• Title, Summary, Keyword: aPTT

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Crystallization Behavior of poly(trimethylene terephthalate) in a Confined Geometry (제한공간에서의 폴리(트리메틸렌 테레프탈레이트)의 결정화 거동)

  • 임정은;이종관;이광희
    • Polymer(Korea)
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    • v.27 no.4
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    • pp.293-298
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    • 2003
  • The development of the crystalline structure of poly(trimethylene terephthalate) (PTT) in a confined geometry was investigated with optical microscope, small angle light scattering, and X-ray diffraction. The rejected distance, which was represented in terms of the parameter $\delta$, played an important role in determining the morphological patterns of poly (ethylene terethphalate) (PET/PTT) blend. In case of stepwise crystallization, the crystallization of PTT commenced in the interspherulitic region between the grown PET crystals and proceeded until the interspherulitic space was filled with the PTT crystals. The spherulitic surface of the PET crtstals acted as the nucleation sites where the PTT molecules preferentially crystallized, leading to the formation of transcrystalline structure. As a result, a mixed morphological pattern was observed in the PTT-rich phase: one was a typical spherulitic texture and the other was a transcrystalline texture. Some of the molecular conformations of PTT, which could adopt in the absence of the space limitation, were probably forbidden in the interlamellar and/or interfibrillar regions of the PET spherulite. This constraint was responsible for difference in the crystallization and melting behavior of PTT between the intra and interspheulitic regions of PET.

Respiratory Effort Monitoring Using Pulse Transit Time in Human (인체에서 맥파전달시간을 이용한 호흡노력 모니터링)

  • 정동근
    • Journal of Biomedical Engineering Research
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    • v.23 no.6
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    • pp.485-489
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    • 2002
  • In this study. respiratory efforts were monitored by the change of pulse transit time (PTT) which is related with the arterial pressure PTT is the time interval between the peak of R wave in ECG and the maximal slope point of photoplethysmogram(PPG). Biosignals, ECG and finger photoplethysmogram(PPG), were converted to digital data, and PTT was evaluated in personal computer with every heart beat. Results were presented as a graph using spline interpolation. The software was implemented in C$\^$++/ as a window-based application program. PTT was periodically changed according to airflow in resting respiration. In the resting respiration, PTT was changed according to the respiratory cycle. The amplitude of PTT fluctuation was increased by deep respiration, and increased by partial airway obstruction. These results suggest that PTT is responsible to respiratory effort which could be evaluated by the pattern of PTT change. And it is expected that PTT could be applied in the monitoring of respiratory effort by noninvasive methods, and is very useful method for the evaluation of respiratory distress.

PTT Service Interworking Between IMS Based Networks and P2P Overlay Networks

  • Tieu, Tuan-Hao;Kim, Younghan;Gim, Gwangyong
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.7 no.7
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    • pp.1638-1656
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    • 2013
  • The demand for multimedia streaming services is increasing rapidly. To meet this demand, there has been much research and many practical developments for providing multimedia services. A push-to-talk (PTT) service is one of the multimedia streaming services that have been deployed not only over IP multimedia subsystem (IMS) but also in peer-to-peer (P2P) overlay networks. The benefit of PTT has been demonstrated in the literature. However, the need for using PTT service in communication can be arbitrary among users, regardless what kind of PTT services they use. This demand does not support current PTT systems, so an expansion of PTT services still be limited. Moreover, the combination of PTT services in IMS and P2P networks will help operators to provide more scalable PTT services. Therefore, in this paper, we proposed a model to support PTT service interworking between IMS and P2P overlay networks. We also introduced our system design and some interworking service scenarios. We confirmed our architecture through implementation and testing.

Comparison of Two Methods for Heparin Sensitivity; Activated Partial Thromboplastin Time Assay using in vitro Heparin-spiked Sample and Anti-Xa Assay using in vivo Heparin-treated Sample

  • Koo, Bon-Kyung;Kwon, Eui-Hoon;Ryu, Kwang-Hyun;Yun, Jae-Won;Kim, Hee-Jin
    • Korean Journal of Clinical Laboratory Science
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    • v.43 no.4
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    • pp.133-137
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    • 2011
  • The monitoring of heparin therapy is using almost aPTT assay. This study is compare to estimating aPTT therapeutic range using in vitro heparin-spiked sample and aPTT therapeutic range using in vivo heparin-treated sample. Normal pooled plasma was collected from 20 healthy representative individuals. 11 concentration of heparinized plasmas from 0 U/mL to 1.0 U/mL at intervals of 0.1 U/mL made by addition of heparin to normal pooled plasma were measured aPTT. The aPTT therapeutic range was performed through correlation analysis between heparin level 0.2 to 0.4 U/mL and aPTT. 30 plasmas from patients on heparin therapy were measured aPTT and anti-Xa activity. The aPTT therapeutic range was performed through correlation analysis between anti-Xa activity 0.3 to 0.7 U/mL and aPTT. The aPTT therapeutic range corresponded by heparin level-vs-aPTT value regression analysis was 60.7 to 102.4 seconds. The aPTT therapeutic range corresponded by anti-Xa activity-vs-aPTT value regression analysis was 85.3 to 147.5 seconds. The validation of heparin sensitivity using in-vitro heparin sample was not considered. The establishing aPTT therapeutic range is recommended anti-Xa activity using in-vivo sample.

