• Title/Summary/Keyword: Contraction rate

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Numerical Study of Non-Newtonian Flow Characteristics in Sudden Contraction-Expansion Channel (급축소-확대관에서 비뉴턴유체의 유동 특성에 관한 수치적 연구)

  • Kim, Hyung Min
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.37 no.6
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    • pp.591-597
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    • 2013
  • Because most existing non-Newtonian models are not suitable for application to the lattice Boltzmann method, theoretical and numerical studies in this regard remain challenging. In this study, the hydrokinetic (HK) model was modified and applied to a 3D sudden contraction-expansion channel flow, and the characteristics of the HK model flow were evaluated to generate non-trivial predictions in three-dimensional strong shear flows. The HK model is very efficient for application to the lattice Boltzmann method because it utilizes the shear rate and relaxation time. However, the simulation would be unstable in a high shear flow field because the local relaxation time sharply decreases with an increase in the shear rate in a strong shear flow field. In the HK model, it may become necessary to truncate the relaxation time and non-dimensional parameter to obtain stable numerical results.

Evaluation of the wound healing ability of an Abeliophyllum distichum Nakai extract in ICR mouse and of antibacterial activity against human cutaneous flora

  • Go, Young Bin;Lee, Ji Hwan;Oh, Han Jin;Kim, Yong Ju;An, Jae Woo;Chang, Se Yeon;Song, Dong Cheol;Cho, Hyun Ah;Cho, Jin Ho
    • Korean Journal of Agricultural Science
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    • v.48 no.3
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    • pp.567-574
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    • 2021
  • In this study, we evaluated the wound healing rate and, inflammatory cells effects of by Abeliophyllum distichum Nakai (ADN) extract in mice. We also assessed the stability of the ADN extract upon exposure to sunlight. Treatments were as follows: 1) CON (only saline solution), T1 (CON + 0.0125% ADN extract), T2 (CON + 0.05% ADN extract), and T3 (CON + 0.5% ADN extract). A 4 mm punch was used in the central part of the dorsal area to separate it from the subcutaneous tissue, causing a full-thickness skin wound. An amount of 1 mL of each sample was sprayed onto the treatment section of the wound with a pipette every day from the day of wound creation, with proper application ensured using brush. In the stability test, the pH was measured at 1, 4, and 8 weeks after exposing the samples of each treatment section to sunlight considering, the higher concentrations of the ADN extract. The results of this study indicate that the effectiveness of the wound contraction rate in the mice to which the ADN extract was applied was low. Moreover, the stability of the sample containing a high concentration of the ADN extract could not be verified. In addition, no significant results were obtained in the inflammatory reaction assessment. Therefore, additional research focusing on wound contraction, stability, and inflammatory cell outcomes of the ADN extract is needed.

Premature Ventricular Contraction Classification through R Peak Pattern and RR Interval based on Optimal R Wave Detection (최적 R파 검출 기반의 R피크 패턴과 RR간격을 통한 조기심실수축 분류)

  • Cho, Ik-sung;Kwon, Hyeog-soong
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.22 no.2
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    • pp.233-242
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    • 2018
  • Previous works for detecting arrhythmia have mostly used nonlinear method such as artificial neural network, fuzzy theory, support vector machine to increase classification accuracy. Most methods require higher computational cost and larger processing time. Therefore it is necessary to design efficient algorithm that classifies PVC(premature ventricular contraction) and decreases computational cost by accurately detecting feature point based on only R peak through optimal R wave. For this purpose, we detected R wave through optimal threshold value and extracted RR interval and R peak pattern from noise-free ECG signal through the preprocessing method. Also, we classified PVC in realtime through RR interval and R peak pattern. The performance of R wave detection and PVC classification is evaluated by using 9 record of MIT-BIH arrhythmia database that included over 30. The achieved scores indicate the average of 99.02% in R wave detection and the rate of 94.85% in PVC classification.

Effects of Aconiti tuber butanol fraction and several cardiotonics on the mechanical properties of cat papillary muscle preparation (수종강심약물(數種强心藥物)과 부자(附子)"부타놀" 분획(分劃)이 심장근(心臟筋)의 기계적(機械的) 성질(性質)에 미치는 영향(影響))

