Bibliografie tematiche / Dielectrical properties

Indice

Articoli di riviste
Tesi
Libri
Capitoli di libri
Atti di convegni
Rapporti di organizzazioni

Letteratura scientifica selezionata sul tema "Dielectrical properties"

Autore: Grafiati

Pubblicato: 5 ottobre 2024

Cita una fonte nei formati APA, MLA, Chicago, Harvard e in molti altri stili

Scegli il tipo di fonte:

Consulta la lista di attuali articoli, libri, tesi, atti di convegni e altre fonti scientifiche attinenti al tema "Dielectrical properties".

Accanto a ogni fonte nell'elenco di riferimenti c'è un pulsante "Aggiungi alla bibliografia". Premilo e genereremo automaticamente la citazione bibliografica dell'opera scelta nello stile citazionale di cui hai bisogno: APA, MLA, Harvard, Chicago, Vancouver ecc.

Puoi anche scaricare il testo completo della pubblicazione scientifica nel formato .pdf e leggere online l'abstract (il sommario) dell'opera se è presente nei metadati.

Articoli di riviste sul tema "Dielectrical properties"

Zang, Chong Guang, e Xian Peng Cao. "PANI / MWNTs / EP Composite Microwave Absorbing Coatings Dielectrical and Microwave Absorbing Properties Analysis". Applied Mechanics and Materials 303-306 (febbraio 2013): 2477–80. http://dx.doi.org/10.4028/www.scientific.net/amm.303-306.2477.

Testo completo

Abstract (sommario):

In this paper, the polyaniline (PANI) coated multi-walled carbon nanotubes (MWNTs) was prepared in situ polymerization. Adding PANI/MWNTs into epoxy resin（EP）, we got PANI / MWNTs / EP composite microwave absorbing materials. Through testing permittivity 、permeability and reflection loss of materials, the paper showed the effect of PANI/MWNTS to the dielectrical and microwave absorbing properties of materials.The results showed： PANI/MWNTs had great effect on dielectrical and microwave absorbing properties of materials. But the imaginary permeability was close to 0. That indicated that it mainly consumed electromagnetic wave by dielectric loss. In 200-1000MHZ, materials had better absorbing property and lower reflection loss (-13.6).

Gli stili APA, Harvard, Vancouver, ISO e altri

Jayamani, Elammaran, e Muhammad Khusairy bin Bakri. "Preliminary Study on the Acoustical, Dielectric and Mechanical Properties of Sugarcane Bagasse Reinforced Unsaturated Polyester Composites". Materials Science Forum 890 (marzo 2017): 12–15. http://dx.doi.org/10.4028/www.scientific.net/msf.890.12.

Testo completo

Abstract (sommario):

In this research, the alkaline treated and untreated sugarcane bagasse was used as reinforcement with unsaturated polyester to make composites. The composites were made with 0 to 20 weight percentage of fibers using compression molding. Acoustical, dielectrical and mechanical properties of the composites were studied according to the American Society for Testing Materials (ASTM) standards. The result shows that the composites with higher sugarcane bagasse loading show higher acoustical and dielectrical properties. The composites tensile strength increased up to 10wt% of fiber loading and then starts decreasing eventually. Tensile strength and sound absorption coefficients of alkali treated fiber composites shown slightly better results than untreated fiber composites. The dielectric constant of treated fiber composites were lower compared with untreated fiber composites.

Gli stili APA, Harvard, Vancouver, ISO e altri

Mobarak, Youssef, M. Bassyouni e M. Almutawa. "Materials Selection, Synthesis, and Dielectrical Properties of PVC Nanocomposites". Advances in Materials Science and Engineering 2013 (2013): 1–6. http://dx.doi.org/10.1155/2013/149672.

Testo completo

Abstract (sommario):

Materials selection process for electrical insulation application was carried out using Cambridge Engineering Selector (CES) program. Melt mixing technique was applied to prepare polyvinyl-chloride- (PVC-) nanofumed silica and nanomontmorillonite clay composites. Surface analysis and particles dispersibility were examined using scanning electron microscope. Dielectrical properties were assessed using Hipot tester. An experimental work for dielectric loss of the nanocomposite materials has been investigated in a frequency range of 10 Hz–50 kHz. The initial results using CES program showed that microparticles of silica and clay can improve electrical insulation properties and modulus of elasticity of PVC. Nano-montmorillonite clay composites were synthesized and characterized. Experimental analyses displayed that trapping properties of matrix are highly modified by the presence of nanofillers. The nanofumed silica and nanoclay particles were dispersed homogenously in PVC up to 10% wt/wt. Dielectric loss tangent constant of PVC-nanoclay composites was decreased successfully from 0.57 to 0.5 at 100 Hz using fillers loading from 1% to 10% wt/wt, respectively. Nano-fumed silica showed a significant influence on the electrical resistivity of PVC by enhancing it up to 1 × 1011 Ohm·m.

Gli stili APA, Harvard, Vancouver, ISO e altri

Skipina, Blanka, Dusko Dudic, Dusan Kostoski e Jablan Dojcilovic. "Dielectrical properties of composites LDPE+CB". Chemical Industry 64, n. 3 (2010): 187–91. http://dx.doi.org/10.2298/hemind091221035s.

