• 제목/요약/키워드: Overall pressure ratio

검색결과 198건 처리시간 0.027초

The Association Between Healthy Beverage Index (HBI) With Metabolic Risk Factors Among Apparently Metabolically Healthy Overweight and Obese Individuals

  • Leila Jahanbazi;Mahdieh Abbasalizad Farhangi;Ayda Zahiri Tousi;Negin Nikrad
    • Clinical Nutrition Research
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    • 제12권3호
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    • pp.218-228
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    • 2023
  • Recent studies have evaluated the association between specific beverage intake and metabolic risks in adults. However, more evidence is needed to examine the association between the Healthy Beverage Index (HBI) and metabolic factors. Therefore, this study investigated the relationship between HBI and metabolic factors in adults. In this cross-sectional study, 338 overweight and obese individuals living in Tabriz, Iran were selected. Data on beverage consumption, demographics, physical activity, and anthropometric characteristics were evaluated using validated standard protocols. The predefined HBI was calculated based on previous studies. The mean value of HBI index among all of the participants was 59.76 ± 6.51. Those at the higher HBI scores had significantly lower waist circumference, waist-to-hip ratio, fat mass, and weight (p < 0.05). HBI and triglyceride scores also had a significant relationship. It has been shown that at higher HBI scores compared to lower scores, high-density lipoprotein cholesterol levels increase while homeostatic model assessment for insulin resistance, low-density lipoprotein cholesterol, total cholesterol, and blood pressure decrease. HBI scores higher among Iranian adults were associated with a better chance of losing weight and weight loss and a better lipid profile, and lower blood pressure. Therefore, HBI can be a useful and helpful tool for assessing the overall quality of beverages adults consume. However, further studies are warranted to confirm the possible health effects of healthy beverage index.

Effects of the design variables and their constraints on the stage performance of an axial flow turbine (축류 터빈의 설계 변수 및 설계 변수의 제한조건이 성능에 미치는 영향)

  • 박호동;정명균
    • Transactions of the Korean Society of Mechanical Engineers
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    • 제15권6호
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    • pp.2109-2124
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    • 1991
  • A simulation program is developed to analyse the performance of an axial flow turbine stage based on the meanline prediction method. The gradient projection method is utilized to minimize the aerodynamic losses under the specified constraints on such as flow coefficient, total pressure ratio, stage power and blade loading coefficient. After obtaining the optimum point for minimizing the stage loss, a sensitivity analysis is carried out ground the optimum point to find the effects of the design variables and the design constraints on the stage performance. The result of the senitivity analysis under a constant blade loading coefficient shows that the total loss is more sensitive to the mean diameter, the absolute flow angle at nozzle outlet, the relative flow angle at rotor outlet and the axial mean velocity compared to the chords and the pitches. Moreover, the design constraints on the degree of reaction at root and the blade length-to-diameter ratio are found to be most influencial on the maximization of the overall aerodynamic efficiency.

Combustion Performance Tests of Fuel-Rich Gas Generator for Liquid Rocket Engine Using an Impinging Injector (충돌형 분사기 형태의 액체로켓엔진용 가스발생기 연소성능시험)

  • 한영민;김승한;문일윤;김홍집;김종규;설우석;이수용;권순탁;이창진
    • Journal of the Korean Society of Propulsion Engineers
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    • 제8권2호
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    • pp.10-17
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    • 2004
  • The results of the combustion performance tests of gas generator which supplies hot gas into the turbine of turbo-pump for liquid rocket engine and uses LOx and kerosene as propellant are described. The gas generator consists of a injector head with F-O-F impinging injector, a water cooled combustion chamber, a gas torch igniter, a turbulence ring and an instrument ring. The effect of turbulence ring and combustion chamber length on performance of gas generator are investigated. The ignition and combustion at design point are stable and the pressure and gas temperature at gas generator exit meets the target. The turbulence ring installed at middle of chamber effectively mixes hot gas with cold gas and the effect of residence time of hot gas in gas generator on combustion efficiency is small. Test results show that the main parameter controlling the gas temperature at gas generator exit is overall O/F ratio.

