scholarly journals Practical Application of an Electric Field Screen to an Exclusion of Flying Insect Pests and Airborne Fungal Conidia from Greenhouses with a Good Air Penetration

2012 ◽  
Vol 4 (5) ◽  
Author(s):  
K. Kakutani ◽  
Y. Matsuda ◽  
T. Nonomura ◽  
H. Toyoda ◽  
J. Kimbara ◽  
...  
Keyword(s):  
Electric Field ◽  
Insect Pests ◽  
Practical Application ◽  
Air Penetration

Bi(Mg1/2Zr1/2)O3-PbZrO3-PbTiO3 relaxor ferroelectric ceramics with large and temperature-insensitive electric field induced strain response

2021 ◽  
Author(s):  
Hongrui Jia ◽  
Zhigang Liang ◽  
Zhen Li ◽  
Fei Li ◽  
Linghang Wang
Keyword(s):  
Electric Field ◽  
Ceramic Materials ◽  
Ferroelectric Ceramic ◽  
Relaxor Ferroelectric ◽  
Ferroelectric Ceramics ◽  
Harsh Environment ◽  
Strain Response ◽  
Practical Application ◽  
Electric Field Induced Strain ◽  
Relaxor Ferroelectric Ceramics

Ferroelectric ceramic materials with large and temperature-insensitive strain response are highly desired for the practical application of actuator in harsh environment conditions. In this work, a novel xBi(Mg1/2Zr1/2)O3-(0.55-x)PbZrO3-0.45PbTiO3 (xBMZ-PZ-0.45PT) ternary...

Resistivity mapping using inductive sources

1989 ◽  
Vol 20 (2) ◽  
pp. 47 ◽  
Author(s):  
J. MacNae ◽  
P. McGowan ◽  
Y. Lamontagne
Keyword(s):  
Electric Field ◽  
Time Derivative ◽  
Constant Current ◽  
Magnetic Component ◽  
Late Time ◽  
Gold Mine ◽  
Practical Application ◽  
Electric Component ◽  
Resistive Zone

In electromagnetic (EM) exploration for conductive targets, measurements of the magnetic component or its time derivative have received more theoretical attention and practical application than have measurements of the electric component. However, the electric component can be shown to be particularly useful in the search for resistive zones not usually detected by the magnetic component. Normalized measurements of the surface voltage differences caused by the constant current induced at late time by the UTEM transmitter are called 'Inductive Source Resistivity' or ISR measurements.Data collected on a grid located just south of the Temora gold mine in N.S.W. clearly show the effectiveness of the ISR technique in detecting a resistive zone of silicification located unconformably under 10S of conductive cover. Due to the relatively slow falloff of the electric field from an inductive source, the technique is ideal for the rapid exploration of large areas.

Design of a Fluid-Based Micro-Scale Electrocaloric Refrigeration System

2013 ◽  
Author(s):  
Dongzhi Guo ◽  
Jinsheng Gao ◽  
Ying-Ju Yu ◽  
Suresh Santhanam ◽  
Gary K. Fedder ◽  
...  
Keyword(s):  
Finite Element ◽  
Electric Field ◽  
System Performance ◽  
Time Lag ◽  
Cooling Power ◽  
Refrigeration System ◽  
Practical Application ◽  
Micro Scale ◽  
Cooling Devices ◽  
Diaphragm Motion

The electrocaloric effect (ECE) is a phenomenon in which reversible temperature and entropy changes of a material due to polarization appear under the application and removal of an electric field. Materials with a giant ECE have recently been reported, suggesting practical application in cooling devices. In this paper, a refrigeration system composed of silicon MEMS cooling elements is designed based on the ECE in a terpolymer. Finite element simulations are performed to explore the system performance. The effect of the form of the applied electric field is studied. The time lag between the electric field and the diaphragm motion is found to affect the cooling power significantly. A parametric study of the operating frequency is also conducted. The results indicate that when the system is operated at a temperature difference of 5 K, a cooling power density of 2 W/cm2 is achieved for one element.

scholarly journals Asymptotic analysis for the electric field concentration with geometry of the core-shell structure

2021 ◽  
Vol 0 (0) ◽  
pp. 0
Author(s):  
Zhiwen Zhao
Keyword(s):  
Electric Field ◽  
Blow Up ◽  
Core Shell ◽  
Singular Behavior ◽  
Practical Application ◽  
Function Type ◽  
The Core ◽  
The Matrix ◽  
Perfect Conductivity

