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Flow sensing exhibits significant potential for monitoring, controlling, and optimizing processes in industries, resource management, and environmental protection. However, achieving wireless real‐time and omnidirectional sensing of gas/liquid flow on a simple, self‐contained device without external power support has remained a formidable challenge. In this study, a compact‐sized, fully self‐powered wireless sensing flowmeter (CSWF) is introduced with a small size diameter of down to less than 50 mm, which can transmit real‐time and omnidirectional wireless signals, as driven by a rotating triboelectric nanogenerator (R‐TENG). The R‐TENG triggers the breakdown discharge of a gas discharge tube (GDT), which enables flow rate wireless sensing through emitted electromagnetic waves. Importantly, the performance of the CSWF is not affected by the R‐TENG's varied output, while the transmission distance is greater than 10 m. Real‐time wireless remote monitoring of wind speed and water flow rate is successfully demonstrated. This research introduces an approach to achieve a wireless, self‐powered environmental monitoring system with a diverse range of potential applications, including prolonged meteorological observations, marine environment monitoring, early warning systems for natural disasters, and remote ecosystem monitoring. [ABSTRACT FROM AUTHOR]

Objective The aim is to solve the technical problem that the gas and liquid produced by a single well cannot be measured accurately in the low permeability gas field with series between wells and mixed wellhead metering mode. Methods Based on the single-phase metering principle of the precession vortex flowmeter and V-cone flowmeter, the miscible metering error of the single-phase flowmeter was analyzed under different operating pressures, gas-liquid ratio and apparent gas velocity through the indoor experiment of air-water two-phase flow. Through the application of dimensional analysis, the correlation formulas of precession frequency and pressure drop, as well as relevant dimensionless number were established, respectively. In addition, the parameters under miscible conditions were modified utilizing laboratory experimental data. A two-parameter combined measurement model of moisture gas suitable for low liquid content was proposed by combining two flowmeters in series. The accuracy of the model was verified by using the real flow data of Yan′an gas field. Results The results showed that in laboratory experiments, when the liquid volume fraction of wet gas was less than 1%, the precession frequency of the precession vortex decreased with the increase of the liquid volume fraction, resulting in an “underread” phenomenon. In contrast, the V-cone flowmeter's metering pressure drop increased with the volume fraction of liquid, resulting in an “overread” phenomenon. When the liquid volume fraction of the V-cone flowmeter was greater than 1%, the liquid content of the gas phase was too large. As a result, the decline law of the vortex precession signal was not clear, and the results of the combined metering model may be distorted. The field real flow test results showed that the average relative error of the gas phase volume flow of the combined metering model was 2.029%, the average relative error of the liquid phase volume flow was 15.066%, and the average absolute error of the volume liquid content was 0.059%. Conclusions The combined measurement model of precession vortex and V-cone flowmeter is used when the liquid content of gas phase is low, the measurement accuracy of the gas phase and liquid phase can meet the needs of on-site production, and the processing design cost is low, which can provide technical support for the gas-liquid mismixing measurement of drainage gas production wells in Yan′an gas field. [ABSTRACT FROM AUTHOR]

A miniature and highly sensitive fiber-optic liquid flowmeter based on Fabry–Perot interferometry (FPI) is proposed and demonstrated for fluid-flow micro-channel testing. The diaphragm deformation and pressure of the proposed sensor for flow rate detection are obtained from numerical and finite element method simulations of the theoretical model. The FPI flowmeter can be applied in real time to measure the ultra-wide dynamic range from 0 mL/min to 90 mL/min, with a response time of hundreds of milliseconds, controlling the flow rate with a resolution of 1.08 mL/min, which is 1.2% of the full scale. The quadratic functional relation between dip wavelength shifts and flow rates is verified by the flow calibration curves of the FPI flowmeter under dynamic pressure conditions. In addition, the effective temperature compensation is realized by connecting an FBG temperature sensor for variable temperature flow detection, and the measured error is reduced by nearly 25-times. The proposed sensor has the potential to measure the liquid flow rate in various applications. [ABSTRACT FROM AUTHOR]

The work is devoted to an increase in the sensitivity and accuracy of the measuring characteristics of the vortex oscillation transducers of submersible vortex flowmeters by upgrading the shape of a bluff body. Based on the numerical simulation methods, it has been found that when the flow rate changes the stability of the Strouhal number, i.e., the error of the measurement method, is significantly affected by the shape of the bluff body facet, onto which the measured medium runs. The best results have been obtained with a facet made in the form of an obtuse triangle, which provides a reduction in changes in the Strouhal number by 40% relative to a simple flat surface. In this case, some reduction in the force effect of vortex formation on the vortex formation sensor does not exceed 10%. [ABSTRACT FROM AUTHOR]