Testo completo

Abstract (sommario):

There is currently great interest in the technological properties of conductive polymer composites because their cost-performance balance. They have a wide range of industrial applications -in anti-static materials, self regulating heaters, current overload and overheating protection devices, and materials for electromagnetic radiation shielding. Measurements of the electrical properties of polymer composites are one of the most convenient and sensitive methods for studying polymer structure. A polymer composite differs substantially from a free polymer in a wide range of properties. The presence of filler affects both the electrical, as well as mechanical properties. One of the most important characteristics of conductive polymer composites is that their electrical conductivity increases nonlinearly with the increase of the concentration of filler particles. When the concentration of filler particles reaches a certain critical value, a drastic transition from an electrical insulator to a conductor is exhibited. This conductivity behavior resulting in a sudden insulator-conductor transition is ascribed to a percolation process, and the critical filler concentration at which the conductivity jump occurs is called ?percolation threshold?. In the past few years, a lot of studies have been carried out to analyze the percolation phenomenon and mechanisms of the conductive behavior in conductive polymer composites. It has been established that the electrical conductivity of conductive polymer composites uncommonly depends on the temperature. Some of such composites show a sharp increase and/or decrease in electrical conductivity at specific temperatures. The conductive temperature coefficient (CTC) of conductive polymer composites has been widely investigated. In these work we investigated how concentration of the CB affects the dielectrical properties of the composite LDPE+CB. The ac electrical conductivity, ?ac, for such composites was measured. The temperature and frequency dependence of the dissipation factor were analyzed. It was found that the ac conductivity and dissipation factor were highly affected by the concentration of the filler.

Gli stili APA, Harvard, Vancouver, ISO e altri

Haddour, Lillia, Mourad Keddam e Nadir Mesrati. "Relationships between Microstructure and Mechanical Properties of Polycristalline Alumina". Applied Mechanics and Materials 625 (settembre 2014): 192–95. http://dx.doi.org/10.4028/www.scientific.net/amm.625.192.

Testo completo

Abstract (sommario):

Some low purity alumina ceramics with an alumina content ranging from 86% to 93% were investigated, in order to explore the effects of microstructural parameters (grain size, intergranular phase) on mechanical (wear) and dielectrical parameters. The microstructure and worn surfaces were analysed using scaning electron microscopy. The correlation between microstructural, dielectrical properties and wear is discussed. It has been proposed that mechanical and electrical properties are two aspects of the same fundamental mechanism. Key words: Al2O3, Microstructure final, Wear resistance, Breakdown.

Gli stili APA, Harvard, Vancouver, ISO e altri

Soni, Neha, Nikita Karma, Lalit Kumar Bhataniya, Paras Dubey e Netram Kaurav. "Investigation of Structural and Dielectric Properties of Sr doped LaCrO3Synthesized by Auto-Combustion Method". Journal of Physics: Conference Series 2603, n. 1 (1 ottobre 2023): 012027. http://dx.doi.org/10.1088/1742-6596/2603/1/012027.

Testo completo

Abstract (sommario):

Abstract We synthesized the undoped lanthanum chromium oxide, LaCrO3 (LCO), and Strontium (Sr) doped La1-xSrxCrO3 (x=0.1) perovskite compounds using auto-combution method. X-ray Diffraction technique reveals that both the samples possess Cubic crystal structure with Pm-3m space group. Furthermore, room temperature dielectrical properties of both the samples were emphasized. Dielectric constant and loss value of both the samples decreases as frequency increases attributed to Maxwell-Wagner type of relaxation.

Gli stili APA, Harvard, Vancouver, ISO e altri

Kang, Jie, Gui Xia Dong e Qiu Xiang Liu. "Research on Properties of AlN-Mo Composite Ceramic". Advanced Materials Research 482-484 (febbraio 2012): 1695–98. http://dx.doi.org/10.4028/www.scientific.net/amr.482-484.1695.

Testo completo

Abstract (sommario):

With CaF2 and CaCO3 as sintering additives, AlN-Mo composite was prepared using hot pressed sintering technique. The phase composition and morphology of AlN-Mo composite ceramics were analyzed using XRD and SEM, respectively. The experimental results show that when CaF2 and CaCO3 additives is in a range of 1~3wt%, the thermal conductivity AlN-Mo composites increases with increasing of the CaF2 content; With the increasing of CaCO3 content, first increases and then decreases. Sintering additives in a certain type and content, the thermal conductivity of AlN-Mo composite ceramics with 20 vol% Mo is higher than containing 18 vol% Mo. The dielectrical property of AlN-Mo composite ceramics was also discussed. The addition of CaF2 can decrease the dielectric constant of AlN-Mo composite ceramics.

Gli stili APA, Harvard, Vancouver, ISO e altri

Maurya, M. K. "Study of Dielectric Properties of Typical Electrical Insulating Materials by Terahertz Wave Spectroscopy". International Journal for Research in Applied Science and Engineering Technology 12, n. 8 (31 agosto 2024): 632–40. http://dx.doi.org/10.22214/ijraset.2024.63973.

