scholarly journals Monitoring of the Operating Membrane Condition Using PZT Based EMI of External Steel Pipe

Water ◽  
2021 ◽  
Vol 13 (23) ◽  
pp. 3407
Author(s):  
Junkyeong Kim ◽  
Jungyeol Eom ◽  
Sangyoup Lee ◽  
Yong-Soo Lee ◽  
Hyung-Soo Kim
Keyword(s):  
Lead Zirconate Titanate ◽  
Membrane Damage ◽  
Pressure Gauge ◽  
Mechanical Impedance ◽  
Pressure Change ◽  
Operating Conditions ◽  
Steel Pipe ◽  
Major Peak ◽  
Decay Test ◽  
Reference Pressure

Membrane systems are increasingly being used for treating water, wastewater, and reused water. However, membrane damage can decrease removal efficiency and hinder downstream applicability. Thus, the operating conditions of the membrane should be monitored. This study monitored the operating conditions of the membrane using lead zirconate titanate (PZT)-based electro-mechanical impedance (EMI) measurements in an external air pipe. Pilot-scale tests were performed to verify the performance of the proposed method. A pressure decay test (PDT) was performed using a PZT-attached air pipe, in which the pressure was measured using PZT, and a pressure gauge was employed to measure the reference pressure. The EMI signals changed according to the variations in the pressure inside the steel air pipe. To index the signal variation, the amplitude of the major peak was extracted and compared with the reference pressure. The amplitude of the major peak was inversely proportional to the pressure change. The pressure estimation equation was derived using a linear regression between the amplitudes of the major peak and the reference pressures. According to the results, the proposed monitoring system that utilizes the EMI of an external steel pipe is a potential solution to improve the sensitivity and speed of the PDT.

Stabilization of the Speed of the Hydraulic Motor Through Throttle Compensation for Volume Losses

2020 ◽  
Vol 26 (3) ◽  
pp. 126-130
Author(s):  
Krasimir Kalev
Keyword(s):  
Flow Rate ◽  
Hydraulic Drive ◽  
Pressure Change ◽  
Operating Conditions ◽  
Drive System ◽  
Inlet Pressure ◽  
Schematic Diagram ◽  
Hydraulic Characteristics ◽  
Hydraulic Motor ◽  
Flow Through

AbstractA schematic diagram of a hydraulic drive system is provided to stabilize the speed of the working body by compensating for volumetric losses in the hydraulic motor. The diagram shows the inclusion of an originally developed self-adjusting choke whose flow rate in the inlet pressure change range tends to reverse - with increasing pressure the flow through it decreases. Dependent on the hydraulic characteristics of the hydraulic motor and the specific operating conditions.

Relationships Between Microstructure and Reliability in Pzt Mems

2001 ◽  
Vol 666 ◽  
Author(s):  
B.W. Olson ◽  
L.M. Randall ◽  
C.D. Richards ◽  
R.F. Richards ◽  
D.F. Bahr
Keyword(s):  
Grain Size ◽  
Lead Zirconate Titanate ◽  
Sol Gel ◽  
Electrical Energy ◽  
Lead Zirconate ◽  
Fatigue Tests ◽  
Operating Conditions ◽  
Processing Route ◽  
Bulge Testing ◽  
Sol Gel Process

ABSTRACTPiezoelectric oxide films, such as lead zirconate titanate (PZT), are now being integrated into MEMS applications. Many PZT derived systems are deposited using a sol-gel process, which can be used in a microelectronics processing route using spin coating as the deposition method. An application of interest for PZT films is in power generation, where a flexing membrane is used to transform mechanical to electrical energy. The current study was undertaken to identify the relationships between the processing, microstructure, and mechanical reliability of these films. Films were deposited onto both monolithic and bulk micromachined platinized silicon wafers using standard sol-gel chemistries, with roughness and grain size tracked using electron and scanning probe microscopy. Mechanical properties were evaluated in a dynamic bulge testing apparatus. Grain size variations in the Pt film between 35 and 125 nm are shown to have little effect on grain size of the subsequent PZT film and the adhesion of the PZT to the Pt film. Only the Pt film with 125 nm grains was shown to undergo any significant interfacial fracture. Fatigue tests suggest film lifetime is primarily limited by the number of pre- existing flaws in the film from processing. Reducing the microcrack density has been shown to produce films and devices that fail at strains of 1.4% and have mechanical fatigue lifetimes in excess of 100 million cycles at strains simulating the operating conditions.