  • Yoon, Choong
    • The Korean Journal of Pharmacology
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    • v.12 no.1
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    • pp.45-55
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    • 1976
  • The effect of positive inotropic agents on the contractile properties of myocardial muscle were studied in the cat papillary muscle preparation. For the purpose, the effects of ouabain $(1{\times}10^{-6}g/ml)$, norepinephrine (0.05r/m1) and Aconiti tuber butanol fraction (AF(5), $1{\times}10^{-4}$, $5{\times}10^{-4}$, $1{\times}10^{-3}$, $2{\times}10^{-3}g/ml$) on the contractile dynamics of the papillary muscle preparation isolated from right ventricle of cat were observed in terms of the characteristics of isometric twitch and the lengh-tension relation, the force-velocity relation and the load-extension relation of the series elastic component of contractile model of A.V. Hill. All the studied inotropic drugs similary increased the rate and the intensity of the developed isometric tension, while shortened the time from onset of contraction to peak tension and the total duration of contraction. In the afterloaded simultaneous isotonic and isometric contraction, they also similary increased the maximal velocity of shortening accompanied with the increasing the maximum developed force. In the load-extension relation all the drugs, however, had no appreciable influence on the properties of the series elastic component. Increasing the concentration, Aconiti tuber butanol fraction produced more pronounced effect on all the studied parameters of isometric and isotonic contraction of cat papillary muscle preparation. From the aspect of contractile dynamics, it seemed that the positive inotropic effect of ouabain, norepinephrine and Aconiti tuber butanol fraction are similary achieved through an influence on the behavior of the contractile component only.

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The Effects on Clothing Weight in the Health State of the Kindergartners (착의량이 유아건강에 미치는 영향)

  • Lee Won-Ja;Choi Jeong-wha
    • Journal of the Korean Society of Clothing and Textiles
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    • v.13 no.1 s.29
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    • pp.13-33
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    • 1989
  • The purpose of this study is to obtain the effects on clothing weight in the health state of the kindergartners. So 1 divided 140 kindergartners into 3 groups. A not trained of light wearing in the control group, B the semi-experimetnal group, C the experimental group. In the field surveys conducted their monthly clothing weight and anthropometric measurements, physique index (obesity index) and motor-ability and rate of cold contraction and of absence, Cornell Medical index from Jun, 1986 to Feb, 1987 in Seoul. 1) The experimental group was even less clothing than the control group in clothing weight during the training period. 2) All the experimental group droped conspicuosly the rate of cold contraction and absence during this period. 3) After this training, the experimental group was better than semi-experimental group and control group in motor-ability especially in standing broad jump, flexibility and tennis ball throw, 25 meter dash. 4) But, 1 could not find the different of anthropometric-measurements, physique-index about this train.

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A Study on the Pattern Development of Knitwear According to Yarn Property - Focused on Shift One-Piece Dress - (니트웨어 소재 특성에 다른 패턴 개발 연구 - 쉬프트 원피스 드레스를 중심으로 -)

  • Yoon Hye-Jun;Song Mi-Ryong
    • The Research Journal of the Costume Culture
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    • v.13 no.6 s.59
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    • pp.896-909
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    • 2005
  • In need of studies on the kinds and structure of thread, the biggest variable factor in knitwear patterns, this study attempts: to examine the physical properties by thread type to basically establish systematic data in order to utilize various mixture and structure of yarn and to contribute to the development of optical patterns by building a systemic and scientific methods to produce knit wear patterns though a statistical analysis of the relation between the variations and physical properties. The results is as follows: with time, a feature of knit, which causes instability making it difficult to maintain the original shape, related to material properties, the weight and expansibility recovery rate have the greatest influence on the variation of wale lengths, though the amount varies by material. The variation of course contraction is closely related to density, the dense fabrics showing the highest values, due to the bust of the human body, the wale length variation of the front is greater than that of the back, by a regression analysis of material properties and the variations is obtained showing the weight, density and expansibility recovery rate have the greatest influence on the wale extension and course contraction of knit.

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Effects of Bangpoongsan on the Cardiovascular System in the Experimental Animals (방풍산(防風散)이 실험동물(實驗動物)의 심혈관계(心血管系)에 미치는 영향(影響))

  • Huh, Jae-Hyeok;Kim, Seh-Gil
    • The Journal of Internal Korean Medicine
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    • v.16 no.1
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    • pp.181-196
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    • 1995
  • The present experiments were designed to investigate the effects of BangPoongSan on the cardiovascular system in the experimental Animals. And thus the change of blood pressure, auricular blood flow, artery contraction, death rate, platelet aggregation repression, plasma coagulation factor activity, plasma antithrombin activity, whole blood viscosity and plasma viscosity were studied. The result were summarized as the followings: 1. BangPoongSan dropped the blood pressure in the spontaneous hypertensive rat. 2. The drug increased the auricular blood flow in rabbit. 3. The drug relaxed the artery contraction by pretreated norepinephrine in white rat. 4. The drug inhibited the death rate of mouse which was led to thromboembolism by serotonin and collagen. 5. The drug inhibited the platelet aggregation in rat. 6. The drug prolonged the prothrombin time and activated partial thromboplastin time on the test of plasma coagulation factor activity in rat, but was not valuable. 7. The drug presented the antithrombin activity in rat. 8. The drug reduced the whole blood viscosity and plasma viscosity in rat, but the latter was not valuable. According to the results, Bangpoongsan increased the blood flow and dropped the blood pressure by dilatation of blood vessel smooth muscle. And the drug presented the antithrombin acivity, inhibited the platelet aggregation and reduced blood viscosity. Therefore these effects are assumed to improve the cardiovascular circulation disorder and prevent thrombosis.

