scholarly journals Study on the Influencing Factors of the Atomization Rate in a Piezoceramic Vibrating Mesh Atomizer

2020 ◽  
Vol 10 (7) ◽  
pp. 2422
Author(s):  
Qiufeng Yan ◽  
Wanting Sun ◽  
Jianhui Zhang
Keyword(s):  
Influencing Factors ◽  
Flow Resistance ◽  
Reverse Flow ◽  
Impact Factors ◽  
Driving Voltage ◽  
Driving Frequency ◽  
Piezoelectric Pump ◽  
Aperture Diameter ◽  
Liquid Concentration ◽  
The Impact

On the basis of previous study in our research group, the phenomenon of the dynamic tapered angle was founded, the occurrence of atomization is regarded to derive from the combined effects of the dynamic variation of the micro-tapered aperture, and the difference between forward and reverse flow resistance has been explained by both theories and experiments. It has been revealed that the main influencing factors of the atomization rate are driving voltage, driving frequency, and so on, while the root causes of the various atomization rates still need to be further clarified. In this paper, a micro-tapered aperture worked as a micron-sized tapered flow tube valveless piezoelectric pump in periodic variation. The working principle of such a micro-tapered aperture atomizer was analyzed in detail, and the corresponding formula of the atomization rate was also established. Through measuring the atomization rates at different working frequencies (f), it was established that when the f was set as 122 kHz, the atomization rate reached a maximum value. By building the relationship between the atomization rate and voltage at a fixed resonance frequency, it can be seen that the atomization rate increased with the increase of driving voltage. Subsequently, in order to measure their atomization rates, the micro-tapered apertures of three different outlet diameters were applied, so that the atomization rate was enhanced with the increase of the micro-tapered aperture diameter. Moreover, through examining the atomization rates at different temperatures, it was observed that the atomization rate rose with increasing temperature; while changing the liquid concentration, the atomization rate was also enhanced by the increase in its concentration. Apparently, the impact factors including working frequency, driving voltage, outlet diameter, temperature, and liquid concentration all exert some effects on the atomization rate. It is worth noting that at the first stage, these influence factors indirectly work on the micro-tapered aperture structure or flow state, followed by further effects on the flow resistance. As above-mentioned, in this work, we considered that the root cause influencing the atomization rate in a piezoceramic vibrating mesh atomizer can be attributed to the flow resistance.

scholarly journals Numerical simulation and experimental study on valveless piezoelectric pump with triangular obstacles

2021 ◽  
Vol 2083 (2) ◽  
pp. 022028
Author(s):  
Yeming Sun ◽  
Yu Wang ◽  
Yiwei Wang
Keyword(s):  
Numerical Simulation ◽  
Flow Rate ◽  
Flow Resistance ◽  
Reverse Flow ◽  
Maximum Output ◽  
Driving Voltage ◽  
Driving Frequency ◽  
Piezoelectric Pump ◽  
Valveless Pump ◽  
Valveless Piezoelectric Pump

Abstract A valve less piezoelectric pump with triangular obstacles is designed and manufactured, which uses piezoelectric vibrator as power source. The working principle and theoretical flow rate of the valveless piezoelectric pump are analyzed, and its flow rate expression is derived. The flow resistance characteristics of triangular obstacles are simulated by numerical simulation. Based on the mass fraction distribution of liquid water, the forward and reverse flow resistance of triangular obstacles and the influence of triangular obstacles on pumping capacity are analyzed. Finally, two groups of test prototypes of the valveless pump are made by using the engraving machine, and the flow measurement test is carried out. The experimental results show that the valveless piezoelectric pump with triangular obstacles can realize the valveless pumping function, and the pumping flow per unit time increases with the increase of triangular obstacles in the channel, and decreases with the increase of the distance between triangular obstacles and the channel. When the driving voltage is 140V and the driving frequency is 10Hz, the maximum output flow of the piezoelectric pump is 16.26ml/min.

scholarly journals ANALYZING IMPACT FACTORS OF AIRPORT TAXIING DELAY BASED ON ADS-B DATA

2017 ◽  
Vol XLII-2/W7 ◽  
pp. 1251-1255 ◽  
Author(s):  
J. Li ◽  
X. Wang ◽  
Y. Xu ◽  
Q. Li ◽  
C. He ◽  
...  
Keyword(s):  
Influencing Factors ◽  
Delay Time ◽  
Environmental Data ◽  
Impact Factors ◽  
The Impact ◽  
The Relationship

