• Title/Summary/Keyword: pressure ratio

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A Study on the Serum Lipid, Apolipoprotein Levels and Their Correlations in Healthy Adults of Gyeongnam Area (경남지역 중${\cdot}$장년층의 혈청지질, 아포지단백질의 농도 및 상호관련성에 관한 연구)

  • Lee, Hoe-Seon;Park, Mi-Young;Kim, Gyeong-Eup;Cheong, Hyo-Sook;Kim, Sung-Hee
    • Journal of Nutrition and Health
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    • v.40 no.6
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    • pp.526-530
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    • 2007
  • The purpose of this study was investigating serum lipid, apolipoprotein levels and their correlations in healthy adults of Gyeongnam area. The BMI (body mass index) was significantly higher (p < 0.001) in male (25.2 ${\pm}$ 2.7 $kg/m^2$) than female (23.8 ${\pm}$ 1.5 $kg/m^2$), however PBF (percent body fat) was significantly higher (p < 0.001) in female (29.6 ${\pm}$ 4.3%) than male (22.7 ${\pm}$ 5.0%). The WHR (waist to hip ratio) and blood pressure in the groups showed there was no significant differences. The levels of serum total cholesterol, LDL-cholesterol and apolipoprotein B were significantly higher (p < 0.01) in male (208.7 ${\pm}$ 27.7 mg/dl, 129.0 ${\pm}$ 26.9 mg/dl, 1.0 ${\pm}$ 0.2 g/L) than female (193.6 ${\pm}$ 29.1 mg/dl, 112.5 ${\pm}$ 29.5 mg/dl, 0.9 ${\pm}$ 0.2 g/L, but HDL-cholesterol level was significantly higher (p < 0.01) in female (54.9 ${\pm}$ 6.6 mg/dl) than male (49.9 ${\pm}$ 7.3 mg/dl). The LDL-C/HDL-C, Apo B/Apo A-I and AI (atherogenic index) were significantly higher (p < 0.001) in male (2.6 ${\pm}$ 0.6, 0.8 ${\pm}$ 0.2, 3.3 ${\pm}$ 0.7) than female (2.1 ${\pm}$ 0.5, 0.6 ${\pm}$ 0.2, 2.6 ${\pm}$ 0.5). The triglyceride level was positively correlated with apolipoprotein B concentration (p < 0.05) and negatively correlated with HDL-cholesterol concentration (p < 0.05), however no significant correlation was found with apolipoprotein A-I. According to these results, we conclude that male adults are expecting higher incidence of cardiovascular disease than female adults and we suggest the serum triglyceride should be kept normal level for the prevention of these diseases.

Characterization and Seawater Filtration Performance of Commerical Microfiltration and Ultrafiltration Membranes (상업용 정밀여과/한외여과막의 특성 분석 및 해수 여과 성능 평가)

  • Choi, Changkyoo;Kim, In S.
    • Journal of Korean Society of Environmental Engineers
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    • v.39 no.9
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    • pp.542-547
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    • 2017
  • This paper was to analyze the membrane characterization of hydrophilicity, surface morphology and membrane chemical anlysis of three commercial microfiltration/ultrafiltration membranes, and evaluate the filtration performance of a seawater to assess the availability for pretreatment of desalination process. From the results of contact angle, Mem-3, fabricated with polyacrylonitrile, was highly hydrophilic. It find out that Mem-3 has more anti-biofouling property. In Field emission scanning electron microscope (FESEM), Mem-1 (polyethylene) and Mem-2 (Polyvinylidenefluoride) showed the sponge-like shape and Mem-3 showed finger-like shape. Membrane chemical analysis by energy dispersive spectrometer (EDS) presented that Mem-2 was mostly fluoride and Mem-3 had s high ratio of N (32.47%) due to the nitrile group. The permeation flowrate per time on suction pressures using deionized water (D.I. water) tends that permeation rate of Mem-3 more increased when the pressure was increased compared to other membranes. From the results of turbidity and total suspended solids (TSS) removal, turbidity of permeate was 0.191 NTU to 0.406 NTU and TSS was 2.2 mg/L to 3.0 mg/L in all membranes, indicating that it was not suitable for the pretreatment of seawater desalination by short-term experiments.

