scholarly journals Corrosion Investigation of Reinforced Concrete Based on Piezoelectric Smart Materials

Materials ◽  
2019 ◽  
Vol 12 (3) ◽  
pp. 519
Author(s):  
Weihua Shi ◽  
Ying Chen ◽  
Peng Liu ◽  
Dongyu Xu
Keyword(s):  
Mass Loss ◽  
Smart Materials ◽  
Initial Period ◽  
Corrosion Process ◽  
Piezoelectric Transducers ◽  
Relative Mass ◽  
Statistical Parameters ◽  
Impedance Technique ◽  
Piezoelectric Impedance ◽  
Reinforcement Bar

An embedded piezoelectric transducer was developed for monitoring the corrosion process of reinforcement bars in concrete based on the piezoelectric impedance technique. The electrochemical method was employed to accelerate the corrosion process of the reinforcement bar with relative mass loss of 0.5–10%, and the resistance spectra of the piezoelectric transducers were investigated to assess the corrosion process. The results show that the corrosion process of the reinforcement bar has significant influence on the resistance spectra of the piezoelectric transducers. Statistical parameters were used to intuitively evaluate the corrosion evolution based on variations of the resistance spectra. The corrosion process of reinforcement bar in concrete can be classified into three periods; that is, the initial period when the relative mass loss is less than 2%, the developing period at a relative mass loss of 2–4%, and the rapid corrosion period when the relative mass loss is higher than 4%.

scholarly journals Windblown Sand-Induced Degradation of Glass Panels in Curtain Walls

Materials ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 607
Author(s):  
Yuxi Zhao ◽  
Rongcheng Liu ◽  
Fan Yan ◽  
Dawei Zhang ◽  
Junjin Liu
Keyword(s):  
Visible Light ◽  
Mass Loss ◽  
Effective Area ◽  
Area Ratio ◽  
Light Transmittance ◽  
Relative Mass ◽  
Impact Time ◽  
Windblown Sand ◽  
Glass Panels ◽  
The Impact

The windblown sand-induced degradation of glass panels influences the serviceability and safety of these panels. In this study, the degradation of glass panels subject to windblown sand with different impact velocities and impact angles was studied based on a sandblasting test simulating a sandstorm. After the glass panels were degraded by windblown sand, the surface morphology of the damaged glass panels was observed using scanning electron microscopy, and three damage modes were found: a cutting mode, smash mode, and plastic deformation mode. The mass loss, visible light transmittance, and effective area ratio values of the glass samples were then measured to evaluate the effects of the windblown sand on the panels. The results indicate that, at high abrasive feed rates, the relative mass loss of the glass samples decreases initially and then remains steady with increases in impact time, whereas it increases first and then decreases with an increase in impact angle such as that for ductile materials. Both visible light transmittance and effective area ratio decrease with increases in the impact time and velocities. There exists a positive linear relationship between the visible light transmittance and effective area ratio.

Reproductive Tactics in an Island Population of Adders, Vipera berus (L.), with a fluctuating Food Resource

1983 ◽  
Vol 4 (1) ◽  
pp. 63-79 ◽  
Author(s):  
Göran Nilson ◽  
Claes Andren
Keyword(s):  
Mass Loss ◽  
Clutch Size ◽  
Food Availability ◽  
Prey Density ◽  
Reproductive Capacity ◽  
Relative Mass ◽  
High Food ◽  
Vipera Berus ◽  
Positive Correlations ◽  
Clutch Mass

AbstractThis paper describes the density fluctuations of the adder Vipera berus and its prey during seven years. The reproduction during high adder density and low food availability was compared with that seven years later in the same population during low adder density and high food availability. Female length was similar but weight status (mass/length 2.56) was significantly higher during high prey density. Female mass loss when giving birth and clutch mass were significantly higher during high availability of food, but relative clutch mass and relative mass loss were similar in the two situations. However, the variance in relative clutch mass was significantly lower with high prey density. Clutch size and mass per young were significantly higher during high prey density. During high food availability there were significant positive correlations between female length (~ age) and birth mass loss, female length and clutch mass, female length and clutch size, clutch mass and mass per young and between relative clutch mass and mass per young. During low food availability there were significant positive correlations between clutch mass and clutch size and relative clutch mass and clutch size. A significant negative correlation was found between female length and relative mass loss. This study do not conform entirely to general theories on reproductive adaptations to varying food availability (r-K strategies). During high prey density both more and heavier young were produced than during scarcity of food. A high correlation of reproductive parameters during high food availability indicates a maximal utilization of reproductive capacity in most females, while the lack of such correlations during low food availability indicates a varying access to food and fat storage possibility among females.