Objective Mixing hydrogen into natural gas will change the properties and flow state of the fluid, thus affecting the metering accuracy of the flowmeter. ANSYS Fluent was used to simulate the velocity distribution of hydrogen-mixed natural gas after bending pipe, and analyze that whether the existing installation conditions of orifice flowmeter and ultrasonic flowmeter are suitable for hydrogen-mixed natural gas pipeline. Methods Simulating the velocity field of hydrogen-mixed natural gas after single 90° bending pipe and double 90° bending pipe, and comparing the velocity distribution of hydrogen-mixed natural gas with different hydrogen content on the pipeline center line and some sections after the bending pipe to analyze whether the installation position of the flowmeter specified in the current standard achieves symmetrical velocity distribution for hydrogen-mixed natural gas, and to determine whether the length of the front straight pipe section of the installation position of the elbow back flowmeter stipulated in the current standard needs to be extended. Results(1) At the 44D and 50D sections after a single 90° bending pipe, the H2 molar fraction with 10%-30% H2 did not return to the symmetrical velocity distribution; (2) At the 44D section and 50D section after the double 90° bending pipe, the flow velocity with 10% H2 has returned to the symmetrical velocity distribution, while the flow velocity with 20%-30% H2 has not returned to the symmetrical velocity distribution; (3) At the 30D section after the double 90° bending pipe, the velocity with 10% H2 did not return to the symmetrical velocity distribution. Conclusions(1) For hydrogen-mixed natural gas, the length of the straight front section of the single bending pipe rear flowmeter stipulated in the current standard should be appropriately extended; (2) For 20%-30% H2, the length of the straight pipe section in front of the flowmeter after the double bending pipe should be appropriately extended; (3) When the orifice aperture ratio decreases, the length of the straight pipe section in front of the orifice flowmeter with 10% H2 should be appropriately extended. [ABSTRACT FROM AUTHOR]

The ability to accurately and precisely measure gas volume and gas flow is a fundamental component in the safe provision of modern anaesthesia. This is vital for the delivery of gasses and monitoring of respiration. A range of techniques are used to measure gas volume and flow, both by direct and indirect measurement. Direct methods of gas volume measurement tend to be large and impractical. By using physical properties of gases indirect measurements can be made. Understanding the principles of these techniques allows interpretation of the data they produce. Descriptions of devices used in anaesthetic practice are given. These devices include the variable orifice flowmeter, differential pressure flowmeter, hot wire anemometer, mechanical flow transducer, ultrasonic flowmeter, Wright respirometer, Vitalograph and peak flowmeter. [ABSTRACT FROM AUTHOR]

An air-coupled transducer was developed in this study, utilizing hollow glass microsphere-organosilicon composites as an acoustically matching layer, which demonstrated outstanding acoustic performance. Firstly, a comparison and analysis of the properties and advantages of different substrates was carried out to determine the potential application value of organosilicon substrates. Immediately after, the effect of hollow glass microspheres with different particle sizes and mass fractions on the acoustic properties of the matching layer was analyzed. It also evaluated the mechanical properties of the matching layer before and after optimization. The findings indicate that the optimized composite material attained a characteristic acoustic impedance of 1.04 MRayl and an acoustic attenuation of 0.43 dB/mm, displaying exceptional acoustic performance. After encapsulating the ultrasonic transducer using a 3D-printed shell, we analyzed and compared its emission and reception characteristics to the commercial transducer and found that its emission acoustic pressure amplitude and reception voltage amplitude were 34% and 26% higher, respectively. Finally, the transducer was installed onto a homemade ultrasonic flow meter for practical application verification, resulting in an accuracy rate of 97.4%. [ABSTRACT FROM AUTHOR]

Flowmeter is an instrument for measuring the flow rate of fluid, which is widely used in industrial, agricultural, environmental and other fields. However, the signal of flowmeter is often affected by various noises and interferences, which reduces the measurement accuracy. In order to improve the signal quality of flowmeter, this paper proposes a flowmeter signal processing method based on adaptive Kalman filter. This method uses the advantages of Kalman filter, combined with adaptive algorithm, dynamically adjusts the process noise covariance matrix and measurement noise covariance matrix, and realizes the effective filtering and estimation of flowmeter signal. This research takes the water flow signal processing based on Kalman filter as an example, and verifies the effectiveness and superiority of this method through simulation and experiment. The results show that this method can effectively suppress the noise and interference in the flowmeter signal, improve the measurement accuracy and stability of the flowmeter, and is suitable for different working conditions and different types of flowmeters. [ABSTRACT FROM AUTHOR]

Among the construction processes of Portland cement concrete pavement (PCCP), the curing compound spraying process is one of the most important processes. If the curing compound spraying amount does not meet the standard or if the curing compound is not applied evenly, distresses occur at the early age of construction, ultimately causing deterioration in concrete pavement performance. The purpose of this study is to develop a real-time monitoring system for a curing compound spraying process based on the Internet of Things (IoT) and sensing technologies to improve the construction quality of concrete pavement. To achieve the goal of this research, we conducted various laboratory and field experiments. The curing compound spraying amount and sprayed status were measured and analyzed using flowmeters, image acquisition sensors, and an image processing program, and the data were provided to workers in real time and simultaneously transmitted to the IoT cloud to form a database. From this study, it is confirmed that the IoT-technology-based curing compound spraying amount and sprayed status monitoring systems can be successfully established to manage construction quality related to the curing of concrete pavement. [ABSTRACT FROM AUTHOR]

