Artykuły w czasopismach: „Electret studies”

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Talwar, I. M., A. P. Srivastava i H. C. Sinha. "Photo-electret studies of pure and doped polystyrene films". Polymer 26, nr 7 (lipiec 1985): 1025–28. http://dx.doi.org/10.1016/0032-3861(85)90223-x.

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Kunzmann, S., B. D rschel, K. H se i U. Zeiske. "Studies on the Surface Charge Distribution of Radon Exposed Electrets Within an Electret Ionisation Chamber". Radiation Protection Dosimetry 66, nr 1 (1.07.1996): 367–70. http://dx.doi.org/10.1093/oxfordjournals.rpd.a031755.

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Sinha, Debottam, K. Anwar, K. Kumari, S. Jaishwal, S. Madeshwaran, S. Keshari, D. Rajan Babu, R. Vidya i Narayanasamy Arunai Nambi Raj. "Studies on the Dielectric Properties of Natural Urinary Stones". Advanced Materials Research 584 (październik 2012): 484–88. http://dx.doi.org/10.4028/www.scientific.net/amr.584.484.

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Kidney or gall-bladder stones are solid accretions (crystals) of dissolved minerals in urine or bile juice found inside the kidneys or urethras and gall bladder, with varying size from as small as a grain of sand to as large as a golf ball, the occurrence whose in the human is well known, although its pathogenesis is not well understood. According to literature, a number of biomaterials, such as collagen, blood vessel walls, DNA, RNA etc., are found to possess the property of electrets which is an electric analogue of a permanent magnet having the capability to retain quasipermanently, an induced polarization. In order to understand about the occurrence and the physical properties of stone formation in the human tissues, the study of its electret behaviour and conductivity becomes imperative which implies the fact of indulging in its growth inhibition, if their deposition is identified using scans. Thus, in this paper, in order to understand the mechanism of growth of these nephrolithiasis, we enumerated the electrical behaviour of the stone, by using the XRD (X-Ray Diffraction) analysis after their collection from different patient in and around the region and subsequently the dielectric constant of the stone was interpreted.

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Tai, L. S., Y. W. Wong, Y. M. Poon i F. G. Shin. "Characteristics of Corona-Charged PET Sandwich Electrets". Materials Science Forum 480-481 (marzec 2005): 123–28. http://dx.doi.org/10.4028/www.scientific.net/msf.480-481.123.

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Polyethylene terephthalate (PET) is one of the major electret materials which has been studied and widely used in charge storage applications for a long time. The homo-charge and hetero-charge formation responsible for the electret effect of PET can be explained by the dipolar polarization, space charge separation and charge injection respectively as a result of contact poling or corona charging. These processes are also verifiable from studies of surface charges and thermally stimulated depolarization current (TSDC) of the PET films. Now consider a stack of PET films charged under the same condition as a single film. It would be intuitively expected that the electret effects of the individual films of the stack should be different due to their different positions in the stack. However, in a recent study on charged PET stacks, it was found that the electret effects of the individual films are quite similar. The surface charges of the individual films are about the same and they sum to make same total as a single charged PET film. On the other hand, the TSDC thermograms of individual films show similar characteristics in the thermal relaxation processes where homo- and hetero- charge effects are still observed. From the TSDC results, especially for the film in the middle of a triple layer sandwich, it shows clearly dipolar polarization and charge injection related peaks. These findings agree with the results of surface charge studies of the individual films.

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Agrawal, R. C., R. K. Gupta i Mohan L. Verma. "Studies of polarization/self-depolarization and electret-type effect in AgI". Ionics 4, nr 1-2 (styczeń 1998): 33–41. http://dx.doi.org/10.1007/bf02375777.

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Myers, David L., i B. Dean Arnold. "Electret Media for HVAC Filtration Applications". International Nonwovens Journal os-12, nr 4 (grudzień 2003): 1558925003os—12. http://dx.doi.org/10.1177/1558925003os-1200412.

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Air filters produced with charged, or electret, media for HVAC filtration applications have gained significant market share and acceptance over the past few years. While these filters provide the advantage of high initial efficiency and low pressure drop, there are concerns about their ability to maintain efficiency in service. Furthermore, there is a tendency to classify all electret media in the same general category without any consideration of media structure, fiber size, and charging technique. Current research suggests that a variety of factors influence the loss of efficiency in use including humidity, exposure to certain chemicals, aging, temperature, and etc. While this is true of some charged media, the effect of environmental factors on filtration performance is highly dependent upon the media technology itself. This paper provides an overview of current electret media types detailing media structure and charging techniques. Fundamental impact of environmental factors on filtration performance is presented along with field studies detailing in-use performance of filterers manufactured with charged media.

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James, James H., James H. Maxwell i Stephen R. Whitesell. "Studies of the speech transducing performance of carbon and electret telephone transmitters". Journal of the Acoustical Society of America 90, nr 6 (grudzień 1991): 2909–18. http://dx.doi.org/10.1121/1.401764.

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Leontaris, F., A. Boziari, A. Clouvas, M. Kolovou i J. Guilhot. "PROCEDURES TO MEASURE MEAN AMBIENT DOSE EQUIVALENT RATES USING ELECTRET ION CHAMBERS". Radiation Protection Dosimetry 190, nr 1 (czerwiec 2020): 6–21. http://dx.doi.org/10.1093/rpd/ncaa061.

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Abstract The capabilities of electret ion chambers (EICs) to measure mean ambient dose equivalent rates were investigated by performing both laboratory and field studies of their properties. First, EICs were ‘calibrated’ to measure ambient gamma dose equivalent in the Ionizing Calibration Laboratory of the Greek Atomic Energy Commission. The EICs were irradiated with different gamma photon energies and from different angles. Calibration factors were deduced (electret’s voltage drop due to irradiation in terms of ambient dose equivalent). In the field studies, EICs were installed at eight locations belonging to the Greek Early Warning System Network (which is based on Reuter-Stokes ionization chambers) for three periods, averaging 5 months each. In the same locations, in situ gamma spectrometry measurements were performed with portable germanium detectors. Gamma ambient dose equivalent rates were deduced by the in situ gamma spectrometry measurements and by soil sample analysis. The mean daily electret potential drop (in Volts) was compared with the mean daily ambient dose equivalent, measured with a portable HPGe detector and Reuter-Stokes high-pressure ionization chambers. From these measurements, ‘field’ calibration factors (electret’s voltage drop due to gamma radiation in terms of ambient dose equivalent) were deduced and found in very good agreement with the values deduced in Laboratory. The influence of cosmic radiation and the intrinsic voltage loss when performing long-term environmental gamma measurements with EICs, was estimated.