Testo completo

Abstract (sommario):

Abstract: This research paper uses a special kind of light is called terahertz waves to study the properties of materials that prevent electricity from flowing, like plastics and glass. Dielectrical insulating materials play an important role in the Insulation coordination of electric power systems such as transformers and high Voltage power cable. Dielectric insulating materials are evaluated based on their dielectric constant, dielectric strength, loss tangent, and thermal stability. The dielectric constant determines the material's ability to store electrical energy, while the dielectric strength indicates the maximum electric field the material can withstand without breaking down. The loss tangent measures energy dissipation as heat, which is crucial for minimizing energy losses in electrical systems. Terahertz (THz) wave spectroscopy has emerged as a powerful technique for the non-destructive evaluation of dielectric properties in electrical insulating materials. This study investigates the application of THz time-domain spectroscopy (THz-TDS) for characterizing typical insulating materials such as polyethylene (PE), polytetrafluoroethylene (PTFE), and epoxy resins. This research can help improve the design and performance of electrical devices, making them safer, more efficient, and more reliable.

Gli stili APA, Harvard, Vancouver, ISO e altri

Journal, Baghdad Science. "Investigation of the dielectric Properties of (PPAB) terminated by phenylenediamine doped by Na2[Fe(CN)5.NO].2H2O using Lumped equivalent circuit". Baghdad Science Journal 13, n. 1 (6 marzo 2016): 174–82. http://dx.doi.org/10.21123/bsj.13.1.174-182.

Testo completo

Abstract (sommario):

The aim of this paper is to demonstrate the effect of Na2[Fe(CN)5.NO].2H2O impurity (0.1 M) concentration on the dielectrical properties of poly (P-Aminobenzaldehyde) terminated by pheneylenediamine in the frequency and temperature ranges (1-100)KHz and (283-348) K respectively.These properties include dissipation factor, series and parallel resistance, series and parallel capacitance, real and imaginary part of the dielectric constant, a.c conductivity and impedance (real and imaginary) part, that have been deduced from equivalent circuit. The investigation shows that adding Na2[Fe(CN)5.NO].2H2O as additive to the polymer lead to increase of the dielectric constant with increasing temperature and it is decreasing with increasing the frequency .The dissipation factor is increasing with as the frequency increased.

Gli stili APA, Harvard, Vancouver, ISO e altri

Turky, Ali Omar, Mohamed Mohamed Rashad, Zaki Ismail Zaki, Ibrahim Ahmed Ibrahim e Mikhael Bechelany. "Tuning the optical and dielectric properties of calcium copper titanate CaxCu3−xTi4O12 nanopowders". RSC Advances 5, n. 24 (2015): 18767–72. http://dx.doi.org/10.1039/c4ra15222k.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Più fonti

Tesi sul tema "Dielectrical properties"

Silva, Igor. "Propriétés des matériaux isolants pour application dans les appareillages moyenne tension à tension continue". Electronic Thesis or Diss., Université Grenoble Alpes, 2024. http://www.theses.fr/2024GRALT043.

Testo completo

Abstract (sommario):

Les récentes avancées dans la technologie du courant continu, du côté du transport à haute tension et de la consommation à basse tension, ont propulsé le courant continu de moyenne tension (MVDC) au premier plan. Cette thèse explore les propriétés isolantes en courant continu de deux matériaux couramment utilisés dans l'équipement de distribution : de l'époxy chargé en micro-silice et le silicone elastomère.Dans une configuration monocouche, chaque matériau a fait l'objet d'une enquête approfondie, mettant l'accent sur les caractéristiques de sorption d'eau et la conduction électrique. Des mesures de courant ont été effectuées pour analyser la conduction dans divers niveaux de champs, à différentes températures et conditions d'absorption d'eau. De plus, la méthode Laser Pressure Pulse (LIPP) a été utilisée pour des mesures de charge d'espace en tant que technique complémentaire. L'étude s'est étendue à une configuration bicouche, combinant les deux matériaux, nous permettant ainsi de confirmer un modèle prédisant les propriétés du multicouche et sa distribution de champs en fonction des valeurs des monocouches.La conduction en courant continu dans l'époxy a montré une forte dépendance à l'absorption d'eau, l'humidité influençant la non-linéarité et modifiant le mécanisme de conduction. À l'inverse, le silicone a démontré une conduction limitée par l'électrode, avec des variations de courant liées à la sorption d'eau par le biais d'un mécanisme limité par saturation. Dans une configuration bicouche hypothétique, où l'époxy représente un manchon et le silicone sert de terminaison de câble, le champ est censé se concentrer dans l'époxy dans des environnements secs, passant au silicone à mesure que l'humidité augmente. La thèse se conclut par des discussions sur les stratégies de sélection des matériaux et la conception de configurations multicouches
Recent advancements in direct-current technology from the high-voltage transport and low-voltage consumption have brought medium-voltage DC (MVDC) to the forefront. This thesis delves into the insulating DC properties of two commonly used materials in distribution equipment: epoxy filled with silica and silicone rubber.In a monolayer configuration, each material underwent extensive investigation, focusing on water sorption characteristics and electrical conduction. Current measurements were conducted to analyze conduction under various fields, temperatures, and water uptake conditions. Additionally, the Laser Pressure Pulse (LIPP) method was employed for space charge measurements as a complementary technique. The study extended to a bilayer configuration, combining both materials, with insights from monolayer experiments informing the properties of the bilayer and predicting field distribution.The DC conduction in epoxy exhibited high dependence on water absorption, with moisture influencing non-linearity and altering the conduction mechanism. Conversely, silicone demonstrated electrode-limited conduction, with current variations tied to water sorption through a saturation-limited mechanism. In a hypothetical bilayer configuration, where epoxy represents a type-C bushing and silicone serves as the cable termination, the field is expected to concentrate in the epoxy in dry environments, shifting to silicone as humidity increases. The thesis concludes with discussions on material selection strategies and the design of multi-layer configurations

