremity edema of terminal cancer patients. Methods: A total of thirty-six terminal cancer patients with lower extremity edema were divided into two groups: the aroma massage group received massage with blending oil which was applied from toes to 10 cm above the knee of the subject for 15 to 20 minutes in each turn, while the control group received sham aroma massage (applied with carrier oil only). The circumferences of the fore-foot, ankle and calf were measured before massage and 30 minutes, 2 hours, and 12 hours after massage. The blood pressure, pulse and body temperature were also measured to find the change of subject's physiologic conditions. Results: There were no significant differences in blood pressure, heart rate, body temperature and lower extremity circumferences between two groups. However, edema at each site was slightly improved in the treatment group after the aroma massage therapy, compared to baseline data (P<0.05). In addition, the reduction of lower extremity circumference was maximal at 2 hours in foot, 30 min in right ankle and 12 hours in right calf after aroma massage therapy (P<0.05). Conclusion: Our results suggest that aroma massage therapy is not effective on the lower extremity edema of terminal cancer patients.

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Comparison of Anticancer Activities of Berberis koreana Extracts Obtained by Different Extraction Processes (추출 공정별 매자나무 추출물의 항암활성 비교)

  • Ha, Ji-Hye;Kwon, Min-Cheol;Seo, Yong-Chang;Choi, Woon-Yong;Chung, Eul-Kwon;Chung, Ae-Ran;Kim, Jin-Chul;Ahn, Ju-Hee;Lee, Hyeon-Yong
    • Korean Journal of Food Science and Technology
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    • v.42 no.2
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    • pp.233-239
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    • 2010
  • This study was conducted to examine the anticancer activities of Berberis koreana extracts according to different extraction processes. The highest extraction yield obtained was 8.26% following extraction by ultrasonification at 60 kHz and $60^{\circ}C$ followed by high pressure at 500MPa. Generally, the extracts from the ultrasonification process showed relatively low cytotoxicities against the human normal cell line, HEK293 showing as low as 15%. This extract inhibited the growth of the digestive related organs cell lines, human stomach adenocarcimoma cell and human epithelial adenocarcinoma cell by up to 80% when administered at 1.0 mg/mL, and showed 2.5-3.5 of selectivity. It was also found that this extract induced the production of nitric oxide levels as high $37.87\;{\mu}M$ from macrophages. For the in vivo experiment using ICR mice, the total serum IgG levels of mice treated with B. koreana extracts from ultrasonification extraction were increased by up to 57 ng/mL. The survival time of this group was longer than that of the other group after the injection of Sarcoma-180 and the increment of their body weights was also greatly suppressed. In addition, the extract showed the highest tumor inhibition activities, leading to a reduction of 78.47%. These results indicate that the highest activities of B. koreana associated with this extraction process can be significantly improved.

Effect of 1 Year E-mail Nutrition Education after Face-to-Face Encounter at Worksite: Changes in Cardiovascular Risk Factors (면대면 영양교육 후 1년간의 E-mail 영양교육이 직장인 남성의 심혈관 질환 위험인자 감소에 미치는 효과)

  • Oh, Hye-Sun;Jang, Mi;Hwang, Myung-Ok;Cho, Sang-Woon;Paek, Yun-Mi;Choi, Tae-In;Park, Yoo-Kyoung
    • Journal of Nutrition and Health
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    • v.42 no.6
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    • pp.559-566
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    • 2009
  • Effective nutrition educations for prevention of chronic diseases for the general population are of great importance these days. The purpose of this study was to evaluate the feasibility of nutrition education for cardiovascular risk factor reduction by e-mail education in male workers. The participants were divided into three groups by age; 28-39 age group, 40-49 age group, and 50-59 age group who got regular checkups for anthropometry and biochemistry. The 1 year program consisted of 15 topics containing information about metabolic syndrome (MS) and healthy eating behavior (intake of salt, fat and alcohol). Seven hundred thirty nine participants volunteered for the study [28-39 age group, n = 240; body mass index (BMI) = 24.9 $\pm$ 2.7 kg/m$^2$: 40' group, n = 276; BMI = 24.8 $\pm$ 2.6 kg/m$^2$: 50' group, n = 223; BMI = 24.9 $\pm$ 2.7 kg/m$^2$]. Percentage body fat (p < 0.05) and percentage of abdominal fat (p < 0.05), total cholesterol (p < 0.05), systolic blood pressure (p < 0.05), and diastolic blood pressure (p < 0.05) were significantly decreased in all participants after the 1 year program. The total number of participants who had MS was decreased from 216 to 199 and especially the incidence of MS was decreased 27% in the group of subjects who were under the age 39. The e-mail worksite nutrition education program shows a substantial contribution to the development of effective CVD and chronic disease control and lifestyle nutrition educations that are applicable to and attractive for the large population at risk.

