scholarly journals Body Water-Mediated Conductivity Actualizes the Insect-Control Functions of Electric Fields in Houseflies

Insects ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 561 ◽  
Author(s):  
Yoshihiro Takikawa ◽  
Takeshi Takami ◽  
Koji Kakutani
Keyword(s):  
Electric Field ◽  
Electric Fields ◽  
Arc Discharge ◽  
Body Water ◽  
The Body ◽  
Static Electric Field ◽  
Free Electrons ◽  
Water Conductivity ◽  
Control Functions ◽  
Negative Pole

In the present study, the relationship between body water loss and conductivity was examined in adult houseflies (Musca domestica). The events an insect experiences in an electric field are caused by the conductive nature of the insect body (i.e., movement of electricity within or its release from the insect). After houseflies were dehydrated, rehydrated, refrigerated, and frozen and thawed, they were placed in static and dynamic electric fields. Untreated houseflies were deprived of their free electrons to become positively charged and then attracted to the insulated negative pole in the static electric field and were exposed to corona and arc discharge from non-insulated negative pole in the dynamic electric field. There was no current in the bodies of dehydrated and frozen flies; hence, there was no attractive force or discharge exposure. In the remaining insects, the results were identical to those in the untreated control insects. These results indicated that the reduction of body water conductivity inhibited the release of electricity from the body in the static electric field and the discharge-mediated current flow through the body in the dynamic electric field. The insect was affected by the electric fields because of its conductivity mediated by body water.

Molecular Dynamics Studies of Nanotube Growth in a Carbon ARC

1994 ◽  
Vol 359 ◽  
Author(s):  
C. J. Brabec ◽  
A. Maiti ◽  
C. Roland ◽  
J. Bernholc
Keyword(s):  
Molecular Dynamics ◽  
Electric Field ◽  
Electric Fields ◽  
Arc Discharge ◽  
Critical Diameter ◽  
Critical Factor ◽  
Carbon Arc ◽  
Dynamics Simulations ◽  
Nanotube Growth ◽  
Brenner Potential

ABSTRACTIt has been shown experimentally that the growth of carbon nanotubes in an arc discharge is open-ended. This is surprising, because dangling bonds at the end of open tubes make the closed tube geometry more favorable energetically. Recently, it has been proposed that the large electric fields present at the tip of tube is the critical factor that keeps the tube open. We have studied the effects of the electric field on the growth of the nanotubes via ab initio molecular dynamics simulations. Surprisingly, it is found that the electric field cannot play a significant role in keeping the tubes open, implying that some other mechanism must be important. Extensive studies of the energetics and simulations of the growth of tubes were performed using a threebody Tersoff-Brenner potential. Our results show that there exists a critical diameter of ∼ 3 nm above which a defect-free growth of a straight tubule is possible. Narrower tubes stabilize configurations with adjacent pentagons that lead to tube-closure and termination of the growth. This explains the absence of tube narrower than 2.2 nm in arc discharge experiments.

scholarly journals BEM Modelling of High Voltage ELF electric field applied to a 3D pregnant woman model

2010 ◽  
Vol 6 (1) ◽  
pp. 31 ◽  
Author(s):  
Cristina Peratta ◽  
Andres Peratta ◽  
Dragan Poljak
Keyword(s):  
Pregnant Woman ◽  
Electric Field ◽  
Electric Fields ◽  
High Voltage ◽  
Medical Information ◽  
Three Dimensional ◽  
Low Frequency ◽  
Element Model ◽  
The Body ◽  
Geometrical Properties

The paper introduces a three dimensional multidomainboundary element model of a pregnant woman and foetus for the analysis of exposure to high voltage extremely low frequency electric fields. The definition of the differentphysical and geometrical properties of the relevant tissues is established according to medical information available in existing literature. The model takes into account changes in geometry, body mass, body fat, and overall chemical composition in the body which influence the electrical properties, throughout the different gestational periods. The developed model is used to solve the case of exposure to overhead power transmission lines at different stages of pregnancy including weeks 8, 13, 26 and 38. The results obtained are in line with those published in the earlier works considering different approaches. In addition, a sensitivity analysis involving varying scenarios of conductivity, foetus postures and geometry for each stage is defined and solved. Finally, a correlation between the externally applied electric field and the current density inside the foetus is established and the zones of maximum exposure are identified.