Gliomatosis Cerebri : Clinical Features and Prognosis (대뇌 신경교종증 : 임상특징 및 예후에 관한 연구)

  • Jo, Dae-Chuol;Hwang, Jeong-Hyun;Sung, Joo-Kyung;Hwang, Sung-Kyu;Hamm, In-Suk;Park, Yeun-Mook;Byun, Seung-Yul;Kim, Seung-Lae
    • Journal of Korean Neurosurgical Society
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    • v.30 no.12
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    • pp.1399-1405
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    • 2001
  • Objectives : Gliomatosis cerebri is an uncommon primary brain tumor characterized by diffuse neoplastic proliferation of glial cells, with the preservation of the underlying cytoarchitecture. The aim of this study is to evaluate clinical features, outcome of surgical treatment and adjuvant therapy of gliomatosis cerebri. Methods : Between Jan. 1990 and Dec. 2000, 12 patients were diagnosed with gliomatosis cerebri based on characteristic radiological and histological findings. The patients' age ranged from 18 to 77(mean 44) years and the male to female ratio was 7 : 5. Nine patients underwent decompressive surgery and three, biopsy only. Postoperative radiation therapy was given in all cases except three. In addition to radiation therapy, four patients received chemotherapy. The mean duration of follow-up period was 18.8 months. Results : The most common presenting symptom were seizure and motor weakness. The mean duration of symptom was 5.9 months. There was 5 bilateral lesions and tumor involved corpus callosum in 5, basal ganglia-thalamus in 4, and brain stem in 2. There was no operative mortality but four patients died during the follow-up. The mean survival period for 11 patients was 20.5 months from the time of diagnosis. In univariate analysis, the lesion involving corpus callosum, basal ganglia-thalamus and brain stem correlated significantly with the short length of survival(p<0.05). Also, postoperative radiation as a adjuvant therapy prolonged the patient's survival(p<0.05). Conclusions : In the management of gliomatosis cerebri patients, early detection by MR imaging, active management of increased intracranial pressure, decompressive surgical removal and postoperative adjuvant therapy such as radiation is thought to be a good treatment modality.

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A Study on the Performance and Combustion Characteristics with CNG Substitution Rate in a Diesel Engine (CNG 혼소율 변화에 따른 디젤엔진의 성능 및 연소 특성에 관한 연구)

  • Jang, Hyeong-Jun;Lee, Sun-Youp;Kim, Chang-Gi;Cho, Jeong-Kwon;Lim, Jong-Han;Yoon, Jun-Kyu
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.18 no.5
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    • pp.700-707
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    • 2017
  • In the international natural gas market, natural gas has markedly low calories. The domestic calories standard of natural gas was changed and the performance and efficiency of many industrial machines using natural gas were affected because of low caloric natural gas. Therefore, in this study, a dual fuel engine fueled with natural gas and diesel was tested to examine the effects of the CNG substitution rate on the combustion characteristics, such as thermal efficiency, COVimep and heat release rate. The CNG substitution rate was defined as the ratio of CNG instead of diesel, which was calculated as the total energy. The conditions of the tested engine were fixed $1800rpm/500N{\cdot}m$. In addition, diesel fuel was injected at $16^{\circ}CA$ BTDC and the fuel pressure was fixed at 85 MPa; the lower heating value of CNG was $10,400kcal/Nm^3$. The results of the engine test showed that the amount of diesel fuel was changed according to the CNG substitution rate. Therefore, when the substitution rate was increased, the amount of diesel fuel was decreased, which affected the energy for ignition. In addition, the ignition delay duration was increased, which affected the thermal efficiency and torque. On the other hand, the COVimep was less than 5% and a stable combustion state of the engine was shown.

Relation between Hair Tissue Mineral Elements and Heart Rate Variabilities of the Metabolic Syndrome (대사증후군에 대한 모발미네랄함량과 심박변이도의 연관성 연구)