Measuring the flow rate in High-Temperature Gas-cooled Reactors is a challenge for traditional flowmeters due to the high flow rate (10 to 15 m/s at nominal operating conditions), high operating temperatures (>700°C), and high neutron flux and gamma fields in the reactor core. This paper discusses developing a novel flowmeter that can work under these extreme conditions. Oak Ridge National Laboratory first proposed using acoustics to measure the flow in the reactor, more specifically, using a Kelvin-Helmholtz resonator to correlate the gas flow rate with vibration frequency. With the primary goal of developing an acoustic measurement technique, we propose an acoustic corrugated pipe as a candidate for the development of a novel gas flowmeter. Experimental investigations on corrugated pipes have confirmed the dependence of the whistling frequency on the gas flow rate. Also, a tube-in-tube configuration is proposed for the flowmeter prototype, which can help mitigate resonance between the system and the flowmeter. Experimental investigation using the prototype has shown good independence from the piping system. Furthermore, Unsteady Reynolds-Averaged Navier-Stokes (URANS) simulations have been performed and validated with a satisfactory agreement, providing confidence that URANS models can adequately predict the characteristic curve (flow rate versus frequency) of the corrugated pipe and can therefore be used to optimize the flowmeter designs cost-effectively. [ABSTRACT FROM AUTHOR]

In this work, a portable venturi tube capable of measuring bidirectional respiratory flow is developed and correlated the measurements to pulmonary function. Pressure signals are transduced using flexible and compressible capacitive foam sensors embedded into the wall of the device. In this configuration, the sensors are able to provide differential pressure readings, from which the airflow rate passing through the tube could be extrapolated. Utilizing the venturi effect, the geometry of the spirometer tube is designed through finite element analysis to measure respiratory airflow during inhalation and exhalation. The device tube is 3D‐printed and used to measure tidal breathing and deep breathing, along with peak expiratory flow rates, on a healthy individual. This spirometer design allows for easy‐to‐use point‐of‐care diagnoses and has the potential to improve the care of respiratory illnesses. [ABSTRACT FROM AUTHOR]

Multiphase flowmeters (MPFMs) measure the flow rates of oil, gas, and brine in a pipeline. MPFMs provide remote access to real-time well production data that are essential for efficient oil field operations. Most MPFMs are complex systems requiring frequent maintenance. An MPFM that is operationally simple and accurate is highly sought after in the energy industry. This paper describes an MPFM that uses only pressure sensors to measure gas and liquid flow rates. The design is an integration of a previously developed densitometer with an innovative Venturi-type flowmeter. New computing models with strong analytical foundations were developed, aided by empirical correlations and machine-learning-based flow-regime identification. A prototype was experimentally validated in a multiphase flow loop over a wide range of field-like conditions. The accuracy of the MPFM was compared to that of other multiphase metering techniques from similar studies. The results point to a robust, practical MPFM. [ABSTRACT FROM AUTHOR]

A miniature and highly sensitive fiber-optic liquid flowmeter based on Fabry–Perot interferometry (FPI) is proposed and demonstrated for fluid-flow micro-channel testing. The diaphragm deformation and pressure of the proposed sensor for flow rate detection are obtained from numerical and finite element method simulations of the theoretical model. The FPI flowmeter can be applied in real time to measure the ultra-wide dynamic range from 0 mL/min to 90 mL/min, with a response time of hundreds of milliseconds, controlling the flow rate with a resolution of 1.08 mL/min, which is 1.2% of the full scale. The quadratic functional relation between dip wavelength shifts and flow rates is verified by the flow calibration curves of the FPI flowmeter under dynamic pressure conditions. In addition, the effective temperature compensation is realized by connecting an FBG temperature sensor for variable temperature flow detection, and the measured error is reduced by nearly 25-times. The proposed sensor has the potential to measure the liquid flow rate in various applications.

Objective: Arteriovenous fistula (AVF) operations are the most common method to facilitate hemodialysis in patients with chronic renal failure. The longevity of AVF is vital in patients undergoing hemodialysis. We investigated the effect of Transit Time Flow Meter (TTFM) use on AVF patency. Methods: 108 patients (42 in the study group, 66 in the control group) who underwent AVF formation for the first time in the last five years were included in the study. In the measurements made with TTFM, if the pulsatility index (PI) was >5 and the mean flow value was <30 mL/min, AVFs were considered insufficient. Results: Age, gender, lowdensity lipoprotein values (LDL), non-dominant extremity, and accompanying peripheral artery disease in the study group of patients were similar, and smoking in the study group and hypertension in the control group were the most common risk factors. PI and mean flow rates with TFTM in the study group were within the normal range. No statistically significant difference was found in the AVF patency rates when we compared the different periods between groups. However, when evaluating the AVF patency of the groups in the whole period, it was determined that the patency of the patients in the study group was better than the control, and this finding was statistically significant. Conclusion: Intraoperative use of TTFM helps detect AVF dysfunction. This method provides a longer vascular patency time. Increases patient comfort by prolonging the function and life of the AVF. [ABSTRACT FROM AUTHOR]