scholarly journals Analysis of Pole-Ascending–Descending Action by Insects Subjected to High Voltage Electric Fields

Insects ◽  
2020 ◽  
Vol 11 (3) ◽  
pp. 187 ◽  
Author(s):  
Yoshinori Matsuda ◽  
Yoshihiro Takikawa ◽  
Koji Kakutani ◽  
Teruo Nonomura ◽  
Hideyoshi Toyoda
Keyword(s):  
Electric Field ◽  
Electric Fields ◽  
Negative Charge ◽  
Sitophilus Oryzae ◽  
Experimental System ◽  
Insect Behavior ◽  
Free Electrons ◽  
Current Voltage ◽  
Direct Current Voltage ◽  
Oppositely Charged

The present study was conducted to establish an electrostatic-based experimental system to enable new investigations of insect behavior. The instrument consists of an insulated conducting copper ring (ICR) linked to a direct current voltage generator to supply a negative charge to an ICR and a grounded aluminum pole (AP) passed vertically through the center of the horizontal ICR. An electric field was formed between the ICR and the AP. Rice weevil (Sitophilus oryzae) was selected as a model insect due to its habit of climbing erect poles. The electric field produced a force that could be imposed on the insect. In fact, the negative electricity (free electrons) was forced out of the insect to polarize its body positively. Eventually, the insect was attracted to the oppositely charged ICR. The force became weaker on the lower regions of the pole; the insects sensed the weaker force with their antennae, quickly stopped climbing, and retraced their steps. These behaviors led to a pole-ascending–descending action by the insect, which was highly reproducible and precisely corresponded to the changed expansion of the electric field. Other pole-climbing insects including the cigarette beetle (Lasioderma serricorne), which was shown to adopt the same behavior.

Fluid Mixing Control Inside a Y-Shaped Microchannel by Using Electrokinetic Instability

2007 ◽  
Author(s):  
Zheyan Jin ◽  
Hui Hu
Keyword(s):  
Electric Field ◽  
Electric Fields ◽  
Fluid Mixing ◽  
Critical Voltage ◽  
Mixing Efficiency ◽  
Mixing Process ◽  
Static Electric Field ◽  
Electrokinetic Instability ◽  
Mixing Control ◽  
Static Electric Fields

An experimental study was conducted to further our understanding about the fundamental physics of electrokinetic instability (EKI) and to explore the effectiveness to enhance fluid mixing inside a Y-shaped microchannel by manipulating convective EKI waves. The dependence of the critical voltage of applied static electric field to trig EKI to generate convective EKI waves on the conductivity ratio of the two adjacent streams was quantified at first. The effect of the strength of the applied static electric field on the evolution of the convective EKI waves and fluid mixing process were assessed in terms of scalar concentration fields, shedding frequency of the convective EKI waves and scalar mixing efficiency. The effectiveness of manipulating the convective EKI waves by introducing alternative electric perturbations to the applied static electric fields was also explored for the further enhancement of the fluid mixing process inside the Y-shaped microchannel.

scholarly journals High Voltage Electric Fields Have Potential to Create New Physical Pest Control Systems

Insects ◽  
2020 ◽  
Vol 11 (7) ◽  
pp. 447 ◽  
Author(s):  
Shin-ichi Kusakari ◽  
Kiyotsugu Okada ◽  
Manabu Shibao ◽  
Hideyoshi Toyoda
Keyword(s):  
Electric Field ◽  
Electric Fields ◽  
Pest Control ◽  
Electric Charge ◽  
High Voltage ◽  
Arc Discharge ◽  
Control Strategies ◽  
Control Measures ◽  
Flying Insects ◽  
Electrostatic Phenomena

