Artículos de revistas: "Transit-time ultrasonic flowmeters"

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Tang, Jing Yuan, Jian Ming Chen, Hong Bin Ma y Guang Yu Tang. "Numerical Analysis of Flow Field Characteristics in Three-Z-Shaped Ultrasonic Flowmeter". Applied Mechanics and Materials 226-228 (noviembre de 2012): 1829–34. http://dx.doi.org/10.4028/www.scientific.net/amm.226-228.1829.

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The flow field characteristics in U-typed bend has been extensively studied for transit time ultrasonic flowmeters designing, but for the flowmeter with three-Z-shaped round pipe there is still lack of corresponding research. This paper presents a computational fluid dynamics (CFD) approach for modeling of the three-Z-shaped ultrasonic flowmeter and studying of internal fluid field characteristics based on Reynolds stress model (RSM). The fluid velocity profile in the three ultrasound path is obtained using CFD and secondary flow in cross section also is analyzed. The simulation results show that the internal flow fields in the flowmeter are not fully developed turbulence with asymmetric axial velocity distribution and dramatic changes along the flow direction, and there are obvious secondary cross flows on theirs cross-sections. The CFD simulations provide useful insights into the flow field associated with ultrasonic flowmeters design.

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Zhang, Hui, Chuwen Guo y Jie Lin. "Effects of Velocity Profiles on Measuring Accuracy of Transit-Time Ultrasonic Flowmeter". Applied Sciences 9, n.º 8 (20 de abril de 2019): 1648. http://dx.doi.org/10.3390/app9081648.

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Ultrasonic wave carries the information for flowing velocity when it is propagating in flowing fluids. Flowrate can be obtained by measuring the propagation time of ultrasonic wave. The principle of transit-time ultrasonic flowmeters used today was based on that the velocity is uniform along the propagation path of the ultrasonic wave. However, it is well known that the velocity profiles in a pipe are not uniform both in laminar flow and turbulent flow. Emphasis on the effects of velocity profiles across the pipe on the propagation time of ultrasonic wave, theoretical flowrate correction factors considering the real velocity profile were proposed for laminar and turbulent flow to obtain higher accuracy. Experiment data of ultrasonic flowmeter and weighting method are compared to verify the proposed theoretical correction factors. The average relative error of proposed correction factor is determined to be 0.976% for laminar flow and 0.25% for turbulent flow.

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3

Coulthard, J. y Y. Yan. "Ultrasonic Cross-Correlation Flowmeters". Measurement and Control 26, n.º 6 (agosto de 1993): 164–67. http://dx.doi.org/10.1177/002029409302600601.

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Cross-correlation transit-time measuring instrumentation is now inherently accurate to a few ppm depending upon the sensing technology, but when ultrasonic sensors are used to measure fluid flow the accuracy is determined mainly by the fluid properties and flow profile. This paper describes the operation of the ultrasonic cross-correlation flowmeter and its performance in different applications.

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4

Ge, Liang, Hongxia Deng, Qing Wang, Ze Hu y Junlan Li. "Study of the influence of temperature on the measurement accuracy of transit-time ultrasonic flowmeters". Sensor Review 39, n.º 2 (7 de marzo de 2019): 269–76. http://dx.doi.org/10.1108/sr-01-2018-0005.

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Purpose The purpose of this study is to deal largely with the influence of temperature variation on the measurement accuracy of transit-time ultrasonic flowmeter. Design/methodology/approach The causes of measurement error due to temperature are qualitatively and quantitatively analyzed, and a mathematical model is established. The experimental data are processed and analyzed, and the temperature compensation coefficient of flow measurement is obtained. Findings The experimental results show that the flow measurement results by temperature compensation are helpful in improving the measurement accuracy of the ultrasonic flowmeter. Practical implications This study has certain application value, which can provide theoretical support for the design of high-precision ultrasonic flowmeters and design guidance. Originality/value It is worth emphasizing that there are few research studies on the influence factors of temperature. This paper focuses on the influence of the temperature change on the flowmeter that is modeled, and the high precision flow parameter test system is designed based on the established model.

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5

Nguyen, Thi Huong Ly y Suhyun Park. "Multi-Angle Liquid Flow Measurement Using Ultrasonic Linear Array Transducer". Sensors 20, n.º 2 (10 de enero de 2020): 388. http://dx.doi.org/10.3390/s20020388.

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Most ultrasonic flowmeters utilize several wedge sensors for transmission and reception. Thus, the location and alignment of the sensors are critical factors that determine the performance of the ultrasonic flowmeter. In this study, we proposed an ultrasound liquid flowmeter utilizing a 128-element linear array transducer with a transmit delay control for varying the incidence angles of ultrasound wave transmission. The performance of the flowmeter was evaluated at flow rates of 0–50 L/min in a specially designed pipe system. Flow estimation was performed with the transit-time method using cross-correlation with phase zero-crossing for sub-sample estimation. While a single plane wave approach performed invasive electromagnetic measurements with only 74% accuracy as a reference, a multiple angular compensation method with 24 angles was proposed to increase the accuracy of measurements up to 93%. This study demonstrated the capability of the non-invasive single-sided ultrasonic flowmeter with a linear array transducer for liquid flow measurements in the metal pipe system.

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6

Moore, Pamela I., Gregor J. Brown y Brian P. Stimpson. "Ultrasonic transit-time flowmeters modelled with theoretical velocity profiles: methodology". Measurement Science and Technology 11, n.º 12 (20 de noviembre de 2000): 1802–11. http://dx.doi.org/10.1088/0957-0233/11/12/321.

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7

Luca, Adrian, Regis Marchiano y Jean-Camille Chassaing. "Numerical Simulation of Transit-Time Ultrasonic Flowmeters by a Direct Approach". IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control 63, n.º 6 (junio de 2016): 886–97. http://dx.doi.org/10.1109/tuffc.2016.2545714.