Clinical Evaluation of 70 Cases of Ventricular Septal Defect in Korea (심실 중격결손증에 대한 임상적 고찰 [70예])

  • 조규석
    • Journal of Chest Surgery
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    • 제11권1호
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    • pp.46-57
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    • 1978
  • Ventricular septal defect was the most common congenital Heart disease admitted to the Severance Hospital from December, 1963 to June 30. 1977. A total of 1,811 cardiac patients received cardiac catheterization in the CardiacCenter of Yonsei University Medical College. Out of the 1,811 cardiac patients, 791 cases had congenital heart disease and of these 172 cases had ventricular septal defect. This amounted to 21.7% of all those with congenital heart disease. Seventy cases of ventricular septal defect operated on in the chest surgery department are presented. Of these 70 cases of ventricular septal defect, 54 cases were male and 16 cases were female. Their ages ranged from 4/12 months to 32 years. The ratio of systolic pressure of the main pulmonary to systemic artery [Pp/Ps] for 29 of the 59 isolated ventricular septal defects was below 45 percent. Pp/Ps ratio for 19 of the 59 isolated ventricular septal defects was 75 percent. The patients were mostly below fifteen years of age. Out of 64 cases, there were 36 cases of type II defects, 20 cases of type I, 4 cases of type III , 2 cases of type IV, one case of both type II and one case of left ventricular right atrial communication. The anomalies associated with ventricular septal defect were 13 in all; 4 cases of aortic insufficiency, 3 cases of ruptured aneurysm of the sortie sinus of valsalva, 2 cases of ruptured aneurysm of the sortie sinus of valsalva with aortic insufficiency, 2 cases of patent ductus arteriosus, one case of ruptured aneurysm of the aortic sinus of valsalva with atrial septal defect [secundum type] and one case of atrial septal defect [secundum type]. Overall mortality was 8.6 percent. The mortality in pulmonary artery banding was 37.5 percent. The causes of mortality were in one case congestive heart failure, in one case asphyxia and in one case respiratory insufficiency. Tile mortality in ventricular septal defect associated with pulmonary hypertension was 7.1 percent. The cause of mortality was in one case low cardiac output syndrome. There was no mortality in the ventricular septal defects without pulmonary hypertension and mortality in the ventricular septal defect. In ventricular septal defect associated with combined anomalies, the causes mortality were in one case respiratory insufficiency and in one case congestive heart failure.

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A Study on the Heat Release Analysis to Compensate the Error due to Assumption of Single Zone in Diesel Engine (디젤 기관 단일 영역 모델 열발생율 계산의 오차 보상에 관한 연구)

  • Ryu Seung-Hyup;Kim Ki-Doo;Yoon Wook-Hyeon;Ha Ji-Soo
    • Journal of Advanced Marine Engineering and Technology
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    • 제30권5호
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    • pp.572-579
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    • 2006
  • Accurate heat release analysis based on the cylinder pressure trace is important for evaluating combustion process of diesel engines. However, traditional single-zone heat release models (SZM) have significant limitations due mainly to their simplified assumptions of uniform charge and homogeneity while neglecting local temperature distribution inside cylinder during combustion process. In this study, a heat release analysis based on single-zone model has been evaluated by comparison with computational simulation result using Fire-code, which is based on multidimensional model (MDM). The limitations of the single-zone assumption have been estimated, To overcome these limitations, an improved model that includes the effects of spatial non-uniformity has been applied. From this improved single-zone heat release model (Improved-SZM), two effective values of specific heat ratios, denoted by ${\gamma}_V$ and ${\gamma}_H$ in this study, have been introduced. These values are formulated as the function of charge temperature changing rate and overall equivalence ratio. Also, it is applied that each equation of ${\gamma}_V$ and ${\gamma}_H$ has respectively different slopes according to several meaningful periods during combustion progress. The heat release analysis results based on improved single-zone model gives a good agreement with FIRE-code results over the whole range of operating conditions of target engine, Hyundai HiMSEN H21/32.

Design and Exergy Analysis for a Combined Cycle using LNG Cold/Hot Energy (액화천연가스 냉온열을 이용한 복합사이클의 설계 및 엑서지 해석)

  • Lee Geun Sik
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • 제17권4호
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    • pp.285-296
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    • 2005
  • In order to reduce the compression power and to use the overall energy contained in LNG effectively, a combined cycle is devised and simulated. The combined cycle is composed of two cycles; one is an open cycle of liquid/solid carbon dioxide production cycle utilizing LNG cold energy in $CO_2$ condenser and the other is a closed cycle gas turbine which supplies power to the $CO_2$ cycle, utilizes LNG cold energy for lowering the compressor inlet temperature, and uses the heating value of LNG at the burner. The power consumed for the $CO_2$ cycle is investigated in terms of a production ratio of solid $CO_2$. The present study shows that much reduction in both $CO_2$ compression power (only $35\%$ of power used in conventional dry ice production cycle) and $CO_2$ condenser pressure could be achieved by utilizing LNG cold energy and that high cycle efficiency ($55.3\%$ at maximum power condition) in the gas turbine could be accomplished with the adoption of compressor inlet cooling and regenerator. Exergy analysis shows that irreversibility in the combined cycle increases linearly as a production ratio of solid $CO_2$ increases and most of the irreversibility occurs in the condenser and the heat exchanger for compressor inlet cooling. Hence, incoming LNG cold energy to the above components should be used more effectively.