The Energy Efficiency Directive (EED, Directive 2012/27/EU) has made mandatory the installation of individual metering systems in the case of buildings with centralized heating/cooling and hot water sources (multi-apartment and multi-purpose buildings), provided it is economically and technically feasible. Individual metering of heating/cooling systems is mainly based on thermal energy meters (TEM), which are widely used for direct metering in heating applications. On the other hand, direct metering of energy consumption in cooling systems still represents a challenge, given the different types of cooling units and the lack of regulations from the technical and legal points of view. In this context, this paper briefly overviews the available centralized cooling systems and the possible solutions for metering and sub-metering, which depend on the specific application. Vapour Compression Refrigeration (VCR) systems are spreading worldwide for air conditioning applications. Particular attention has been paid to the direct metering of cooling energy and specifically to refrigerant flow rate measurement, which represents a critical issue because of the small-diameter pipes and the different thermodynamic properties of the fluid used. Thus, an experimental campaign has been developed and carried out in order to compare a clamp-on ultrasonic flowmeter with a more accurate Coriolis one in a direct expansion (DE) system. The experimental tests have been performed at two different temperature conditions, showing a relative error in the mass flow rate measurements within ±10%. [ABSTRACT FROM AUTHOR]

For the small and medium diameter mono ultrasonic flowmeter due to the small number of channels vulnerable to uneven flow field distribution, a dual-channel ultrasonic water flowmeter based on the time difference method is proposed. The hardware system of the flowmeter consists of STM32L431 low-power module, high-precision timing module TDC-GP22 and other components. According to the dual-channel pipe segment structure, the data fusion method based on Kalman filter algorithm is proposed to fuse the measurement data of the two channels and complete the filtering process, which improves the measurement accuracy of the flowmeter. The experimental test shows that the flowmeter measurement error is within 2.5%, and the Kalman fusion filtering algorithm can effectively improve the flowmeter measurement accuracy.

Although partitioning of water distribution systems (WDSs) into district metered areas (DMAs) is challenging, it can be effectively used for refined management and leakage control. A two-step novel process for DMA partitioning is proposed in this study, i.e. clustering and dividing. The first step is to cluster nodes through an improved METIS graph partitioning method. The second step is to optimize the location of flowmeters and gate valves on boundary pipes by obtaining the feasible solutions. The good solutions that constitute the Pareto front were produced, which could be a tough and time-consuming task. The paper proposes the innovative and efficient dividing phase: (a) selecting the important boundary pipes by hydraulic analysis; (b) using the improved particle swarm optimization algorithm; (c) proposing three objective functions. The proposed method is applied to Modena and EXNET networks to demonstrate its feasibility. HIGHLIGHTS The improved METIS algorithm generated DMAs based on the water demand and pipe length.; The position of the flowmeter or gate valve in the boundary pipes is optimized through multiple objectives, that is, the minimum number of flowmeters, pressure balance and leakage reduction rate of three aspects.; The pressure balance takes into account the node pressure balance in each partition and minimizes the node pressure.;

Many scientific groups are engaged in the development of experimental stands for assessing blood flow through large arteries. Such stands are used to verify the results of numerical modeling, as well as for direct analysis of hemodynamics or the behavior of vascular walls or biological tissue substitutes. When developing stands, a task arises which is selecting and calibrating flowmeters that are used to measure blood flow at the entrance to the vessel and at its exits. Ultrasonic devices are quite expensive, the cost of vane flowmeters is an order of magnitude lower, but their readings may be unreliable due to the fact that they may have high hydraulic resistance. In this work, impeller flowmeters of the YF-S401 model (China) were investigated. Calibration was carried out, numerical simulation of the impeller rotation under the water flow action flowing through the flowmeters was performed, their modernization was carried out, and hydraulic resistances before and after modernization were calculated. Flowmeters were used in an experimental stand based on a pump that simulates the work of a human heart. The volumetric blood flow at the entrance to the carotid artery model with stenosis and at the exits from the internal and external carotid arteries were measured at the stand. The measured values were compared with similar characteristics obtained by numerical simulation. It was revealed that in order to use flowmeters in an experimental stand to study the dynamics of blood flow, their modernization is necessary. The modernization consisted of increasing the diameter of the inlet. Before modernization, the flow meter readings and the results of numerical modeling diverged by more than 50%. After modernization, the results of numerical modeling and flow meter readings began to differ by no more than 6%. A program has been developed that allows you to automatically collect data on blood flow from wing flowmeters. An experimental stand assembled on the basis of a pump that simulates the work of the heart and wing flowmeters can be used to evaluate blood flows using models of large human vessels.

A novel fiber-tip micro flowmeter based on optofluidic microcavity filled with silver nanoparticles solutions (SNS) is proposed. CW fiber laser was used to heat SNS that can emit heat obviously due to the excellent optic-thermo effect. The heat generated by the silver nanoparticles would be taken away as the microfluidic flows over the fiber microcavity until thermal balance is established under different velocity. The effective refractive index (RI) of the SNS changed followed by temperature of the thermal balance. The dips of the Fabry–Perot interference spectrum shift and the flow velocity can be demodulated. Moreover, the sensor can measure the flow rate with a high sensitivity due to the superior thermal conductivity and specific heat capacity of sidewalls. The max flow rate sensitivity can reach 1.5 nm/(μL/s) in the large range of 0–5 μL/s with a detection limitation (DL) of 0.08 μL/s. The Micron scale probe-type flowmeter has strong robustness and can be used to measure flow rate in tiny space. The heating medium also has an excellent biological compatibility and is not contact with the fluidics directly. As such, we believe that the proposed fiber-tip micro flowmeter has great application potentials in haematology, oil prospecting, ocean dynamics and drug research.