Sex Steroid Hormone and Ophthalmic Disease (성호르몬과 안질환)

  • Kim, Jin-Ju;Yu, Hyeong-Gon;Ku, Seung-Yup
    • Clinical and Experimental Reproductive Medicine
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    • v.37 no.2
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    • pp.89-98
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    • 2010
  • Sex and its tropic hormones influence the lacrimal system, corneal anatomy and disease, aqueous humor dynamics and glaucoma, crystalline lens and cataract, and retinal disease. Dry eye occurs especially frequently during pregnancy, oral contraceptive use, and after menopause, during which androgen levels decrease. Androgen control development, differentiation, and lipid production of sebaceous glands throughout the body, and androgen deficiency also leads to meibomian gland dysfunction and evaporative dry eye. On the other hand, estrogen causes a reduction in size, activity, and lipid production of sebaceous glands. Sex and its tropic hormones also influence the corneal anatomy and disease, and corneal thickening occurred on the second day of the menstrual cycle and around the time of ovulation and appeared to be related to estrogen levels. Fuchs' dystrophy is more commonly seen in postmenopausal women than men and may be linked to hormonal changes that occur with aging. In addition, overexpression of estrogen and progesterone receptors in the conjunctiva of vernal keratoconjunctivitis patients. Serum progesterone levels also may be associated with intraocular pressure especially in pregnant women, and for the women. For women with cataracts, hormone levels were typical of menopause, and there was a significant negative correlation between estradiol and follicular stimulating hormone levels. In addition, serum testosterone levels are associated with the development of diabetic retinopathy. Although the role of sex hormones on the eye is largely unknown, and the results should be interpreted with caution until replicated, the functions of sex hormones in ocular disease remains to be investigated, because they may be involved in structure and function of the ocular components, which are important in the pathogenesis of ocular disease.

Comparative Study on Mechanical Properties and Dimensional Stability of Staypak and Wood-Polymer Composites from Populus alba × P. Glandulosa wood (현사시나무로 제조(製造)된 열압축목재(熱壓縮木材)와 목재(木材)-고분자(高分子) 복합체(複合體) 재질(材質)의 비교연구(比較硏究))

  • Pak, Sang-Bum;Ahn, Won-Yung
    • Journal of the Korean Wood Science and Technology
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    • v.13 no.2
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    • pp.14-34
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    • 1985
  • One of the techniques for altering the properties of wood that has received considerable attention in the last twenty years is the formation of a wood-polymer composite (WPC) by irradiation and heat-catalyst polymerization of a monomer incorporated into the wood matrix. Wood-polymer composites are the new products having the superior mechanical and physical properties and the combinated characteristics of wood and plastic. The purpose of this experiment was to obtain the basic data for the improvement of wooden materials by manufacturing WPC and Staypak. The species examined was Hyunsasi-Namoo (Populus alba ${\times}$ P. glandulosa) which had not been utilized yet. Methylmethacrylate (MMA) as monomer, benzoyl peroxide (BPO) as initiator and methyl alcohol as bulking agent were used. The monomer containing BPO was impregnated into wood pieces by the dipping and the vacuum process for 2 hours. After impregnation, the treated samples were polymerized on the hot press with pressure and heat-catalyst methods. The results obtained were summarized as follows 1. The monomer loading into wood by the dipping process was 12.13 percent and 29.99 percent by the vacuum. The polymer loading into wood by the dipping process was 6.79 percent and 15.44 percent by the vacuum. 2. Comparing with Staypak, antishrink efficiency (ASE) of WPC was 12.5 to 13.6 percent on the radial direction and 14.70 to 18.63 percent on the tangential. Antiswelling efficiency (AE) was 14.40 to 17.22 percent on the radial direction and 17.18 to 42.1 8 to 42.14 percent on the tangential. Reduction in water absorptivity (RWA) was 8.19 to 15.5 percent. As a whole, the vacuum process was better than the dipping. 3. The specific gravity of control, Staypak and WPC were 0.44, 0.66 and 0.61 to 0.62, respectively. 4. In the bending strength test, the strength in case that the load direction is on the radial surface was greater than that which the load direction is on the tangential. 5. Increasing rate of stress at proportional limit in compression perpendicular to grain was 72.26 percent in case of WPC by the dipping process, 78.93 percent by the vacuum and 99.09 percent in case of Staypak.