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Cui, L. L., M. H. Song, Y. X. Kong, L. Cheng, D. Wang, Y. H. Xiao i J. Jiang. "The comparative studies of charge storage stabilities among three PP/porous PTFE/PP electret". Journal of Electrostatics 67, nr 2-3 (maj 2009): 412–16. http://dx.doi.org/10.1016/j.elstat.2009.01.013.

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Montserrat, Salvador, Pedro Colomer i Juan Belana. "Physical ageing studies on amorphous poly(ethylene terephthalate). Part 1.—Enthalpic relaxation and electret properties". J. Mater. Chem. 2, nr 2 (1992): 217–23. http://dx.doi.org/10.1039/jm9920200217.

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Kunzmann, S., B. D rschel, F. Havlik i D. Nikodemov . "Studies on the Practical Application of Electret Ionisation Chambers for Radon Dosimetry Under Special Conditions". Radiation Protection Dosimetry 63, nr 4 (2.02.1996): 275–79. http://dx.doi.org/10.1093/oxfordjournals.rpd.a031540.

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Bi, Mingzhao, Shiwen Wang, Xiaofeng Wang i Xiongying Ye. "Freestanding-electret rotary generator at an average conversion efficiency of 56%: Theoretical and experimental studies". Nano Energy 41 (listopad 2017): 434–42. http://dx.doi.org/10.1016/j.nanoen.2017.09.057.

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Kubon, U., R. Schilling i J. H. Wendorff. "Studies on the influence of physical aging processes on electret properties of amorphous poly(methyl methacrylate)". Colloid & Polymer Science 266, nr 2 (luty 1988): 123–31. http://dx.doi.org/10.1007/bf01452809.

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Bortulev, Pavel I., Sergei V. Vissarionov, Tamila V. Baskaeva, Dmitry B. Barsukov, Ivan Yu Pozdnikin, Tatyana V. Murashko, Vladimir E. Baskov i Makhmud S. Poznovich. "The Use of Electret In the Surgical Treatment of Children With Perthes Disease: Early Outcomes". Traumatology and Orthopedics of Russia 28, nr 1 (15.01.2022): 46–57. http://dx.doi.org/10.17816/2311-2905-1726.

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The study aimed to evaluate the immediate results of the use of electret in the surgical treatment of children with Perthes disease. Material and Methods. The study was based on the results of a comprehensive examination of 10 patients (10 hip joints; average age, 7.20.7 years). To stabilize the joint and comply with the principle of containment therapy, all children underwent triple pelvic osteotomy, which was supplemented by a transphyseal implantation electret. Postoperatively, all patients were evaluated for the severity of pain syndrome and amplitude of movements and underwent ultrasonography, radiometry of the main indicators of the structure and stability of the hip joint, computed tomography, and magnetic resonance imaging of the hip joints. Results. The visual analog scale questionnaire indicated the presence of a moderately pronounced pain syndrome on postoperative day 3, with its complete relief by day 7. Ultrasound studies showed the absence of synovitis, and goniometry revealed the achievement of physiological indicators of flexion and abduction to the end of the hospitalization period. According to the radiation methods, all patients had elimination of subluxation with the restoration of hip joint stability and a significant improvement in the shape of the femoral head with the appearance of its single bone contour. The volume of the bone part of the femoral head increased by 15%35% from the original, and there was a significant improvement in the shape of the cartilaginous model with the complete absence of a necrosis focus in the femoral head, close to the physiological position of the labrum acetabulum. Conclusion. The use of electret in the surgical treatment of children with Perthes disease in Catterall groups IIIIV and hip subluxation due to the anti-inflammatory effect makes it possible to alleviate pain syndrome and manifestations of synovitis early after surgery and to begin rehabilitation treatment with the achievement of the physiological amplitude of movements in the hip joint in the immediate postoperative period. The osteoreparative effect of the electrostatic electret field alone or in combination with anti-inflammatory treatment increased the volume of the newly formed bone tissues of the femoral head with a decrease in the area of its defect or disappearance of compression of the central part of the epiphysis with the differentiation of the initial elements of the trabecular pattern, in comparison with the homogeneous high-intensity structure of the femoral head.

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Klimiec, Ewa, Piotr Zachariasz, Halina Kaczmarek, Bogusław Królikowski i Sławomir Mackiewicz. "Elasticity investigation of thin cellular structure films for piezoelectric sensors". Sensor Review 42, nr 2 (23.12.2021): 204–13. http://dx.doi.org/10.1108/sr-07-2021-0220.

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Purpose This paper aims to present the details of isotactic polypropylene (it-PP) films with a cellular structure (air-cavities) dedicated to pressure sensors. The polymer composites (thin films enriched with 5 and 10 wt% of mineral fillers as Sillikolloid P 87 and glass beads) should exhibit suitable structural elasticity within specific stress ranges. After the deformation force is removed, the sensor material must completely restore its original shape and size. Design/methodology/approach Estimating the stiffness tensor element (C33) for polymer films (nonpolar space-charge electrets) by broadband resonance ultrasound spectroscopy is a relatively simple method of determining the safe stress range generated in thin pressure sensors. Therefore, ultrasonic and piezoelectric studies were carried out on four composite it-PP films. First, the longitudinal velocity (vL) of ultrasonic waves passing through the it-PP film in the z-direction (thickness) was evaluated from the ω-position of mechanical resonance of the so-called insertion loss function. In turn, the d33 coefficient was calculated from accumulated piezoelectric charge density response to mechanical stress. Findings Research is at an early stage; however, it can be seen that the mechanical orientation of the it-PP film improves its piezoelectric properties. Moreover, the three-year electric charge stability of the it-PP film seems promising. Originality/value Ultrasonic spectroscopy can be successfully handled as a validation method in the small-lot production of polymer films with the air-cavities structure intended for pressure sensors. The structural repeatability of polymer films is strongly related to a homogeneous distribution of the electric charge on the electret surface.

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Rajeev, V. R., i K. N. Narayanan Unni. "Polymer electret-based organic field-effect transistor memory with a solution-processable bilayer (PαMS/ cross-linked PVP) gate dielectric". European Physical Journal Applied Physics 97 (2022): 17. http://dx.doi.org/10.1051/epjap/2022210175.

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Pentacene based organic field-effect transistors (OFETs) were fabricated, with both cross-linked poly vinyl phenol (CL-PVP) and a bilayer of poly(α-methylstyrene) (PαMS)/ CL-PVP as gate dielectric. The PαMS layer decreases the surface energy of the gate dielectric and increases the hydrophobic nature, which leads to favorable growth of pentacene and the corresponding field-effect mobility, though at a higher gate voltage span, increases three times compared to that of the device with only CL-PVP as the gate dielectric. OFET with bilayer polymer gate dielectric exhibited non-volatile memory behavior with an on-off ratio 103, retention time >103 s and a large memory window of −25 V. The memory effect observed in the device was due to the charge trapping in the PαMS layer, with CL-PVP acting as a blocking dielectric. Our studies indicate that the bilayer dielectric, comprising of solution-processable PαMS/CL-PVP is a good choice for obtaining non-volatile electret memory on an OFET platform.