This article presents a microelectromechanical system (MEMS) Coriolis-based mass-flow-to-digital converter ($\Phi $ DC) that can be used with both liquids and gases. It consists of a micromachined Coriolis mass flow sensor and a CMOS interface circuit that drives it into oscillation and digitizes the resulting mass flow information. A phase-locked loop (PLL) drives the sensor at its resonance frequency ($f_{D}$), while a low 1/ $f$ noise switched-capacitor (SC) proportional–integral (PI) controller maintains a constant drive amplitude. Mass flow through the sensor causes Coriolis-force-induced displacements, which are detected by co-integrated sense capacitors. In-phase (${I}$) and quadrature (${Q}$) components of these displacements are then digitized by two continuous-time delta–sigma modulators (CT- $\Delta \Sigma $ Ms) with finite impulse response (FIR)-DACs and passive mixers. Their outputs are used to accurately estimate and cancel sense path delay, thus improving sensor stability. To ensure constant sensitivity over a wide range of fluid densities, a background sensitivity tuning (BST) scheme adjusts the sense capacitors’ bias voltage as a function of $f_{D}$ , which is a good proxy for fluid density. Implemented in a standard 0.18- $\mu \text{m}$ CMOS technology, the interface circuit consumes 13 mW from a 1.8-V supply. The proposed MEMS Coriolis $\Phi $ DC achieves a state-of-the-art noise floor of 80 $\mu \text{g}$ /h/ $\sqrt {\text {Hz}}$ and a zero stability (ZS) of ±0.31 mg/h, which is at par with MEMS thermal flow sensors. [ABSTRACT FROM AUTHOR]

Abstract Background Peak inspiratory and expiratory flows (PIF, PEF) are parameters used to evaluate the mechanics of the respiratory system. These parameters can vary based on whether they are measured using mechanical devices vs. spirometry and based on the barometric pressure at which the measurements are obtained. Our objectives were (1) to report the normal values and variability of PEF and PIF of a Latin American population living at a moderate altitude (2240 m above sea level), (2) to analyze the adjustment of reference values obtained at sea level with those obtained in healthy subjects living at a moderate altitude, and (3) to assess the correlation between PEF obtained by spirometry (PEFs) and PEF obtained by mechanical devices (PEFm). Methods In this prospective and transversal study, men and women with good respiratory health aged between 2.8 and 68 years old were invited to participate. Randomly, they underwent spirometry (to measure PEFs and PIFs) and mechanical flowmetry (to measure PEFm). Results A total of 314 subjects participated, with an average age of 24.3 ± 16.4 years; 59% were Women. The main determinants for the reference equations were age, weight, height and sex at birth. The agreement of the PEFm, PEFs and PIFs values was inconsistent with that reported by other authors, even at the same barometric pressure. The association between PEFm and PEFs was r = 0.91 (p

An air-coupled transducer was developed in this study, utilizing hollow glass microsphere-organosilicon composites as an acoustically matching layer, which demonstrated outstanding acoustic performance. Firstly, a comparison and analysis of the properties and advantages of different substrates was carried out to determine the potential application value of organosilicon substrates. Immediately after, the effect of hollow glass microspheres with different particle sizes and mass fractions on the acoustic properties of the matching layer was analyzed. It also evaluated the mechanical properties of the matching layer before and after optimization. The findings indicate that the optimized composite material attained a characteristic acoustic impedance of 1.04 MRayl and an acoustic attenuation of 0.43 dB/mm, displaying exceptional acoustic performance. After encapsulating the ultrasonic transducer using a 3D-printed shell, we analyzed and compared its emission and reception characteristics to the commercial transducer and found that its emission acoustic pressure amplitude and reception voltage amplitude were 34% and 26% higher, respectively. Finally, the transducer was installed onto a homemade ultrasonic flow meter for practical application verification, resulting in an accuracy rate of 97.4%.

Among the construction processes of Portland cement concrete pavement (PCCP), the curing compound spraying process is one of the most important processes. If the curing compound spraying amount does not meet the standard or if the curing compound is not applied evenly, distresses occur at the early age of construction, ultimately causing deterioration in concrete pavement performance. The purpose of this study is to develop a real-time monitoring system for a curing compound spraying process based on the Internet of Things (IoT) and sensing technologies to improve the construction quality of concrete pavement. To achieve the goal of this research, we conducted various laboratory and field experiments. The curing compound spraying amount and sprayed status were measured and analyzed using flowmeters, image acquisition sensors, and an image processing program, and the data were provided to workers in real time and simultaneously transmitted to the IoT cloud to form a database. From this study, it is confirmed that the IoT-technology-based curing compound spraying amount and sprayed status monitoring systems can be successfully established to manage construction quality related to the curing of concrete pavement.