<p style='text-indent:20px;'>In the perfect conductivity problem arising from composites, the electric field may become arbitrarily large as <inline-formula><tex-math id="M1">\begin{document}$ \varepsilon $\end{document}</tex-math></inline-formula>, the distance between the inclusions and the matrix boundary, tends to zero. In this paper, by making clear the singular role of the blow-up factor <inline-formula><tex-math id="M2">\begin{document}$ Q[\varphi] $\end{document}</tex-math></inline-formula> introduced in [<xref ref-type="bibr" rid="b27">27</xref>] for some special boundary data of even function type with <inline-formula><tex-math id="M3">\begin{document}$ k $\end{document}</tex-math></inline-formula>-order growth, we prove the optimality of the blow-up rate in the presence of <inline-formula><tex-math id="M4">\begin{document}$ m $\end{document}</tex-math></inline-formula>-convex inclusions close to touching the matrix boundary in all dimensions. Finally, we give closer analysis in terms of the singular behavior of the concentrated field for eccentric and concentric core-shell geometries with circular and spherical boundaries from the practical application angle.</p>

scholarly journals Exclusion of Flying Insect Pests From a Plastic Hoop Greenhouse by a Bamboo Blind-Type Electric Field Screen

2020 ◽  
Vol 12 (2) ◽  
pp. 50
Author(s):  
Yoshihiro Takikawa ◽  
Yoshinori Matsuda ◽  
Teruo Nonomura ◽  
Koji Kakutani ◽  
Shin-ichi Kusakari ◽  
...  
Keyword(s):  
Electric Field ◽  
Insect Pests ◽  
Western Flower Thrips ◽  
Leaf Miner ◽  
Tomato Plants ◽  
Voltage Range ◽  
Flower Thrips ◽  
Positive Voltage ◽  
Tomato Leaf Miner ◽  
Direct Current Voltage

The present study describes an economically efficient method for controlling viruliferous whiteflies in a plastic hoop greenhouse, using a bamboo blind-type electric field screen (Bb-EFS) to create a pest-free space. The Bb-EFS had a layer of insulated round iron conductor bars (IBs) and two electrostatic direct current voltage generators that supplied negative or positive voltage to the IBs. The IBs were placed parallel at 4-mm intervals and were connected alternately to a negative or positive voltage generator. Adult test insects (whiteflies, western flower thrips, and tomato leaf miner flies) were blown at up to 5 m/s towards the IBs to identify the voltage range that would capture all the test insects. The results showed that a force &ge; 5.0 kV was strong enough for the IBs to capture all test insects, despite a wind speed of 5 m/s. The Bb-EFS was practical for a greenhouse that experienced frequent invasion by numerous viruliferous whiteflies. Seedlings grew normally inside the Bb-EFS-installed greenhouse. As a supplementary method, an electrostatic insect sweeper and electrostatic flying insect catcher were used to trap whiteflies that avoided the Bb-EFS. Both pieces of apparatus were convenient and easy to operate onsite in a greenhouse environment and were used to trap whiteflies residing on tomato plants or flying inside the greenhouse during daily plant care. These methods controlled the whitefly population to negligible levels, and nearly all tomato plants produced normal fruits.

scholarly journals A Promising Physical Pest-Control System Demonstrated in a Greenhouse Equipped With Simple Electrostatic Devices That Excluded All Insect Pests: A Review

2019 ◽  
Vol 11 (18) ◽  
pp. 1 ◽  
Author(s):  
Yoshihiro Takikawa ◽  
Koji Kakutani ◽  
Yoshinori Matsuda ◽  
Teruo Nonomura ◽  
Shin-ichi Kusakari ◽  
...  
Keyword(s):  
Control System ◽  
Electric Field ◽  
Solanum Lycopersicum ◽  
Pest Control ◽  
Direct Current ◽  
Insect Pests ◽  
Free Air ◽  
Current Voltage ◽  
Direct Current Voltage ◽  
Oppositely Charged

Applied electrostatic engineering can be used to construct greenhouses that prevent entry of insect pests. Two types of electric field screen were used to exclude pests from the greenhouse: single- and double-charged dipolar electric field screens (S- and D-screen, respectively). The S-screen consisted of iron insulated conductor wires (ICWs) arrayed in parallel (ICW-layer), a grounded metal net on either side of the ICW-layer, and a direct current voltage generator. S-screens were attached to the side windows of the greenhouse to repel whiteflies (Bemisia tabaci) that approached the nets. The D-screen was installed in a small anteroom at the greenhouse entrance to capture whiteflies entering through it. The ICW-layers of the D-screen were oppositely charged with equal voltages and arrayed alternately, and an insulator board or grounded metal net was placed on one side of the ICW-layer. The ICW-layers captured whiteflies entering the electric field of the double-charged dipolar electric field. Three screens equipped with yellow or gray boards or a grounded metal net were installed in the anteroom based on the airflow inside the room, as most whiteflies were brought in by air when the door was opened. Two D-screens with boards were useful for directing the airflow toward the wall with the netted D-screen. This screen eliminated the insects and the pest-free air was circulated inside the greenhouse. The D-screen with the yellow board attracted the whiteflies and was effective for trapping them when there was no wind. Our method kept the greenhouse pest-free throughout the entire period of tomato (Solanum lycopersicum) cultivation.

scholarly journals Theoretical and practical aspects of the development of devices for suppressing dust streams such as "electrostatic gate" for industrial ventilation systems