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Paranthaman, P., i N. Sathiesh Kumar. "Wire Electric Discharge Machining Studies on Aluminium MMC Reinforced with Silicon Nitride". Journal of Advanced Research in Dynamical and Control Systems 11, nr 12-SPECIAL ISSUE (31.12.2019): 1227–32. http://dx.doi.org/10.5373/jardcs/v11sp12/20193329.

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Hindák, Frantiek, i Jan marda. "Light and electron microscope studies of Asterocapsa salina, spec. nova (Cyanophyta/Cyanoprokaryota)". Algological Studies/Archiv für Hydrobiologie, Supplement Volumes 121 (1.10.2006): 43–57. http://dx.doi.org/10.1127/1864-1318/2006/0121-0043.

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Studenyak, I. P. "electric conductivity studies of composites based on (Cu1-xAgx)6PS5I superionic conductors". Semiconductor Physics Quantum Electronics and Optoelectronics 17, nr 4 (10.11.2014): 425–28. http://dx.doi.org/10.15407/spqeo17.04.425.

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Jakowski, N., A. Jungstand, K. Schlegel, H. Kohl i K. Rinnert. "The ionospheric response to perturbation electric fields during the onset phase of geomagnetic storms". Canadian Journal of Physics 70, nr 7 (1.07.1992): 575–81. http://dx.doi.org/10.1139/p92-093.

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The generation and propagation of ionospheric storms are studied by analyzing EISCAT radar, and vertical-sounding and total-electron-content data obtained under different geophysical conditions. Both, case studies as well as the average storm pattern of percentage deviations of different ionospheric parameters from their corresponding reference values such as total electron content, F2-layer critical frequency foF2, F2-layer height hmF2, and slab thickness τ indicate the action of a perturbation electric field during the first few hours during the onset phase of geomagnetic storms. Considering the onset phase of the storm on July 28–29, 1987 evidence has been found that high-latitude electric fields may penetrate to lower latitudes before the ring current has developed. In most cases this process is accompanied by a positive phase in the upper ionosphere and F2-layer ionization. Different mechanisms are assumed to be responsible for the daytime and nighttime behaviour, respectively. The negative phase propagates equatorward with velocities in the order of 70–350 m s−1 following a strong heating of the thermosphere and ionosphere due to the auroral electrojet.

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Haldoupis, C., K. Schlegel i G. Hussey. "Auroral E-region electron density gradients measured". Annales Geophysicae 18, nr 9 (30.09.2000): 1172–81. http://dx.doi.org/10.1007/s00585-000-1172-x.

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Abstract. In the theory of E-region plasma instabilities, the ambient electric field and electron density gradient are both included in the same dispersion relation as the key parameters that provide the energy for the generation and growth of electrostatic plasma waves. While there exist numerous measurements of ionospheric electric fields, there are very few measurements and limited knowledge about the ambient electron density gradients, ∇Ne, in the E-region plasma. In this work, we took advantage of the EISCAT CP1 data base and studied statistically the vertical electron density gradient length, Lz=Ne/(dNe/dz), at auroral E-region heights during both eastward and westward electrojet conditions and different ambient electric field levels. Overall, the prevailing electron density gradients, with Lz ranging from 4 to 7 km, are found to be located below 100 km, but to move steadily up in altitude as the electric field level increases. The steepest density gradients, with Lz possibly less than 3 km, occur near 110 km mostly in the eastward electrojet during times of strong electric fields. The results and their implications are examined and discussed in the frame of the linear gradient drift instability theory. Finally, it would be interesting to test the implications of the present results with a vertical radar interferometer.Key words: Ionosphere (auroral ionosphere; ionospheric irregularities; plasma waves and instabilities)

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Tagashira, H. "Some Recent Studies of Electron Swarms in Gases". Australian Journal of Physics 45, nr 3 (1992): 365. http://dx.doi.org/10.1071/ph920365.

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Some recent studies of electron swarms in gases under the action of an electric field are introduced. The studies include a new type of continuity equation for electrons having a form in which the partial derivative of the electron density with respect to position and to time are interchanged, a method to deduce the time-of-flight and arrival-time-spectrum swarm parameters based on a Fourier-transformed Boltzmann equation, an examination of the correspondence between experimental and theoretical electron drift velocities, and an automatic technique to deduce the electron-gas molecule collision cross section from electron drift velocity data. We also briefly introduce a method for the deduction of electron collision cross sections with gas molecules having vibrational excitation cross sections greater than the elastic momentum transfer cross section by using a gas mixture technique, an integral type of method for solution of the Boltzmann equation with salient numerical stability, a quantitative analysis of the effect of Penning ionisation, and the behaviour of electron swarms under radio frequency electric fields.

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Marchenko, Andriy, Volodymyr Shpakovskyy i Volodymyr Volikov. "Cordunum pistons increase diesel engine economy and reliability". Acta Innovations, nr 33 (1.10.2019): 28–37. http://dx.doi.org/10.32933/actainnovations.33.3.

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Taking into account the oil resources depletion the requirements to fuel consumption of internal combustion engines are now increasing as well as to their reliability and durability. With the continual increase in the number of internal combustion engines in operation, along with the problem of parts of the cylinder piston group wearing out has caused exhaust from such engines to be one of the main source of harmful pollutant emissions in cities. Therefore, environmental requirements have in turn increased dramatically. The engine resource and its efficiency largely depend on the process of fuel combustion in the combustion chamber. Experimental studies aimed to improve the working process on diesel engines by piston insulation have shown an effective decrease in fuel consumption by reducing heat loss and more complete fuel combustion. When oxide ceramic coatings were used on the piston and cylinder head, the maximum power increased and the specific fuel consumption decreased. However ceramic coatings are not widely used due to their peeling. We have developed a technology for the galvanic plasma treatment of pistons, which made it possible to obtain on the pistons surface made of aluminum alloys a ceramic corundum layer with high adhesion to the base metal that does not peel and has electret properties. In 1993, pistons with a corundum surface layer were installed in a shunting diesel locomotive and life-time running tests were conducted. Such pistons increased wear resistance, reduced the wear of cylinder liners, increased the strength of the annular jumpers, and were not prone to burnouts and scuffing. They provided an increase in the resource of the cylinder-piston group of the diesel engine by more than 125 thousand engine hours. The paper provides an analysis of the effect of corundum pistons thermal insulation on significant increasing the, engine power and fuel consumption reduction. Basing on experimental bench studies of a gasoline engine, a tractor diesel engine and long-term operational life tests of diesel engines, an attempt had been made to explain the reasons for the improvement in the engines’ efficiency.