Multiphase flowmeters (MPFMs) measure the flow rates of oil, gas, and brine in a pipeline. MPFMs provide remote access to real-time well production data that are essential for efficient oil field operations. Most MPFMs are complex systems requiring frequent maintenance. An MPFM that is operationally simple and accurate is highly sought after in the energy industry. This paper describes an MPFM that uses only pressure sensors to measure gas and liquid flow rates. The design is an integration of a previously developed densitometer with an innovative Venturi-type flowmeter. New computing models with strong analytical foundations were developed, aided by empirical correlations and machine-learning-based flow-regime identification. A prototype was experimentally validated in a multiphase flow loop over a wide range of field-like conditions. The accuracy of the MPFM was compared to that of other multiphase metering techniques from similar studies. The results point to a robust, practical MPFM.

Single mode-Multimode-Single mode (SMS) sensors have been attracted a relevant attention because of their simple manufacturing, their capability of sensing different quantities, and their enhanced sensitivity compared to the most common fiber optic sensor represented by Fiber Bragg Gratings (FBGs). Moreover, SMS sensors exhibit blue-shift sensitivity to strain, opposite to FBGs, making them suitable in applications where strain-temperature cross-sensitivity may be an issue. SMS sensors are made by splicing a short multimode, preferably a two mode or quasi two-mode, optical fiber jumper between single mode pigtails. The interference of the modes propagating at different phase velocities produces a spectral pattern that shifts with temperature, strain or any perturbation of the phase difference among the modes. In this paper we review the main features of SMSs as temperature sensors and we present a potential biomedical application in an all-fiber flowmeter based on the hot-wire principle: a fiber-coupled laser source at 980 nm is used as a controllable heating source of the SMS sensor that, when immersed in fluid flow, converts the temperature variation, caused by the heat removal, into a wavelength shift of the transmitted spectrum. Thermal characterization and proof-of-concept experiments show the feasibility and functionality of the sensor and provide an outlook on possible developments and potential applications. [ABSTRACT FROM AUTHOR]

This research deals with the oscillation frequency of a classical and simple flip-flop jet nozzle with one feed-back loop based on the measurements of pressure and velocity. From these measurements, the traces of pressure difference between both ends of a connecting tube are modeled by a triangular wave, and the flow velocities in the connecting tube are calculated numerically. The resulting accumulated flow work, which consists of the time integral of mass flux into the re-circulation region on the low pressure side wall from the re-circulation region on the opposite high-pressure side wall through the connecting tube, is more adequate to determine jet-oscillation frequency than any other time integrals. This includes those of momentum flux and kinetic-energy flux. It is confirmed that jet-oscillation frequency predicted on the basis of this accumulated flow work agrees well with experiment. [ABSTRACT FROM AUTHOR]

Telah dilakukan pembuatan sistem otomasi untuk ekstraksi radiocessium pada filter preparasi dan filter pengambilan sampel dalam menentukan kualitas air. Sistem otomasi dilakukan dengan cara mengintegrasikan antara pompa, flowmeter dan sensor pendeteksi cairan mengunakan perangkat keras Arduino Uno. Struktur pemrograman yang ditanamkan pada perangkat Arduino menggunakan bahasa pemrograman C dan dikomunikasikan secara serial dengan komputer menggunakan bahasa pemrograman LabVIEW. Validasi sistem otomasi pada mode sampling dilakukan dengan membandingkan antara volume set poin dengan volume yang dihasilkan serta membandingkan tingkat kejernihan cairan. Untuk mengetahui tingkat keberhasilan preparasi pada filter ekstraksi dilakukan pengambilan data pada cairan yang digunakan sebagai media ekstraksi. Data hasil rekaman flowmeter diperoleh persamaan y = 2601.3𝑥-31.183 dengan linearitas sebesar 0.9788. Karakteristik ADC pada cairan ekstraksi berkisar antara 30 – 60. nilai tersebut digunakan sebagai referensi pada mode preparasi media ekstraksi filter radiocesium. Hasil validasi sistem otomasi tersebut menampilkan kesesuaian antara parameter yang di input dengan yang dihasilkan serta kestabilan pada pembacaan parameter.

Single mode-Multimode-Single mode (SMS) sensors have been attracted a relevant attention because of their simple manufacturing, their capability of sensing different quantities, and their enhanced sensitivity compared to the most common fiber optic sensor represented by Fiber Bragg Gratings (FBGs). Moreover, SMS sensors exhibit blue-shift sensitivity to strain, opposite to FBGs, making them suitable in applications where strain-temperature cross-sensitivity may be an issue. SMS sensors are made by splicing a short multimode, preferably a two mode or quasi two-mode, optical fiber jumper between single mode pigtails. The interference of the modes propagating at different phase velocities produces a spectral pattern that shifts with temperature, strain or any perturbation of the phase difference among the modes. In this paper we review the main features of SMSs as temperature sensors and we present a potential biomedical application in an all-fiber flowmeter based on the hot-wire principle: a fiber-coupled laser source at 980 nm is used as a controllable heating source of the SMS sensor that, when immersed in fluid flow, converts the temperature variation, caused by the heat removal, into a wavelength shift of the transmitted spectrum. Thermal characterization and proof-of-concept experiments show the feasibility and functionality of the sensor and provide an outlook on possible developments and potential applications.