An Energy-Regenerative Suspension System

2018 ◽  
Author(s):  
Thomas Lato ◽  
Huiyong Zhao ◽  
Lin Zhao ◽  
Yuping He
Keyword(s):  
Fuel Economy ◽  
Pressure Gauge ◽  
Suspension System ◽  
Operating Conditions ◽  
Dissipated Energy ◽  
Stroke Length ◽  
Shock Absorbers ◽  
Road Roughness ◽  
Vehicle Suspension System ◽  
Variable Speed Motor

This paper presents an energy-regenerative suspension device that is able to harvest some of the wasted energy that is generated in a suspension system. For a traditional road vehicle suspension system, shock absorbers are mainly dissipating energy to reduce vibration. The dissipated energy may be collected to improve the fuel economy of road vehicles. In this research, CarSim and Simulink are used to simulate and determine the harvestable energy in a conventional shock absorber under different operating conditions. A conceptual energy-regenerative absorber is designed and tested using a fabricated prototype. A variable speed motor is implemented to adapt the change of stroke length of a mechanism due to the various road roughness. Instruments, e.g., laser tachometer, pressure gauge, ammeter, voltmeter, and stopwatch, are used to collect data. The simulation and prototype testing results indicate that the proposed energy-regenerative suspension device could harvest dissipated energy to improve vehicle fuel economy.

Interfacial debonding detection in fiber-reinforced polymer rebar–reinforced concrete using electro-mechanical impedance technique

2017 ◽  
Vol 17 (3) ◽  
pp. 461-471 ◽  
Author(s):  
Weijie Li ◽  
Shuli Fan ◽  
Siu Chun Michael Ho ◽  
Jianchao Wu ◽  
Gangbing Song
Keyword(s):  
Reinforced Concrete ◽  
Lead Zirconate Titanate ◽  
Health Monitoring ◽  
Mechanical Impedance ◽  
Lead Zirconate ◽  
Fiber Reinforced Polymer ◽  
Carbon Fiber Reinforced Polymer ◽  
Fiber Reinforced ◽  
Reinforced Polymer ◽  
Monitoring Technique

For reinforced concrete structures, the use of fiber-reinforced polymer rebars to replace the steel reinforcement is a topic that is receiving increasing attention, especially where corrosion is a serious issue. However, fiber-reinforced polymer rebar–reinforced concrete always carries the risk of structural failure initiated from the debonding damage that might occur at the reinforcement–concrete interface. This study employed an electro-mechanical impedance–based structural health monitoring technique by applying lead–zirconate–titanate ceramic patches to detect the debonding damage of a carbon fiber–reinforced polymer rebar reinforced concrete. In the experimental study, a carbon fiber–reinforced polymer rebar reinforced concrete specimen was fabricated and it was subjected to a pullout test to initiate the debonding damage at the reinforcement–concrete interface. The impedance and admittance signatures were measured from an impedance analyzer according to the different debonding conditions between the reinforcement and the concrete. Statistical damage metrics, root-mean-square deviation and mean absolute percentage deviation, were used to quantify the changes in impedance signatures measured at the lead–zirconate–titanate patches due to debonding conditions. The results illustrated the capability of the electro-mechanical impedance–based structural health monitoring technique for detecting the debonding damage of fiber-reinforced polymer rebar–reinforced concrete structures.

Evaluation of the ISHM Method Applied for Composite Rotors

2019 ◽  
Author(s):  
Karina M. Tsuruta ◽  
Lucas A. A. Rocha ◽  
Aldemir Ap. Cavalini ◽  
Roberto M. Finzi Neto ◽  
Valder Steffen
Keyword(s):  
Lead Zirconate Titanate ◽  
Electrical Impedance ◽  
Optimization Procedure ◽  
Mechanical Impedance ◽  
Lead Zirconate ◽  
Sensors And Actuators ◽  
Present Contribution ◽  
Structure Damage ◽  
Electromechanical Impedance ◽  
Rotor Shaft