Identifying the factors that cause taxiing delay on airports is a prerequisite for optimizing aircraft taxiing schemes, and helps improve the efficiency of taxiing system. Few of current studies had quantified the potential influencing factors and further investigated their intrinsic relationship. In view of these problems, this paper uses ADS-B data to calculate taxiing delay time by restoring taxiing route and identifying key status points, and further analyzes the impact factors of airport taxiing delay by investigating the relationship between delay time and environmental data such as weather, wind, visibility etc. The case study in Guangzhou Baiyun Airport validates the effectiveness of the proposed method.

scholarly journals Modeling and Compensation of Dynamic Hysteresis with Force-Voltage Coupling for Piezoelectric Actuators

Micromachines ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 1366
Author(s):  
Wen Wang ◽  
Jiahui Wang ◽  
Ruijin Wang ◽  
Zhanfeng Chen ◽  
Fuming Han ◽  
...  
Keyword(s):  
Piezoelectric Actuators ◽  
Hysteresis Phenomenon ◽  
Dynamic Force ◽  
Driving Voltage ◽  
Driving Frequency ◽  
Positioning Accuracy ◽  
Output Displacement ◽  
Dynamic Hysteresis ◽  
Hysteresis Nonlinearity ◽  
The Impact

Piezoelectric actuators are widely used in the field of micro- and nanopositioning due to their high frequency response, high stiffness, and high resolution. However, piezoelectric actuators have hysteresis nonlinearity, which severely affects their positioning accuracy. As the driving frequency increases, the performance of piezoelectric actuators further degrades. In addition, the impact of force on piezoelectric actuators cannot be ignored in practical applications. Dynamic hysteresis with force-voltage coupling makes the hysteresis phenomenon more complicated when force and driving voltage are both applied to the piezoelectric actuator. Existing hysteresis models are complicated, or inaccurate in describing dynamic hysteresis with force-voltage coupling. To solve this problem, a force-voltage-coupled Prandtl–Ishlinskii (FVPI) model is proposed in this paper. First, the influence of driving frequency and dynamic force on the output displacement of the piezoelectric actuators are analyzed. Then, the accuracy of the FVPI model is verified through experiments. Finally, a force integrated direct inverse (F-DI) compensator based on the FVPI model is designed. The experimental results from this study show that the F-DI compensator can effectively suppress dynamic hysteresis with force-voltage coupling of piezoelectric actuators. This model can improve the positioning accuracy of piezoelectric actuators, thereby improving the working accuracy of the micro- or nano-operating system.

scholarly journals Design and Testing of a Valveless Piezoelectric Pump with Conical Vortex Diodes

2020 ◽  
Vol 306 ◽  
pp. 04003
Author(s):  
Lei Zou ◽  
Kai Li ◽  
Jun Huang
Keyword(s):  
Flow Resistance ◽  
Reverse Flow ◽  
Maximum Output ◽  
Piezoelectric Pump ◽  
Element Analysis ◽  
Output Pressure ◽  
Drive Frequency ◽  
The Difference ◽  
Conical Vortex ◽  
Valveless Piezoelectric Pump

The valveless piezoelectric pump delivers fluid based on the difference of flow resistance of internal tube. In this paper, a vortex diode with conical tangential tube is proposed, which possesses the great characteristic of reverse cut-off, and the analysis of the forward and reverse flow resistance of the conical vortex diode is verified by finite element analysis. Then, a valveless piezoelectric pump with conical vortex diodes as the internal channel is designed, and the prototype is manufactured. The results of the output performance experiment show that the maximum output flow rate of the valveless piezoelectric pump is 10.44 g/min at the drive frequency of 45Hz, and the maximum output pressure is 560 Pa at the drive frequency of 35Hz. The proposal of the valveless piezoelectric pump provides a good reference for more new types of valveless piezoelectric pumps.

