• Food Science and Biotechnology
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• 제17권2호
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• pp.324-329
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• 2008

The effect of ultra-high pressure homogenization on the emulsifying properties of whey protein was investigated in a model emulsion made with whey protein isolate and soya oil under various pH. The emulsifying properties, the average diameter of the oil droplets ($d_{vs}$), and the protein load, were measured for each emulsion produced at different homogenization pressures (50 to 200 MPa) and pH values (4.6 to 8.0). According to the results of variance analysis and response surface, the pH had more influence on oil droplet size and protein load than homogenization pressure. The model equations, which were obtained by response surface analysis, show that pH and homogenization pressure had the major effect on oil droplet size and protein load. Higher homogenization pressure decreased the average droplet size and the protein load. Homogenization at high pressure, as opposed to low pressure, causes no overprocessing, but the effect was pH-dependent. The average diameter of the oil droplets increased slightly by decreasing the pH from 8.0 to 6.5 and then increased dramatically toward the isoelectric point of whey protein (i.e., at pH 4.6). Moreover associated droplets were found at acidic pH and their size was increased at high temperature.

• 한국농공학회논문집
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• 제54권5호
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• pp.49-55
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• 2012

In order to derive the efficient utilization of low pressure compressed air fogging system, cooling efficiencies with control types were analyzed through cooling experiments in tomato greenhouses. The control types were set up with temperature control, humidity control, temperature and humidity control, and time control. It showed that the cooling effects were 0.7 to $3.3^{\circ}C$ on average and maximum of 4.3 to $7.0^{\circ}C$, the humidification effects were 3.5 to 13.5 % on average and maximum of 14.3 to 24.4 %. Both the cooling and humidification effect were the highest in the time control method. The cooling efficiency of the air fogging system was not high with 8.3 to 27.3 % on average. However, the cooling efficiency of 24.6 to 27.3 % which appears from the time control is similar to the cooling efficiency of high pressure fogging system experimented in Japan. The air fogging system is operated by low pressure, but its efficiency is similar to high pressure. We think because it uses compressed air. From this point of view, we suggest that the air fogging system can get the cooling efficiency of similar levels to that of high pressure fogging system and it will have an advantage from clogging problem of nozzle etc.

• 한국분말재료학회지
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• 제10권4호
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• pp.262-269
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• 2003

Nano-sized Ni-ferrite powder was fabricated by spray pyrolysis process using the waste solution resulting from shadow mask processing. The average particle size of the powder was below 100 nm. The effects of the concentration of raw material solution, the nozzle tip size and air pressure on the properties of powder were studied. As the concentration increased, the average particle size of the powder gradually increased and its specific surface area decreased, but size distribution was much wider and the fraction of the Ni-ferrite phase greatly increased as the concentration increasing. As the nozzle tip size increased from 1 mm to 2 mm, the average particle size of the powder decreased. In case of 3 mm nozzle tip size, the average particle size of the powder increased slightly. On the other hand, in case of 5 mm nozzle tip size, average particle size of the powder decreased. Size distribution of the powder was unhomogeneous, and the fraction of the Ni-ferrite phase decreased as the nozzle tip size increasing. As air pressure increased up to 1 kg/$cm^2$, the average particle size of the powder decreased slightly, on the other hand, the fraction of the Ni-ferrite phase was almost constant. In case of 3kg/$cm^2$ air pressure, average particle size of the powder and the fraction of the Ni-ferrite phase remarkably decreased, but size distribution was narrow.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집E
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• pp.702-707
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• 2001

The characteristics of flow in dividing regions are precise, therefore their classification is very important not only in industry but also in hydrodynamics. By now, many studies of flow in dividing regions have been performed, but flow characteristics that use visualization in dividing regions have not been studied. The present study of the PIV and the CFD exhibit average velocity distributions, kinetic energy distributions and total pressure distributions etc of the total flow field due to the development of the accurate visualization optical laser and of optical equipment. Also, PIV is accurate with the flows characteristics of the dividing region as continuous analysis is done using input equipment. The study analyzes average velocity vector field, average kinetic energy, x-axis stress distributions, average and total pressure distributions of dividing regions with flow for visualization of the PIV and the CFD measurement in a dividing rectangular duct.