Gli stili APA, Harvard, Vancouver, ISO e altri

Hu, Chuan. "Study of the thermal properties of low k dielectric thin films /". Full text (PDF) from UMI/Dissertation Abstracts International, 2000. http://wwwlib.umi.com/cr/utexas/fullcit?p9992820.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Duong, Danny. "The complex dielectric properties of aqueous ammonia from 2 GHz - 8.5 GHz in support of the NASA Juno mission". Thesis, Georgia Institute of Technology, 2011. http://hdl.handle.net/1853/42891.

Testo completo

Abstract (sommario):

A new model for the complex dielectric constant, ε, of aqueous ammonia (NH4OH) has been developed based on laboratory measurements in the frequency range between 2-8.5 GHz for ammonia concentrations of 0-8.5 %NH3/volume and temperatures between 277-297 K. The new model has been validated for temperatures up to 313 K, but may be consistently extrapolated up to 475 K and ammonia concentrations up to 20 %NH3/volume. The model fits 60.26 % of all laboratory measurements within 2σ uncertainty. The new model is identical to the Meissner and Wentz (2004) model of the complex dielectric constant of pure water, but it contains a correction for dissolved ammonia. A description of the experimental setups, uncertainties associated with the laboratory measurements, the model fitting process, the new model, and its application to approximating jovian cloud opacity for NASA's Juno mission to Jupiter are provided.

Gli stili APA, Harvard, Vancouver, ISO e altri

Farnsworth, Kimberly Dawn Richards. "Variable frequency microwave curing of polymer dielectrics". Diss., Georgia Institute of Technology, 1999. http://hdl.handle.net/1853/10928.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Patel, Kaushal Sharad. "Technique for determining through-plane modulus of thin polymer dielectrics". Diss., Georgia Institute of Technology, 1998. http://hdl.handle.net/1853/10993.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Moulart, Alexandre Marc. "High dielectric and conductive composites for electromagnetic crystals". Thesis, Georgia Institute of Technology, 2002. http://hdl.handle.net/1853/17092.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Manepalli, Rahul Nagaraj. "Electron beam curing of thin film polymer dielectrics". Diss., Georgia Institute of Technology, 2000. http://hdl.handle.net/1853/11036.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Tear, Gareth Richard. "Shock properties of homogeneous anisotropic dielectrics". Thesis, Imperial College London, 2016. http://hdl.handle.net/10044/1/53828.

Testo completo

Abstract (sommario):

Anisotropy, the directional dependence of a physical quantity, is present in numerous physical processes involved in the shock compression of solid materials. The effect that a particular property’s anisotropy has on the propagation of a shock wave is obscured by other effects such as those from strain rate and material heterogeneity. Recent studies have focussed on single- and bi-crystal metals to understand the effect of crystal anisotropy on the mechanics of shock wave propagation. This thesis extends this work to optically transparent non-metallic dielectric single crystals by developing an optical model for anisotropic dielectrics and performing experimental measurements to test the validity of that optical model. Current optical models for shock compressed materials use an isotropic Gladstone- Dale model or isotropic modifications of the Gladstone-Dale model. This thesis extends the isotropic Gladstone-Dale model to an anisotropic photoelastic model for the optical behaviour of linear anisotropic materials under shock compression in the elastic regime. The model uses static photoelastic tensor values available in the literature to predict material response under uniaxial strain in an arbitrary crystal orientation. The effect of varying photoelastic tensor values is studied using Monte Carlo techniques, and confidence intervals on dynamic predictions are presented. Polarimetry is applied to experimentally measure birefringence under shock compression delivered using plate impact on a single stage light gas gun. This method is used to validate the linear photoelastic model developed in this thesis. Experiments were performed on < 10-10 > (a-cut) sapphire up to 15 GPa longitudinal stress and < 10-10 > (a-cut) calcite up to 2 GPa longitudinal stress. It was found that the birefringence of a-cut sapphire under shock compression behaved in agreement with the model in the elastic regime for a 5% error on the photoelastic tensor. Furthermore it was found that birefringence predictions for a-cut calcite as given by the same model did not agree with experimentally measured results. The discrepancy was 0.3% at 1.2 GPa, in excess of 5 standard deviations. Possible reasons for the discrepancy are put forward. Current optical models for shock compressed materials use an isotropic Gladstone-Dale model or isotropic modifications of the Gladstone-Dale model. This thesis extends the isotropic Gladstone-Dale model to an anisotropic photoelastic model for the optical behaviour of linear anisotropic materials under shock compression. The model uses static photoelastic tensor values available in the literature to predict material response under uniaxial strain in an arbitrary crystal orientation. The effect of varying photoelastic tensor values is studied using Monte Carlo techniques, and confidence intervals on dynamic predictions are presented. Polarimetry is applied to experimentally measure birefringence under shock compression. This method is used to validate the linear photoelastic model developed in this thesis. Experiments were performed on ⟨1 0 1 0⟩ (a-cut) sapphire and ⟨1 0 1 0⟩ (a-cut) calcite. It was found that the birefringence of a-cut sapphire under shock compression behaved in agreement with the model. Furthermore it was found that birefringence predictions for a-cut calcite as given by the same model did not agree with experimentally measured results. Possible reasons for the discrepancy are put forward.