  • Kim, Hyun-Jin;Ie, Jae-Eun;Heo, Su-Jeong;Cho, Hyun-Ju;Myoung, Sung-Min
    • Journal of Korean Medicine for Obesity Research
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    • v.9 no.2
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    • pp.33-45
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    • 2009
  • Objectives This study was performed to evaluate the relation between hair tissue mineral elements(HTME) and Heart rate variability(HRV) of the metabolic syndrome(MS). Methods 89 persons(41-69 ages) who visited Oriental hospital for medical examination were divided MS group(n=22) and control group(n=67). HTME and HRV were compared, and were analyzed correlation with five contents of the MS. Results (1) In total subjects, waist circumference had a positive correlation with Pb. Blood pressure had a negative correlation with Mg. High density lipoprotein cholesterol(HDL-chol) had a negative correlation with Pb, Sb and K, while positive correlation with Ca/K. Triglyceride(TG) had a negative correlation with Mg and Na/K, while positive correlation with K and Ca/Mg. (2) In total subjects, TG and fasting blood sugar(FBS) had negative correlation with high frequency(HF), while positive correlation with low frequency/high frequency ratio(LF/HF). (3) In MS group, most of the level of toxic minerals were higher, and the level of major nutritional minerals were lower, but there were no statistical signficance. In two groups, there is no contrast between the correlations of the MS contents and HTME. (4) In MS group, HF was significantly lower and LF/HF was higher than normal group. LF/HF had a negative correlation with waist circumference in MS group, while positive correlation in normal group. (5) In total subjects, TP had a positive correlation with Mg. In two groups, there is no contrast between the correlations of the MS contents and HRV. However LF/HF had a positive correlation with Na in MS group, TP and LF had negative correlation with Ca, while RMSSD and HF had negative correlation with Cu in normal group. Conclusion These results may suggest that HTME and HRV are useful in diagnosing and preventing the metabolic syndrome.

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Effect of Hydrogen(H2) Addition on Flame Shape and Combustion Products in Mixed Coflow Diffusion Flames of Methane(CH4), Ethane(C2H6) and Propane(C3H8) (동축류 메탄(CH4), 에탄(C2H6), 프로판(C3H8) 혼합 확산화염내의 수소(H2) 첨가가 화염 형상 및 연소 생성물에 미치는 영향)

  • Park, Ho-Yong;Yoon, Sung-Hwan;Rho, Beom-Seok;Lee, Won-Ju;Choi, Jae-Hyuk
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.25 no.6
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    • pp.780-787
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    • 2019
  • As a carbon-free, green growth alternative, internal and external interest in hydrogen energy and technology is growing. Hydrogen was added to co-axial methane, methane-propane, and methane-propane-ethane diffusion flames, which are the main ingredients of LNG, to evaluate its effect on flame formation and combustion products. The variation in combustion products produced by adding hydrogen gradually to diffusion pyrolysis at room temperature and normal pressure conditions was observed experimentally by using a gas analyzer, and the shape of diffusion pyrolysis was observed step by step using a digital camera. The experimental results showed that the production volume of nitrogen oxides tended to increase and became close to linear as hydrogen was added to the diffusion pyrotechnic. This is because the relatively high temperature of heat insulation and fast combustion speed of hydrogen facilitated the production of thermal NOx. On the other hand, CO2 production tended to decrease as hydrogen was added to reduce the overall carbon ratio contained in the mixed diffusion flame of methane, methane-propane, and methane-ethane-propane. This means that the mixed fuel use of LNG-hydrogen in ships may potentially reduce emissions of CO2, a greenhouse gas.

Preparation of Asymmetric Folyethersulfone Hollow Fiber Membranes for Flue Gas Separation (온실기체 분리용 폴리이서설폰 비대칭 중공사 막의 제조)

  • Kim Jeong-Hoon;Sohn Woo-Ik;Choi Seung-Hak;Lee Soo-Bok
    • Membrane Journal
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    • v.15 no.2
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    • pp.147-156
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    • 2005
  • It is well-known that polyethersulfone (PES) has high $CO_2$ selectivity over $N_2\;(or\;CH_4)$ and excellent pressure resistance of $CO_2$ plasticization among muy commercialized engineering plastics[1-4]. Asymmetric PES hollow fiber membranes for flue gas separation were developed by dry-wet spinning technique. The dope solution consists of PES, NMP and acetone. Water and water/NMP mixtures are used in outer and inner coagulants, respectively. Gas permeation rate (i.e., permeance) and $CO_2/N_2$ selectivity were measured with pure gas, respectively and the micro-structure of hollow fiber membranes was characterized by scanning electron microscopy. The effects of polymer concentration, ratio of NMP to acetone, length of air gap, evaporation condition and silicone coating were investigated on the $CO_2/N_2$ separation properties of the hollow fibers. Optimized PES hollow fiber membranes exhibited high permeance of $25\~50$ GPU and $CO_2/N_2$ selectivity of $30\~40$ at room temperature and have the apparent skin layer thickness of about $0.1\;{\mu}m$. The developed PES hollow fiber membranes, would be a good candidate suitable for the flue gas separation process.