An electric field is the space surrounding an electric charge, within which it is capable of exerting a perceptible force on another electric charge. Especially under high voltage, electric fields induce various electrostatic phenomena, some of which could be utilized to provide remarkable pest control measures. The main focus of the present study was to introduce an attractive force generated by a surface charge on an insulated electrified conductor, which was successfully used to construct an electric field screen that prevented airborne nuisances (spores, flying insects, pollen, and fine smoke) from entering the interiors of various facilities. Another focus was the disinclination of insects to enter the electric field, thus, giving the electric field screen the ability to repel insects. Charges accumulated on the surfaces of non-insulated conductors are mobile through discharge, based on their potential difference. Such arc discharge was strong enough to destroy insects that were exposed to it. Some precedent illustrative examples are cited to explain the principles of attraction, dielectrophoretic movement of spores, and discharge-mediated positive electrification of insects, and to discuss how electric fields are generated and used in electric field-based pest control strategies.

TWO-PHOTON-ABSORPTION SPECTRA OF QUANTUM-WELL EXCITONS IN STATIC ELECTRIC FIELDS

1991 ◽  
Vol 05 (17) ◽  
pp. 1133-1138
Author(s):  
KAZUHITO FUJII ◽  
AKIRA SHIMIZU ◽  
JOHAN BERGQUIST ◽  
SOTOMITSU IKEDA ◽  
TAKESHI SAWADA
Keyword(s):  
Electric Field ◽  
Quantum Well ◽  
Absorption Spectra ◽  
Electric Fields ◽  
Band Gap Energy ◽  
Photon Absorption ◽  
Static Electric Field ◽  
Quantum Well Structures ◽  
Two Photon Absorption ◽  
Two Photon

We have measured two-photon-absorption spectra of GaAs/Al 0.4 Ga 0.6 As quantum-well structures in a static electric field for photon energies near half the band gap energy, and found drastic field-induced-changes in the spectra. The two-photon-absorption peak at half the energy of the lowest light-hole exciton is induced by the static electric field normal to the quantum well layers, in agreement with a theory that takes account of quasi-two-dimensional exciton effects. With increasing the electric field, however, this peak grows more drastically than the theoretical prediction, and it approaches a large value predicted by another simplified theory based on a two-level model.

scholarly journals Quasi-static electric fields phenomena in the ionosphere associated with pre- and post earthquake effects

2008 ◽  
Vol 8 (1) ◽  
pp. 101-107 ◽  
Author(s):  
M. Gousheva ◽  
D. Danov ◽  
P. Hristov ◽  
M. Matova
Keyword(s):  
Pacific Ocean ◽  
Electric Field ◽  
Electric Fields ◽  
Seismic Data ◽  
Seismic Activity ◽  
Vertical Component ◽  
Satellite Orbits ◽  
Static Electric Field ◽  
Earthquake Zone ◽  
Earthquake Effects

Abstract. To prove a direct relationship between the quasi-static electric field disturbances and seismic activity is a difficult, but actual task of the modern ionosphere physics. This paper presents new results on the processing and analysis of the quasi-static electric field in the upper ionosphere (h=800–900 km) observed from the satellite INTERCOSMOS-BULGARIA-1300 over earthquakes' source regions (seismic data of World Data Center, Denver, Colorado, USA). Present research focuses on three main areas (i) development of methodology of satellite and seismic data selecting, (ii) data processing and observations of the quasi-static electric field (iii) study and accumulation of statistics of possible connection between anomalous vertical electric fields penetrating from the earthquake zone into the ionosphere, and seismic activity. The most appropriate data (for satellite orbits above sources of forthcoming or just happened seismic events) have been selected from more than 250 investigated cases.The increase of about 5-10-15 mV/m in the vertical component of the quasi-static electric field observed by INTERCOSMOS-BULGARIA-1300 during seismic activity over Southern Ocean, Greenland Sea, South-Weat Pacific Ocean, Indian Ocean, Central America, South-East Pacific Ocean, Malay Archipelago regions are presented. These anomalies, as phenomena accompanying the seismogenic process, can be considered eventually as possible pre-, co- (coeval to) and post-earthquake effects in the ionosphere.