The Impact of Anglicizing Former German-Language Psychology Journals on Authorship and Citation Frequencies

2012 ◽  
Vol 17 (3) ◽  
pp. 190-198 ◽  
Author(s):  
Günter Krampen ◽  
Thomas Huckert ◽  
Gabriel Schui
Keyword(s):  
Side Effects ◽  
English Language ◽  
General Trend ◽  
Native Language ◽  
Impact Factors ◽  
German Language ◽  
Journal Articles ◽  
Number Of Citations ◽  
The Impact ◽  
Number Of Authors

Exemplary for other than English-language psychology journals, the impact of recent Anglicization of five former German-language psychology journals on (1) authorship (nationality, i.e., native language, and number of authors, i.e., single or multiple authorships), (2) formal characteristics of the journal (number of articles per volume and length of articles), and (3) number of citations of the articles in other journal articles, the language of the citing publications, and the impact factors (IF) is analyzed. Scientometric data on these variables are gathered for all articles published in the four years before anglicizing and in the four years after anglicizing the same journal. Results reveal rather quick changes: Citations per year since original articles’ publication increase significantly, and the IF of the journals go up markedly. Frequencies of citing in German-language journals decrease, citing in English-language journals increase significantly after the Anglicization of former German-language psychology journals, and there is a general trend of increasing citations in other languages as well. Side effects of anglicizing former German-language psychology journals include the publication of shorter papers, their availability to a more international authorship, and a slight, but significant increase in multiple authorships.

THE MODEL FOR MANAGING INVESTMENTS IN THE MOSCOW ENVIRONMENT BASED ON A POWER REGRESSION EQUATION

2020 ◽  
Vol 2 (7) ◽  
pp. 91-99
Author(s):  
E. V. KOSTYRIN ◽  
◽  
M. S. SINODSKAYA ◽  
Keyword(s):  
Solid Waste ◽  
Influencing Factors ◽  
Pair Correlation ◽  
Approximation Error ◽  
Regression Equation ◽  
Regression Equations ◽  
The Impact ◽  
The Relationship ◽  
Average Approximation ◽  
Average Approximation Error

The article analyzes the impact of certain factors on the volume of investments in the environment. Regression equations describing the relationship between the volume of investment in the environment and each of the influencing factors are constructed, the coefficients of the Pearson pair correlation between the dependent variable and the influencing factors, as well as pairwise between the influencing factors, are calculated. The average approximation error for each regression equation is determined. A correlation matrix is constructed and a conclusion is made. The developed econometric model is implemented in the program of separate collection of municipal solid waste (MSW) in Moscow. The efficiency of the model of investment management in the environment is evaluated on the example of the growth of planned investments in the activities of companies specializing in the export and processing of solid waste.

scholarly journals Exploring Factors Influencing Scenarios Evolution of Waste NIMBY Crisis: Analysis of Typical Cases in China

2021 ◽  
Vol 18 (4) ◽  
pp. 2006
Author(s):  
Ling He ◽  
Qing Yang ◽  
Xingxing Liu ◽  
Lingmei Fu ◽  
Jinmei Wang
Keyword(s):  
Network Theory ◽  
Development Process ◽  
Dynamic Bayesian Network ◽  
Impact Factors ◽  
Social Stability ◽  
Ground Theory ◽  
Evolution Path ◽  
Dynamic Scenario ◽  
The Impact

As the impact factors of the waste Not-In-My-Back Yard (NIMBY) crisis are complex, and the scenario evolution path of it is diverse. Once the crisis is not handled properly, it will bring adverse effects on the construction of waste NIMBY facilities, economic development and social stability. Consequently, based on ground theory, this paper takes the waste NIMBY crisis in China from 2006 to 2019 as typical cases, through coding analysis, scenario evolution factors of waste NIMBY crisis are established. Furtherly, three key scenarios were obtained, namely, external situation (E), situation state (S), emergency management (M), what is more, scenario evolution law of waste NIMBY crisis is revealed. Then, the dynamic Bayesian network theory is used to construct the dynamic scenario evolution network of waste NIMBY crisis. Finally, based on the above models, Xiantao waste NIMBY crisis is taken as a case study, and the dynamic process of scenario evolution network is visually displayed by using Netica. The simulation results show that the scenario evolution network of Xiantao waste NIMBY crisis is basically consistent with the actual incident development process, which confirms the effectiveness and feasibility of the model.

scholarly journals Research on a Piezoelectric Pump with Flexible Valves

2021 ◽  
Vol 11 (7) ◽  
pp. 2909
Author(s):  
Weiqing Huang ◽  
Liyi Lai ◽  
Zhenlin Chen ◽  
Xiaosheng Chen ◽  
Zhi Huang ◽  
...  
Keyword(s):  
Flow Rate ◽  
Fluid Transport ◽  
Smooth Transition ◽  
Driving Voltage ◽  
Piezoelectric Pump ◽  
Venous Valve ◽  
Output Pressure ◽  
Small Flow ◽  
Working Principle ◽  
Opening And Closing