Gli stili APA, Harvard, Vancouver, ISO e altri

Boon, Dirk Francois. "The link between daily rainfall and satellite radar backscatter data from the ERS-2 scatterometer in the Free State Province, South Africa". Diss., Pretoria : [s.n.], 2007. http://upetd.up.ac.za/thesis/available/etd-10272008-132211.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Ben, ghzaiel Tayssir. "Synthèse, caractérisation et étude des propriétés magnétiques et diélectriques de nanocomposites Polyaniline/hexaferrite pour l'absorption des micro-ondes". Thesis, Université Paris-Saclay (ComUE), 2017. http://www.theses.fr/2017SACLN003/document.

Testo completo

Abstract (sommario):

Ces travaux de thèse consistent à élaborer des nanocomposites Polyaniline/hexaferrite pour l’absorption des micro-ondes. L’idée principale est la mise en œuvre de matériaux composites à base de polymères conducteurs intrinsèques telle la Polyaniline que nous avons dopée avec différents types d’acides (HCl, CSA, NSA et TSA…) et l’hexaferrite de baryum de type magnétoplombite (M) stœchiométrique ou substitué. Au niveau de l’hexaferrite de baryum, la substitution du Fe3+ s’est faite par les ions Al3+, Bi3+, Cr3+ et Mn3+.L’hexaferrite de baryum et les hexaferrites substitués par les différents ions cités ci-dessus ont été synthétisés par voie hydrothermale dynamique en faisant varier divers paramètres au cours de la synthèse (pH, température, temps, rapport [OH-]/[NO3-]…).L’élaboration des composites Polyaniline/hexaferrite (pur ou substitués) a été effectuée par polymérisation oxydative en utilisant plusieurs techniques de synthèse : la polymérisation chimique en solution (en tenant compte de la nature de l’acide utilisé) avec ou sans agitation (Aqueous-Based Polymerization with or without stirring) et la polymérisation oxydative par voie solide (Solid-Based Polymerization). L’optimisation de ces différentes techniques de synthèse après caractérisations physicochimiques (DRX, FTIR, ATG, MEB, EDX), diélectriques (ε’, ε’’, σdc) et magnétiques (Mr, Ms, Hc, Tc, µ’, µ’’) des échantillons, a montré que la polymérisation par voie solide se trouve la méthode la plus facile, économique et respectueuse de l’environnement. Elle est aussi adaptée à la production du composite Pani/BaFe12O19 avec de bonnes propriétés structurales, physiques et magnétiques. L’étude de la substitution du Fe3+ dans le BaFe12O19 par Al3+, Bi3+, Cr3+ et Mn3+ a montré une forte dépendance des propriétés structurales et magnétiques avec la distribution de ces ions dans la maille cristalline hexagonale. En effet, les ions Al3+, Cr3+ et Mn3+ ont une tendance à occuper les sites tétraédriques, alors que le Bi3+ occupe les sites octaédriques. Une augmentation de Hc associée à la taille des cristallites a été observée pour les particules substituées avec l'Al et le Cr alors qu’une modification de l'anisotropie magnetocristalline (fort terme d'ordre supérieur) a été mise en évidence pour les substitutions Bi et Mn, dû à leur grand rayon ionique. L’incorporation des hexaferrites substitués dans la Polyaniline pour obtenir des composites Pani/BaMeFe11O19, où Me = Al, Bi, Cr et Mn, révèle une variation des propriétés électromagnétiques dans la gamme de fréquences allant de 1 à 18 GHz. En effet, ces variations sont dues à la formation de dipôles entre l’ion de substitution et les cations O2- dans le ferrite qui sont responsables de la résonance ferromagnétique, de l'anisotropie magnétocristalline et des interactions avec la matrice polymérique. Le composite Pani/BaFe12O19 présente des absorptions dans la bande X qui se déplacent vers la bande Ku avec la substitution du fer confirmant
This thesis deals with the formulation of Polyaniline/hexaferrite nanocomposite for absorbing electromagnetic waves. The main idea is the process of composite materials based on polymers intrinsic conductors such as polyaniline that we doped with different types of acids (HCl, CSA, NSA, and ... TSA) and barium hexaferrite with magnetoplumbite structure with or without substitution according to desired stoichiometries. In the barium hexaferrite, the substitution of Fe 3+ is made by Al3+, Bi3+, Cr3+ and Mn3+ ions.The barium hexaferrite and its substitutions by different ions mentioned above were synthesized dynamic hydrothermal method by varying various parameters during the synthesis (pH, temperature, time, ratio [OH-]/[NO3-] ...).The elaboration of polyaniline/hexaferrite composite (pure or substituted) was carried out by oxidative polymerization using various synthesis techniques: Aqueous-Based Polymerisation with or without agitation (taking into account the nature of the acid used) (ABP) and Solid-Based Polymerization (SBP). The optimization of these various synthesis techniques after physicochemical (XRD, FTIR, TGA, SEM, EDX), dielectric (ε ', ε' ', σdc) and magnetic (Mr, Ms, Hc, Tc, µ', µ'') characterizations of the samples showed that the solid route is the easiest method, economical and environmentally friendly. It is also suitable for the production of composite Pani/BaFe12O19 with good structural, physical and magnetic properties.The study of the substitution of Fe 3+ in the BaFe12O19 by Al3+, Bi3+, Cr3+ and Mn3+ showed a strong dependence of the structural and magnetic properties with the distribution of these ions in the hexagonal crystal lattice. In fact, Al3+, Cr3+ and Mn3+ ions tend to occupy the tetrahedral sites, while the Bi3+ favoured the octahedral sites. An increase in Hc associated with the small crystallite size observed for particles substituted with Al and Cr and the enhancement magnetocristalline anisotropy (strong higher order term) for Bi and Mn due to their high ionic radius.The incorporation of the substituted hexaferrite in the polyaniline to obtain Pani/BaMeFe11O19 composite, where Me = Al, Bi, Cr and Mn, reveals a variation in electromagnetic properties in the frequency range from 1 to 18 GHz. In fact, these variations are due to the formation of dipoles between the substituting ion and surrounding O2- cations in the ferrite which are responsible for the ferromagnetic resonance, the magnetocrystalline anisotropy and the exchange interaction with the polymer. The composite Pani/BaFe12O19 shows absorption bands at the X-band that shift to the Ku-band with the substitution of iron, confirming the potential of these materials for microwave applications