2019 ◽  
Vol 104 ◽  
pp. 01014 ◽  
Author(s):  
Maxim S. Minkin ◽  
Denis N. Kuimov ◽  
Mikhail A. Shahramanyan
Keyword(s):  
Electric Field ◽  
Corona Discharge ◽  
Fine Fraction ◽  
Physical Characteristics ◽  
Uniform Electric Field ◽  
Fine Dust ◽  
Practical Application ◽  
Industrial Ventilation ◽  
Ventilation Systems

The main objective of this work is to study the behavior of fine dust fractions (aerosols) of different nature in a non-uniform electric field (corona discharge) under electric, gravitational, aerodynamic and other disturbances. Determination of fundamental principles, and development of methods for controlling fine-fraction particles with predetermined physical characteristics. This article also presents the results of practical application of the developed methods.

scholarly journals A Promising Physical Pest-Control System Demonstrated in a Greenhouse Equipped with Simple Electrostatic Devices that Excluded all Insect Pests

2019 ◽  
Author(s):  
Yoshihiro Takikawa ◽  
Koji Kakutani ◽  
Yoshinori Matsuda ◽  
Teruo Nonomura ◽  
Shin-ichi Kusakari ◽  
...  
Keyword(s):  
Control System ◽  
Electric Field ◽  
Solanum Lycopersicum ◽  
Pest Control ◽  
Direct Current ◽  
Insect Pests ◽  
Free Air ◽  
Current Voltage ◽  
Direct Current Voltage ◽  
Oppositely Charged

Applied electrostatic engineering can be used to construct greenhouses that prevent entry of insect pests. Two types of electric field screen were used to exclude pests from the greenhouse: single- and double-charged dipolar electric field screens (S- and D-screen, respectively). The S-screen consisted of iron insulated conductor wires (ICWs) arrayed in parallel (ICW-layer), a grounded metal net on either side of the ICW-layer, and a direct current voltage generator. S-screens were attached to the side windows of the greenhouse to repel whiteflies (Bemisia tabaci) that approached the nets. The D-screen was installed in a small anteroom at the greenhouse entrance to capture whiteflies entering through it. The ICW-layers of the D-screen were oppositely charged with equal voltages and arrayed alternately, and an insulator board or grounded metal net was placed on one side of the ICW-layer. The ICW-layers captured whiteflies entering the electric field of the double-charged dipolar electric field. Three screens equipped with yellow or gray boards or a grounded metal net were installed in the anteroom based on the airflow inside the room, as most whiteflies were brought in by air when the door was opened. Two D-screens with boards were useful for directing the airflow toward the wall with the netted D-screen. This screen eliminated the insects and the pest-free air was circulated inside the greenhouse. The D-screen with the yellow board attracted the whiteflies and was effective for trapping them when there was no wind. Our method kept the greenhouse pest-free throughout the entire period of tomato (Solanum lycopersicum) cultivation.

AN ELECTRIC FIELD SCREEN CAN CREATE PEST-FREE SPACE WITH BETTER AIR PENETRATION IN OPEN-WINDOW GREENHOUSES

2012 ◽  
pp. 559-566
Author(s):  
K. Kakutani ◽  
Y. Matsuda ◽  
T. Nonomura ◽  
H. Toyoda ◽  
J. Kimbara ◽  
...  
Keyword(s):  
Electric Field ◽  
Free Space ◽  
Open Window ◽  
Air Penetration

scholarly journals High strain response and low hysteresis in BaZrO3-modified KNN-based lead-free relaxor ceramics

2021 ◽  
Author(s):  
Jian Zhang ◽  
Zixuan Liu ◽  
Tao Zhang ◽  
Yunfei Liu ◽  
Yinong Lyu
Keyword(s):  
Phase Transition ◽  
Electric Field ◽  
High Strain ◽  
Large Strain ◽  
Piezoelectric Actuators ◽  
Solid State Reaction Method ◽  
Lead Free ◽  
Practical Application ◽  
Practical Applications ◽  
T Phase

Abstract The high driving electric field and the large strain hysteresis was subject to a challenge for piezoelectric actuators’ practical applications. In order to obtain the piezoceramics with giant strain and low hysteresis at small electric field, a ternary solid solution (0.97- x )(K 0.48 Na 0.52 )Nb 0.965 Sb 0.035 -0.03Bi 0.5 (K 0.18 Na 0.82 ) 0.5 ZrO 3 - x BaZrO 3 ( x = 0-0.06) was designed and synthesized by the traditional solid-state reaction method. The relationships among phase transition, microstructure, and electrical properties of the ceramics samples were systemically investigated. Under a low electric field of 4 kV/mm, the ceramic with x = 0.02 obtained a high strain of 0.29 % ( S max / E max = 729 pm/V) and a low hysteresis of 13.8 %. The excellent piezoelectric properties are mainly attributed to rhombohedral-orthorhombic-tetragonal (R-O-T) phase boundary and the relaxor-to-ferroelectric phase transition. We believe that our research can not only provide the pathway of achieving KNN-based ceramics with high strain and low hysteresis but also promote the practical application of lead-free piezoelectric actuators.

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