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Yuhuan Dou, Yuhuan Dou, i Xiaojian Shu Xiaojian Shu. "Studies of super-short pulse generated by a free-electron lasers at perfect synchronism". Chinese Optics Letters 11, s2 (2013): S21401–321404. http://dx.doi.org/10.3788/col201311.s21401.

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Pashkevych, Volodymyr, Volodymyr Krayovskyy, Mariya Rokomanyuk, Petro Haranuk, Volodymyr Romaka, Yurii Stadnyk, Lyubov Romaka, Andriy Horyn i Daniel Fruchart. "STUDIES OF THERMOMETRIC MATERIAL Lu1-xZrxNiSb". Measuring Equipment and Metrology 83, nr 1 (2022): 10–16. http://dx.doi.org/10.23939/istcmtm2022.01.010.

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The results of experimental research of perspective thermometric material Lu1-xZrxNiSbwhich can be used for the production of sensitive elements of thermoelectric and electroresistive thermometers are presented. Thermometric materials Lu1-xZrxNiSb, x=0.01–0.10, were made by fusing a charge of components in an electric arc furnace with a tungsten electrode (cathode) in an atmosphere of purified argon under a pressure of 0.1 kPa on a copper water-cooled hearth (anode). Heat treatment of alloys consisted of homogenizing annealing at a temperature of 1073 K. Annealing of samples was carried out for 720 h in vacuumed up to 1.0 Pa ampoules of quartz glass in muffle electric furnaces with temperature control with an accuracy of ±10 K. Diffraction arrays were obtained on a diffractometer DRON-4.0 (FeKα radiation), and the structural characteristics of Lu1-xZrxNiSbwere calculated using the Fullprof program. The chemical and phase compositions of the samples were monitored using a scanning electron microscope (Tescan Vega 3 LMU). The study of the temperature dependences of the resistivity ρ(T,x) and the thermopower coefficientα(T,x) Lu1-xZrxNiSb was performed in the temperature range of 80÷400 K on samples in the form of rectangular parallelepipeds measuring ~1.0×1.0×5.0 mm3 . Measurements of the values of the specific magnetic susceptibility χ(x) of Lu1-xZrxNiSb samples were performed by the relative Faraday method at a temperature of 273 K using a thermogravimetric installation with an electronic microbalance EM-5-ZMP in magnetic fields up to 10 kGs. Microprobe analysis of the concentration of atoms on the surface of Lu1-xZrxNiSb samples, x=0.01–0.10, established their correspondence to the initial compositions of the charge, and X-ray phase analysis showed no traces of extraneous phases on the sample diffractograms, except for the main phase. The nonmonotonic nature of the change in the values of the unit cell period of the thermometric material an (x) Lu1-xZrxNiSb, x=0.01–0.10, which differs from the results of modeling structural characteristics using software packages AkaiKKR and Elk. The nonmonotonic change in the values of the period of the unit cell a(x) Lu1-xZrxNiSband the presence of the extremum dependence suggests that the impurity Zr atoms introduced into the matrix of the LuNiSb basic semiconductor can simultaneously occupy partially different crystallographic positions in different ratios. The temperature resistivities ρ and the thermopower coefficientα of the LuNiSb base semiconductor contain high- and lowtemperature activation regions, which is characteristic of doped and compensated semiconductors. The introduction into the LuNiSb structure of the lowest concentration of impurity Zr atoms in the experiment (x=0.01) radically changes both the behavior of the temperature dependences of the resistivity ρ and the thermopower coefficientα and the type of the main electric current carriers. The values of the resistivity ρ(T,x) Lu1-xZrxNiSbonly increase with increasing temperature, which is characteristic of the metallic type of electrical conductivity and is due to the mechanisms of scattering of current carriers. This nature of the change in electrical resistance ρ(T,x) is evidence that the Fermi level εF has left the bandgap εg and is in the conduction band εC. This is indicated by the negative values of thermopower coefficientα(T,x) at all concentrations and temperatures. Studies of the magnetic susceptibility χ(x) showed that the samples as a basic semiconductor LuNiSb, as well as the thermometric material Lu1-xZrxNiSb, at all concentrations of impurities Zr, are Pauli paramagnetic. There is a synchronicity of the behavior of χ(x) with the dependences of the resistivity ρ(x, T) and the thermopower coefficient α(x, T), which is due to the change in the density of states at the Fermi level g(εF). The results of experimental studies of the Lu1-xZrxNiSbthermometric material completely coincide with the results of modeling its kinetic characteristics under the presence of vacancies in the crystallographic positions 4a and 4c of the Lu and Ni atoms, respectively. Such studies allow making adjustments in the structural studies of thermometric material with an accuracy that significantly exceeds the accuracy of X-ray research methods. The obtained results will allow us to clarify the spatial arrangement of atoms in the nodes of the unit cell, as well as to identify the mechanisms of electrical conductivity to determine the conditions for the synthesis of thermosensitive materials with maximum efficiency of thermal energy conversion into electricity.

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Kellerman, A. C., R. A. Makarevich, F. Honary i T. L. Hansen. "On the relationship between auroral absorption, electrojet currents and plasma convection". Annales Geophysicae 27, nr 2 (2.02.2009): 473–86. http://dx.doi.org/10.5194/angeo-27-473-2009.

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Abstract. In this study, the relationship between auroral absorption, electrojet currents, and ionospheric plasma convection velocity is investigated using a series of new methods where temporal correlations are calculated and analysed for different events and MLT sectors. We employ cosmic noise absorption (CNA) observations obtained by the Imaging Riometer for Ionospheric Studies (IRIS) system in Kilpisjärvi, Finland, plasma convection measurements by the European Incoherent Scatter (EISCAT) radar, and estimates of the electrojet currents derived from the Tromsø magnetometer data. The IRIS absorption and EISCAT plasma convection measurements are used as a proxy for the particle precipitation component of the Hall conductance and ionospheric electric field, respectively. It is shown that the electrojet currents are affected by both enhanced conductance and electric field but with the relative importance of these two factors varying with magnetic local time (MLT). The correlation between the current and electric field (absorption) is the highest at 12:00–15:00 MLT (00:00–03:00 MLT). It is demonstrated that the electric-field-dominant region is asymmetric with respect to magnetic-noon-midnight meridian extending from 09:00 to 21:00 MLT. This may be related to the recently reported absence of mirror-symmetry between the effects of positive and negative IMF By on the high-latitude plasma convection pattern. The conductivity-dominant region is somewhat wider than previously thought extending from 21:00 to 09:00 MLT with correlation slowly declining from midnight towards the morning, which is interpreted as being in part due to high-energy electron clouds gradually depleting and drifting from midnight towards the morning sector. The conductivity-dominant region is further investigated using the extensive IRIS riometer and Tromsø magnetometer datasets with results showing a distinct seasonal dependence. The region of high current-absorption correlation extends from 21:00 to 06:00 MLT near both equinoxes, however, it is narrower and rotated towards the morning (02:00–07:00 MLT) in summer, while in winter the correlation shows much greater variability with MLT. During periods of high current-electric-field correlation, the relationship between electric field and absorption can be described as an inverse proportionality, which can be explained by limitation of the electrojet current by the magnetospheric generator. Possible cases of electron heating absorption are also investigated with absorption showing no obvious dependence on the ion velocity or electron temperature.

