• Title/Summary/Keyword: Two Phases

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Computations of Compressible Two-phase Flow using Accurate and Efficient Numerical Schemes

  • Kim, Chong-Am
    • 한국전산유체공학회:학술대회논문집
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    • 2006.10a
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    • pp.13-17
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    • 2006
  • RoeM and AUSMPW+ schemes are two of the most accurate and efficient schemes which are recently developed for the analysis of single phase gas dynamics. In this paper, we developed two-phase versions of these schemes for the analysis of gas-liquid large density ratio two-phase flow. We adopt homogeneous equilibrium model (HEM) using mass fraction to describe different two phases. In the Eulerian-Eulerian framework, HEM assumes dynamic and thermal equilibrium of the two phases in the same computational mesh. From the mixture equation of state (EOS), we derived new shock-discontinuity sensing term (SDST), which is commonly used in RoeM and AUSMPW+ for the stable numerical flux calculation. The proposed two-phase versions of RoeM and AUSMPW+ schemes are applied on several air-water two-phase test problems. In spite of the large discrepancy of material properties such as density, enthalpy, and speed of sound, the numerical results show that both schemes provide very satisfactory solutions.

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Kinetic Characterization of Swelling of Liquid Crystalline Phases of Glyceryl Monooleate

  • Lee, Jae-Hwi;Choi, Sung-Up;Yoon, Mi-Kyeong;Choi, Young-Wook
    • Archives of Pharmacal Research
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    • v.26 no.10
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    • pp.880-885
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    • 2003
  • Research in this paper focuses on the kinetic evaluation of swelling of the liquid crystalline phases of glyceryl monooleate (GMO). Swelling of the lamellar and cubic liquid crystalline phases of GMO was studied using two in vitro methods, a total immersion method and a Franz cell method. The swelling of the lamellar phase and GMO having 0 %w/w initial water content was temperature dependent. The swelling ratio was greater at $20^{\circ}^C than 37^{\circ}^C$ . The water uptake increased dramatically with decreasing initial water content of the liquid crystalline phases. The swelling rates obtained using the Franz cell method with a moist nylon membrane to mimic buccal drug delivery situation were slower than the total immersion method. The swelling was studied by employing first-order and second-order swelling kinetics. The swelling of the liquid crystalline phases of GMO could be described by second-order swelling kinetics. The initial stage of the swelling (t < 4 h) followed the square root of time relationship, indicating that this model is also suitable for describing the water uptake by the liquid crystalline matrices. These results obtained from the current study demonstrate that the swelling strongly depends on temperature, the initial water content of the liquid crystalline phases and the methodology employed for measuring the swelling of GMO.

Effectiveness of the Respiratory Gating System for Stereotectic Radiosurgery of Lung Cancer (Lung Cancer의 Stereotactic Radiosurgery시 Respiratory Gating system의 유용성에 대한 연구)

  • Song Heung Kwon;Kim Min Su;Yang Oh Nam;Park Cheol Su;Kwon Kyung Tae;Kim Jeong Man
    • 대한방사선치료학회:학술대회논문집
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    • 2005.06a
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    • pp.13-17
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    • 2005
  • Introduction : For stereotactic radiosurgery (SRS) of a tumor in the region whose movement due to respiration is significant, like Lung lower lobe, the gated therapy, which delivers radiation dose to the selected respiratory phases when tumor motion is small, was peformed using the Respiratory gating system and its clinical effectiveness was evaluated. Methode and Materials : For two SRS patients with a tumor in Lung lower lobe, a marker block (infrared reflector) was attached on the abdomen. While patient' respiratory cycle was monitored with Real-time Position Management (RPM, Varian, USA), 4D CT was performed (10 phases per a cycle). Phases in which tumor motion did not change rapidly were decided as treatment phases. The treatment volume was contoured on the CT images for selected treatment phases using maximum intensity projection (MIP) method. In order to verify setup reproducibility and positional variation, 4D CT was repeated. Result : Gross tumor volume (GTV) showed maximum movement in superior-inferior direction. For patient $\#$1, motion of GTV was reduced to 2.6 mm in treatment phases ($30\%\~60\%$), while that was 9.4 mm in full phases ($0\%\~90\%$) and for patient $\#$2, it was reduced to 2.3 mm in treatment phases ($30\%\~70\%$), while it was 11.7 mm in full phases ($0\%\~90\%$). When comparing two sets of CT images, setup errors in all the directions were within 3 mm. Conclusion : Since tumor motion was reduced less than 5 mm, the Respiratory gating system for SRS of Lung lower lobe is useful.