Gli stili APA, Harvard, Vancouver, ISO e altri

Più fonti

Libri sul tema "Dielectrical properties"

M, Nair K., Guha J. P, Okamoto A e International Ceramic Science and Technology Congress (3rd : 1992 : San Francisco, Calif.), a cura di. Dielectric ceramics: Processing, properties, and applications. Westerville, Ohio: American Ceramic Society, 1993.

Cerca il testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

International, Conference on Properties and Applications of Dielectric Materials (2nd 1988 Beijing China). Proceedings: Second International Conference on Properties and Applications of Dielectric Materials, Beijing, China, September 12-16, 1988. Beijing, China: Tsinghua University Press, 1988.

Cerca il testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

International Conference on Properties and Applications of Dielectric Materials (2nd 1988 Beijing, China). Proceedings: Second International Conference on Properties and Applications of Dielectric Materials, Beijing, China, September 12-16, 1988. New York, NY (345 E. 47th St., New York 10017): Institute of Electrical and Electronics Engineers, Inc., 1988.

Cerca il testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

V, Kozlov G., a cura di. Submillimetrovai͡a︡ diėlektricheskai͡a︡ spektroskopii͡a︡ tverdogo tela. Moskva: "Nauka", 1990.

Cerca il testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Church, Ronald H. Dielectric properties of low-loss minerals. [Pittsburgh]: U.S. Dept. of the Interior, 1988.

Cerca il testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Church, Ronald H. Dielectric properties of low-loss minerals. Washington, DC: U.S. Bureau of Mines, 1988.

Cerca il testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Zohdi, Tarek I. Electromagnetic Properties of Multiphase Dielectrics. Berlin, Heidelberg: Springer Berlin Heidelberg, 2012. http://dx.doi.org/10.1007/978-3-642-28427-4.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

James, Havriliak Stephen, a cura di. Dielectric and mechanical relaxation in materials: Analysis, interpretation, and application to polymers. Munich: Hanser Publishers, 1997.

Cerca il testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Gladkov, S. O. Dielectric Properties of Porous Media. Berlin, Heidelberg: Springer Berlin Heidelberg, 2003.

Cerca il testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Paluch, Marian, a cura di. Dielectric Properties of Ionic Liquids. Cham: Springer International Publishing, 2016. http://dx.doi.org/10.1007/978-3-319-32489-0.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Più fonti

Capitoli di libri sul tema "Dielectrical properties"

Imani, M. T., D. Zámbó, J. Miethe, P. Werle e N. C. Bigall. "On the Dielectrical, Electrical and Thermo-Physical Properties of Magnetite Nanoparticle-Doped Synthetic Ester". In Lecture Notes in Electrical Engineering, 540–48. Cham: Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-030-31680-8_54.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Zubkov, S. V. "Crystal Structure and Dielectrical Properties of Complex Perovskite-like Solid Solutions Bi3Ti1−xSnxNbO9 (x = 0.0, 0.1, 0.35)". In Springer Proceedings in Physics, 231–38. Cham: Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-030-19894-7_17.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Sirdeshmukh, Dinker B., Lalitha Sirdeshmukh e K. G. Subhadra. "Dielectrics". In Atomistic Properties of Solids, 373–404. Berlin, Heidelberg: Springer Berlin Heidelberg, 2011. http://dx.doi.org/10.1007/978-3-642-19971-4_11.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Fothergill, J. C. "Electrical Properties". In Dielectric Polymer Nanocomposites, 197–228. Boston, MA: Springer US, 2009. http://dx.doi.org/10.1007/978-1-4419-1590-0_7.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Fothergill, J. C. "Electrical Properties". In Dielectric Polymer Nanocomposites, 197–228. Boston, MA: Springer US, 2009. http://dx.doi.org/10.1007/978-1-4419-1591-7_7.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Delerue, Christophe, e Michel Lannoo. "Dielectric Properties". In Nanostructures, 77–103. Berlin, Heidelberg: Springer Berlin Heidelberg, 2004. http://dx.doi.org/10.1007/978-3-662-08903-3_3.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Buchner, Richard. "Dielectric Properties". In Encyclopedia of Applied Electrochemistry, 316–21. New York, NY: Springer New York, 2014. http://dx.doi.org/10.1007/978-1-4419-6996-5_6.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Zeller, H. R., e E. Cartier. "Electron Scattering and Dielectric Breakdown in Liquid and Solid Dielectrics". In The Liquid State and Its Electrical Properties, 455–64. Boston, MA: Springer US, 1988. http://dx.doi.org/10.1007/978-1-4684-8023-8_18.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Irwin, Patricia, Wei Zhang, Yang Cao, Xiaomei Fang e Daniel Qi Tan. "Mechanical and Thermal Properties". In Dielectric Polymer Nanocomposites, 163–96. Boston, MA: Springer US, 2009. http://dx.doi.org/10.1007/978-1-4419-1590-0_6.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Atti di convegni sul tema "Dielectrical properties"