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8

Mousavi, Seyed Foad, Seyed Hassan Hashemabadi y Jalil Jamali. "New semi three-dimensional approach for simulation of Lamb wave clamp-on ultrasonic gas flowmeter". Sensor Review 40, n.º 4 (19 de junio de 2020): 465–76. http://dx.doi.org/10.1108/sr-08-2019-0203.

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Purpose The purpose of this study is to numerically simulate the Lamb wave propagation through a clamp-on ultrasonic gas flowmeter (UGF) in contact mode, using a new semi three-dimensional approach. Moreover, experimental and analytical modeling results for transit time difference method have been used to confirm the simulation results at different gas flow velocities from 0.3 to 2.4 m/s. Design/methodology/approach The new semi three-dimensional approach involves the simulation of the flow field of the gas in a three-dimensional model and subsequently the simulation of wave generation, propagation and reception in a two-dimensional (2D) model. Moreover, the analytical model assumes that the wave transitions occur in a 2D mode. Findings The new approach is a semi three-dimensional approach used in this work, has better accuracy than a complete 2D simulation while maintaining the computing time and costs approximately constant. It is faster and less expensive than a complete 3D simulation and more accurate than a complete 2D simulation. It was concluded that the new approach could be extended to simulate all types of ultrasonic gas and non-gas flowmeters, even under harsh conditions. Originality/value In this work, a new approach for the numerical simulation of all types of ultrasonic flowmeters is introduced. It was used for simulation of a Lamb wave ultrasonic flow meter in contact mode.

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9

Dadashnialehi, Amir y Behzad Moshiri. "Online monitoring of transit-time ultrasonic flowmeters based on fusion of optical observation". Measurement 44, n.º 6 (julio de 2011): 1028–37. http://dx.doi.org/10.1016/j.measurement.2011.02.010.

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10

Heritage, J. E. "The performance of transit time ultrasonic flowmeters under good and disturbed flow conditions". Flow Measurement and Instrumentation 1, n.º 1 (octubre de 1989): 24–30. http://dx.doi.org/10.1016/0955-5986(89)90006-x.

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11

van Willigen, Douwe M., Paul L. M. J. van Neer, Jack Massaad, Nico de Jong, Martin D. Verweij y Michiel A. P. Pertijs. "An Algorithm to Minimize the Zero-Flow Error in Transit-Time Ultrasonic Flowmeters". IEEE Transactions on Instrumentation and Measurement 70 (2021): 1–9. http://dx.doi.org/10.1109/tim.2020.3007907.

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12

Mahadeva, D. V., R. C. Baker y J. Woodhouse. "Further Studies of the Accuracy of Clamp-on Transit-Time Ultrasonic Flowmeters for Liquids". IEEE Transactions on Instrumentation and Measurement 58, n.º 5 (mayo de 2009): 1602–9. http://dx.doi.org/10.1109/tim.2009.2012954.

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13

Iooss, B., C. Lhuillier y H. Jeanneau. "Numerical simulation of transit-time ultrasonic flowmeters: uncertainties due to flow profile and fluid turbulence". Ultrasonics 40, n.º 9 (noviembre de 2002): 1009–15. http://dx.doi.org/10.1016/s0041-624x(02)00387-6.

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14

Murakawa, Hideki, Shuhei Ichimura, Katsumi Sugimoto, Hitoshi Asano, Shuichi Umezawa y Katsuhiko Sugita. "Evaluation method of transit time difference for clamp-on ultrasonic flowmeters in two-phase flows". Experimental Thermal and Fluid Science 112 (abril de 2020): 109957. http://dx.doi.org/10.1016/j.expthermflusci.2019.109957.

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15

Simurda, Matej, Lars Duggen, Nils T. Basse y Benny Lassen. "Fourier Collocation Approach With Mesh Refinement Method for Simulating Transit-Time Ultrasonic Flowmeters Under Multiphase Flow Conditions". IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control 65, n.º 2 (febrero de 2018): 244–57. http://dx.doi.org/10.1109/tuffc.2017.2775283.

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16

Tang, Xiaoyu, Xiang Xie, Bo Fan y Youxian Sun. "A Fault-Tolerant Flow Measuring Method Based on PSO-SVM With Transit-Time Multipath Ultrasonic Gas Flowmeters". IEEE Transactions on Instrumentation and Measurement 67, n.º 5 (mayo de 2018): 992–1005. http://dx.doi.org/10.1109/tim.2018.2795298.

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17

Zhu, Mingrui y Hongliang Zhou. "Time of Flight Measurement Method Combining Threshold Method and Cross-Correlation Method". Journal of Physics: Conference Series 2656, n.º 1 (1 de diciembre de 2023): 012014. http://dx.doi.org/10.1088/1742-6596/2656/1/012014.

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Abstract With various benefits such as a large range ratio, suitability for large-diameter measurement, and lack of excess pressure drop, ultrasonic flowmeters (UFMs) have been widely adopted in natural gas measurement. The accuracy of flow measurement in transit-time UFMs is mostly dependent on the accurate measurement of time of flight (TOF). The threshold method, the cross-correlation (CC) method, and the model-based method are examples of traditional TOF calculation techniques. However, the threshold method is susceptible to such factors as waveform distortion, amplitude attenuation, and noise, the CC method is constrained by the sampling frequency, and the model-based method necessitates a significant investment in calculation time and resources. Based on the analysis of the shortcomings of traditional TOF measurement methods, a TOF measurement method that combines the threshold method and CC method is presented. This method integrates the advantages of the high measurement resolution of the threshold method and the strong robustness of the CC algorithm. The results demonstrate that the flow rate accuracy and the repeatability of the TOF are greatly improved by this method.

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Gryshanova, Іryna. "ULTRASONIC MEASUREMENT TECHNOLOGY IN AUTOMATED CONTROL OF WATER RESOURCES". Bulletin of Kyiv Polytechnic Institute. Series Instrument Making, n.º 62(2) (24 de diciembre de 2021): 37–41. http://dx.doi.org/10.20535/1970.62(2).2021.249193.