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Devidas, G. B., Sunar Abdul Khader, Asiya Parveez, Nityananda Das i T. Sankarappa. "Dielectric Studies of Ferrimagnetic-Piezoelectric Composites". Materials Science Forum 1019 (styczeń 2021): 129–34. http://dx.doi.org/10.4028/www.scientific.net/msf.1019.129.

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Magneto-electric composites of two distinct phases, ferrimagnetic-piezoelectric system with general compositional formula (x) ferromagnetic + (1-x) piezoelectric were synthesized using a hybrid technique, mechano-chemical method by sintering the mixtures of piezo-electric BaTiO3 (BTO) and ferri-magnetic Mg0.2Cu0.5Zn0.3Fe2O4 (MCZF). Here, ferri-magnetic phase component MCZF (Mg0.2Cu0.5Zn0.3Fe2O4) was prepared using auto-combustion method, whereas piezo-electric BTO was procured commercially from Sigma-Aldrich. Here, the general composition of composites is given by (x) Mg0.2Cu0.5Zn0.3Fe2O4+(1-x) BaTiO3(x=15%, 30% and 45%). Presences of two phases in these magneto-electric composites were probed using X-ray diffraction (XRD) studies. Peaks observed in the XRD spectrum indicated spinel cubic structure for MCZF ferrite and tetragonal perovskite structure for BTO and, both spinel and pervoskite structures for synthesized composites. Micro-structure of the samples has been investigated using Field Emission Scanning Electron Microscope (FESEM). Frequency dependent dielectric properties of synthesized composites were measured from 100 Hz to 1 MHz at room temperature using a precision HIOKI make LCR HI-TESTER. Dielectric dispersion was observed at lower frequencies for the synthesized composites.

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Pi, X., M. Mendillo, P. Spalla i D. N. Anderson. "Longitudinal effects of ionospheric responses to substorms at middle and lower latitudes: a case study". Annales Geophysicae 13, nr 8 (31.08.1995): 863–70. http://dx.doi.org/10.1007/s00585-995-0863-8.

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Abstract. An ionospheric model is used to simulate total electron content (TEC) disturbance events observed at middle and lower latitude sites near 75°W and 7°E longitudes. Within this longitudinal range, daytime TEC disturbances show patterns that are correlated with substrom activity seen in both auroral electrojet and ring current behavior. In modeling studies of the observed ionospheric effects, both electric field and neutral wind perturbations are examined as possible mechanisms. The morphological features of the required electric field perturbations near drawn and dusk are compared with those at other times to examine the local time characteristics of magnetospheric influence. Large-scale traveling atmospheric disturbances (TADs), an alternative candidate for the disturbance source, are also characterized and compared with known thermospheric behavior.

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Koromyslova, Anna V., i Evgeniy M. Pervushov. "Uppermost Turonian bryozoans from the Lower Volga River region: scanning electron microscopy and micro-computed tomography studies". Neues Jahrbuch für Geologie und Paläontologie - Abhandlungen 305, nr 3 (30.09.2022): 263–95. http://dx.doi.org/10.1127/njgpa/2022/1090.

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Jayasinghe, Jeevani W. "Application of Genetic Algorithm for Binary Optimization of Microstrip Antennas: A Review". AIMS Electronics and Electrical Engineering 5, nr 4 (2021): 315–33. http://dx.doi.org/10.3934/electreng.2021016.

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<abstract> Researchers have proposed applying optimization techniques to improve performance of microstrip antennas (MSAs) in terms of bandwidth, radiation characteristics, polarization, directivity and size. The drawbacks of the conventional MSAs can be overcome by optimizing the antenna parameters while keeping a compact configuration. Applying a global optimizer is a better technique than using a local optimizer or a trial and error method for performance enhancement. This paper discusses genetic algorithm (GA) optimization of microstrip antennas presented by the antenna research community. The GA optimization procedure, antenna parameters optimized by using GA and the optimization objectives are presented by reviewing the literature. Further, evolution of GA in the field of MSAs and its significance are explored. Application of GA optimization to design broadband, multiband, high-directivity and miniature antennas is demonstrated with the support of several case studies giving an insight for further developments in the field. </abstract>

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Sahoo, Bijaya Kumar. "Constructing Electron-Atom Elastic Scattering Potentials Using Relativistic Coupled-Cluster Theory: A Few Case Studies". Atoms 10, nr 3 (6.09.2022): 88. http://dx.doi.org/10.3390/atoms10030088.

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In light of the immense interest in understanding the impact of an electron on atoms in the low-energy scattering phenomena observed in laboratories and astrophysical processes, we propose an approach to construct potentials using relativistic coupled-cluster (RCC) theory for the determination of electron-atom (e-A) elastic scattering cross-sections (eSCs). The net potential of an electron, scattered elastically by an atom, is conveniently expressed as the sum of the static (Vst) and exchange (Vex) potentials due to interactions of the scattered electron with the electrons of the atom and potentials due to polarization effects (Vpol) on the scattered electron by the atomic electrons. The Vst and Vex potentials for the e-A eSC problems can be constructed with a knowledge of the electron density function of the atom, while the Vpol potential can be obtained using the polarizabilities of the atom. In this paper, we present the electron densities and electric polarizabilties of Be, Mg, Ne and Ar atoms using two variants of the RCC method. Using these quantities, we construct potentials for e-A eSC problems. To obtain Vpol accurately, we evaluate the second- and third-order electric dipole and quadrupole polarizabilities using a linear response approach.

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32

Cumings, John, Eva Olsson, Amanda K. Petford-Long i Yimei Zhu. "Electric and Magnetic Phenomena Studied byIn SituTransmission Electron Microscopy". MRS Bulletin 33, nr 2 (luty 2008): 101–6. http://dx.doi.org/10.1557/mrs2008.22.

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AbstractThere is a wide array of technologically significant materials whose response to electric and magnetic fields can make or break their utility for specific applications. Often, these electrical and magnetic properties are determined by nanoscale features that can be most effectively understood through electron microscopy studies. Here, we present an overview of the capabilities for transmission electron microscopy for uncovering information about electric and magnetic properties of materials in the context of operational devices. When devices are operated during microscope observations, a wealth of information is available about dynamics, including metastable and transitional states. Additionally, because the imaging beam is electrically charged, it can directly capture information about the electric and magnetic fields in and around devices of interest. This is perhaps most relevant to the growing areas of nanomaterials and nanodevice research. Several specific examples are presented of materials systems that have been explored with these techniques. We also provide a view of the future directions for research.