Suggesting a new testing device for determination of tensile strength of concrete

  • Haeri, Hadi;Sarfarazi, Vahab;Hedayat, Ahmadreza
    • Structural Engineering and Mechanics
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    • 제60권6호
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    • pp.939-952
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    • 2016
  • A compression to tensile load transforming (CTT) device was developed to determine indirect tensile strength of concrete material. Before CTT test, Particle flow code was used for the determination of the standard dimension of physical samples. Four numerical models with different dimensions were made and were subjected to tensile loading. The geometry of the model with ideal failure pattern was selected for physical sample preparation. A concrete slab with dimensions of $15{\times}19{\times}6cm$ and a hole at its center was prepared and subjected to tensile loading using this special loading device. The ratio of hole diameter to sample width was 0.5. The samples were made from a mixture of water, fine sand and cement with a ratio of 1-0.5-1, respectively. A 30-ton hydraulic jack with a load cell applied compressive loading to CTT with the compressive pressure rate of 0.02 MPa per second. The compressive loading was converted to tensile stress on the sample because of the overall test design. A numerical modeling was also done to analyze the effect of the hole diameter on stress concentrations of the hole side along its horizontal axis to provide a suitable criterion for determining the real tensile strength of concrete. Concurrent with indirect tensile test, the Brazilian test was performed to compare the results from two methods and also to perform numerical calibration. The numerical modeling shows that the models have tensile failure in the sides of the hole along the horizontal axis before any failure under shear loading. Also the stress concentration at the edge of the hole was 1.4 times more than the applied stress registered by the machine. Experimental Results showed that, the indirect tensile strength was clearly lower than the Brazilian test strength.

Potassium intake of Korean adults: Based on 2007~2010 Korea National Health and Nutrition Examination Survey (한국 성인의 칼륨 섭취 현황 : 2007~2010년 국민건강영양조사 자료 이용)

  • Lee, Su Yeoun;Lee, Sim-Yeol;Ko, Young-Eun;Ly, Sun Yung
    • Journal of Nutrition and Health
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    • 제50권1호
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    • pp.98-110
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    • 2017
  • Purpose: The purpose of this study was to evaluate the dietary potassium intake, Na/K intake molar ratio, consumption of 18 food groups, and foods contributing to potassium intake of Korean adults as well as the relationships among quartile of potassium intake level and blood pressure, blood biochemical index. Methods: This study was conducted using the Korea National Health and Nutrition Examination Survey, 2007~2010. The total number of subjects was 20,291. All analyses were conducted using a survey weighting to account for the complex survey design. Results: Overall average intakes of potassium were 2,934.7, 3,070.6, 3,078.1, and 3,232.0 mg/day, and they significantly increased by year in Korean adults. The average dietary potassium intake was close to adequate intake (AI), whereas that of women was considerably lower than the AI. The Na/K intake molar ratio in males (2.89~3.23) was higher than in females (2.62~2.95). The major food groups contributing to potassium intake were vegetables, cereals, and fruits/meats. The two major foods contributing to potassium intake were polished rice and cabbage kimchi. The rankings of food source were as follows; polished rice > cabbage kimchi > potato > oriental melon > sweet potato > seaweed > radish > apple > black soybean. In 50~64 year old females, systolic blood pressure (SBP) significantly decreased (p < 0.01) and HDL-cholesterol significantly increased (p < 0.05) as potassium intake increased. Triglyceride (TG) was significantly higher in the other quartile of potassium intake level than in the first quartile (p < 0.05). Conclusion: In conclusion, our study suggests the need for an appropriate set of dietary reference intakes according to caloric intake by sex and age groups and for development of eating patterns to increase potassium intake and decrease sodium intake.