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Control of water resources is becoming an important strategic issue. That is why authorities set the goal for wa-ter agencies to manage the availability of water and create regulations to its rational use. The main point in water control is measurement. There are three important aspects of measurements of water resources: at water extraction from nature, at the consumption and at custody transfer. Control of water consumption sometimes is based not on measurements, but on preliminary estimation, for example, by pumping. Ultrasonic measurement technology as a key feature of automated control of resources has a potential role in this market. In contrast to mechanical (turbine) meters, ultrasonic meters have a priority because they also give a possibility to realize smart metering. In contrast to electromagnetic meters, which also measure with high accuracy and realize smart functions, ultrasonic meters much more suitable for rough water, wastewater and sewage. Such water resources are usually poorly controlled, which means that no one knows their exact cost. Measurement is mandatory to control cost and for billing. Accuracy is important issue, especially when we say about measurements in large pipe diameters. There is practically no alternative to ultrasonic flow meters. Market of diverse meters concentrated on diameters under 400 mm. For larger diameters, only ultrasonic meters are in use. They have many chords, difficult algorithms for data processing. Thus, they are applicable over a very wide flow range. In this paper, we discover transit-time ultrasonic flow meters to understand features of their measurement theory taking into account all factors affecting their work. This article describes errors inherent in these flowmeters during measurements. As far as accuracy is significantly important in billing, the cost of 1% measurement error in consumption of water resources for small (DN50÷DN150 mm) and large (DN200÷DN1200 mm) pipe diameters has been evaluated and analyzed. The losses from the installation of low-quality metering devices are demonstrated and discussed.

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Kurniadi, Deddy. "Transit Time Multipath Ultrasonic Flowmeter: An Issue on Acoustic Path Arrangement". Applied Mechanics and Materials 771 (julio de 2015): 3–8. http://dx.doi.org/10.4028/www.scientific.net/amm.771.3.

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The multipath ultrasonic flow meter using transit time measurement is being widely used for industrial gas flow measurement. Since the AGA report no. 9 has released, the application of this flowmeter in natural gas metering system has become a technical standard. Currently, the commerical multipath ultrasonic flowmeter employs parallel acoustic path arrangement which consists of four, five or six pairs of ultrasonic transducer. This paper discusses an issue on the acoustic path arrangement of multipath ultrasonic flowmeter in an asymmetric flow profile. From this study, the parallel path arrangement gives relatively inconsistent measurement results when the flow velocity profile was asymmetric.

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20

Grzelak, Sławomir, Jarosław Czoków, Marcin Kowalski y Marek Zieliński. "Ultrasonic Flow Measurement with High Resolution". Metrology and Measurement Systems 21, n.º 2 (1 de junio de 2014): 305–16. http://dx.doi.org/10.2478/mms-2014-0026.

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Abstract The ultrasonic flowmeter which is described in this paper, measures the transit of time of an ultrasonic pulse. This device consists of two ultrasonic transducers and a high resolution time interval measurement module. An ultrasonic transducer emits a characteristic wave packet (transmit mode). When the transducer is in receive mode, a characteristic wave packet is formed and it is connected to the time interval measurement module inputs. The time interval measurement module allows registration of transit time differences of a few pulses in the packet. In practice, during a single measuring cycle a few time-stamps are registered. Moreover, the measurement process is also synchronous and, by applying the statistics, the time interval measurement uncertainty improves even in a single measurement. In this article, besides a detailed discussion on the principle of operation of the ultrasonic flowmeter implemented in the FPGA structure, also the test results are presented and discussed

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Alsaqoor, Sameh, Piotr Piechota, Ali Alahmer, Samer As’ad, Nabil Beithu, Wiesław Wędrychowicz, Artur Andruszkiewicz y Patryk Kotomski. "Examining Transit-Time Ultrasonic Flowmeter Inaccuracies during Changing Gas Velocity Profiles". Processes 11, n.º 5 (29 de abril de 2023): 1367. http://dx.doi.org/10.3390/pr11051367.

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This study investigates the impact of changes in velocity profiles on the measurement inaccuracies of gas flow streams detected by an ultrasonic flowmeter. The cross-sectional velocity profile was influenced by the downhill flow rate, causing variations in the shape factor coefficient. The flowmeter processing equation should consider the factor of shape coefficient variations. Consideration for these variations can result in errors in the measurement of the flow stream. The processing equation assumes a single, constant value for the shape factor coefficient, which can lead to inaccuracies. This article covers the inaccuracies of the transit-time ultrasonic flowmeter caused by a change in the velocity profile of the flowing gas, such as air. A realistic flow system was established with measured flow rates ranging from 43 m3/h to 225 m3/h. The findings of this study can serve as a valuable reference for the design and implementation of more accurate and efficient flow measurement systems that can enhance process efficiency.

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Gerasimov, S. I., V. D. Glushnev y I. N. Zhelbakov. "Determination of Propagation Times of Finite Ultrasonic Signals in the UFM Measuring Path". Journal of Physics: Conference Series 2096, n.º 1 (1 de noviembre de 2021): 012189. http://dx.doi.org/10.1088/1742-6596/2096/1/012189.

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Abstract This article provides a brief analysis of the error in calculating the discrete crosscorrelation function of the transit-time ultrasonic flowmeter signals. Special attention is paid to the study of the influence of the obtained discrete correlation function inaccuracy on the ultrasonic flowmeter’s propagation times determining error. It is known that for real time-limited acoustic signals, the discrete correlation function values are calculated with a significant error. The consequence of this is the appearance of the measurement error of the time delay between signals. The reason for this phenomenon is incorrect truncation of finite length digital sequences of the received acoustic signals. The report presents and describes an improved cross-correlation method for determining the time difference. The new algorithm takes into account the existing discretizing parameters of the received UPS – sampling frequency, sequence size and the truncated signal’s shape. Theoretical analytical expressions for the signals discrete cross-correlation function estimating are obtained as an approximation of a continuous function (the method of trapezoids and Simpson is used as an integral replacement). The numerical simulation by MatLab explains the error formation essence in the signal times difference calculating.