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33

Murray-Wallace, Colin V., i Albert Goede. "Aminostratigraphy and electron spin resonance studies of late Quaternary sea level change and coastal neotectonics in Tasmania, Australia". Zeitschrift für Geomorphologie 35, nr 2 (8.08.1991): 129–49. http://dx.doi.org/10.1127/zfg/35/1991/129.

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Dr. O. P. Choudhary, Dr O. P. Choudhary, B. S. Dhote B.S. Dhote, S. K. Bharti S.K. Bharti i S. Sathapathy S. Sathapathy. "The Advantages of the Scanning Electron Microscope in the Forensic Studies of Hair in Domesticated and Wild Animals". International Journal of Scientific Research 3, nr 2 (1.06.2012): 191–92. http://dx.doi.org/10.15373/22778179/feb2014/62.

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Glukhova O. E. i Slepchenkov M. M. "Graphene/nanotube quasi-1D structures in strong electric fields". Physics of the Solid State 64, nr 5 (2022): 571. http://dx.doi.org/10.21883/pss.2022.05.53519.264.

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In silico studies of the behavior of graphene/nanotube quasi-one-dimensional (1D) structures with covalent bonded graphene and nanotube in strong electric fields with a strength of 10^7-108 V/cm have been carried out. The atomic structure, band structure, electron transmission function, electrical conductivity, and regularity of the electronic structure changes in strong fields have been studied. It is found that the electron transmission function of quasi-1D structures has an intensity peak at the Fermi level in contrast to nanotubes and graphene. As a result of quantum molecular dynamics modeling, the regularities of deformation of the atomic framework and its destruction under the action of ponderomotive force have been established. We have found a critical value of the strength at which the electric field detaches the graphene from the tube. It is ~2·108 V/cm. A further increase leads to the detachment of graphene from the tube with its simultaneous destruction. Keywords: graphene/nanotube structures, electrical conductivity, ponderomotive force, strong electric fields.

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36

Kumar, Abhijeet, i Arpit Kumar. "Contactless temperature and distance measuring device: A low-cost, novel infrared ―based "Badge"-shaped structural model for measuring physical distance and body temperature". AIMS Electronics and Electrical Engineering 6, nr 1 (2022): 43–60. http://dx.doi.org/10.3934/electreng.2022004.

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<abstract> This work eases the feasibility of infrared thermometer application and reliability to introduce a novel design with upgraded applications & functions. The custom-designed compact device "Badge" structured comprises the operative methods through the electronic packages of an optimal level. The physical and social distance measured by the ToF (Time of Flight) infrared laser sensor within 1 m from the subject and the measuring equipment (MLX90632 SMD QFN and VL530LX ToF). When the distance is not maintained, or the physical distance condition is not met, the flashing LED, or vibration should trigger an indication (warning for physical distancing and alteration for pyrexia warning, respectively). Statistical analysis and simulation-based studies criticized the accuracy of ±0.5°F and relational model of the independent and dependent variable for this device with significant R2 = 0.99 and P < = 1; values with the lowest accuracy error of ±0.2°F and least residual sum of squares 0.01462 values. The portable, lightweight, and dynamic body temperature monitoring altered the application from static to continuous, complete structural design. This alternative provides the best technique to combine worn (personnel) medical devices with primary healthcare instruments to help body temperature measurements that are not contactable, fast, and accurate. It builds a way of processing through the protocol Covid-19. </abstract>

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Kaczmarek, Halina, Marta Chylińska, Ewa Klimiec, Bogusław Królikowski, Grzegorz Sionkowski i Monika Machnik. "Piezo-electrets from polypropylene composites doped with mineral fillers". Pure and Applied Chemistry 91, nr 6 (26.06.2019): 967–82. http://dx.doi.org/10.1515/pac-2018-0702.

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Abstract PP-based composites with two mineral fillers (perlite or glass beads) were manufactured by extrusion, and then subjected to orientation in a ratio of 3:1. Electrets were obtained in the polarization process under the influence of a constant electric field. Sample morphology was tested by SEM whereas the crystallinity was determined by XRD. Mechanical strength and thermal stability of composites was studied by tensile tests and thermogravimetric analysis, respectively. The piezoelectric characteristics were appointed by measurement of the electrical charge and current voltage in the polarized samples. The dependence of thermally stimulated depolarized current (TSDC) on temperature was also investigated. The piezoelectric coefficient (d33), the electret stability over time as well as activation energy of depolarization process have been determined. It was found that low filler content (i.e. 2.5 and 5 wt.% of glass beads and perlite, respectively) significantly improve piezoelectric properties of isotactic polypropylene (i-PP).

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Raghunathareddy, M. V., G. Indumathi i K. R. Niranjan. "Highly sensitive optical MEMS based photonic biosensor for colon tissue detection". AIMS Electronics and Electrical Engineering 6, nr 3 (2022): 285–95. http://dx.doi.org/10.3934/electreng.2022017.

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<abstract> Biological component of cells, protein has been effectively studied and investigated using biological sensors. Photonic crystal-based sensor is highly sensitive optical nanostructure it can be manipulated to affect the motion of photon for users' application. In the proposed work microcavity based photonic crystal biosensor has been designed and investigated for its different optical sensing evaluation parameters such as transmission efficiency, sensitivity, Q factor and peak resonant wavelengths. Sensor is designed and analyzed for early detection of colon cancer tissues in blood. Radius of defect micropillar has been increased from 0.16 µm to 0.19 µm. High Quality factor 10232 has been achieved with the micro pillar radius of 0.17 µm and sensitivity 700nm/RIU. Similarly, radius of 0.16 µm, 0.18 µm and 0.19 µm has attained quality factor and sensitivity such as 5324, 7232, 8343 and 111 nm/RIU, 320 nm/RIU and 340 nm/RIU respectively. Compared other work in literature, proposed work has shown better sensing capability. Designed sensor has shown remarkable output and feasibility for future fabrication. </abstract>

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Patnaik, Samarjit, Manas Ranjan Nayak i Meera Viswavandya. "Smart deployment of energy storage and renewable energy sources for improving distribution system efficacy". AIMS Electronics and Electrical Engineering 6, nr 4 (2022): 397–417. http://dx.doi.org/10.3934/electreng.2022024.