Research on Corrosion Characteristics of Mild Steel in Sea Water at Weihai

2012 ◽  
Vol 229-231 ◽  
pp. 31-34
Author(s):  
Yan Gang Wang ◽  
Xing Hua Tong ◽  
Yong Jiang ◽  
Yong Liu ◽  
Lin Sen Zhu
Keyword(s):  
Electrochemical Impedance Spectroscopy ◽  
Mild Steel ◽  
Sea Water ◽  
Electrochemical Impedance ◽  
Initial Period ◽  
Corrosion Layer ◽  
Corrosion Process ◽  
Polarization Curves ◽  
Technology Research ◽  
Electrochemical Test

The corrosion characteristics of mild steel in real sea water are investigated by electrochemical test in this paper. Polarization curves and electrochemical impedance spectroscopy (EIS) are got by electrochemical workstation. From polarization curves, it is found that the corrosion rate rises at the initial period, and it becomes the highest on the 3rd day, then drops, and it tends to be stable after about 15 days, which is confirmed by EIS. In addition, the experiments also show that the corrosion layer can suppress the corrosion process. The electrochemical corrosiveness of the mild steel is analyzed in this study, and it lays a foundation for anticorrosion technology research.

scholarly journals The Study of a Control Signal’s Phase Shift Influence on the Efficiency of a System for Active Vibration Damping Based on MFC Piezoelectric Transducers

2020 ◽  
Vol 318 ◽  
pp. 01005
Author(s):  
Marek Płaczek
Keyword(s):  
Phase Shift ◽  
Smart Materials ◽  
Composite Structures ◽  
Fiber Composite ◽  
Vibration Damping ◽  
Piezoelectric Transducers ◽  
Piezoelectric Composite ◽  
Active Vibration Damping ◽  
Active Vibration ◽  
The Impact

Active vibration damping of mechanical systems based on applications of smart materials has a large application potential and is getting more and more popular. In active vibration systems the fast response of actuators to the signals generated by sensors is one of the most important element that decides of the system’s efficiency because the idea is to generate force by active elements that will suppress the vibrations detected by the sensors. In this paper results of laboratory tests of a control signal’s phase shift influence on the efficiency of a system for active vibration damping based on application of Macro Fiber Composite (MFC) piezoelectric transducers are presented. MFCs are modern piezoelectric composite transducers produced as a thin, elastic films and can be easily installed on the surface of the mechanical subsystem or laminated in composite structures. The impact of the phase shifting between signals generated to power the actuator on the damping efficiency was verified and analysed. It was verified in what phase angle the damping of vibration has the best efficiency and if the shift of the signals causes the linear loss of the system efficiency. It was also verified whether it causes the same effects in both directions of shifting (advance or delay in the phase of the signal supplying the damper relative to the signal generated by the beam’s vibration).

scholarly journals Oxytree Pruned Biomass Torrefaction: Process Kinetics

Materials ◽  
2019 ◽  
Vol 12 (20) ◽  
pp. 3334 ◽  
Author(s):  
Kacper Świechowski ◽  
Sylwia Stegenta-Dąbrowska ◽  
Marek Liszewski ◽  
Przemysław Bąbelewski ◽  
Jacek A. Koziel ◽  
...  
Keyword(s):  
Mass Loss ◽  
Kinetic Parameters ◽  
Batch Reactor ◽  
Waste To Energy ◽  
Energy Crop ◽  
Relative Mass ◽  
K Value ◽  
Cultivation Method ◽  
Soil Class

