Bibliografie tematiche / Pyroelectric coefficient

Letteratura scientifica selezionata sul tema "Pyroelectric coefficient"

Autore: Grafiati

Pubblicato: 1 giugno 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 "Pyroelectric coefficient".

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 "Pyroelectric coefficient":

Sarker, Md Rashedul H., Jorge L. Silva, Mariana Castañeda, Bethany Wilburn, Yirong Lin e Norman Love. "Characterization of the pyroelectric coefficient of a high-temperature sensor". Journal of Intelligent Material Systems and Structures 29, n. 5 (1 agosto 2017): 938–43. http://dx.doi.org/10.1177/1045389x17721376.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Abstract (sommario):

Temperature is one of the most important thermodynamic properties measured and controlled in energy generation systems. To operate the energy system at optimum operating conditions for lower emission and higher efficiency, it is important to measure real-time temperatures. Furthermore, temperature sensing in intense environments is necessary since most sensors in energy systems get exposed to elevated temperatures, corrosive environments, and elevated pressures. One of the solutions for developing harsh environment sensors is to use ceramic materials, especially functional ceramics such as pyroelectrics. Pyroelectric ceramics could be used to develop active sensors for both temperature and pressure due to their capabilities in coupling energy among mechanical, thermal, and electrical domains. In this study, Lithium niobate (LiNbO3) pyroelectric ceramic material was used to develop a temperature sensor for high-temperature applications. LiNbO3 has high Curie temperature (1210°C) compared to other pyroelectric ceramic materials. A high Curie temperature material is important since the polarization properties of the material break down above the Curie temperature. Hence, the use of a material with a higher Curie temperature, such as LiNbO3, makes it promising to be used as a sensing material for high-temperature applications. A study was performed to actively measure the temperature up to 500°C using a pyroelectric ceramic lithium niobate (LiNbO3) as a sensor material. Due to the non-linear pyroelectric response of LiNbO3, the temperature-dependent pyroelectric coefficient of LiNbO3 was measured with a dynamic pyroelectric coefficient technique in temperature ranges up to 500°C. Temperature-dependent pyroelectric coefficient of LiNbO3 was found to increase from −0.5 × 10−5 to −3.70 × 10−5 C/m2°C from room temperature to 500°C. The LiNbO3 sensor was then tested for higher temperature sensing at 220°C, 280°C, 410°C, and 500°C and has shown 4.31%, 2.1%, 0.4%, and 0.6% deviation, respectively, compared with thermocouple measurements.

Davydov C. Yu. "Pyroelectric coefficient estimations for aluminum and gallium compounds". Physics of the Solid State 64, n. 5 (2022): 510. http://dx.doi.org/10.21883/pss.2022.05.53508.248.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Abstract (sommario):

Analytical expression for pyroelectric coefficient p for the compounds with wurtzit structure is given. Obtained values of p for AlN and GaN are in satisfactory agreement with the first-principles calculations. Pyroelectric effect in the uniform epitaxial films and heterostructures is discussed. Keywords: pyroelectric coefficient, wurtzite structure, monocrystal, thin film, heterostructure.

Pintilie, L., I. Pintilie e I. Matei. "Equivalent pyroelectric coefficient of a pyroelectric bimorph structure". Journal of Applied Physics 88, n. 12 (15 dicembre 2000): 7264–71. http://dx.doi.org/10.1063/1.1327284.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Liang, Ting, Si Jia Lin, Ying Li, Cheng Lei e Chen Yang Xue. "Research on the Effect of Mechanical Processing on Lithium Tantalate Crystal Pyroelectric Coefficient". Advanced Materials Research 834-836 (ottobre 2013): 880–84. http://dx.doi.org/10.4028/www.scientific.net/amr.834-836.880.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Abstract (sommario):

Lithium tantalate (LT) is a kind of excellent pyroelectric materials that can be made into high performance pyroelectric detector. As the detector voltage response and detection rate inversely proportional to the thickness of the infrared sensing element, So the thinning of lithium tantalate crystals becomes a key of success. This design uses CMP method to produce 50 μm thickness of LT wafer, and via charge integration method with computer automatic test system to test the pyroelectric coefficient of crystals with different thickness and surface roughness. The pyroelectric coefficient of crystal achieved 203 μC·m-2k-1 proves the favorable pyroelectric properties.

Fan, Mao Yan, Yang Yang Zhang, Qing Feng Zhang, Guang Zu Zhang e Lin Lu. "Piezoelectric, Dielectric and Pyroelectric Property in Morphotropic Phase Boundary MnO₂ Doped Bi_0.5(Na_0.82K_0.18)_0.5TiO₃/P(VDF-TrFE) 0-3 Composites". Advanced Materials Research 535-537 (giugno 2012): 55–60. http://dx.doi.org/10.4028/www.scientific.net/amr.535-537.55.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Abstract (sommario):