The Energy Efficiency Directive (EED, Directive 2012/27/EU) has made mandatory the installation of individual metering systems in the case of buildings with centralized heating/cooling and hot water sources (multi-apartment and multi-purpose buildings), provided it is economically and technically feasible. Individual metering of heating/cooling systems is mainly based on thermal energy meters (TEM), which are widely used for direct metering in heating applications. On the other hand, direct metering of energy consumption in cooling systems still represents a challenge, given the different types of cooling units and the lack of regulations from the technical and legal points of view. In this context, this paper briefly overviews the available centralized cooling systems and the possible solutions for metering and sub-metering, which depend on the specific application. Vapour Compression Refrigeration (VCR) systems are spreading worldwide for air conditioning applications. Particular attention has been paid to the direct metering of cooling energy and specifically to refrigerant flow rate measurement, which represents a critical issue because of the small-diameter pipes and the different thermodynamic properties of the fluid used. Thus, an experimental campaign has been developed and carried out in order to compare a clamp-on ultrasonic flowmeter with a more accurate Coriolis one in a direct expansion (DE) system. The experimental tests have been performed at two different temperature conditions, showing a relative error in the mass flow rate measurements within ±10%.

At a combined cycle power plant, gas turbine cooling air flowrate data is required for operation and maintenance because it is an important for analyzing not only the temperature of both stators and blades but also plant efficiency. However, it is very difficult to measure the data. An ultrasonic flowmeter cannot be used since the measurement position becomes hot, usually exceeding 300 degrees centigrade. An insert type flowmeter is also difficult to use as it requires additional pipe processing for installation and also causes a pressure loss. Accordingly, we tried to use the heater method, which we proposed and validated in our previous papers. In this method, a circumferential heater is attached to the outside of a pipe and then the axial temperature distribution along the outside of the pipe, which is influenced by the fluid velocity in the pipe, is measured by thermocouples. The velocity is analyzed on the basis of the temperature distribution along the pipe. Measurements were conducted for two kinds of cooling air pipe at an advanced combined cycle power plant. In one, cooling air is extracted from the 13th stage of a compressor and supplied to the 2nd stators of the gas turbine; in the other, cooling air is extracted from the 9th stage of the compressor and supplied to the 3rd stators of the gas turbine. As a result, it was clarified that the cooling air flowrate had a positive dependence on atmospheric temperature at the plant. The dependence was also compared to that of a tit 1,600 degrees centigrade-class combined cycle power plant, with a power output of 700 MW.

In order to solve the problem of single well without liquid phase measurement in Sulige Gas Field under the process mode of interwell series connection and wellhead wet gas measurement, a method of combining throttle flowmeter and vortex flowmeter to measure wet gas-liquid two-phase flow was proposed. The overall structure of flowmeter was simplified by integrating two kinds of flowmeter measuring tubes and adopting differential pressure static pressure, frequency and temperature integrated sensors. The indoor air-water two-phase flow experimental platform was used to test the measurement accuracy of the wet gas flowmeter. The results show that when the instantaneous liquid volume is 0.05-4 m3/h, the gas and liquid measurement errors of the combined wet gas flowmeter are within 5% and 20% respectively. The measurement accuracy of the wet gas flowmeter was tested at the wellhead of the gas well by using the separation metering device. The results show that the average error of gas and liquid phase measurement in the bubble exhaust well is less than 5% and 20% respectively, which can accurately reflect the liquid production law of the gas well and guide the optimization of the bubble discharge and filling system; the gas phase measurement error in the plunger gas lift well is less than 8%, and the liquid phase measurement error is large, but it can accurately reflect the liquid production characteristics of the plunger gas well, which could provide the basis for working condition diagnosis and production system optimization of plunger gas well.

Background: Peak inspiratory and expiratory flows (PIF, PEF) are parameters used to evaluate the mechanics of the respiratory system. These parameters can vary based on whether they are measured using mechanical devices vs. spirometry and based on the barometric pressure at which the measurements are obtained. Our objectives were (1) to report the normal values and variability of PEF and PIF of a Latin American population living at a moderate altitude (2240 m above sea level), (2) to analyze the adjustment of reference values obtained at sea level with those obtained in healthy subjects living at a moderate altitude, and (3) to assess the correlation between PEF obtained by spirometry (PEFs) and PEF obtained by mechanical devices (PEFm).Methods: In this prospective and transversal study, men and women with good respiratory health aged between 2.8 and 68 years old were invited to participate. Randomly, they underwent spirometry (to measure PEFs and PIFs) and mechanical flowmetry (to measure PEFm).Results: A total of 314 subjects participated, with an average age of 24.3 ± 16.4 years; 59% were Women. The main determinants for the reference equations were age, weight, height and sex at birth. The agreement of the PEFm, PEFs and PIFs values was inconsistent with that reported by other authors, even at the same barometric pressure. The association between PEFm and PEFs was r = 0.91 (p < 0.001), and the correlation coefficient of concordance was 0.84.Conclusions: The PEFm, PEFs, and PIFs measurements in individuals living at moderate altitudes are different from those found by other authors in cities with different barometric pressures and ethnicities. [ABSTRACT FROM AUTHOR]