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The Comparison of PTT and Systolic Blood Pressure in a hemorrhaged Rat (출혈을 일으킨 흰쥐에서의 PTT와 수축기 혈압 비교)

  • Shim, Young-Woo;Lee, Ju-Hyung;Yang, Dong-In;Kim, Deok-Won
    • Proceedings of the IEEK Conference
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    • pp.138-140
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    • 2009
  • Hemorrhage shock occupies high rate in trauma patient's mortality and blood pressure is the variance that judges early diagnosis and the effect of remedy. Systolic blood pressure is related to pulse transit time(PTT). PTT means the time that is required to flow from the heart to peripheral artery. PTT is influenced from the length, cross section and stiffness of the blood vessels. It is hard to evaluate the correlation between systolic blood pressure and PTT because they are variable in human body. In this paper, we evaluated the correlation between the systolic blood pressure and PTT in normal and hemorrhage states using standardized rat. PTT is defined as the time differences between the R peak and the peak of pulse wave. The analyzed time differences of ECG and blood pressure are analyzed every 5minutes for 30 seconds when there is before and after bleeding. Before bleeding, systolic blood pressure and PTT are steadily preserved but when the bleeding comes started, systolic blood pressure is declined. However PTT was increased and decreased. Under the circumstance that the standardized rat is controlled by age, the length of the blood vessels, and any disease, it shows that PTT measurement using systolic blood pressure of bleeding is impossible.

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A Numerical Modelling for the Prediction of Phase Transition Time(Ice-Water) in Frozen Gelatin Matrix by Ohmic Thawing Process

  • Kim, Jee-Yeon;Park, Sung-Hee;Min, Sang-Gi
    • Proceedings of the Korean Society for Food Science of Animal Resources Conference
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    • pp.407-411
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    • 2004
  • Ohmic heating occurs when an electric current is passes through food, resulting in a temperature rise in the product due to the conversion of the electric energy into heat. The time spent in the thawing is critical for product sterility and quality. The objective of this study is to conduct numerical modelling between the effect of ohmic thawing intensity on PTT(phase transition time) at constant concentration and the effect of matrix concentrations on PTT at constant voltage condition. the stronger ohmic thawing intensity resulted in decreasing the PTT. High ohmic intensity causes short PTT. And the higher gelatin concentration, the faster increment of PTT. A numerical modeling was executed to predict the PTT influenced by the power intensity using exponential regression and the PTT influenced by gelatin concentration using logarithmic regression. Therefore, from this numerical model of gelatin matrix, it is possible to estimate exact values extensively.

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Performance of Poly(trimethylene terephthalate) Fabric for Swimsuit (폴리트리메틸렌테레프탈레이트를 사용한 수영복 소재의 성능)

  • 정승은;박정희;최정화
    • Journal of the Korean Society of Clothing and Textiles
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    • v.28 no.6
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    • pp.819-829
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    • 2004
  • This study was carried out to suggest a new swimsuit fabric with improved durability, comfort and appearance, by employing PTT(polytrimethylene terephthalate). Objective and subjective performances of newly woven PTT/PU (polyurethane) blend fabric were estimated and compared with nylon/PU(80/20) which is currently used for swimsuit. According to the questionnaire, the most serious problems of swimsuit fabrics were such that they were easily degraded by chlorinated water and this made fabric inelastic and transparent. After exposure to the chlorinated water, PTT blend fabrics showed higher retention of breaking strength, bursting strength, elastic recovery and crystallinity. suggesting that PTT/PU(87/13) was the most excellent material in durability. PTT blend fabrics absorbed less water and dried faster than nylon/PU and thus PTT/PU(87/13) was shown to be the best in respect of comfort. All of the specimens used in this study exhibited satisfactory colorfastness to sea water, chlorinated water and light except that nylon/PU(80/20) represented weak colorfastness to chlorinated water. From the subjective wearing sensation test, PTT/PU(82/18) was shown to posess the best wearing sensation. From the overall evaluation or objective and subjective properties, PTT blend fabrics exhibited superior performances to nylon/PU(80/20), suggesting that they can be successfully used as a new durable and comfortable swimsuit fabric.