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Effects of Interferential Current Stimulation on the Peripheral Blood Velocity in Healthy Subjects (간섭전류자극이 말초 혈류속도에 미치는 영향)

  • Park Jang-Sung;Lee Jae-Hyoung
    • The Journal of Korean Physical Therapy
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    • v.11 no.2
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    • pp.37-42
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    • 1999
  • The purpose of this study was to determine whether percutaneous interferential current stimulation on thoracic sympathetic ganglia with amplitude modulated frequency (AMF) $90\~100$ bps and subthreshold of muscle contraction for 10 minutes on peripheral blood flow velocity in healthy subjects. Thirty-seven healthy volunteers were assigned randomly into an experimental group (n=25) and a control group (n=12). the experimental group received interferential current stimulation with subthreshold of the muscle contraction of current at AMF $90\~100$ bps on $1st\~5th$ thoracic sympathetic ganglial region for 10 minutes. The control group received same handling and electode placement, but no current was applied. Using a Doppler blood flow meter, the radial arterial blood flow velocities and the pulse raters were determined for two-way analysis of variance for repeated measures on time and group. There were no significant difference between the two groups with respect to the changes in arterial blood flow velocity and pulse rate over the four measurement times. Interferential current stimulation did not change in mean blood flow velocity and pulse rate. We conclude that interferential current stimulation on the thoracic sympathetic ganglia, as used in this study, did not dilate peripheral artery. This results suggests that interferential current stimulation dose not alter the activtiy of sympathetic nerve.

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Flux Analysis of Air-conditioner Coupling (에어컨디셔너의 냉매배관을 연결하는 커플링의 유동해석)

  • Lee, Su-Yul;Kim, Woo-Seung;Cho, Soo;Sung, Uk-Joo;Park, Hee-Mun;Sim, Kyung-Jong
    • Proceedings of the SAREK Conference
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    • 2009.06a
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    • pp.1031-1036
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    • 2009
  • This study is intended to identify how quick disconnect coupling which connects with refrigerant piping of air-conditioner using R-22 refrigerant has effect on characteristics of flux. in the case where the air-conditioner installs utilizes quick disconnect coupling, COP has an effect on the quantity of cooling load because of changing flow rate and physical properties of refrigerant which flow into an entrance of expansion valve from coupling. Variation of flow rate can be regulated by changing expansion-contraction angle; $\alpha$ of an entrance and an exit of coupling. In this study, quick disconnect coupling is presented flow of coupling by using FLUENT as heat flow program. To have an effect on the expansion entrance valve, and by changing expansion-contraction angle; $\alpha$ of an entrance and an exit

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Differences of Cesarean Section Rates according to San-Yin-Jiao(SP6) Acupressure for Women in Labor (삼음교 지압에 따른 산부의 제왕절개율 차이)

  • 장순복;박용원;조재성;이미경;이병철;이수정
    • Journal of Korean Academy of Nursing
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    • v.34 no.2
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    • pp.324-332
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    • 2004
  • Purpose: The purpose of this study was to explain differences of cesarean section rates according to San- Yin-Jiao(SP6) acupressure for women in labor. Method: A noneqivalent control group pre test - post test design was used to explain differences of cesarean section rates according to SP6 acupressure. The participants were 209 women who were assigned to one of three groups SP6 acupressure(n=86), SP6 touch(n=47), and control group(n=76). For 30 minutes, the SP6 acupressure group received SP6 acupressure, and the SP6 touch group received SP6 touch for the duration of each uterine contraction. The Control group was encouraged to deep breath and relax for the duration of each uterine contraction for 30 minutes. Result: The rates of cesarean section were 12.8%, 29.8%, and 22.4% for the SP6 acupressure group, SP6 touch group, and control group respectively. There was a significant difference among groups (p=0.049). Cesarean section rateswere significantly different between the SP6 acupressure and non-SP6 acupressure group(p=0.035). Conclusion: This finding shows that 30 minutes of SP6 acupressure was effective in decreasing the cesarean section rate. Therefore, SP6 acupressure during labor could be applied as an effective nursing intervention.