142 research outputs found

    Numerical Modelling and Simulation of Two-Phase Flow Flushing Method for Pipeline Cleaning in Water Distribution Systems

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    Secondary pollution by microorganisms and substances peeling of from the “growth ring” causes clean water deterioration during the water distribution process. In order to reduce the secondary pollution, our previous research investigated the best settings of a two-phase flow flushing method for pipeline cleaning in water distribution systems experimentally, and a case study was carried out for comparison of the efficiencies between two-phase and single-phase flow methods. In this paper, based on the results of the experimental study, numerical modelling and a simulation study are carried out by FLUENT to evaluate the performance of the two-phase flow flushing method for removal of the “growth ring”. Results: the simulation results match the experimental results; pressure, water-phase flow velocity and water-phase volume ratio distributions in a section of pipe are simulated and analysed; the shear force against time in a period is obtained; elbow pipes cause flushing energy loss, and therefore, at most one section of elbow pipe is flushed in one flushing perio

    A Wireless Passive SAW Delay Line Temperature and Pressure Sensor for Monitoring Water Distribution System

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    Wireless passive surface acoustic wave (SAW) sensor has been widely used in many applications. This paper presents a feasibility study on a designed wireless passive SAW delay line temperature and pressure sensor for monitoring water distribution systems. The substrate of the sensor node is a Y-Z orientation cut LiNbO3 crystalline with 0.5 mm thickness. The Interdigital transducer (IDT) was fabricated centrally on the surface of the substrate with an antenna connected. There are three reflectors fabricated on the same surface of the IDT. One reflector is on one side and the other two are on the other side of the IDT. A simulated water pipe platform with testing devices was assembled to test the feasibility of the sensor node working in water pipe environment. The experimental result showed that the designed sensor worked properly but 4/5 amplitude of signals is lost compared to the experimental results in the open-air environment

    SAW Delay Line based Smart Sensing in Water Distribution System

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    Wireless Passive Surface Acoustic Wave (SAW) sensors have attracted great attention in numerous applications. They are powered by interrogating Radio Frequency (RF) pulses rather than batteries. In this study, a wireless passive SAW temperature and pressure delay line sensor was adapted in a designed framework which can control the ambient liquid temperature and pressure and characterised. The experimental results meet the theoretical analysis that the related phase delay of the response signal depends linearly on the temperature (pressure) when the pressure (temperature) keeps constant

    A Fast Near-Infrared Image Colorization Deep Learning Mode

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    Near-infrared(NIR) image colorization is the main research content in the field of current near-infrared image application. It has a wide range of application value. For the problem of image colorization, such as diffuse color and even color error, and can not be automated, A fast near-infrared image colorization model consisting of a lightweight image recognition network module and an image colorization CNN module with a fusion layer, firstly using a lightweight image recognition network for image recognition of near-infrared images, and then selecting from the IamgeNet image library The image of the same class as the scene is used as the training set of the colorized network. After training with the colored CNN module with the fusion layer, the near-infrared image is input as the testing set for colorization. The experimental results show that the color is colored by the algorithm. The image details are clear, the color transfer effect is good and the running speed is fast

    An MDE-based Methodology for Closed-World Integrity Constraint Checking in the Semantic Web

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    Ontology-based data-centric systems support open-world reasoning. Therefore, for these systems, Web Ontology Language (OWL) and Semantic Web Rule Language (SWRL) are not suitable for expressing integrity constraints based on the closed-world assumption. Thus, the requirement of integrating the open-world assumption of OWL/SWRL with closed-world integrity constraint checking is inevitable. SPARQL, recommended by World Wide Web (W3C), is a query language for RDF graphs, and many research studies have shown that it is a perfect candidate for closed-world constraint checking for ontology-based data-centric applications. In this regard, many research studies have been performed to transform integrity constraints into SPARQL queries where some studies have shown the limitations of partial expressivity of knowledge bases while performing the indirect transformations, whereas others are limited to a platform-specific implementation. To address these issues, this paper presents a flexible and formal methodology that employs Model-Driven Engineering (MDE) to model closed-world integrity constraints for open-world reasoning. The proposed approach offers semantic validation of data by expressing integrity constraints at both the model level and the code level. Moreover, straightforward transformations from OWL/SWRL to SPARQL can be performed. Finally, the methodology is demonstrated via a real-world case study of water observations data