Chaturmukha, V. S., C. S. Naveen, M. P. Rajeeva, B. S. Avinash, H. S. Jayanna e Ashok R. Lamani. "Dielectrical properties of PANI/TiO2 nanocomposites". In DAE SOLID STATE PHYSICS SYMPOSIUM 2015. Author(s), 2016. http://dx.doi.org/10.1063/1.4947720.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Levchenko, A. N., I. M. Pritula, V. B. Tyutyunnik, A. O. Penkina, A. V. Kosinova e M. I. Kolybayeva. "Crystal growth sector effect on dielectrical properties of carbamide doped KDP crystals". In 2013 International Conference on Advanced Optoelectronics and Lasers (CAOL). IEEE, 2013. http://dx.doi.org/10.1109/caol.2013.6657645.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Zhang, Dong, Wei Song, Xuan Wang, Zhi Sun, Bai Han, Jinxin Li e Qingquan Lei. "Research on the preparation of LDPE/Fe3O4 composite films and its dielectrical property". In 2012 IEEE 10th International Conference on the Properties and Applications of Dielectric Materials (ICPADM). IEEE, 2012. http://dx.doi.org/10.1109/icpadm.2012.6318935.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Kaur, Pawanpreet, Rabia Pandit, K. K. Sharma e Ravi Kumar. "Effects of Ni3+ substitution on structural and temperature dependent dielectrical properties of NdFeO3". In SOLID STATE PHYSICS: Proceedings of the 58th DAE Solid State Physics Symposium 2013. AIP Publishing LLC, 2014. http://dx.doi.org/10.1063/1.4872949.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Kumar, R. Nirmal, S. Muthupandi, K. Hemalatha, C. Paulrasu e S. Prathap. "Effect of ions on vibrational, mechanical and dielectrical properties of SADP single crystal". In 2ND INTERNATIONAL CONFERENCE ON MATERIALS FOR ENERGY AND ENVIRONMENT 2020. AIP Publishing, 2023. http://dx.doi.org/10.1063/5.0140993.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Li, Chaoqun, Jiang Wang e Guliang Fu. "Enhanced dielectrical and mechanical properties of polypropylene/ poly (vinylidene fluoride) blends with chlorinated polyethylene". In 2023 IEEE 6th International Electrical and Energy Conference (CIEEC). IEEE, 2023. http://dx.doi.org/10.1109/cieec58067.2023.10167094.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Haas, A., e J. Kindersberger. "Evaluation of influence of mineral oil immersion on dielectrical properties of silicone polymers by Thermal Analysis". In 2009 IEEE Conference on Electrical Insulation and Dielectric Phenomena (CEIDP). IEEE, 2009. http://dx.doi.org/10.1109/ceidp.2009.5377900.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Gäbler, Simone, Henning Heuer, Gert Heinrich e Richard Kupke. "Quantitatively analyzing dielectrical properties of resins and mapping permittivity variations in CFRP with high-frequency eddy current device technology". In 41ST ANNUAL REVIEW OF PROGRESS IN QUANTITATIVE NONDESTRUCTIVE EVALUATION: Volume 34. AIP Publishing LLC, 2015. http://dx.doi.org/10.1063/1.4914628.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Lelak, Jaroslav, Janka Sulova, Rastislav Valach, Attila Kment e Marek Pipa. "Comparison of dielectrical properties of LV cables with different fire barriers ensuring circuit integrity under fire conditions at high ambient temperatures". In 2020 International Conference on Diagnostics in Electrical Engineering (Diagnostika). IEEE, 2020. http://dx.doi.org/10.1109/diagnostika49114.2020.9214634.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Li, Shengtao, e Yang Feng. "High Dielectric and Energy Storage Polymer Dielectrics". In 2021 IEEE International Conference on the Properties and Applications of Dielectric Materials (ICPADM). IEEE, 2021. http://dx.doi.org/10.1109/icpadm49635.2021.9493998.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Rapporti di organizzazioni sul tema "Dielectrical properties"

Johnson, Francis S. Dielectric Properties of Magnetoplasmas. Fort Belvoir, VA: Defense Technical Information Center, novembre 1989. http://dx.doi.org/10.21236/ada293571.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Rajca, Andrzej. Organic Polymers with Magneto-Dielectric Properties. Fort Belvoir, VA: Defense Technical Information Center, marzo 2007. http://dx.doi.org/10.21236/ada467781.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Giatti, Brandon. Optical Properties of Nanostructured Dielectric Coatings. Portland State University Library, gennaio 2000. http://dx.doi.org/10.15760/etd.1939.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Friedman, Shmuel, Jon Wraith e Dani Or. Geometrical Considerations and Interfacial Processes Affecting Electromagnetic Measurement of Soil Water Content by TDR and Remote Sensing Methods. United States Department of Agriculture, 2002. http://dx.doi.org/10.32747/2002.7580679.bard.