Food Intake and Bio-physiological indicators in Korean Rural Adults (농촌지역 일부 성인이 섭취한 식품과 관련된 생리적 지수)

  • Goo, Je-Gi;Kim, Yun-Kyung
    • Journal of agricultural medicine and community health
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    • v.34 no.3
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    • pp.375-385
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    • 2009
  • Objectives: The objective of this study was to identify the association of food intake with bio-physiological indicators: blood pressure, body mass index (BMI), waist/hip ratio (WHR), cholesterol and urine sugar among rural people. Methods: The subjects were 890 inhabitants from 14 towns of G County in Honam province. Data were collected by interview and self-reported with structured questionnaires from April 6th to 30th 2005. Data were analyzed with the frequency, percentage, t-test, $x^2$-test, ANOVA, Scheffe test and ANCOVA using SPSS 12.0 program. Results: Pre-hypertensive and hypertensive group was 27.0%, overweight and obese 27.1%, more than 0.90 in WHR 42.0%, more than 201 mg/dl of cholesterol 23.9%, and positive urine sugar was 8.7% in general. Among eleven food groups, fruit intakes were more effective in normotensive group than in the others. Vegetables, liquors, and milk products were 0.90 WHR more effective than the others. Milk products and liquors in BMI, and grains, beans and seaweed in low cholesterol group were more effective than the others. Conclusions: Bio-physiological indicators are related significantly only with fruits, milk products, meats, cereal and liquors among eleven food categories. Further study on the relationship between food intake, physical activities, smoking, drinking and lifestyle with bio-physiological indicators are suggested.

Biotope Mapping and Evaluation in Gangseo-Gu of Busan Metropolitan City (부산광역시 강서구의 비오톱 지도작성 및 평가)

  • Choi, Song-Hyun
    • Journal of the Korean Association of Geographic Information Studies
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    • v.11 no.3
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    • pp.92-106
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    • 2008
  • The purpose of this study is to identify land use types and to develop and evaluate biotope maps for Gangseo-Gu (ward) in Busan Metropolitan City, South Korea, using the Degree of Hemeroby. Hemeroby is a measurement concept or tool to assess the magnitude of human impact on ecosystems. Gangseo-Gu is the second largest Gu in Busan and is under strong development pressure. Before the field survey, biotopes were pre-classified based on digital maps, aerial photos and high-resolution satellite images. The method employed in biotope survey and mapping was adopted from the modified method used in Seoul, which carried out the first biotope mapping in Korea in 2000. In the field survey, a comprehensive biotope mapping method was used. The results showed that the total surface area of biotopes in Gangseo-gu was $172,620,207m^2$(42,655 acres) and there were 29 biotope types with 13,631 polygons. The ratio of urban or built-up area 22.6% and the remaining areas were forest and open spaces, of which 22.6% were actual forest areas and 35.6% were paddy fields and other field areas. The Hemeroby Index of Gangseo-gu was 54.7, which suggests that Gangseo-gu has not yet been developed extensively and needs a long-term conservation and coordinated development plan.

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Studies on Magnetic Properties of Die-upset Pr-Fe-B Magnets (Die-upset법에 의한 Pr-Fe-B자석의 자기적 성질에 관한 연구)

  • 이경섭;서수정;박현순;이병규;정지연
    • Journal of the Korean Magnetics Society
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    • v.3 no.3
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    • pp.201-207
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    • 1993
  • Starting ingot of $Pr_{15}Fe_{77}B_{8}$ were prepared by vacuum induction melting under argon atmosphere. The ingot were induction melted in a quartz crucible and then ejected as a molten alloy throuth a 0.6 mrn orifice onto a rotating cop¬per wheel. An anisotropic magnet was prepared from ribbon by hot deformation techniques. A fully dense precursor magnet first made by pressing ribbons at $680^{\circ}C$ under a pressure of $21.8\;kg/mm^{2}$. A substantially oriented magnets were obtained by die-upset under various conditions. As the compression ratio increases, the $B_{r}$ value increases pronouncedly though $_{i}H_{c}$ decreases. Also, XRD analyses show increased diffraction peak from (006). From these results, it can be known that the magnetic easy axis was formed along the compression axis. As the die-upset speed increases, $_{i}H_{c}$ increases though $B_{r}$ decreases. The $B_{r}$ increases up to $750^{\circ}C$ of die-upset temperature and above this temperature decreases. The value of $4{\pi}M_{s}$ of the $Pr_{15}Fe_{77}B_{8}$ alloy prepared is found to be 11.8 KG. When the alloy was compressed by 0.8 under the die-upset speed of 0.05 m/sec at $750^{\circ}C$, $B_{r}$ was 11.0 KG indicating that the alloy has excellent magnetic anistropy. However, this alloy has some limitation because of low $_{i}H_{c}$.

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