Imitating the structure of the venous valve and its characteristics of passive opening and closing with changes in heart pressure, a piezoelectric pump with flexible valves (PPFV) was designed. Firstly, the structure and the working principle of the PPFV were introduced. Then, the flexible valve, the main functional component of the pump, was analyzed theoretically. Finally, an experimental prototype was manufactured and its performance was tested. The research proves that the PPFV can achieve a smooth transition between valved and valveless by only changing the driving signal of the piezoelectric (PZT) vibrator. The results demonstrate that when the driving voltage is 100 V and the frequency is 25 Hz, the experimental flow rate of the PPFV is about 119.61 mL/min, and the output pressure is about 6.16 kPa. This kind of pump can realize the reciprocal conversion of a large flow rate, high output pressure, and a small flow rate, low output pressure under the electronic control signal. Therefore, it can be utilized for fluid transport and pressure transmission at both the macro-level and the micro-level, which belongs to the macro–micro combined component.

scholarly journals Aphid–Plant–Phytovirus Pathosystems: Influencing Factors from Vector Behaviour to Virus Spread

Agriculture ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 502
Author(s):  
Junior Corneille Fingu-Mabola ◽  
Frédéric Francis
Keyword(s):  
Influencing Factors ◽  
Virus Transmission ◽  
Physical Factors ◽  
Factors Affecting ◽  
Vector Borne Diseases ◽  
Vector Behaviour ◽  
Crop Fields ◽  
Host Seeking ◽  
The Impact ◽  
Vector Efficiency

Aphids are responsible for the spread of more than half of the known phytovirus species. Virus transmission within the plant–aphid–phytovirus pathosystem depends on vector mobility which allows the aphid to reach its host plant and on vector efficiency in terms of ability to transmit phytoviruses. However, several other factors can influence the phytoviruses transmission process and have significant epidemiological consequences. In this review, we aimed to analyse the aphid behaviours and influencing factors affecting phytovirus spread. We discussed the impact of vector host-seeking and dispersal behaviours mostly involved in aphid-born phytovirus spread but also the effect of feeding behaviours and life history traits involved in plant–aphid–phytovirus relationships on vector performances. We also noted that these behaviours are influenced by factors inherent to the interactions between pathosystem components (mode of transmission of phytoviruses, vector efficiency, plant resistance, …) and several biological, biochemical, chemical or physical factors related to the environment of these pathosystem components, most of them being manipulated as means to control vector-borne diseases in the crop fields.

scholarly journals Do Agricultural Machinery Services Facilitate Land Transfer? Evidence from Rice Farmers in Sichuan Province, China

Land ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 466
Author(s):  
Xi Yu ◽  
Xiyang Yin ◽  
Yuying Liu ◽  
Dongmei Li
Keyword(s):  
Negative Impact ◽  
Sichuan Province ◽  
Impact Factors ◽  
Farm Labor ◽  
Agricultural Machinery ◽  
Rice Farmers ◽  
Land Transfer ◽  
Land Rental ◽  
Rental Markets ◽  
The Impact

Agricultural machinery services play an increasingly important role in the land transfer market, especially in developing countries. Prior studies have explored the impact factors of machinery use on agricultural production and land transfer, respectively. However, little research has focused on the relationship between the adoption of agricultural machinery services and the land transfer of rice farmers. To bridge this gap, this study investigated the correlation between machinery services and land transfer, using unique survey data of 810 rice farmers collected from Sichuan province in China. Additionally, this study further explored the impact mechanism on land transfer of rural households with IV-Probit and IV-Tobit models. The empirical results show the following: (i) Agricultural machinery services have a significantly positive and robust effect on both the incidence and area of rice farmers’ land transfer-in, while the impact degree is different. Specifically, with other conditions remaining unchanged, and with a 1% increase in the proportion of machinery services, the average probability of land transfer-in of rice farmers increased by 2.4%, and the area of land transfer-in increased by 13.4 mu, on average. (ii) For control variables, head education, agricultural certificates and whether the majority of land, are in a flat area have positive impacts on land transfer-in behavior. Yet, age and off-farm labor have a negative impact on land transfer-in area. Moreover, our findings highlight the importance of agricultural machinery services in stimulating the development of rural land rental markets.

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