    A Multi-Iteration Enhanced 2P-SMA Method for Improved Error Reduction on a WP-SAW Water Temperature and Pressure Sensor

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    Due to the instability of the characteristics of materials, fabrication processes and user handling, newly designed and fabricated wireless passive surface acoustic wave (WP-SAW) sensor nodes have inconsistent sensing performance. Furthermore, ambient environmental interferences aggravate inconsistences under complex working conditions. In this paper, a multi-iteration enhanced two-point simple moving average (MI-2P-SMA) method is proposed for sensing error reduction of a WP-SAW reflective delay line water temperature and pressure sensor. This method is improved from the traditional 2P-SMA method for better performance on error reduction. The results show: the MI-2P-SMA method does not change the original characteristics of experimental data; it can reduce relative errors of the WP-SAW reflective delay line water temperature and pressure sensor and has better performance than a traditional 2P-SMA method; it reduces the number of data points and the extent of this reduction is dependent on iteration time

    Clinicopathological and Prognostic Characteristics of Hepatoid Adenocarcinoma of the Stomach

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    The present study was undertaken to clarify the association of the clinicopathological features of hepatoid adenocarcinoma (HAC) in the stomach, a special kind of carcinoma that histologically resembled hepatocellular carcinoma (HCC) and is characterized by large amounts of α-fetoprotein (AFP) in serum, with the clinical prognosis. We collected the data of the clinicopathological features and the follow-up information from a total of 31 HACs from January 2005 to December 2012 in our hospital. High lymphatic (54.8%) and distant (25.8%) metastasis rates before surgery, large proportion of advanced HACs (71.0%) at admission, short median overall survival time (6 months), and low three-year survival rate (22.6%) suggested that HAC in the stomach was an aggressive disease, resulting in a poor prognosis. And pTNM stages, immunohistochemical staining of AFP, CEA, CK7, and CK20 had statistically relation with the survival as the independent risk factors, P<0.05. Therefore, early and clear differentiation of HAC from cancerous or noncancerous conditions with AFP elevation and assessment of high risk patients by histopathology may improve the clinical prognosis

    An Experimental Study of Two-Phase Pulse Flushing Technology in Water Distribution Systems

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    Abstract: The deterioration of drinking water during distribution process is caused by many factors. The microorganisms and substances peeling off from the “growth-ring” make the secondary pollution in drinking water distribution systems. To reduce the secondary pollution, two-phase pulse flushing technology is introduced to quickly remove the “growth-ring”. In this study, experiment is undertaken for investigating the efficiency of the two-phase pulse flushing and finding the best setting combination. A case study is undertaken to compare the efficiencies between the two-phase pulse and the single-phase flushing. The best setting combination of the two-phase pulse flushing is at the frequency 4 s–6 s (air inflow time is 4 s and air cut off time is 6 s) and the round air inflow nozzle is set at the bottom of the pipe. Two-phase pulse flushing technology can save 95% of water and 6 h 40 min flushing time

    Water Pressure Sensing based on Wireless Passive SAW Technology

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    The conventional water pressure measurement method requires batteries as power sources for pressure sensors. This method is unreliable because the risk of damaging batteries is high especially in harsh environment. This paper provides a novel method that wireless passive surface acoustic wave (SAW) pressure sensor is introduced for water pressure measurement. Wireless passive SAW sensors do not need direct power supply. Therefore, batteries are not required by using this new technology. The main types of wireless passive SAW sensors are reviewed. The performance of wireless passive SAW sensor is tested. The water pressure sensing framework is propose
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