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<abstract>Climate change, global warming, the depletion of fossil fuels, and rising energy demand are the main forces behind the increase in renewable energy sources. However, the unpredictability of power output from these renewable energy sources presents distribution system integration issues such as limited feeder capacity, unstable voltage, and network power loss. This study analyses the African vulture optimisation algorithm to determine the best allocation of distribution generators, with an emphasis on reducing the ageing of distribution transformers and delaying investment in feeders. The optimization technique provides faster global convergence and outperforms existing bio-inspired algorithms verified with benchmark uni-modal functions as a result of a larger crossover between the exploration and exploitation phases. The key aim is to decrease active power loss while simultaneously enhancing security margin and voltage stability. The IEEE 69-bus RDS system is utilised to validate the case studies for appropriate allocation of photovoltaic, wind turbine generation, and battery energy storage systems units, as well as offering the ideal energy management approach. During simulation, uncertainty on the characteristics of renewable energy source is accounted for. The results demonstrate the efficacy of the proposed algorithm with a substantial improvement in voltage profile, the benefit of lower CO2 emissions, an increase in security margin of up to 143%, and the advantage of extending the feeder investment deferral period by more than 50 years. In addition, the distribution transformer ageing acceleration factor improves significantly in the case of an increase in load demand.</abstract>

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40

Paton, B. E. "Advanced studies and developments of the E.O. Paton Electric Welding Institute in the field of welding and related technologies". Paton Welding Journal 2018, nr 12 (28.12.2018): 4–15. http://dx.doi.org/10.15407/tpwj2018.12.01.

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Malkov, M. A., i V. I. Sotnikov. "Instabilities, anomalous heating, and stochastic acceleration of electrons in colliding plasmas". Physics of Plasmas 29, nr 8 (sierpień 2022): 082108. http://dx.doi.org/10.1063/5.0094014.

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The collision of two expanding plasma clouds is investigated, emphasizing instabilities and electron energization in the plasma mixing layer. This work is not only directly relevant to laboratory experiments with explosively created laser or z-pinch plasmas but may also elucidate naturally occurring plasma collisions in astrophysical or space physics contexts. In the previous publications [Malkov and Sotnikov, Phys. Plasmas 25, 102108 (2018) and Sotnikov et al., Phys. Plasmas 27, 122113 (2020)], we have studied, analytically and numerically, the flow emerging from interpenetrating coronas launched by two parallel wires vaporized in a vacuum chamber. The main foci of the studies have been on the general flow pattern and lower-hybrid and thin-shell instabilities that under certain conditions develop in the collision layer. The present paper centers around the initial phase of the interpenetration of the two plasmas. Two-stream ion–ion instability, efficient electron heating, and stochastic acceleration dominate plasma mixing at this phase. Both the adiabatic (reversible) electron heating and stochastic (irreversible) acceleration and heating mechanisms, powered by unstably driven electric fields, are considered. The irreversibility results from a combination of electron runaway acceleration in the wave electric fields and pitch-angle scattering on ions and neutrals.

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42

Ning, Li, Mu Jie i Kong Fancun. "Numerical Studies on Bow Waves in Intense Laser-Plasma Interaction". Laser and Particle Beams 2023 (15.02.2023): 1–11. http://dx.doi.org/10.1155/2023/9414451.

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Laser-driven wakefield acceleration (LWFA) has attracted lots of attention in recent years. However, few writers have been able to make systematic research into the bow waves generated along with the wake waves. Research about the bow waves will help to improve the understanding about the motion of the electrons near the wake waves. In addition, the relativistic energetic electron density peaks have great potential in electron acceleration and reflecting flying mirrors. In this paper, the bow waves generated in laser-plasma interactions as well as the effects of different laser and plasma parameters are investigated. Multidimensional particle-in-cell simulations are made to present the wake waves and bow waves by showing the electron density and momentum distribution as well as the electric field along x and y directions. The evolution of the bow wave structure is investigated by measuring the open angle between the bow wave and the wake wave cavity. The angle as well as the peak electron density and transverse momentum is demonstrated with respect to different laser intensities, spot sizes, plasma densities, and preplasma lengths. The density peak emits high-order harmonics up to 150 orders and can be a new kind of “flying mirror” to generate higher order harmonics. The study on the bow waves is important for further investigation on the electron motion around the wake waves, generation of dense electron beams, generation of high-order harmonics, and other research and applications based on the bow waves.

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Tan, Xiaoli, Hui He i Jian-Ku Shang. "In situ Transmission Electron Microscopy Studies of Electric-field-induced Phenomena in Ferroelectrics". Journal of Materials Research 20, nr 7 (1.07.2005): 1641–53. http://dx.doi.org/10.1557/jmr.2005.0213.

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High electric fields were delivered to specimens during imaging in the transmission electron microscopy (TEM) chamber to reveal details of electric field-induced phenomena in ferroelectric oxides. These include the polarization switching in nanometer-sized ferroelectric domains and the grain boundary cavitation in a commercial lead zirconate titanate (PZT) polycrystalline ceramic, the domain wall fracture in a Pb(Mg1/3Nb2/3)O3–PbTiO3 single crystal, and the transformation of incommensurate modulations in Pb0.99Nb0.02[(Zr1−xSnx)1−yTiy]0.98O3 (PZST100x/100y/2) polycrystalline ceramics. In the PZT ceramic, a cavitation process was uncovered for the electric field-induced intergranular fracture. In the ferroelectric single crystal, a preexisting crack was observed to deflect and to follow a 90° domain wall, indicating the presence of severe incompatible piezoelectric strains at thedomain wall. In the antiferroelectric PZST ceramics, the electric field-induced antiferroelectric-to-ferroelectric phase transformation was accompanied with the disappearance of incommensurate modulations.

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Gochuyeva, A. F., Kh Kh Hashimov i I. Y. Bayramov. "Photoelectret effect in polymer-AIIBVI (CdS, ZnS) composites of photosensitive semiconductors". Chalcogenide Letters 20, nr 4 (kwiecień 2023): 285–91. http://dx.doi.org/10.15251/cl.2023.204.285.

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The photoelectret effect in composite heterostructures consisting of polar (fluorinecontaining) and non-polar (polyolefins) polymers - high density polyethylene (HDPE), low density polyethylene (LDPE), F42, F2-ME and the inorganic phase AııBvı (CdS, ZnS) has been studied. It has been established that the difference in photoelectret potentials in a given volume share of the inorganic phase mainly depends on the polarity of the polymer matrix. A possible mechanism of the photoelectret effect formed under the combined action of a strong electric field and light in these composites. It has been experimentally established that the potential barrier formed at the polymer- AııBvı semiconductor interface separates the electric charge carriers formed as a result of the internal photoelectric effect and ensures the formation of an electret potential difference. The electret charge state of polymer- AııBvı composites was studied using the spectrum of thermally stimulated current.

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45

Sharma, Gaurav, i Guennadi A. Kouzaev. "Miniature glass-metal coaxial waveguide reactors for microwave-assisted liquid heating". AIMS Electronics and Electrical Engineering 7, nr 1 (2023): 100–120. http://dx.doi.org/10.3934/electreng.2023006.