• 한국정밀공학회지
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• 제24권7호
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• pp.126-132
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• 2007

Pressure-induced decubitus is a serious disease among the elderly people. Interface pressure occluding vascular perfusion is known to be a cause of decubitus. Therefore, it is essential to quantify the relationship between vascular perfusion and interface pressure among the elderly people to understand more about decubitus. Nine healthy elderly people (57.8$\pm$ 5.6 years, 63.3$\pm$ 7.0kg, 1.68$\pm$ 0.05m) were participated. Three healthy young people (31.7$\pm$ 3.2 years, 74.7$\pm$ 8.4kg, 1.75$\pm$ 0.04m) were also examined to be compared with the elderly group. Capillary vascular perfusion on the ischial tuberosity was recorded in the sitting posture as pressures were applied from 15mmHg to 135mmHg. The average interface pressure to occlude vascular perfusion (the average occlusion pressure) under the ischial tuberosity was 115.7mmHg in the elderly group. This value was not significantly different from the average occlusion pressure of the young group. Obesity effect on the occlusion pressure was investigated among the elderly group. The result was not significantly different between the obesity and the normal group in this study. This is a preliminary study to unveil the complicated cause of pressure-induced decubitus associated with occlusion of vascular perfusion. More subjects are required for the future study.

• 농촌의학ㆍ지역보건
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• 제18권1호
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• pp.43-54
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• 1993

In order to find the factors associated with the death of hypertensives, 12 year follow-up study for 267 hypertensives whose average blood pressure were 140/90 mmHg or above during their first health screening in 1979-1980 at YongJin Township, Wanju Country, North Cholla Province by the Community Health Team of Chonju Presbyterian Medical Center. The study results are as follows : 1. Initial general characteristics of hypertensives were studied. The age distribution of studied hypertensives showed 27.3% in 40-49 years, 25.8% in 50-59 years, 29.6% in 60-69 years and 17.2% In 70 + years old group. Marital status showed that 82.8% of hypertensives had their wife or husband. 74. 5% were employed on agriculture. 56.5% of hypertensives were illiterate. 2. Among the hypertensives, 91.6% of male and 22.8% of female reported that they were smokers. 82.6% of hypertensives had body mass index lower than 25 Kg/$m^2$. 46.8% of average systolic blood pressure were 160mmHg or above and 54.3% of average diastolic blood pressure were 95mmHg or above. 3. Twenty percent of hypertensives reported that they were treating hypertension at the beginning of follow up, while 68.5% reported that they were not treated. 28.1% reported that they were treating hypertension within 6 months before last follow-up. but 69.3% reported that they were not treated for hypertension within Ii months before last follow up. So 50.6% were classified as never treated group and 41.2% as treated group. 4. Average blood pressure for initial 3 years were calculated. The change of average systolic blood pressure was observed as $161.3{\pm}19.4mmHg$ at the first year, $145.6{\pm}28.0mmHg$ at the second year and $141.4{\pm}37.2mmHg$ at the third year. Average diastolic blood pressure were changed from $96.2{\pm}14.4mmHg$ at the first year to $90.6{\pm}18.6mmHg$ at the second year and $86.4{\pm}22.9mmHg$ at the third year. 5. By the follow-up of hypertensives, 54 hypertensives (46.2%) among 117 male hypertensives and 50 hypertensives (33.3%) among 150 female hypertensives died for 12 years. 42.6% of male death and 52.0% of female death were caused by cerebrovascular diseases. 6. Through univariate statistical test about the association between general characteristics or cardiovascular risk factors of hypertensives and mortality for 12 years, age variable among male and among female age, marital status, occupation. educational level. systolic blood pressure and treatment status were shown as significant variable to influence upon the mortality. 7. By multiple logistic regression analysis, among male age and systolic blood pressure were selected as significant variable to be associated with the total mortality for 12 years. Among female age, systolic blood pressure and treatment status were selected as statistically significant variable to be associated with the total mortality for 12 years.

• 한국운동역학회지
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• 제19권4호
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• pp.771-778
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• 2009

본 연구는 구두 굽 높이 변화에 따른 보행 시 족저압력을 비교, 분석함으로써 구체적인 데이터를 정량화하여 높은 굽을 착용함으로 인한 전족부의 압력 증가가 발에 미치는 영향을 알아보고자 한다. 본 연구에 사용된 구두는 선행연구를 바탕으로 여대생이 선호하는 구두 굽 높이 3cm, 7cm를 선택하였으며 여대생 10명을 대상으로 발을 전족부와 후족부로 나누어 수직힘, 최대압력, 평균압력을 측정하였다. 그 결과 전족부에서의 평균압력은 7cm 높이 구두가 높게 나타났으며, 후족부에서는 7cm 높이 구두가 낮게 나타났다. 통계처리 결과 전족부위에서는 3cm 굽 높이와 7cm 굽 높이의 최대압력 비교에서 유의한 차이가 나타났으며(p<.05), 후족부위에서는 수직힘, 최대압력, 평균압력 모두 유의한 차이가 나타났다(p<.05). 이상과 같이 구두를 착용함으로서 전족부의 최대압력이 높아지는 것은 물론이고 후족부위의 수직힘, 최대압력, 평균압력도 높아지는 것을 알 수 있었다. 이러한 현상은 전족부위에 높은 압력분포로 구속압이 증가하여 발가락의 변형을 유발할 수 있으며 후족부위에 압력증가는 장시간 착용 시 뒤꿈치의 통증을 유발할 수 있다. 따라서 굽이 있는 구두를 착용할 때 굽 높이가 7cm일 때 보다는 3cm일 때, 굽 높이가 낮을수록 전족부의 변형 예방과 후족부의 통증을 줄일 수 있을 것으로 기대된다.