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Mousavi, Seyed Foad, Seyed Hassan Hashemabadi y Hossein Azizi Moghaddam. "Design, simulation, fabrication and testing of ultrasonic gas flowmeter transducer (sensor)". Sensor Review 39, n.º 2 (7 de marzo de 2019): 277–87. http://dx.doi.org/10.1108/sr-03-2018-0051.

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Purpose Invasive transit-time ultrasonic flow measurement involves the use of ultrasonic transducers, which sense the flowing fluid and are the most important parts of an ultrasonic flowmeter. In this study, two ultrasonic transducers were designed, numerically simulated and fabricated to be used in an ultrasonic gas flowmeter. Design/methodology/approach PZT-5H piezoceramic elements with specific dimensions were designed and used as beating heart inside the transducers. Different methods, including impedance-frequency analysis, optical emission spectroscopy and performance tests in pressurized chambers were used to evaluate the piezoelectric elements, ultrasonic transducer housings and the fabricated transducers, respectively. In addition, finite element method results showed its ability for design stages of ultrasonic transducer. Findings Experimental results for transit time difference (TTD) and the normalized received voltage were compared with simulation results at the same conditions. There was a quite good agreement between the two method results. Extensive simulation results showed that under the considered range of environmental conditions, the change of acoustic path length has the most impact on TTD, with respect to temperature and pressure. A change of 1 mm in acoustic path length leads to 0.74 per cent change in TTD, approximately. In addition, for normalized received voltage, 1 bar change in pressure has the most impact and its value is as high as 3.76 per cent. Practical implications This method is possibly used in ultrasonic gas flowmeter fabrication. Originality/value In this work, design, fabrication, experimental tests and numerical simulation of ultrasonic transducers are presented.

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Li, Bin, Yang Gou, Jie Chen y Zhengyu Zhang. "Peak Ratio Characteristic Value Sequence Based Signal Processing Method for Transit-Time Ultrasonic Gas Flowmeter". Energies 14, n.º 2 (14 de enero de 2021): 426. http://dx.doi.org/10.3390/en14020426.

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The transit-time ultrasonic gas flowmeter plays a vital part in the measurement field with its unique advantages. In recent years, it has developed into a research hotspot in the field of gas flow measurement. However, while the ultrasonic signal propagates in gas, the amplitude fluctuation of the ultrasonic signal is produced under the condition of energy attenuation and unstable flow field. This leads to inaccurate transit time of ultrasonic signal that causes flow calculation errors. Aiming at this problem, a signal processing method is proposed in this paper for the transit-time ultrasonic gas flowmeter based on the peak ratio characteristic value sequence (PRCVS). Through the research on the mathematical model of ultrasonic signal, the ratio of the amplitude of adjacent peaks is defined as the peak ratio characteristic value (PRCV) of the peak. According to the corresponding relationship between the PRCV and the peak serial number, a set of reference PRCVS is established. By matching the characteristic value of the ultrasonic signal with the reference characteristic value sequence, the peak serial number can be determined. In this research, the PRCVS-based signal processing method is applied to the gas flow measurement system based on time-to-digital converter (TDC) that has strict requirements on the peak serial number which can verify the validity of the method. The calibration experiment of basic measurement performance test and the unstable flow field experiment of the curved pipe were performed on the gas flow standard device, which verified the stability and validity of the method proposed in this paper.

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Chaikhouni, Amer y Abdulwahid Almulla. "Ultrasonic transit time flowmetry in robotic totally endoscopic CABG". Heart Views 12, n.º 2 (2011): 79. http://dx.doi.org/10.4103/1995-705x.86020.

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Zhou, Shun, Xiao Jing Li y Su Qing Xue. "Research of New Ultrasonic Domestic Gas Meter". Advanced Materials Research 760-762 (septiembre de 2013): 1136–38. http://dx.doi.org/10.4028/www.scientific.net/amr.760-762.1136.

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In recent years, with the rapid development of science and technology, the ultrasonic flowmeter has been widely applied. It measures the flow of liquid by using the liquid velocity information of the ultrasonic transmits in the liquid. The advantages of the meter are non-contact, no pressure loss, low cost, simple structure, wide measuring scope. In this paper, by absorbing and referring to the domestic and foreign advanced technology, the author developed an ultrasonic domestic gas meter based on transit-time difference method and MSP430.And it can measure fluid flow accurately. Experiments show that the system is stable and reliable, test data has good repeatability. The system lays a good foundation in developing the high-performance ultrasonic flowmeter in the future.

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Weihua Kuang y Xufeng Pang. "Flow Characteristics Study of Transit Time Ultrasonic Flowmeter Based on Fluent". INTERNATIONAL JOURNAL ON Advances in Information Sciences and Service Sciences 4, n.º 21 (30 de noviembre de 2012): 413–21. http://dx.doi.org/10.4156/aiss.vol4.issue21.52.

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Chen, Jie, Siyuan Chen, Bin Li y Jiwei Lu. "Research on a transit-time liquid ultrasonic flowmeter under unstable flow fields". Measurement Science and Technology 30, n.º 5 (22 de marzo de 2019): 055902. http://dx.doi.org/10.1088/1361-6501/ab026d.

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Chen, Qiang, Weihua Li y Jiangtao Wu. "Realization of a multipath ultrasonic gas flowmeter based on transit-time technique". Ultrasonics 54, n.º 1 (enero de 2014): 285–90. http://dx.doi.org/10.1016/j.ultras.2013.06.001.

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Silva, Fellipe Allevato Martins da, Marco Antônio von Krüger y Wagner Coelho de Albuquerque Pereira. "Continuous flow phantom for the calibration of an ultrasonic transit-time flowmeter". Revista Brasileira de Engenharia Biomédica 30, n.º 1 (2014): 3–10. http://dx.doi.org/10.4322/rbeb.2014.003.