scholarly journals Turkestan Cockroaches Avoid Entering a Static Electric Field upon Perceiving an Attractive Force Applied to Antennae Inserted into the Field

Insects ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 621
Author(s):  
Yoshinori Matsuda ◽  
Teruo Nonomura ◽  
Hideyoshi Toyoda
Keyword(s):  
Electric Field ◽  
Attractive Force ◽  
Avoidance Behaviour ◽  
Static Electric Field ◽  
Free Electrons ◽  
Iron Plate ◽  
Electrostatic Induction ◽  
Negative Surface ◽  
Negative Surface Charge ◽  
Positively Charged

This study analysed the mechanism of avoidance behaviour by adult Turkestan cockroaches (Shelfordella lateralis Walker) in response to a static electric field (S-EF) formed in the space between a negatively charged polyvinyl chloride-insulated iron plate (N-PIP) and a grounded metal net (G-MN). The negative surface charge supplied to the iron plate by a voltage generator caused the G-MN to polarise positively via electrostatic induction. In the S-EF, the negative charge of the N-PIP created a repulsive force that pushed free electrons in the field toward the ground via the G-MN. When insects released in the space surrounded by the S-EF inserted their antennae into the S-EF, they pulled them back reflexively and moved backward. The analysis indicated that an electric current flowed transiently toward the ground when an insect inserted its antennae into the S-EF. The insect became positively charged via this discharge and was attracted to the opposite pole (N-PIP). In response to this attractive force, the insect pulled its antennae back quickly. The positive electrification caused by the removal of free electrons from the antenna tip triggered the avoidance behaviour.

scholarly journals Surface-Integrated Electric Field Sensor for the Detection of High-Voltage Power Lines

Sensors ◽  
2021 ◽  
Vol 21 (24) ◽  
pp. 8327
Author(s):  
Gunbok Lee ◽  
Jeong-Yeon Kim ◽  
Gildong Kim ◽  
Jae Hee Kim
Keyword(s):  
Electric Field ◽  
Electric Fields ◽  
High Voltage ◽  
Strong Electric Field ◽  
The Body ◽  
Power Lines ◽  
Induced Voltage ◽  
Electric Field Sensor ◽  
Field Sensor ◽  
High Voltage Power Lines

When a drone is used for inspection of facilities, there are often cases in which high-voltage power lines interfere, resulting in the drone being caught or falling. To prevent this type of incident, drones must be capable of detecting high-voltage power lines. Typically, a strong electric field is formed around the high-voltage lines. To detect the electric fields around high-voltage lines, this study proposes an electric field sensor that may be integrated within the body of a drone. In a laboratory environment, a voltage of 25 kV was applied to an overhead line, and the induced voltage in the proposed sensor was measured at various electric field intensities. Over an electric field range of 0.5 to 10.1 kV/m, a voltage of 0 to 0.77 V was measured with each proposed sensor. In addition, the electric field and the voltage induced in the sensor were measured in a real-world railway environment with overhead lines. Under these conditions, the proposed sensor has the compensated value of 4.5 when the measured electric field was 4.05 kV/m. Therefore, the proposed sensor may be applied in drones to measure large electric fields and to detect the presence of high-voltage lines in its vicinity.

scholarly journals Growth performance of pearl goldfish juvenile carassius auratus cultured in 3 ppt salinity with different exposure time of electric field

2015 ◽  
Vol 10 (2) ◽  
pp. 165
Author(s):  
Kukuh Nirmala ◽  
Rizky Armansyah ◽  
Agus Priyadi
Keyword(s):  
Growth Rate ◽  
Electric Field ◽  
Growth Performance ◽  
Electric Fields ◽  
Body Length ◽  
Exposure Time ◽  
Carassius Auratus ◽  
The Body ◽  
Salinity Water ◽  
Average Body