• 대한지역사회영양학회지
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• 제18권3호
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• pp.269-282
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• 2013

This study was carried out to investigate bone mineral density (BMD), blood pressure, calcium, sodium intake and related biochemical variables, and to analyze the relationship between BMD, and blood pressure, physical characteristics, nutrient intakes of Korean adult women. The study subjects were 30~80years old, 513 women living in Seoul and Kyunggi area who participated in 2011 KNHANES. The study subjects were divided into three BMD groups; normal, n = 259 (50.4%), osteopenia, n = 169 (32.9%), and osteoporosis, n = 85 (16.7%). Average height and weight and fat free mass decreased with a decrease in BMD. Average BMD of normal, osteopenia, osteoporosis were 0.87, 0.79, $0.70g/cm^2$, and T-score were 0.42, -0.66, -1.62, respectively. Higher systolic blood pressure, alkaline phosphatase, and triglyceride were significantly associated with a decrease in the BMD. The rates of hypertension were significantly increased from normal to osteoporosis. i.e. 18.5% in normal, 34.3% in osteopenia and 63.5% in osteoporosis. Average nutrientintakes such as protein, fat, calcium, phosphorus, iron, sodium, potassium, vitamin A, vitamin B, vitamin B2, and vitamin C were significantly lower in subjects with lower BMD.n. Average calcium intake of normal, osteopernia and osteoporosis were 528.50, 416.96, 389.56 mg, respectively. There were significant negative correlations between calcium, phosphorus and age, systolic blood pressure, triglyceride. Also, there were negative correlation systolic blood pressure (incomplete sentence). In this study, we found low BMD according to low calcium intake increase the risk of osteoporosis and hypertension rather than sodium intake, also calcium intake decreased with increase age. Therefore, in order to prevent osteoporosis and hypertension, subjects need to be educated regarding the importance of calcium nutrients in diet.

• 대한기계학회논문집B
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• 제32권6호
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• pp.479-486
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• 2008

The objective of this study is to investigate experimentally the characteristics of pressure drop in SMX type motionless mixers. The motionless mixers used are SMX-O, SMX-H, SMXL-O and SMXL-H ones. The SMX-H and SMXL-H mixer elements have been designed to reduce the pressure drop as compared with the SMX-O and SMXL-O ones. The Reynolds number based on the bulk average properties of the water is in a range of 5000 to 13000. The pressure drops across the motionless mixers are measured and the friction factors are calculated using the pressure drop data. On the average, the friction factors of the SMX-H and SMXL-H mixers are about 8% and 15% lower than those of the SMX-O and SMXL-O ones. In addition, the proposed correlations from the experimental data for the friction factor are presented and compared with those obtained from the literature.

• International Journal of Air-Conditioning and Refrigeration
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• 제10권3호
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• pp.129-137
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• 2002

In this study, evaporation pressure drop experiments were conducted with two types of plate and shell heat exchangers (P&SHE) using R-22. An experimental refrigerant loop has been established to measure the evaporation pressure drop of R-22 in a vertical P&SHE. The flow channels were formed by stacking three plates having a corrugated channel of a chevron angle of 45 dog. The R-22 flows down in one channel exchanging heat with the hot water flowing up in the other channel. The effect of the refrigerant mass flux, average heat flux, system pressure and vapor quality were explored in detail. During the experiment, the quality change between the inlet and outlet of the refrigerant channel ranges from 0.03 to 0.15. The present data showed that two types of P&SHE have similar trends. The pressure drop in-creases with the vapor quality for both types of P&SHE. At a higher mass flux, the Pressure drop is higher for the entire range of the vapor quality. Also, the increase in the average heat flux increases the pressure drop. Finally, at a higher system pressure, the pressure drop is found to be slightly lower compared to the lower system pressure.