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Chen, Guoyu, Guixiong Liu, Bingeng Zhu y Wensheng Tan. "3D Isosceles Triangular Ultrasonic Path of Transit-Time Ultrasonic Flowmeter: Theoretical Design and CFD Simulations". IEEE Sensors Journal 15, n.º 9 (septiembre de 2015): 4733–42. http://dx.doi.org/10.1109/jsen.2015.2422696.

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Simurda, Matej, Benny Lassen, Lars Duggen y Nils T. Basse. "A Fourier Collocation Approach for Transit-Time Ultrasonic Flowmeter Under Multi-Phase Flow Conditions". Journal of Computational Acoustics 25, n.º 04 (21 de noviembre de 2017): 1750005. http://dx.doi.org/10.1142/s0218396x17500059.

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A numerical model for a clamp-on transit-time ultrasonic flowmeter (TTUF) under multi-phase flow conditions is presented. The method solves equations of linear elasticity for isotropic heterogeneous materials with background flow where acoustic media are modeled by setting shear modulus to zero. Spatial derivatives are calculated by a Fourier collocation method allowing the use of the fast Fourier transform (FFT) and time derivatives are approximated by a finite difference (FD) scheme. This approach is sometimes referred to as a pseudospectral time-domain method. Perfectly matched layers (PML) are used to avoid wave-wrapping and staggered grids are implemented to improve stability and efficiency. The method is verified against exact analytical solutions and the effect of the time-staggering and associated lowest number of points per minimum wavelengths value is discussed. The method is then employed to model a complete TTUF measurement setup to simulate the effect of a flow profile on the flowmeter accuracy and a study of an impact of inclusions in flowing media on received signals is carried out.

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Novosád, Jan, Jaroslav Pulec, Petra Dančová y Tomáš Vít. "CFD analysis of the ultrasonic gas meter channel". EPJ Web of Conferences 264 (2022): 01025. http://dx.doi.org/10.1051/epjconf/202226401025.

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This paper describes a process of numerical testing and optimization of the ultrasonic gas meter channel. A conventional ultrasonic flowmeter requires a large installation space due to the quality and stability of the velocity profile. Previously, the shape of the inner gas meter channel was optimized to reach a suitable flow field for ultrasonic measurement. The goal of this work is to find an optimal design of reduced size gas meter to achieve a stable velocity profile with minimum disturbances regardless of the entry conditions in the smallest possible space. Flow characteristics for volume flow rate in the range (1 to 250) m3/h were tested and the parameters of the gas meter were adjusted. Obtained results show good match with the requirements. Future work should aim to the measurement of transit time and the stability of measured values on the optimized design. Finally, it will enable to create the analogy between numerically obtained velocity fields and real transit time measurement.

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Chen, Qiang, Weihua Li y Jiangtao Wu. "Corrigendum to “Realization of a multipath ultrasonic gas flowmeter based on transit-time technique” [Ultrasonics 54 (2014) 285–290]". Ultrasonics 54, n.º 6 (agosto de 2014): 1715. http://dx.doi.org/10.1016/j.ultras.2014.02.011.

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SATO, Shinichi, Kunihiko OHNISHI, Shujiro SUGITA y Kunio OKUDA. "Measurement of portal venous flow by pulsed Doppler flowmeter: Comparison with transit time ultrasonic blood flowmeter measurements." Kanzo 28, n.º 2 (1987): 224–30. http://dx.doi.org/10.2957/kanzo.28.224.

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Buess, C., P. Pietsch, W. Guggenbuhl y E. A. Koller. "A pulsed diagonal-beam ultrasonic airflow meter". Journal of Applied Physiology 61, n.º 3 (1 de septiembre de 1986): 1195–99. http://dx.doi.org/10.1152/jappl.1986.61.3.1195.

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The construction and specific function of a new ultrasonic flowmeter are described. The mean velocity of the respiratory airflow is calculated by measuring the transit times of short ultrasonic pulse trains, simultaneously transmitted upstream and downstream at a 500-Hz rate. The flowmeter system consists of a control unit and a separate flow head. The former includes the power supplies, a controlling microprocessor, most of the signal-processing circuitry, and three analog outputs for flow, volume, and temperature. The flow head contains the respiratory tube with a constant circular cross section (length 90 mm, diam 20 mm, dead space 35 ml), a fast temperature sensor, two electronic circuits for processing of flow and temperature data, and a sound transmission channel with two capacitive ultrasonic wide-band transducers. This respiratory airflow meter, suitable for spirometric maneuvers (vital capacity, forced vital capacity) as well as for long-term breath-by-breath respiratory analysis, is extremely fast (response time 1–2 ms) and accurate (volume accuracy with room air +/- 0.7%), with low noise (below 9 ml/s), a wide flow range (bidirectional from 0 to 9 l/s), and a flat frequency response up to 70 Hz.

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Wiranata, Lalu Febrian y Deddy Kurniadi. "The development of simultaneous transducer ultrasonic with dual-transducer to measure flow velocity in the pipe". EUREKA: Physics and Engineering, n.º 4 (27 de julio de 2023): 77–86. http://dx.doi.org/10.21303/2461-4262.2023.002761.

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There are still several obstacles to calculating fluid flow rate measurement on custody transfer, such as the distribution of one-phase fluid flow rate, less sTable pressure, and fluid flow rate changes, which are still the main problems in the process of a measuring system. To calculate the flow rate of one phase fluid, there is a method often used, namely transit time. In practice, the transit time works to send the ultrasonic pulse from upstream to downstream, which had to have a delay because the transducer must switch the function of a transducer to become transmitter or receiver. So, this paper proposed a new strategy of measurement multipath ultrasonic flowmeter (UFLW) with a simultaneous transit time method using a dual transmitter and receiver. The simultaneous method is a measuring technique that utilizes a pair of ultrasonic transducers as both trigger and receiver. The first transducer serves as the transmitter, while the second functions as the receiver, capturing the signal at the same time without changing their positions or roles. In order to implement the configuration setup, let’s try to use 3 paths configuration with 6 pairs of transducers, 3 on the upstream and 3 on the downstream. To estimate the flow velocity, let’s use long short-term memory (LSTM), which is one of the recurrent neural networks (RNN) architectures in the deep learning algorithm, and to evaluate the performance, let’s use the Bland-Altman plot and root mean squared error (RMSE) and validation loss of the LSTM model. The result shows RMSE 0.289 from the actual flow velocity, which means an LTSM with simultaneous multipath ultrasonic can reduce the error between prediction and actual measurement

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38

Zatolokin, V. V., Y. U. Alisherov, Y. Y. Vechersky, D. S. Panfilov y B. N. Kozlov. "Transit-time flowmetry measurement features of coronary bypass grafts after multiple percutaneous coronary interventions". Siberian Journal of Clinical and Experimental Medicine 38, n.º 3 (16 de octubre de 2023): 179–84. http://dx.doi.org/10.29001/2073-8552-2023-39-3-179-184.