MnO2 doped Bi0.5(Na0.82K0.18)0.5TiO3/P(VDF-TrFE) 0-3 composites with high pyroelectric coefficient were prepared for different volume fractions of MnO2 doped Bi0.5(Na0.82K0.18)0.5TiO3 ceramic powder in P(VDF-TrFE) copolymer matrix. The dielectric constant, dielectric loss and the piezoelectric coefficient increased as MnO2 doped Bi0.5(Na0.82K0.18)0.5TiO3 ceramic volume fraction increased. The pyroelectric coefficient and figure of merit of Bi0.5(Na0.82K0.18)0.5TiO3/P(VDF-TrFE) with different MnO2 amount and 0.8mol% MnO2 doped Bi0.5(Na0.82K0.18)0.5TiO3/P(VDF-TrFE) as a function of ceramic volume fraction were studied respectively. The results indicated that 0.8mol% MnO2 doped Bi0.5(Na0.82K0.18)0.5TiO3/P(VDF-TrFE) in 20vol% ceramic volume fraction show the best pyroelectric properties with pyroelectric coefficient p= 7.8×10-5C/m2K and figure of merit FD=11.4×10-6Pa-0.5.

Asaji, Tetsuo, e Alarich Weiss. "Pyroelectricity of Molecular Crystals: Benzene Derivatives". Zeitschrift für Naturforschung A 40, n. 6 (1 giugno 1985): 567–74. http://dx.doi.org/10.1515/zna-1985-0607.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Abstract (sommario):

The pyroelectric coefficient at constant stress was measured for meta-nitroaniline, meta-amino-phenol, and 2,3-dichlorophenol in the temperature range 90 Ù T/ K ⪅ % melting point. A change in sign of the pyroelectric coefficient was observed in meta-nitroaniline and 2,3-dichlorophenol. At room temperature p3s is 9 m Cm−2 K−1 for meta-nitroaniline, 42 m Cm−2 K−1 for meta-aminophenol, and 0.3 m Cm−2 K−1 for 2,3-dichlorophenol (at 263 K for the latter one). By a classical harmonic oscillator model the contribution to the pyroelectric coefficient due to molecular dipole librational motions was estimated to be fairly small for meta-nitroaniline. The temperature dependence of the coefficient of meta-nitroaniline is discussed on the basis of Boguslawski's theory. The importance of internal polar optical modes for the temperature dependence of the pyroelectric coefficient of molecular crystals is shown.

Jiang, Zibo, e Zuo-Guang Ye. "Application study of Mn-doped PIN-PMN-PT relaxor ferroelectric crystal grown by Vertical Gradient Freeze method". Ferroelectrics 557, n. 1 (11 marzo 2020): 9–17. http://dx.doi.org/10.1080/00150193.2020.1713358.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Abstract (sommario):

A 3-inch Mn:PIN-36%PMN-32%PT (Generation III) relaxor ferroelectric crystal was grown using the Vertical Gradient Freeze method. Crystals of [1, 11] and [111] orientations were prepared and studied, evaluating their dielectric constants, piezoelectric coefficients, electromechanical coupling coefficients, loss tangents and pyroelectric coefficients. It is shown that in pyroelectric applications, [111]-poled crystals are particularly suitable for high performance sensors due to a relatively high pyroelectric coefficient, low loss tangent. In addition, the specific heat is lower as compared to LiTaO3. It is also shown that the alternating current (AC) poling has a more significant effect on the [001]-poled crystal than on the [011]- and [111]-poled crystals due to the lattice distortion induced by a strong electric field along the [001] direction.

Sharofidinov Sh. Sh., Kukushkin S. A., Staritsyn M. V., Solnyshkin A. V., Sergeeva O. N., Kaptelov E. Yu. e Pronin I. P. "Structure and properties of composites based on aluminum and gallium nitrides grown on silicon of different orientations with a buffer layer of silicon carbide". Physics of the Solid State 64, n. 5 (2022): 516. http://dx.doi.org/10.21883/pss.2022.05.53510.250.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Abstract (sommario):

The microstructure and pyroelectric properties of AlxGa1-xN composite epitaxial layers grown on SiC/Si(111) and SiC/Si(110) hybrid substrates by the chloride-hydride epitaxy have been studied. The phenomenon of spontaneous formation of a system of heterojunctions consisting of periodic AlxGa1-xN layers of different composition located perpendicular to the direction of growth, was discovered during the growth of layers. Measurements of the pyroelectric coefficients of these heterostructures have shown that regardless of the orientation of the initial Si substrate and their pyroelectric coefficients have close values of the order of γ~(0.7-1)·10-10 C/cm2K. It is shown that to increase the magnitude of the pyroresponse it is necessary to deposit an AlN layer with a thickness exceeding 1 μm on the AlxGa1-xN/SiC/Si surface. This leads to record values of the pyroelectric coefficient γ~18·10-10 C/cm2K for AlN crystals and films. Keywords: silicon carbide-on-silicon substrates, chloride-hydride epitaxy, AlGaN epitaxial layers, aluminum nitride, gallium nitride, pyroelectric properties.