Compressional Properties of PTT BCF and Nylon BCF Carpets (PTT BCF카펫과 나일론 BCF카펫의 압축특성(壓縮特性)에 관(關)한 연구(硏究))

  • Yun, Myung-Hui;Kim, Jong-Jun;Jeon, Dong-Won
    • Journal of Fashion Business
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    • v.8 no.5
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    • pp.115-124
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    • 2004
  • PTT(polytrimethylene terephthalate) is a thermoplastic that can be melt-spun into fibers and has extensive applications in carpets, textiles and apparel, engineering thermoplastics, nonwovens, and films or sheets. This polymer combines the good properties of nylon and polyester. Compared with other synthetic fibers such as nylon and acrylic, the PTT fibers feel softer, dye easier with vibrant colors, stretch and recover better. Moreover, the PTT fibers for carpets resist most stainings, clean better, and dry faster. The PTT was first patented in 1941, but it was not until the 1990's, when Shell Chemicals developed the practical method of producing PDO, the raw material for PTT. Many studies have been done including the retention of carpet texture using an image analysis technique, or compressional resilience of the carpet for long term use. In this study, PTT and nylon BCF carpets were compared in terms of the compressional properties including the resilience, using one of the KES system for repetitive measurements. The compression resilience(RC) values of the PTT BCF carpets far exceed those of nylon 6 BCF carpets. The RC values of the PTT BCF carpet(cut) specimens are $42{\sim}45%$ for 5 successive compression deformations, while those of the nylon BCF carpet specimens(cut) are $26{\sim}28%$. There is also a similar trend in the RC values for the other type of carpet which is the loop type. This resilience is one of the important factors of carpet usage evaluation.

Dyeing of PTT Fiber(1) - Effect of Heat Setting on Dyeing and Physical Properties of PTT Fiber - (PTT 섬유의 염색성 (1) - 열처리한 PTT 섬유의 염색성 및 물성 -)

  • 이두환;정동석;이문철
    • Textile Coloration and Finishing
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    • v.14 no.5
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    • pp.268-276
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    • 2002
  • Poly(trimethylene terephthalate)(PTT) and Poly(ethylene terephthalate)(PET) fibers were annealed at various temperatures ranging from $100^\circ{C}$ to $230^\circ{C}$ for 10 min under tension and tension free. Dyeing rates and absorption isotherms of both fibers were obtained with C.I. Disperse Red 60 at 100, 120 and $130^\circ{C}$ in water system. Also X-ray diffraction pattern, moisture regain and water absorption were investigated. The dyeing rate of PTT fiber is faster than PET fiber, and dyeing of PTT fiber begin at lower temperature compared to PET fiber. The absorption isotherms from both fibers with disperse dye we nearly linear up to the saturation dye uptake, which increase with dyeing temperature. Equilibrium dye uptake of PTT fiber annealed under tension above $180^\circ{C}$ was remarkably decreased because of a changes in the fine structure of fiber. The intensities of X-ray diffraction peaks of both annealed fibers were increased with increasing in annealed temperature. The reflections observed at $2\theta$=$15.8^\circ$, $24^\circ$ and $25.2^\circ$ were assigned reflection of crystal at the planes of (010), $(1\bar02,\;\bar112),\;and\;(\bar13,\; \bar113)$ respectively, and the peak became sharp with heat setting temperature.

Analysis of Relations Between Physiologic Parameters and Pulse Transit Time on the Ultrasound Therapy (초음파 재활치료 시 PTT와 생리변수의 상관관계 분석)

  • Kim, Sung-Min;Choi, Sang-Hyuk;Lee, Man-Pyo;Choi, Byeong-Cheol;Jung, Whoi-Seong;Park, Sung-Yoon
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.56 no.8
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    • pp.1514-1520
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    • 2007
  • Currently, the signal of the human body is measured with various methods, and a noninvasive investigation of various methods is useful diagnosis method. PTT(Pulse Transit Time) which is noninvasive investigation make use of to estimate the physiological phenomena. PTT has a latent information of cardiovascular system. So we have the experiments for analysis of the relations between PTT and physiological parameters. We examine to correlate to the physiological parameters, an age and degree of paralysis on the ultrasound therapy. The 40 patients who has a such paralysis join our experiment, and we obtain the PTT data that normal condition and states after ultrasound therapy. We study that PTT after the ultrasound therapy for patients who have a paralysis was related to an age and degree of paralysis.