The paper proposes a new type of gas flowmeters based on measurements of the deformations of the thermal field of the heater in the presence of a flow using vibrating wires. The advantage of such flowmeters as compared with the known ones using a similar thermal principle of operation is the improved accuracy of temperature measurements compared to resistance thermometers or thermocouples. The use of thin wires can also increase the speed of flowmeters. The use of wires 20–30 mm long allows the creation of wide-aperture inlet holes for gas streams. A natural property of the developed flowmeters is also in their bidirectionality. A sample of a flowmeter based on vibrating wires was made and the calibration experiments were carried out. An experiment was carried out in which a flowmeter was used to measure the acceleration. [ABSTRACT FROM AUTHOR]

The key equipment of oil and gas pipelines is the important treasure of a country because they are related to national energy security. For many years, the key equipment has been imported, which become a bottleneck restricting the high-quality development of oil and gas industry in China. Thus, great attention was attracted from the CPC Central Committee and the State Council to localization, and it was decided to fully guard against and mitigate the risk of "stranglehold" through independent research. With the powerful support of the National Energy Administration and China Machinery Industry Federation, CNPC launched the localization work for equipment in oil and gas pipelines in 2007, set up two batches of major projects of science and technology localization, cooperated with 35 domestic manufacturers. As a result, a major breakthrough was made in the localization of 6 kinds of key equipment, such as compressor unit, oil pump set and valve, which breaks the foreign monopoly, ensures the independence and controllability of oil and gas energy, and further promotes the development of domestic equipment manufacturing to the high end.

The paper considers the application of nuclear magnetic resonance for measurement of fluid-flow. The paper is of an experimental nature. Flowmeter based on nuclear magnetic resonance is extremely precise. The combined measurement uncertainty can be 0.1 %. Such a value of measurement uncertainty indicates that it is a matter of a deterministic and not of a stochastic quantity. This high degree of reliability of the method is theoretically and mathematically described. The paper presents a measurement scheme for flow measurement. Water flow measurement was performed on the principle of nuclear magnetic resonance and on the basis of tritiated water (which is considered to be the most accurate classical method). The obtained results show that the measurement of flow based on nuclear magnetic resonance is more accurate (especially at higher flow). This is explained by the higher inertial mass of HTO tritiated water molecules than the standard H2 O mass and the possible transition of tritiated water to H3HeO. In this way, it has been proven that tracing water based on nuclear magnetic resonance is the only real tracing of water by water. The obtained results show that tracing water with tritiated or heavy water is not tracing water by water which is explained by different inertial masses.

A new capacitive microelectromechanical system (MEMS) microcantilever gas flow sensor is introduced for application in industrial gas flow measurement pipelines. The chip encompasses microcantilevers with different lengths (50, 100, 250, and $400~\mu \text{m}$) and the same thickness and wideness of 2 and $50~\mu \text{m}$ , respectively. Besides MEMS sensor development, we have designed a customized bypass channel based on the orifice principle for the placement of the MEMS sensor chip. Accordingly, a minibypass has been designed, which alleviates the harsh flow condition on the sensor that will be placed in the flowmeter housing. Simulations and the experimental study revealed that the sensor is capable of measuring airflows from 0 to 25 m/s with a sensitivity of $2\times 10 ^{-4}$ pF/m/s, and this can be expanded to other gas flow measurements with a certain bandwidth. This measurement allows us to apply this sensor for measuring moderate flows up to ~200 m/s in ~10-cm diameter pipes based on the current design for bypass. According to experimental results, the sensor output capacitance varied from 3.3445 to 3.350 pF for a range of airflow between 0 and 25 m/s. We have shown that capacitive microcantilever MEMS flow sensors could be used for flow measurements in heavy-load industrial applications. [ABSTRACT FROM AUTHOR]

Large flowmeters are used in many industrial facilities, including power plants, coolingwater stations for refineries, and petrochemical plants. These flowmeters are employed for various purposes, including billing. Just like all machines, flowmeters are subject to failure. Drift is a particular type of failure in which the flowmeter produces an error in measurement that would incrementally increase with time. Maintenance technicians calibrate and fix all measuring equipment, including flowmeters. Nevertheless, downsizing policies and budget cuts in most contemporary industrial facilities have made these technicians overwhelmed with work. A mathematical and computer-based drift-detection scheme is developed to reduce the burden of the maintenance staff. The detection scheme only uses the flowmeter's flow data and the discrete Fourier transform (DFT). The detection scheme was applied over the flow data from an actual flowmeter that drifted during its operation. DFT application over the data produced by the flowmeter led to expected results and other unexpected results. This paper discusses both results and suggests areas for further study. Practically speaking, the scheme would facilitate the early detection of drifts in flowmeters having seasonal flow regardless of type or manufacturer. [ABSTRACT FROM AUTHOR]