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A Study on the Changes in Ventilator Care Rate and Outcome of Very Low Birth Weight Infants During Last Four Years (최근 4년간 극소 저출생 체중아의 인공 호흡기 치료율과 경과 변화에 관한 연구)

  • Jung, Byun Kyung;Kim, Yeoung Ju;Lee, Sang Geel
    • Clinical and Experimental Pediatrics
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    • v.46 no.11
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    • pp.1073-1079
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    • 2003
  • Purpose : Recently there has been a decrease in ventilator care rate and duration of very low birth weight infants(VLBWI) in Fatima Hospital. The aims of this study were to survey the frequency and duration of ventilation in VLBWI and to develop a non-invasive neonatal intensive care unit (NICU) policy. Methods : We performed a retrospective study of 284 newborn of infants less than 1,500 gm admitted to NICU and discharged from January 1998 to December 2001. Patients were intubated or applied continuous positive airway pressure(CPAP) via nasal prong immediately after presenting signs of respiratory distress. We analyzed epidemiologic data to study the changes in ventilator care rate, duration and outcome of ventilator care groups. Results : Of 284 newborn infants, 146 required invasive management, such as endotracheal intubation and assisted ventilation. The characteristics, the severity of clinical symptoms and laboratory findings in ventilator care groups at birth showed no significant differences. The annual proportion of infants requiring assisted ventilation decreased according to increasing gestational age. The median duration of ventilation decreased markedly from 6.0 days in 1998 to 2.7 days in 2001. Final complications and outcomes in ventilator care groups showed no significant differences. Conclusion : Our study shows a significant reduction in the invasiveness of the treatment of VLBW infants, which was not associated with an increased mortality or morbidity. A non-invasive strategy for the VLBW infant with minimal to moderate respiratory distress after birth in NICU is better than immediate invasive management. Non-invasive nasal CPAP is a simpler and safer method than invasive assisted ventilation.

Serum Lipid Profile and Nutritional Status in 6~7 Year Old Obese Children (6~7세 비만아에서 혈청 지질과 영양 상태에 관한 연구)

  • Rim, Jee-Yeon;Moon, Ji-Young;Lee, Chul-Gab;Moon, Kyung-Rye
    • Pediatric Gastroenterology, Hepatology & Nutrition
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    • v.11 no.2
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    • pp.160-168
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    • 2008
  • Purpose: This study was designed to characterize the nutritional status and assess obesity to determine the relationship between obesity and serum lipid profiles in 6~7 year old children. Methods: In 2007, we surveyed 483 children (233 boys and 250 girls) aged 6~7 years. The total cholesterol, triglyceride levels and HDL-cholesterol were measured in the fasting state. Dietary information was obtained by a questionnaire. Results: The prevalence of obesity was 9.9%. There was no significant difference between genders. The mean caloric intake was 1,781 kcal in boys and 1,640 kcal in girls. The prevalence of excessive calories was 33% in boys and 30% in girls. The prevalence of a total cholesterol ${\geq}$200 mg/dL was 8.4%, TG ${\geq}$130 mg/dL was 5.0%, LDL-cholesterol ${\geq}$130 mg/dL was 3.1%, and HDL-cholesterol <35 mg/dL was 4.4%. The prevalence of hypertension was 2.1%. There was no significant difference between genders. The systolic blood pressure, triglyceride levels and LDL-cholesterol were significantly related to an increased obesity index (p<0.05). The mean caloric intake and nutritive component were not related to the obesity index. The obesity group was compared to the control group: for triglycerides ${\geq}$130 mg/dL the odds ratio was 4.08; for LDL-cholesterol ${\geq}$130 mg the odds ratio was 2.85; for a TC/HDL-cholesterol ${\geq}$4.0 the odds ratio was 1.16. The BMI and triglyceride levels in the group with hypertension were higher than control group (p<0.05). There were significant positive correlations between the BMI and blood pressure as well as the LDL-cholesterol and triglycerides (p<0.05). The BMI was not correlated with the mean caloric intake or nutrition. Conclusion: The prevalence of hypertension and hyperlipidemia in 6~7 year old children was significantly related to an increased obesity index. The management of obesity in 6~7 year old children should include a reduction in the risk for hyperlipidemia and hypertension.