Abstract The use of SHM (structural health monitoring) techniques has shown promising results for fault detection in rotating machines, making possible to identify various malfunctions. SHM methods provide maintainability and safe operation for these systems. The objective of the present work is to evaluate the SHM method based on the electromechanical impedance (ISHM) to detect faults in a composite rotor shaft. Composite materials present complex damage mechanisms due to their anisotropy and heterogeneity. Moreover, the process of damage detection in these materials is more challenging than in metallic structures. The ISHM approach uses piezoelectric (PZT – Lead Zirconate Titanate) patches as sensors and actuators coupled to the monitored structure. Variations in their electrical impedance are associated with changes in the mechanical integrity of the system. The electrical impedance of the PZT sensor is directly related to the mechanical impedance of the structure, which changes according to variations in the mass, stiffness, and damping properties of the structure. Damage metrics are used to quantify variations in the electrical impedance (impedance signatures) of the PZT patches. Despite the ISHM approach be able to detect incipient faults, it presents some disadvantages. For instance, the impedance signatures are susceptible to temperature variation. In the present contribution, to detect damages in the considered composite rotor shaft, the ISHM technique was implemented based on a data normalization methodology. Thus, an optimization procedure based on hybrid optimization was used to avoid false diagnostics.

scholarly journals An Ultrasonic Rheometer to Measure Gas Absorption in Ionic Liquids: Design, Calibration and Testing

Sensors ◽  
2020 ◽  
Vol 20 (12) ◽  
pp. 3544
Author(s):  
Michele Schirru ◽  
Michael Adler
Keyword(s):  
Thermal Cycling ◽  
Lead Zirconate Titanate ◽  
Tungsten Bronze ◽  
Hydrogen Gas ◽  
Operating Conditions ◽  
Gas Absorption ◽  
Time Duration ◽  
Suitable Material ◽  
Lead Metaniobate ◽  
Titanate Lead

The first goal of this study is to identify the ideal piezoelectric material for the manufacturing of rheological reflectance ultrasonic sensors. The second goal is to integrate the ultrasonic rheometer within a gas absorption reactor and to measure viscosity changes in an ionic liquid (IL) caused by gas absorption. To achieve the objectives, bismuth titanate, lead titanate, lead metaniobate and lead zirconate titanate materials in layer, tungsten bronze and perovskite structures were assembled on aluminum delay lines and tested under thermal cycling between room temperature and 150 °C. The results showed that lead metaniobate in tungsten bronze structure is the most suitable material for long time duration thermal cycling. Therefore, the ultrasonic rheometer was assembled using this material and installed in a pressurized reactor to test a reference IL at the operating conditions of 50 °C and at a pressure of 80 bar. The reference IL was saturated with nitrogen as well as hydrogen gas. Viscosity signals remained constant under the hydrogen atmosphere, while in nitrogen atmosphere the absorption of the gas lead to a rise in the value of viscosity.

scholarly journals Looseness Monitoring of Bolted Spherical Joint Connection Using Electro-Mechanical Impedance Technique and BP Neural Networks

Sensors ◽  
2019 ◽  
Vol 19 (8) ◽  
pp. 1906 ◽  
Author(s):  
Jing Xu ◽  
Jinhui Dong ◽  
Hongnan Li ◽  
Chunwei Zhang ◽  
Siu Chun Ho
Keyword(s):  
Neural Networks ◽  
Lead Zirconate Titanate ◽  
Back Propagation ◽  
Mechanical Impedance ◽  
High Strength ◽  
Lead Zirconate ◽  
Spherical Joint ◽  
High Strength Bolt ◽  
Space Grid ◽  
Joint Connection

The bolted spherical joint (BSJ) has wide applications in various space grid structures. The bar and the bolted sphere are connected by the high-strength bolt inside the joint. High-strength bolt is invisible outside the joint, which causes the difficulty in monitoring the bolt looseness. Moreover, the bolt looseness leads to the reduction of the local stiffness and bearing capacity for the structure. In this regard, this study used the electro-mechanical impedance (EMI) technique and back propagation neural networks (BPNNs) to monitor the bolt looseness inside the BSJ. Therefore, a space grid specimen having bolted spherical joints and tubular bars was considered for experimental evaluation. Different torques levels were applied on the sleeve to represent different looseness degrees of joint connection. As the torque levels increased, the looseness degrees of joint connection increased correspondingly. The lead zirconate titanate (PZT) patch was used and integrated with the tubular bar due to its strong piezoelectric effect. The root-mean-square deviation (RMSD) of the conductance signatures for the PZT patch were used as the looseness-monitoring indexes. Taking RMSD values of sub-frequency bands and the looseness degrees as inputs and outputs respectively, the BPNNs were trained and tested in twenty repeated experiments. The experimental results show that the formation of the bolt looseness can be detected according to the changes of looseness-monitoring indexes, and the degree of bolt looseness by the trained BPNNs. Overall, this research demonstrates that the proposed structural health monitoring (SHM) technique is feasible for monitoring the looseness of bolted spherical connection in space grid structures.