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The Comparison of the Coping Patterns of Cancer Patients and Their Caregivers According to the Phases of Illness (암환자와 가족원의 질병단계에 따른 대처 방법의 비교)

  • 양영희
    • Journal of Korean Academy of Nursing
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    • v.28 no.4
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    • pp.970-979
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    • 1998
  • Cancer has been considered a life-threatening disease and coping patterns could have a strong impact the physical and psychological health of patients and their family. The purpose of this study was to identify the change of coping patterns according to the phases of illness in the patients with cancer and their family caregivers and to compare the coping patterns of patients with those of their caregivers. The phases of illness consisted of 1st(initial) stage, 2nd(metastatic or recurred) stage and 3rd (terminal) stage based on literature. The coping methods were measured using the modified Ways of Coping Questionnaire by Lazarus & Folkman(1984). Seventy-nine patients(35 in stage 1, 31 in stage 2, and 13 in stage 3) and ninety-two caregivers (38 in stage 1, 30 in stage 2 and 24) agreed to participate from two general hospitals in Seoul and Choongnam. No significant changes were found in the coping patterns according to the phases of illness in both groups. Patients in stage 2 and caregivers in stages 2 and 3 problem-focused coping methods were significantly used more than emotion-focused coping methods. Patients in stage 1 significantly used two coping strategies that were cognitive reconstruction and emotion expression more than caregivers. Patients in stage 2 significantly used emotion-focused coping methods including minimizing threat, blame, and emotion expression excepting wishful thinking more than caregivers. We need more research to identify the relationship between the coping methods and their efficiencies through longterm observation and attempt to develope the nursing interventions that could have an improvement on positive coping methods and provide guidance on the problems the patients experience.

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Intrusive Phases and Igneous Pricesses in the Yeongju Batholith (영주저반의 관입상과 화성과정)

  • 황상구
    • Economic and Environmental Geology
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    • v.32 no.6
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    • pp.669-688
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    • 1999
  • The Yeongju granitoid batholith is a plutonic complex of huge area (1180km2) intruding the metamorphic rocks of the Yeongnam massif. The batholith, which is divided into fivelithofacies, consists of three separate plutons. The oldest Buseok pluton comprises four lithofacies: hornblende biotite tonalite, porphyrotoc biotite granodiorite, equigranular biotite grandiorite and biotite granite. The middle Chunyang pluton has been called as Chunyang granite that ranges in compostion from granodiorite to granite. The youngest Jangsu pluton is intrusions that has lithofacies of two mica granite. The contact between Buseok pluton and the rest two plutons shows obvious intrusive relations, but relation between the Chunyang and the Jangsu pluton is far away, so gives no indication of relative ages. Changes in nextures and micristructures, as well as in the mineral contents, take place between rock types og the plutons. only the Buseok pluton shows faliations of two type: magmatic foliation and regional mylonal foliation. K-Ar age deteminations fall into 171.7$\pm$3.2~162.3$\pm$3.1 Ma in the Buseok pluton, 153.9$\pm$2.9 Ma in the Chunyang pluton and 145.3$\pm$2.7 Ma in the jangsu Pluton. The batholith presents three separate intrusive phases which range in composition from tonalite to granite to granite. Each intrusive phase apperars to have been intruded in a pulse from an underlying, differentiating magma. The petrochemical data showthat three plutons are within the diagnostic range for continental arc orogenic tectonic setting, whereas Jangsu pluton approaches postorogenic setting. The data suggest that three plutons are calc-aclkalline series, and that temporal compositional variations change progerssively from tonalite through grandiorite to granite between the intrusive phases. so we consider that the magmas for all the phases were probably derived from a differentiation by fractional crystallization of a parental magma. The tonalite magma of the Buseok phase was tapped was tapped from a chamber deep in the crust, and then would have to rise at a rapid rate to its final level of emplacement. The tonalite magma in the chamber was gradually enolved through granodiorite magma into granite magma by fractional crystallization. The magmas of the younger phases were respectively tapped with temporal interval from a evolved magma of the chamber that rose into a shallower lever in the crust, and rose to their present level of emplacement.

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2-phase Excitation Method for Reducing Vibration and Noise of an SRM (SRM의 진동소음 저감을 위한 2권선 여자방식)

  • Choi, Gi-Young;Ahn, Jin-Woo;Hwang, Young-Moon
    • Proceedings of the KIEE Conference
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    • 1999.11b
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    • pp.76-78
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    • 1999
  • In this paper, the 2-phase excitation method is proposed to reduce vibration and noise. This excitation method produces reluctance torque by mutual action between two phases as well as conventional-reluctance torque due to two phases excitation at a time. The vibration and acoustic noise is reduced thought the sequential phase excitation. This is because that the scheme reduces abrupt change of excitation level by distributed. balanced excitation.

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Energy and Macronutrient Intakes during Menstrual Cycle in Young Women (월경주기동안의 여대생의 열량섭취와 열량구성비)

  • 김석영;차복경;박필숙
    • Korean Journal of Community Nutrition
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    • v.3 no.2
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    • pp.210-217
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    • 1998
  • The purpose of this study was to examine changes in energy and macronutrient intakes during the premenstrual(days -10-1) and postmenstrual(days 5-14) phases. Thirty-two college female students recorded their food consumption and dietary patterns over 5 weeks from September 8 to October 12, 1997. Mean daily energy and macronutrient intakes and the percentage of energy intake from protein and carbohydrate were relatively consistent over the two menstrual cycle phases, but the energy intake from fat increased 1%(P<0.05)during the postmenstrual phase. Two different dietary patterns were identified by the shifts in energy intake between postmenstrual and premenstrual phases. Seventy five percent of subjects revealed a consistent pattern with the results of previous studies investigating food intake over the menstrual cycle, in which the premenstrual phase is associated with an increment in energy, carbohydrate, and protein intake. In contrast, energy, protein, and fat intakes increased during the postmenstrual phase in 25% of the subjects. We conclude that cyclical fluctuations in energy and macronutrient intakes occur in both postmenstrual and premenstrual dietary pattern groups across the two menstrual phased with the opposite directions.