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Tracheal gas insufflation (TGI) in patients with increased deadspace fraction: the effect and its determining factors (사강호흡율이 증가된 환자에서 기관내 가스주입법(Tracheal Gas Imsufflation)이 가스교환에 미치는 효과와 그 결정인자)

  • Lim, Chae Man;Jung, Bok Hyun;Koh, Youn Suck;Lee, Sang Do;Kim, Woo Sung;Park, Pyung Hwan;Kim, Dong Soon;Kim, Won Dong
    • Tuberculosis and Respiratory Diseases
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    • v.44 no.1
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    • pp.136-145
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    • 1997
  • Background : Tracheal Gas Insufflation (TGI) is one of the newer ancillary measures in mechanical ventilation employed to enhance carbon dioxide elimination. TGI exerts its effect through reduction of deadspace ventilation, but the factors determining its effect are not well studied yet. Method : The subjects were seven mechanically-ventilated patients ($58.8{\pm}10.6$ yrs) who showed increased physiologic deadspace greater than 60%. After 30 nun of stabilization with 100% oxygen on pressure control ventilation, continuous flow TGI was administered via the insufflation lumen of Hi-Lo Jet Tracheal Tube (Mallincrodt, USA) for 15 min at 3 L/min and 5 L/min each. Results : $PaCO_2$ was decreased ($51.4{\pm}17.6$ at baseline, $49.1{\pm}18.9$ at TGJ 3 L/min $45.0{\pm}14.9$ mm Hg at TGI 5 L/min, p=0.050), and pH was increased ($7.37{\pm}0.12$, $7.38{\pm}0.13$, $7.39{\pm}0.12$, respectively, p=0.037) while mixed expired $CO_2$ ($P_ECO_2$) was not changed significantly from baseline (p=0.336) by TGI. Physiologic deadspace(Vdphy) was decreased ($73.0{\pm}7.9$% at baseline, $69.8{\pm}10.0$% at TGI 3 L/min, and $67.1{\pm}10.1$% at TGI 5 L/min, p=0.015). $AaDO_2$(p=0.147), Vt(p=0.2140), Pmean(p=0.7788) and mean arterial pressure(p=0.4169) were not changed. The correlation between % maximal decrease of Vdphy were r=0.790 with the ratio of baseline Vdana/Vdphy(p=0.035) and r=-0.754 with baseline Vdalv(p=0.050). Conclusion: TGI was effective in reducing $PaCO_2$ and deadspace, and the deadspace-reducing effect was best correlated with baseline anatomic/physiologic deadspace ratio.

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Effect of Weight Control Program on Obesity Degree and Blood Lipid Levels among Middle-aged Obese Women (중년여성대상 체중조절 프로그램이 체구성 및 혈액지질 개선에 미치는 영향)

  • Nam Jung-He
    • The Korean Journal of Food And Nutrition
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    • v.19 no.1
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    • pp.70-78
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    • 2006
  • This study was performed to investigate the effect of 12-week weight control program including nutrition education, diet therapy and regular exercise on body weight, obesity degree, BMI and blood lipid levels among middle aged obese women. The 31 middle aged obese women participated in the weight control program for 12-week. The body weight, body composition, blood lipid levels and food habit were measured before and after the weight control program. Changes in body weight after 12 week weight control program showed the slight reduction from $67.4{\pm}10.8kg\;to\;65.1{\pm}9.2kg$. Obesity degree and BMI were decreased from $128.4{\pm}19.1%,\;27.8{\pm}3.9\;to\;123.4{\pm}15.7%,\;26.8{\pm}3.0$, respectively. Waist-hip ratio was also decreased from $0.98{\pm}10.16\;to\;0.94{\pm}0.04$. LBM was also slightly reduced from $39.9{\pm}5.6kg\;to\;37.0{\pm}8.5kg$ with the reduction of body fat. The levels of systolic blood pressure, total cholesterol and triglyceride were slightly decreased, HDL-chol level was significantly increased from $43.1{\pm}14.1mg/dL\;to\;50.4{\pm}16.5mg/dL$. Waist-hip ratio was also slightly decreased after 12 weeks. Food habit score was significantly increased after nutriton education and personal counseling about their eating behaviors and nutritional status.