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<abstract> Microwave (MW) irradiation is recognized as an effective tool in industries related to pharmaceuticals, chemistry, nanoparticle synthesis, food, etc. In the hardware field, some research efforts are concentrated on creating miniature reactors using low-cost technologies aimed at on-demand chemistry or parallel synthesis of many drugs. This paper reports on the development and characterization of novel miniature chemical-resistant glass-metal coaxial reactors based on a modified Liebig condenser. It is composed of two concentric glass tubes, one for the central conductor carrying MW current, and the other for the copper-foiled cylinder surrounding the first pipe. The gap between them is filled with a liquid that is pumped and evacuated by using shielded thin inlet/outlet glass tubes, which are melted and opened into this cylindrical cavity. The reactor's geometry allows for the direct soldering of miniature MW SMA coaxial connectors of 50-Ω impedance. The developed components are studied analytically, numerically and experimentally. The frequency properties of reactors are measured with a network analyzer. The temperature trends are explored by using a variable high-power MW generator, power meters and temperature sensors. These reactors demonstrate their relative insensitivity toward variations in the permittivity of filling liquids in the range of $3.75 < \varepsilon < 30$, as shown in simulations and measurements. They demonstrate the increase by two orders in the longitudinal modal penetration depth and a more homogeneous heating along reactors as compared to their hollow coaxial prototypes. These glass-metal miniature reactors can be used in on-demand continuous-flow accelerated liquid heating, chemistry and pharmacy. </abstract>

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Глухова, О. Е., i М. М. Слепченков. "Графен/нанотрубные квази-1D-структуры в сильных электрических полях". Физика твердого тела 64, nr 5 (2022): 578. http://dx.doi.org/10.21883/ftt.2022.05.52340.264.

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In silico studies of the behavior of graphene/nanotube quasi-one-dimensional (1D) structures with covalent bonded graphene and nanotube in strong electric fields with a strength of 10^7–10^8 V/cm have been carried out. The atomic structure, band structure, electron transmission function, electrical conductivity, and regularity of the electronic structure changes in strong fields have been studied. It is found that the electron transmission function of quasi-1D structures has an intensity peak at the Fermi level in contrast to nanotubes and graphene. As a result of quantum molecular dynamics modeling, the regularities of deformation of the atomic framework and its destruction under the action of ponderomotive force have been established. We have found a critical value of the strength at which the electric field detaches the graphene from the tube. It is ~ 2 ∙ 10^8 V/cm. A further increase leads to the detachment of graphene from the tube with its simultaneous destruction.

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47

Wang, De-hua. "Time-dependent electric field effect on the photodetachment dynamics of negative ions". Canadian Journal of Physics 95, nr 5 (maj 2017): 507–13. http://dx.doi.org/10.1139/cjp-2016-0845.

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This paper addresses the photodetachment dynamics of a negative ion in a time-dependent electric field based on the semiclassical open-orbit theory. The photodetached electron probability density in a real time domain is studied in a gradient electric field for the first time. It is found that because of the influence of the gradient electric field, two or more electron trajectories can arrive at a given point on the detector, and the interference effect between these electron trajectories causes oscillatory structures in the electron probability density. Our calculation results suggest that when the external electric field changes very slowly with time, only two electron trajectories can arrive at a given point on the detector and the electron probability density exhibits a regular two-term oscillatory pattern. However, when the electric field changes quickly with time, four electron trajectories can reach the detector, which makes the oscillatory structures in the electron probability density become much more complicated. In addition, the electric field strength, photon energy, and the position of the detector can affect the electron probability density of this system sensitively. Our study provides a clear and intuitive picture for the photodetachment dynamics of the negative ion in the external electric field from a time-dependent viewpoint and may guide the future experimental researches on the photodetachment microscopy of negative ions in the time-dependent electric field.

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Charalambous, C., M. Danikas, Y. Yin, N. Vordos, J. W. Nolan i A. Mitropoulos. "Study of the Behavior of Water Droplets Under the Influence of a Uniform Electric Field on Conventional Polyethylene and on Crosslinked Polyethylene (XLPE) with MgO Nanoparticles Samples". Engineering, Technology & Applied Science Research 7, nr 1 (12.02.2017): 1323–28. http://dx.doi.org/10.48084/etasr.813.

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It is well known that polyethylene (PE) and cross-linked polyethylene (XLPE) are suitable insulating materials for underground cables. Samples of PE and of XLPE with MgO nanoparticles were investigated regarding their flashover behaviour with a uniform electric field and water droplets of various conductivities. In the present paper, the effect of the mounting arrangement of the water drops on the value of the flashover voltage and the effect of the volume of dripping water on the flashover voltage were also studied. Surface damages were analyzed using Scanning Electron Microscopy (SEM) studies and the study of the nano-structure of the samples was studied using the SAXS system.

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Das, P. K., R. Kanishka, P. Bhattacharya, N. Majumdar, S. Mukhopadhyay i S. Sarkar. "Numerical Studies on Primary Ionization in TPC". Journal of Physics: Conference Series 2349, nr 1 (1.09.2022): 012010. http://dx.doi.org/10.1088/1742-6596/2349/1/012010.

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Identification followed by directionality measurement using reconstruction of tracks is very crucial for studying the reaction vertex kinematics. In the field of low-energy nuclear physics, Active-Target Time Projection Chambers (AT-TPCs) can be used to study the nuclear reaction kinematics through tracking of the reaction products which is important for cross-section measurement. Ions produced in primary ionization by any charged particle along their track in the active gas volume of TPC can be utilized for track reconstruction with position-sensitive electron collection system placed inside an electric field. The TPC gas volume acts as the tracker of the reaction products and the target for the reaction with the incoming projectile simultaneously which is advantageous to conventional detector arrays. In this context, the design of the electric field in the drift volume of the TPC is an important criterion for precise tracking as the tracking capability of the TPC is strongly governed by the homogeneity of the electric field. Due to the lesser mobility of positive ions produced in primary ionization, their accumulation in the drift volume can distort the local electric field. In low-energy nuclear physics, this effect may be substantial due to the significant amount of ionization produced by the low-energy projectile and reaction products. Here we report the spatial information of primary space charges produced by cosmic muon and alpha particle obtained with geant4 [1] and Heed [2] simulation packages. We have used photo absorption and ionization physics lists in geant4 for the simulation and compared the results with that of the Heed. The simulation results for the change in pressure of gas volume will be reported. These results can be used for finding the distortion of the electric field due to the space charge in the drift region of the TPC which can be helpful for designing an AT-TPC for low-energy nuclear reaction experiments.

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50

Pillai, P. K. C., i Paramdeep Khurana. "Applications of polymer electrets for pollution studies". Applied Physics Letters 52, nr 18 (2.05.1988): 1540–41. http://dx.doi.org/10.1063/1.99076.

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