Oxytree is a fast-growing energy crop with C4 photosynthesis. In this research, for the first time, the torrefaction kinetic parameters of pruned Oxytree biomass (Paulownia clon in Vitro 112) were determined. The influence of the Oxytree cultivation method and soil class on the kinetic parameters of the torrefaction was also investigated. Oxytree pruned biomass from a first-year plantation was subjected to torrefaction within temperature range from 200 to 300 °C and under anaerobic conditions in the laboratory-scale batch reactor. The mass loss was measured continuously during the process. The relative mass loss increased from 1.22% to 19.56% with the increase of the process temperature. The first-order constant rate reaction (k) values increased from 1.26 × 10−5 s−1 to 7.69 × 10−5 s−1 with the increase in temperature. The average activation energy for the pruned biomass of Oxytree torrefaction was 36.5 kJ∙mol−1. Statistical analysis showed no significant (p < 0.05) effect of the Oxytree cultivation method and soil class on the k value. The results of this research could be useful for the valorization of energy crops such as Oxytree and optimization of waste-to-carbon and waste-to-energy processes.

ANALYSIS OF PROPERTIES AND TRIBOLOGICAL WEAR OF THE Co-Cr ALLOYS USED FOR PROSTHETIC CONSTRUCTIONS

Tribologia ◽  
2019 ◽  
Vol 287 (5) ◽  
pp. 5-12
Author(s):  
Joanna AUGUSTYN-NADZIEJA ◽  
Łukasz FROCISZ ◽  
Janusz KRAWCZYK ◽  
Krzysztof PAŃCIKIEWICZ
Keyword(s):  
Wear Resistance ◽  
Friction Coefficient ◽  
Abrasive Wear ◽  
Mass Loss ◽  
Abrasive Wear Resistance ◽  
Relative Mass ◽  
Similar Degree ◽  
Test Duration ◽  
Wear Depth ◽  
Metal Metal

The paper presents the results of investigations performed in the scope of the tribological wear of prosthetic cast alloys Co-Cr with micro-additions Mo and W. Abrasive wear resistance tests were carried out by means of a T-05 tester in the roller-block friction system in dry sliding metal-metal contact. A qualitative and quantitative evaluation of the alloy microstructure was made in correlation with hardness and abrasive wear. The analysis of the abrasive wear resistance of the examined alloys included an analysis of such parameters as the relative mass loss of the sample, the mean friction coefficient value, and the wear depth. It was established that the examined alloys Co-Cr-Mo-W are characterize by a low value of the friction coefficient, independent of the tribological test duration, which points to the lack of changes in the wear mechanism with the increase of the test duration time. The abrasive wear resistance of the tested materials are related to the morphology of the phases at the alloys microstructure after the solidification. A similar width of the interdendritic areas results in a similar degree of mass loss for the examined materials.

Human Physiological Signal Recognition Based on Piezoelectric Impedance Technique

2014 ◽  
Vol 687-691 ◽  
pp. 4089-4092
Author(s):  
Jun Zhang ◽  
Jie Huang ◽  
Hong Mei Tang ◽  
Xian Hua Li ◽  
Qing Yang Cai
Keyword(s):  
Human Body ◽  
Physiological Signals ◽  
Signal Recognition ◽  
Coupling Impedance ◽  
Experiment Platform ◽  
Physiological Signal ◽  
Impedance Technique ◽  
Piezoelectric Coupling ◽  
Piezoelectric Impedance ◽  
Set Up

In order to verify whether the piezoelectric impedance technology can be applied to detect the physiological signals of human body, the principle of piezoelectric coupling impedance theory and piezoelectric impedance technology using for human physiological signal detection was introduced in this paper. With an experiment platform set up, detection experiments based on the piezoelectric impedance technology were created. And the experimental1 was improved to avoid the influence of man-made factors on experiment result. Two methods were used to deal with the experimental data. The results show that the piezoelectric impedance technique can be applied to identify the human body physiological signal, and offers a totally new idea to detect the physiological signals of human body.

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