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Tensile Properties of High Mn Austenitic Stainless Steel with Two Phases of Martensite and Austenite (마르텐사이트와 오스테나이트의 2상 조직을 갖는 고 Mn 오스테나이트계 스테인리스강의 인장성질)

  • Kim, Young-Hwa;Kang, Chang-Yong
    • Journal of Ocean Engineering and Technology
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    • v.27 no.4
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    • pp.9-13
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    • 2013
  • The tensile properties of high manganese austenitic stainless steel with the two phase structures of deformation-induced martensite and reversed austenite were studied. Reversed austenite with an ultra-fine grain size of less than $0.3{\mu}m$ was obtained by reversion treatment. The two phases structures of deformation-induced martensite and reversed austenite were obtained by an annealing treatment in the range of $500^{\circ}C-700^{\circ}C$ for various times in 70% cold- rolled high-manganese austenitic stainless steel. The volume fraction of the reversed austenite increased rapidly with increases in the annealing temperature and time. In the stainless steel with the two phases of austenite and martensite, the strength decreased rapidly, while the elongation increased slowly and then rapidly increased with an increase in the volume fraction of the reversed austenite. Therefore, the strength and elongation were strongly controlled by the volume fraction of reversed austenite. A good combination of high strength and elongation could be obtained by the mixed structure of reversed austenite and deformation-induced martensite.

Blood glucose levels, insulin concentrations, and insulin resistance in healthy women and women with premenstrual syndrome: a comparative study

  • Zarei, Safar;Mosalanejad, Leili;Ghobadifar, Mohamed Amin
    • Clinical and Experimental Reproductive Medicine
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    • v.40 no.2
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    • pp.76-82
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    • 2013
  • Objective: To compare the blood glucose levels, insulin concentrations, and insulin resistance during the two phases of the menstrual cycle between healthy women and patients with premenstrual syndrome (PMS). Methods: From January of 2011 to the August of 2012, a descriptive cross-sectional study was performed among students in the School of Medicine of Jahrom University of Medical Sciences. We included 30 students with the most severe symptoms of PMS and 30 age frequency-matched healthy controls. We analyzed the serum concentrations of glucose, insulin, and insulin resistance by using the glucose oxidase method, radioimmunometric assay, and homeostasis model assessment of insulin resistance equation, respectively. Results: No significant differences between the demographic data of the control and PMS groups were observed. The mean concentrations of glucose of the two study groups were significantly different during the follicular and luteal phases (p=0.011 vs. p<0.0001, respectively). The amounts of homeostasis model assessment of insulin resistance of the two study groups were significantly different in the luteal phase (p=0.0005). Conclusion: The level of blood glucose and insulin resistance was lower during the two phases of the menstrual cycle of the PMS group than that of the controls.

The Development and Application of the New Model of Moon Phases (새로운 달 위상 모형의 개발과 그 적용)

  • Chae, Dong-Hyun
    • Journal of Korean Elementary Science Education
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    • v.27 no.4
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    • pp.385-398
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    • 2008
  • The purpose of this study is to understand the effect of The Model of Phases of the Moon on conception changes for preservice teachers. The researcher interviewed two preservice teachers under the agreement with them on their participation in the research just before he performed a class using The New Model of Phases of the Moon. The post-interview with the same content as the pre-interview was preformed one month later. The main content of the interview is as follows; 'Explain the shape of the Moon by drawing it.', 'Explain the relative different position among the Sun, Earth, and Moon depending on phases of the Moon by drawing them.', 'What do you think of the cause of phases of the Moon?', 'Draw a picture to explain why we always see only one side of the moon.' The results of the research are as follows. First, the class with New Model of Phases of the Moon was able to perceive the relationship of Sun, Earth, and Moon in three-dimensions rather than in two-dimensions and it helped to change their misconception that the Moon's shadow causes the Moon's shape. Secondly, the class with New Model of Phases of the Moon helped preservice teachers understand better the different positional relationships among the Sun, Earth, and Moon depending on the Moon shapes. Third, the class adopting the New Model of Phases of the Moon help preservice teachers form scientific conceptions on the causes of phase change of the Moon. Fourth, the class with the New Model of Phases of the Moon is not appropriate for explaining the reason why only one face of the Moon is seen. Based upon the results above, the researcher realized the limitation of this model and suggested that this model would help learners understand phase change of the Moon and increase space perception ability.

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