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The functionality of coronary bypass grafts after surgical myocardial revascularization in patients with coronary heart disease directly depends on the state of the target coronary arteries. In the presence of widespread and diff use atherosclerotic lesions or microcirculatory dysfunctions, a high frequency of coronary bypass dysfunctions is noted in the near future. In some cases, shunt dysfunction can lead to severe hemodynamic instability, accompanied by acute circulatory disorders.Aim: To assess the function of coronary bypass grafts during myocardial revascularization using the method of ultrasonic flowmetry in patients with and without a history of multiple percutaneous coronary interventions (PCI).Material and methods. The retrospective study included 47 patients who underwent coronary artery bypass surgery. A total of 145 coronary bypass grafts were performed. All patients were divided into 2 groups. Group 1 (PCI group) included patients after multiple previous PCI (n = 25; 74 coronary bypass grafts), group 2 (without PCI) included patients without previous PCI (n = 22; 71 coronary bypass grafts). All patients underwent intraoperative ultrasonic flowmetry of coronary bypass grafts using the VeriQ system (Medistim, Norway).Results. When analyzing the status of coronary bypass grafts in patients after multiple PCI, a significantly low mean volumetric blood flow rate was noted (29.5 ± 8.3 ml/min and 48.2 ± 11.6 ml/min, respectively, p = 0.0001) and lower diastolic filling (55.2 ± 8.2% and 71.9 ± 7.1%, p = 0.0001). Also in the group of patients after multiple PCI, there were 2 (2.7%) cases of revision of the distal anastomosis due to a high pulsatile index and low volumetric blood flow velocity. However, no such events were noted in the group without PCI.Conclusions. Previous percutaneous coronary interventions are compromising factors for the state of the coronary bed, which reduces the functional status of coronary bypass grafts and may increase the perioperative risk of surgical myocardial revascularization.

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39

Welch, W. J., X. Deng, H. Snellen y C. S. Wilcox. "Validation of miniature ultrasonic transit-time flow probes for measurement of renal blood flow in rats". American Journal of Physiology-Renal Physiology 268, n.º 1 (1 de enero de 1995): F175—F178. http://dx.doi.org/10.1152/ajprenal.1995.268.1.f175.

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This study validates the accuracy of miniature ultrasonic transit-time flow probes for measuring renal blood flow (RBF) in the rat. Probes for 1-mm and 2-mm vessels were calibrated ex vivo using excised arteries at varying flow rates and hematocrit (Hct). Correlation between measured and true flow rates for the 2-mm probe were identical (r = 1.0) at both normal and subnormal Hct values. Correlation for the 1-mm probe was high (r = 0.994) at normal Hct, but varied at both high flow rates and subnormal Hct values. In vivo correlation of RBF measurements using the 1-mm probe with the clearance and extraction of p-aminohippuric acid showed a high correlation (r = 0.84; n = 72, P < 0.0001) over a wide range of flow rates (0.5-21 ml/min) and Hct (36-74%). Zero flow levels remained steady, averaging -0.2 +/- 0.2 ml/min during occlusion in the living animal and -0.1 +/- 0.3 ml/min after exsanguination. This study shows that the ultrasonic transit-time flowmeter (1-mm and 2-mm probes) is a reasonably accurate and reliable method with which to measure RBF in the anesthetized, acute-instrumented rat.

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40

Kupnik, M., A. Schroder, P. O'Leary, E. Benes y M. Groschl. "Adaptive Pulse Repetition Frequency Technique for an Ultrasonic Transit-Time Gas Flowmeter for Hot Pulsating Gases". IEEE Sensors Journal 6, n.º 4 (agosto de 2006): 906–15. http://dx.doi.org/10.1109/jsen.2006.876042.

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41

Konje, Justin C., David J. Taylor y Michael J. Rennie. "Application of ultrasonic transit time flowmetry to the measurement of umbilical vein blood flow at caesarean section". BJOG: An International Journal of Obstetrics and Gynaecology 103, n.º 10 (octubre de 1996): 1004–8. http://dx.doi.org/10.1111/j.1471-0528.1996.tb09551.x.

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42

Shimura, Hiroo, Yasuo Watanabe, Nobuyuki Imanishi y Takeshi Shibuya. "A new simultaneous method for measuring the blood flow in small experimental animals using the transit-time ultrasonic volume flowmeter". Japanese Journal of Pharmacology 40 (1986): 101. http://dx.doi.org/10.1016/s0021-5198(19)59058-8.

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43

Jakab, F., Z. Ráth, F. Schmal, P. Nagy y J. Faller. "A New Method to Measure Portal Venous and Hepatic Arterial Blood Flow Patients Intraoperatively". HPB Surgery 9, n.º 4 (1 de enero de 1996): 239–43. http://dx.doi.org/10.1155/1996/15760.