Testo completo

Abstract (sommario):

Time Domain Reflectometry (TDR) and other in-situ and remote sensing dielectric methods for determining the soil water content had become standard in both research and practice in the last two decades. Limitations of existing dielectric methods in some soils, and introduction of new agricultural measurement devices or approaches based on soil dielectric properties mandate improved understanding of the relationship between the measured effective permittivity (dielectric constant) and the soil water content. Mounting evidence indicates that consideration must be given not only to the volume fractions of soil constituents, as most mixing models assume, but also to soil attributes and ambient temperature in order to reduce errors in interpreting measured effective permittivities. The major objective of the present research project was to investigate the effects of the soil geometrical attributes and interfacial processes (bound water) on the effective permittivity of the soil, and to develop a theoretical frame for improved, soil-specific effective permittivity- water content calibration curves, which are based on easily attainable soil properties. After initializing the experimental investigation of the effective permittivity - water content relationship, we realized that the first step for water content determination by the Time Domain Reflectometry (TDR) method, namely, the TDR measurement of the soil effective permittivity still requires standardization and improvement, and we also made more efforts than originally planned towards this objective. The findings of the BARD project, related to these two consequential steps involved in TDR measurement of the soil water content, are expected to improve the accuracy of soil water content determination by existing in-situ and remote sensing dielectric methods and to help evaluate new water content sensors based on soil electrical properties. A more precise water content determination is expected to result in reduced irrigation levels, a matter which is beneficial first to American and Israeli farmers, and also to hydrologists and environmentalists dealing with production and assessment of contamination hazards of this progressively more precious natural resource. The improved understanding of the way the soil geometrical attributes affect its effective permittivity is expected to contribute to our understanding and predicting capability of other, related soil transport properties such as electrical and thermal conductivity, and diffusion coefficients of solutes and gas molecules. In addition, to the originally planned research activities we also investigated other related problems and made many contributions of short and longer terms benefits. These efforts include: Developing a method and a special TDR probe for using TDR systems to determine also the soil's matric potential; Developing a methodology for utilizing the thermodielectric effect, namely, the variation of the soil's effective permittivity with temperature, to evaluate its specific surface area; Developing a simple method for characterizing particle shape by measuring the repose angle of a granular material avalanching in water; Measurements and characterization of the pore scale, saturation degree - dependent anisotropy factor for electrical and hydraulic conductivities; Studying the dielectric properties of cereal grains towards improved determination of their water content. A reliable evaluation of the soil textural attributes (e.g. the specific surface area mentioned above) and its water content is essential for intensive irrigation and fertilization processes and within extensive precision agriculture management. The findings of the present research project are expected to improve the determination of cereal grain water content by on-line dielectric methods. A precise evaluation of grain water content is essential for pricing and evaluation of drying-before-storage requirements, issues involving energy savings and commercial aspects of major economic importance to the American agriculture. The results and methodologies developed within the above mentioned side studies are expected to be beneficial to also other industrial and environmental practices requiring the water content determination and characterization of granular materials.

Gli stili APA, Harvard, Vancouver, ISO e altri

L. E. Lagos e M. A. Ebadian. Dielectric Properties of Low-Level Liquid Waste. Office of Scientific and Technical Information (OSTI), ottobre 1998. http://dx.doi.org/10.2172/932.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Curtis, John O. Dielectric Properties of Soils, Fort Carson, CO. Fort Belvoir, VA: Defense Technical Information Center, agosto 1996. http://dx.doi.org/10.21236/ada386356.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Curtis, John O. Dielectric Properties of Landmine Fillers (Waxes and Sands). Fort Belvoir, VA: Defense Technical Information Center, gennaio 1997. http://dx.doi.org/10.21236/ada386138.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Patitz, W. E., B. C. Brock e E. G. Powell. Measurement of dielectric and magnetic properties of soil. Office of Scientific and Technical Information (OSTI), novembre 1995. http://dx.doi.org/10.2172/167219.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Hubert, C. A., J. A. Lubin, W. H. Yang e T. E. Huber. Synthesis and Optical Properties of Dense Semiconductor-Dielectric Nanocomposites. Fort Belvoir, VA: Defense Technical Information Center, gennaio 1993. http://dx.doi.org/10.21236/ada271304.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Cooke, D. W., E. H. Farnum, F. W. Clinard, Jr, B. L. Bennett e A. M. Portis. Optical properties of silica fibers and layered dielectric mirrors. Office of Scientific and Technical Information (OSTI), aprile 1996. http://dx.doi.org/10.2172/270459.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Offriamo sconti su tutti i piani premium per gli autori le cui opere sono incluse in raccolte letterarie tematiche. Contattaci per ottenere un codice promozionale unico!