Design and operating experiences of municipal MBRs in Europe

2008 ◽  
Vol 58 (12) ◽  
pp. 2319-2327 ◽  
Author(s):  
H. Itokawa ◽  
C. Thiemig ◽  
J. Pinnekamp
Keyword(s):  
Membrane Bioreactor ◽  
Membrane Damage ◽  
Full Scale ◽  
Operating Conditions ◽  
Small Scale ◽  
Membrane Unit ◽  
Effluent Quality ◽  
Membrane Flux ◽  
The Moment ◽  
And Control

The number of membrane bioreactor (MBR) installations is increasing worldwide, not only for small-scale industrial WWTPs but also for larger-scale municipal WWTPs. In Europe, MBR has been installed in municipal WWTPs since late 1990s, and more than 100 full-scale plants are operated at the moment. In this paper, present state of European municipal MBRs is described in terms of design and operating conditions, as well as operating problems and their solutions, based on the information collected from 17 full-scale WWTPs by interview and questionnaire survey. Decisive factors of MBR installation at these plants were footprint and effluent quality. Full-aerobic and pre-denitrification were the most common reactor configurations, nearly half of them being equipped with independent filtration tanks. Operating conditions of bioreactor and filtration, including membrane flux and cleaning strategy, were different from plant to plant, as a result of plant-specific optimization experiences, even among the similar type of membrane. Operating problems specific for MBR were reported, including blocking/failure of pre-screen, sludging/hair-clogging of membrane, damage on membrane unit, air in permeate pipes, as well as conventional troubles including occurrence of scum and initial trouble in instrumentation and control systems. Aspects for further optimization of MBR design were also pointed out by the operators.

Qualification of Gasket Performance for Vacuum Applications

2010 ◽  
Author(s):  
Walter Lee ◽  
Abdel-Hakim Bouzid ◽  
James Huang
Keyword(s):  
Elevated Temperatures ◽  
Flow Behavior ◽  
Pressure Gauge ◽  
Pressure Rise ◽  
Operating Conditions ◽  
Test Method ◽  
Vacuum System ◽  
Molecular Flow ◽  
Vacuum Level ◽  
The Impact

Gasket performance for vacuum applications has not been well studied. Although a wealth of sealability data has been generated for pressurized systems, little is done with vacuum conditions. A new test method has been developed to study the sealing performance of gaskets for vacuum services. The tests were conducted on a standard ROTT test rig, where a vacuum chamber surrounding the gasket was created by an air pump and monitored by a pressure gauge capable of measuring pressures down to 0.1 Torr. Two levels of vacuum were used: 50 Torr and 3 Torr. Each tested gasket was compressed to various assembly stresses corresponding to the levels defined in the ROTT procedure. After the gasket was compressed to a desired stress and a target vacuum level was reached, the pumping stopped, and the leak rate was measured, using the pressure rise method. The similar leakage results with two very different vacuum levels confirm that sealing a vacuum system is simply to seal ∼1 bar of air. The air leakage was further compared with the helium leak rates obtained from the standard ROTT test with a pressure of 21 bar to determine the correlation between the two data sets. To better understand the effects of pressure and molecular size of a gas, two additional tests at 2 bar, with helium and with nitrogen, were performed. The comparison among all test data suggests that the gases at relatively low pressures follow a molecular flow behavior up to about 55 MPa of gasket stress on the tested material. As a result, a tightness curve that can be used to estimate the vacuum leakage has been established. For applications involving elevated temperatures, thermal behaviors of gaskets determined by other PVRC tests, such as the HOBT and ARLA, can be used to understand the impact of temperature on vacuum performance. A stress-tightness-temperature framework is proposed that can be used to estimate the tightness and leakage of the gasket at high temperatures. Knowing the air leak rates under different operating conditions, a gasket user will be able to determine the suitability of the gasket for a specific vacuum requirement as well as the optimal assembly stress to maintain the desired vacuum level.

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