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The intraoperative measurement of the afferent circulation of the liver, namely the hepatic artery flow and portal venous flow was carried out upon 14 anesthetized patients having carcinoma in the splanchnic area, mainly in the head of the pancreas by means of transit time ultrasonic volume flowmeter. The hepatic artery flow, portal venous flow and total hepatic flow were 0.377±0.10; 0.614±0.21; 0.992±0.276 l/min respectively.The ratio of hepatic arterical flow to portal venous flow was 0.66±0.259 There was a sharp, significant increase in hepatic arterial flow (29.8±6.1%, p<0,01) after the temporary occlusion of the portal vein, while the temporary occlusion of hepatic artery did not have any significant effect on portal venous circulation. The interaction between hepatic arterial flow and portal venous flow is a much disputed question, but according to the presented data here, it is unquestionable, that the decrease of portal venous flow immediately results a significant increase in hepatic artery circulation.

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44

Sigaev, I. Yu, M. A. Keren, I. V. Slivneva, Z. D. Shonia y D. I. Marapov. "The Algorithm for Using Transit-time Flow Measurement and High-resolution Epicardial Ultrasound for Intraoperative Grafts Assessment during Coronary Artery Bypass Surgery". Kardiologiia 62, n.º 8 (30 de agosto de 2022): 3–10. http://dx.doi.org/10.18087/cardio.2022.8.n1823.

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Aim To develop an algorithm for using ultrasonic flowmetry (USF) and epicardial ultrasonic scanning (EpiUSS) for intraoperative assessment of anatomic and functional viability of conduits.Material and methods For viability assessment of 460 coronary grafts in 150 patients who were operated at the Bakulev National Medical Research Center for Cardiovascular Surgery (2018–2021 г.), markers of graft failure were analyzed using the USF and EpiUSS data confirmed by results of graft angiography. According to RОС analysis, the Qmean and PI values indicative of the graft failure were determined. A CHAID decision tree was developed for assessing the prognostic significance of the analyzed parameters. Based on this prognostic model, an algorithm was developed for intraoperative diagnosis of anatomic and functional graft viability during coronary bypass surgery.Results The Qmean ≤20.5 ml/min values were associated with an increased relative risk (RR) of detecting graft failure (RR, 8.2; 95 % confidence interval, CI, 4.4–15.2). The developed model shows a high accuracy of predicting the graft failure (AUC = 0.906±0.03). The RR of graft failure at PI ≥2.65 was 3.3 (95 % CI, 2.17–5.08). The prognostic model for PI (AUC = 0.745±0.042) was sufficiently accurate with respect of possible graft failure. Nodes of high and low risk for graft failure were determined in the developed decision tree. The obtained model was characterized by high sensitivity and specificity (100 and 84.3 %, respectively).Conclusion The combined use of USF and EpiUSS allows a highly accurate assessment of both morphological and functional characteristics of graft flow. The developed algorithm for the intraoperative diagnosis of anatomic and functional graft viability can be recommended for clinical use.

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Nelson, Emily P., Thomas F. Scherer y Xinhua Jia. "Flow Rate and Volume Estimates from Variable Frequency Drive Operated Drainage Sump Pumps". Applied Engineering in Agriculture 40, n.º 1 (2024): 51–67. http://dx.doi.org/10.13031/aea.15790.

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Highlights This article provides an overview of operations and benefits of using a variable frequency drive to operate agricultural subsurface drainage system sump pumps. A methodology is proposed to monitor flow rates leaving agricultural subsurface drainage pump stations via a MATLAB algorithm. The results of this research were mixed because the algorithm estimates did not always match with the corresponding flowmeter measurements. Abstract. Subsurface drainage plays a crucial role in excess water removal through perforated pipes buried in the soil. The Red River Valley of eastern North Dakota and west central Minnesota often requires pumped drainage outlets due to its flat topography, with many modern systems incorporating variable frequency drives (VFD) for improved efficiency. VFDs adjust pump speeds to match drainage needs, but this dynamic operation complicates accurate flow rate estimation for edge-of-field monitoring. This project aimed to devise an automated method for calculating flow rate estimates from VFD pumping systems involving tank geometry, operational water levels, and pump duty cycling. Linear regressions with calibration data from a transit-time ultrasonic flowmeter produced mixed outcomes. Some linear regressions revealed errors in calculated versus measured flow rate of =14%, while other regressions showed errors nearing 40%. To address this, future efforts should explore methods incorporating the pump’s electrical characteristics. This approach would provide a more accurate representation of the unstable and intricate pumping operations during transient conditions. Keywords: Edge-of-field monitoring, Flow rate, Pump, Red River Basin, Subsurface drainage, Variable frequency drive

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GÜNGÖR, Murat Alparslan. "Analyzing the Fluid Flow of Transit-Time Ultrasonic Flowmeter with Image Processing Technique and Developing a Quality Metric Depending on Pipe Profile". Balkan Journal of Electrical and Computer Engineering 8, n.º 3 (30 de julio de 2020): 193–200. http://dx.doi.org/10.17694/bajece.654414.

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47

Jakab, F., Z. Ráth, F. Schmal, P. Nagy y J. Faller. "Changes in Hepatic Hemodynamics due to Primary Liver Tumours". HPB Surgery 9, n.º 4 (1 de enero de 1996): 245–48. http://dx.doi.org/10.1155/1996/62057.

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Data regarding the afferent circulation of the liver in patients with primary hepatocellular carcinoma are controversial, we have carried out measurement of hepatic arterial and portal venous flow intraoperatively by transit time ultrasonic volume flowmetry. In patients with primary hepatocellular carcinoma the hepatic artery flow increased to 0.55±0.211 compared with the control value of 0.37±0.102 1/min. (p<0.01). The portal venous flow decreased from 0.61±0.212 l/min, to 0.47±l/min. p<0.01). Due to the opposite changes in the afferent circulation the total hepatic blood flow did not change significantly, compared with controls.The ratio of hepatic arterial flow to portal vein flow increased to 1.239±0.246 in patients with hepatocellular carcinoma, which is double of the control value (0.66±0.259 l/min). After resection this ratio did not change.The resection did not alter hepatic artery or portal venous flow significantly, although the total hepatic blood flow decreased significantly (p<0.01).On the basis of our early results it is possible that the ratio of the two circulations may be to deel measured with doppler ultrasound and provide diagnostic information.