A Study on Buckling Characteristics of 2-way Grid Single-Layer Domes Considering Rigidity-Effect of Roofing Covering Materials (지붕마감재 강성효과를 고려한 2방향 그리드 단층돔의 좌굴특성에 관한 연구)

  • Park, Sang-Hoon;Suk, Chang-Mok;Jung, Hwan-Mok;Kwon, Young-Hwan
    • Journal of Korean Association for Spatial Structures
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    • 제2권1호
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    • pp.85-92
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    • 2002
  • Two way grid single-layer domes are of great advantage in fabrication and construction because of the simple fact that they have only four members at each junction. But, from a point of view of mechanics, the rectangular latticed pattern gives rise to a nonuniform rigidity-distribution in the circumferential direction. If the equivalent rigidity is considered in the axial direction of members, the in-plane equivalent shearing rigidity depends only on the in-plane bending rigidity of members and its value is very small in comparison to that of the in-plane equivalent stretching rigidity. It has a tendency to decrease buckling -strength of dome considerably by external force. But it is possible to increase buckling strength by the use of roofing covering materials connected to framework. In a case like this, shearing rigidity of roofing material increases buckling strength of the overall structure and can be designed economically from the viewpoint of practice. Therefore, the purpose of this paper, in Lamella dome and rectangular latticed dome that are a set of 2-way grid dome, is to clarify the effects of roofing covering materials for increasing of buckling strength of overall dome. Analysis method is based on FEM dealing with the geometrically nonlinear deflection problems. The conclusion were given as follows: 1. In case of Lamella domes which have nearly equal rigidity in the direction of circumference, the rigidity of roofing covering materials does not have a great influence on buckling-strength, but in rectangular latticed domes that has a clear periodicity of rigidity, the value of its buckling strength has a tendency to increase considerably with increasing rigidity of roofing covering materials 2. In case of rectangular latticed domes, as rise-span-ratio increases, models which is subjected to pressure -type-uniform loading than vertical-type-uniform loading are higher in the aspects of the increasing rate of buckling- strength according to the rate of shear reinforcement rigidity, but in case of Lamella dome, the condition of loading and rise-span-ratio do not have a great influence on the increasing rate of buckling strength according to the rate of shear reinforcement rigidity.

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Comparison of Food Intakes and Serum Lipid Levels in Overweight and Obese Women by Body Mass Index (과체중 및 비만여성의 식습관, 식이섭취실태 및 혈청지질 양상 비교)

  • Kim, Ok-Hyun;Jung, Ha-Na;Kim, Jung-Hee
    • Korean Journal of Community Nutrition
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    • 제12권1호
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    • pp.40-49
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    • 2007
  • This study was done to investigate the health-related habits, dietary intakes and serum lipid levels in overweight and obese women by body mass index(BMI). Subjects were 137 pre-menopausal women aged 19 to 49 years. They were divided by 3 groups, overweight($23{\leqq}BMI<25$), obese($25{\leqq}BMI<30$) and morbidly obese($BMI{\geq}30$) according to their BMI. Body composition was determined by bioelectrical impedance analysis(BIA) method. Dietary intakes were examined by 3-day record method and nutrient intakes were analyzed by the Computer Aided Nutritional analysis program for professionals(CAN-pro 3.1). Serum lipid levels were measured using automatic biochemical analyzer(Selectra E). The average age, height weight and BMI of subjects were 31.7 years old, 159.3cm, 69.4kg, and $27.4kg/m^2$, respectively. Their average consumption of energy were 1712kca1 and 86.4% of estimated energy requirement(EER). Their mom ratio of carbohydrate:protein:fat was 55.2:14.6:30.2. Particularly, the fat consumption of subjects tended to be elevated with increasing BMI. There was no significant difference in nutrient intakes among 3 groups. But the mom intakes of Ca, Fe, vitamin C and Na of all the subjects were 70.1%, 81.2%, 75.7% of recommended intake(RI) and 258.9% of adequate intake(AI), respectively, The intakes of vegetables and seaweeds were significantly higher in morbidly obese group while the intake of fruits was higher in overweight group compared to the other groups. Serum lipid analysis showed that there were no significant differences in the levels of total cholesterol, triglyceride and LDL-cholesterol among the groups. But the serum HDL-cholesterol level of the overweight group was significantly higher than that of the other groups. LDL-/HDL-cholesterol ratio and AI index were significantly higher in the morbidly obese group compared to the other groups. In addition, The systolic blood pressure of morbidly obese group was significantly higher compared to the other groups. Overall data suggest that morbidly obese women have to more concern about reducing systolic blood pressure and nm lipid levels by decreasing their fat consumption and salt intakes as well as loosing body fat. In addition, all the subjects participated in this study have to be careful about their meals and health-related behaviors in order to prevent obesity-related chronic diseases.