<p>ABSTRACT</p><p><br />Growth rate of pearl goldfish juvenile Carassius auratus relatively slow to reach market size which will take approximately three months. To accelerate its growth can be done by providing exposure of the fish to low-power electric fields (10 V) via 3 ppt salinity water, with the goal of providing the close isoosmotic conditions, and also to streamline the flow of electricity from the electrodes to the body of the fish. This study aims to calculate the survival and growth rate of pearl goldfish juvenile of S sizes (2‒4 cm of body length) which were maintained at 3 ppt salinity water and treated by different exposure time of electric field (zero, two, four, and six minutes before feeding) with 10 volt electric power. Fish were cultured at a density of 2 fish/L in the (20×30×20 cm3) aquaria in volume of 6 L of water. Test fish had an average body length of 4.11±0.05 cm and the average body weight of 2.89±0.05 g. Exposure time of electric field were zero, two, four, and six minutes before the fish are fed, performed every day as much as three times i.e. morning, afternoon, and evening. The research design used was completely randomized design with four treatments, namely 0, 2, 4, and 6 (time for exposure is zero/control, two, four, and six minute) with three replications. The results show test fishes exposed to 10 volt electrical field for zero, two, four, and six minutes, have no significant effect on survival rate (P&gt;0.05). For growth performance, four minute exposure treatment gives the best results compared to controls (P&lt;0.05), supported by an increase in the percentage of the ratio of gut length to body length of the fish and higher feed efficiency.<br />Keywords: long exposure to the electric field, growth performance, pearl goldfish</p><p><br />ABSTRAK</p><p><br />Pertumbuhan benih ikan hias maskoki mutiara Carassius auratus relatif lambat, karena untuk mencapai ukuran jual memerlukan waktu sekitar tiga bulan. Untuk mempercepat pertumbuhannya dapat dilakukan dengan pemberian paparan medan listrik berdaya rendah (10 V) ke air media budidaya yang dinaikkan salinitasnya menjadi 3 ppt, dengan tujuan memberikan kondisi mendekati isoosmotik, dan juga untuk mengefektifkan arus listrik dari elektroda ke tubuh ikan. Penelitian ini bertujuan untuk menghitung tingkat kelangsungan hidup dan pertumbuhan benih ikan maskoki mutiara ukuran S (2‒4 cm) yang dipelihara pada media bersalinitas 3 ppt yang diberi perlakuan lama waktu pemaparan medan listrik (nol, dua, empat, dan enam menit sebelum ikan diberi pakan) dengan daya 10 volt. Ikan dipelihara dengan kepadatan 2 ekor/L dalam akuarium berukuran 20×30×20 cm3 dengan volume air 6 L. Ikan uji yang digunakan memiliki panjang rata-rata 4,11±0,05 cm dan bobot rata-rata 2,89±0,05 g/ekor. Pemberian paparan medan listrik dilakukan selama nol, dua, empat, dan enam menit sebelum ikan diberi pakan, dilakukan setiap hari sebanyak tiga kali yaitu pagi, siang, dan sore hari. Rancangan penelitian terdiri atas empat perlakuan, yaitu 0, 2, 4, dan 6 (lama paparan nol/kontrol, dua, empat, dan enam menit) yang diulang masing-masing tiga kali ulangan. Hasil pemaparan arus listrik 10 volt selama nol, dua, empat, dan enam menit, tidak memberikan pengaruh yang nyata pada kelangsungan hidup (p&gt;0,05). Untuk kinerja pertumbuhan, perlakuan paparan empat menit memberikan hasil yang terbaik dibandingkan kontrol (p&lt;0,05), didukung oleh peningkatan persentase nilai rasio panjang usus terhadap panjang tubuh ikan serta nilai efisiensi pakan yang lebih tinggi.</p><p><br />Kata kunci: lama paparan medan listrik, kinerja pertumbuhan, ikan maskoki mutiara</p>

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