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Persson, P. B., J. E. Baumann, H. Ehmke, E. Hackenthal, H. R. Kirchheim y B. Nafz. "Endothelium-derived NO stimulates pressure-dependent renin release in conscious dogs". American Journal of Physiology-Renal Physiology 264, n.º 6 (1 de junio de 1993): F943—F947. http://dx.doi.org/10.1152/ajprenal.1993.264.6.f943.

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The effect of blocking the formation of endothelium-derived relaxing factor/nitric oxide (EDNO) on pressure-dependent renin release (RR) was studied in six conscious foxhounds with chronically implanted catheters in the abdominal aorta and the renal vein. Renal blood flow (RBF) was measured with an ultrasonic transit-time flowmeter. RR was determined by multiplying the renal venous-arterial plasma renin activity difference with renal plasma flow. Renal artery pressure (RAP) was reduced in steps by a pneumatic occluder placed around the suprarenal abdominal aorta. A dose of 1,000 mg NG-nitro-L-arginine methyl ester (L-NAME) was given as a bolus to inhibit EDNO formation. In response to L-NAME, RAP increased (98 +/- 3 vs. 128 +/- 3 mmHg; P < 0.05), heart rate decreased (88 +/- 7 vs. 51 +/- 5 beats/min; P < 0.05), RBF decreased (280 +/- 19 vs. 185 +/- 24 ml/min; P < 0.05), and RR decreased (62 +/- 11 vs. 28 +/- 7 U; P < 0.05), whereas glomerular filtration rate changed little (38 +/- 3 vs. 35 +/- 4 ml/min; not significant). Below roughly 90 mmHg, RR was considerably attenuated by L-NAME as RAP was reduced in steps. At the lowest RAP (50 mmHg) RR was 1,946 +/- 406 U during control vs. 697 +/- 179 U after L-NAME (P < 0.05). Thus L-NAME inhibited pressure-dependent RR. This was especially pronounced in the low-pressure range.

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Shoji, Tetsuya, Yoshikazu Yonemitsu, Kimihiro Komori, Mitsugu Tanii, Hiroyuki Itoh, Shihoko Sata, Hiroaki Shimokawa, Mamoru Hasegawa, Katsuo Sueishi y Yoshihiko Maehara. "Intramuscular gene transfer of FGF-2 attenuates endothelial dysfunction and inhibits intimal hyperplasia of vein grafts in poor-runoff limbs of rabbit". American Journal of Physiology-Heart and Circulatory Physiology 285, n.º 1 (julio de 2003): H173—H182. http://dx.doi.org/10.1152/ajpheart.00996.2002.

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We previously demonstrated that sustained disturbance of endothelium-dependent vasorelaxation and poor distal runoff in ischemic limbs were critical factors affecting the neointimal development of autologous vein grafts (VGs). Also, we recently showed the superior therapeutic potential of basic fibroblast growth factor (bFGF/FGF-2) boosted by the recombinant Sendai virus (SeV) for severe limb ischemia compared with that of vascular endothelial growth factor. Here, the effect of FGF-2 on neointimal hyperplasia of VGs was examined in a rabbit model of poor-runoff limbs. Two weeks after initial surgery for the induction of poor-runoff, SeV-expressing human FGF-2 (SeV-hFGF2) or that encoding firefly luciferase (109 plaque-forming units/head) was injected into the thigh and calf muscle. At that time, the femoral vein was implanted in the femoral artery in an end-to-end manner in some groups. FGF-2 gene-transferred limbs demonstrated significantly increased blood flow assessed not only by laser Doppler flow image but also by ultrasonic transit-time flowmeter (USTF). USTF also showed a significant increase in the blood flow ratio of the deep femoral artery to external iliac artery, indicating that collateral flow was significantly restored in the thigh muscles ( P < 0.01). Reduction of neointimal hyperplasia was also observed in the VGs treated by SeV-hFGF2; these grafts demonstrated significant restoration of endothelium-dependent vasorelaxation. These findings thus extend the indications of therapeutic angiogenesis using SeV-hFGF2 to include not only limb salvage but also prevention of late graft failure.

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Stith, R. D. y K. J. Dormer. "Pressor and endocrine responses to lesions of canine rostral ventrolateral medulla". American Journal of Physiology-Heart and Circulatory Physiology 266, n.º 6 (1 de junio de 1994): H2520—H2526. http://dx.doi.org/10.1152/ajpheart.1994.266.6.h2520.

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To understand the mechanism(s) of reduction in arterial pressure (AP) after kainic acid cytotoxic lesions in the rostral ventrolateral medulla (RVLM), recordings of AP, cardiac output (CO), heart rate (HR), plasma catecholamines, and cortisol were obtained from awake relaxed dogs. Mongrels (n = 12) were instrumented with a solid-state pressure transducer in the descending aorta and a pulse transit-time ultrasonic flowmeter on the aortic arch. After the dogs recovered from thoracotomy, AP, CO, HR, and plasma levels of epinephrine, norepinephrine, and cortisol were recorded periodically or measured at rest over 2–3 wk followed by unilateral, cytotoxic lesion placement in the rostral C1 area of the RVLM. After the dogs recovered from lesion surgery, the measurements were repeated, and, compared with prelesion control values, they showed significantly decreased AP (-23.1 mmHg) and total peripheral resistance (-0.014 peripheral resistance units) but no significant changes in CO or HR. The reduction in AP may be caused partially by significant reductions in plasma epinephrine (-47%), norepinephrine (-34%), and cortisol (-66%) levels. Lesion sites corresponded to the rostral C1 area, immunocytochemically positive for phenylethanolamine-N-methyltransferase (PNMT). These observations support the concept that a discrete site in the RVLM, demarcated by a rostral subgroup of PNMT-immunoreactive cell bodies, contributes to direct sympathoexcitatory support of resting AP. The neurotransmitter responsible for vasomotor tone, however, remains unknown. This study also provides new information suggesting a role for catecholamine and cortisol regulation from this putative vasomotor center.

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