Hesterberg, Rolf, Michel Bonin, Martin Sommer, Matthias Burgener, Bernhard Trusch, Dragan Damjanovic e Jürg Hulliger. "Vapour growth, morphology, absolute structure and pyroelectric coefficient of meta-nitroaniline single crystals". Journal of Applied Crystallography 52, n. 3 (7 maggio 2019): 564–70. http://dx.doi.org/10.1107/s160057671900414x.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Abstract (sommario):

The growth speed of (hkl) faces in the vapour phase, the absolute structure obtained by X-ray crystallography, and the value and the sign of the pyroelectric coefficient of meta-nitroaniline (mNA) were analysed in detail. The in situ observation of morphologically well developed faces of several mNA crystals growing in evacuated ampoules reveals no pronounced growth speed anisotropy for polar faces defining the unique axis 2 of the mm2 group. Scanning pyroelectric microscopy confirms mono-domain mNA crystals. X-ray measurements in the space group Pca21 show that the molecular planes coincide with the {\bar 211} and {\bar 2\bar 1\bar 1} faces, and the nitro groups cover the {201} face in the opposite direction to the crystal tip, characterizing the polar habitus studied here. At room temperature, the sign of the pyroelectric coefficient is positive for a measured effective value of 6.3 µC m−2 K−1, in good agreement with values reported by other authors. From previous elastic and piezoelectric published data, the secondary pyroelectric effect was calculated to be positive and far greater than the effective one, yielding a negative value for the primary pyroelectric coefficient.

Шарофидинов, Ш. Ш., С. А. Кукушкин, М. В. Старицын, А. В. Солнышкин, О. Н. Сергеева, Е. Ю. Каптелов e И. П. Пронин. "Структура и свойства композитов на основе нитридов алюминия и галлия, выращенных на кремнии разной ориентации с буферным слоем карбида кремния". Физика твердого тела 64, n. 5 (2022): 522. http://dx.doi.org/10.21883/ftt.2022.05.52331.250.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Abstract (sommario):

The microstructure and pyroelectric properties of AlxGa1-xN composite epitaxial layers grown on SiC/Si(111) and SiC/Si(110) hybrid substrates by the chloride-hydride epitaxy have been studied. The phenomenon of spontaneous formation of a system of heterojunctions consisting of periodic AlxGa1-xN layers of different composition located perpendicular to the direction of growth, was discovered during the growth of layers. Measurements of the pyroelectric coefficients of these heterostructures have shown that regardless of the orientation of the initial Si substrate and their pyroelectric coefficients have close values of the order of γ ~ (0.7-1)•10-10 С/cm2K. It is shown that to increase the magnitude of the pyroresponse it is necessary to deposit an AlN layer with a thickness exceeding 1 μm on the AlxGa1-xN/SiC/Si surface. This leads to record values of the pyroelectric coefficient γ ~ 18•10-10 С/cm2K for AlN crystals and films

Più fonti

Tesi sul tema "Pyroelectric coefficient":

Kaddoussi, Hana. "Étude de l'effet électrocalorique en corrélation avec les propriétés structurales, pyroélectrique et ferroélectrique de la solution Ba1-xCax(Zr0,1Ti0,9)1-ySnyO3". Electronic Thesis or Diss., Amiens, 2016. http://www.theses.fr/2016AMIE0025.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Abstract (sommario):

Trois solutions solides à base de BZT sous forme de céramiques, ont été étudiées. Leurs propriétés pyroélectrique et ferroélectrique ont été déterminées dans le but de caractériser leurs performances électrocaloriques. Deux approches différentes ont été effectuées pour le calcul de l'effet électrocalorique : l'enregistrement des cycles d'hystérésis P-E en fonction de la température et la mesure du courant pyroélectrique. Ces deux méthodes d'investigations aboutissent à des résultats équivalents.Nous avons mis en évidence le caractère ferroélectrique dans tous les composés étudiés et montré que les meilleurs coefficients électrocaloriques sont obtenus à la température de transition FE-PE et dépendent des taux substitution. La symétrie cristalline de toutes les compositions a été confirmée et une étude de résolution structurale a été menée sur deux compositions (x=0,05 et x=0,20) de la phase contenant du Ca2+. Par la méthode directe, un coefficient EC de l’ordre de 0,30 K.mm/kV sous un champ électrique appliqué de 8 kV/cm, a été obtenu pour 5BCZT. Par ailleurs, nous avons montré qu'une faible quantité d'insertion de Sn dans BZT entraine une diminution de la température de transition vers l'ambiante, tout en gardant la même réponse EC. Cependant, la combinaison des deux éléments (Sn et Ca) dans BZT entraine l'amélioration du coefficient EC, avec un étalement de la transition ce qui permet de maintenir une réponse EC importante, dans un intervalle étendu de température souhaitable pour les applications
Three solid solutions as ceramics based on BZT matrix, were investigated. Pyroelectric and ferroelectric properties were determined in order to characterize their electrocaloric performance. Two different approaches have been made to calculate the electrocaloric effect: recording P-E hysteresis loops as a function of temperature and measuring the pyroelectric current. These two investigative methods lead to equivalent results. We have highlighted the ferroelectric behavior in all the studied compounds and shown that the higher electrocaloric coefficients are obtained at the FE-PE phase transition temperature and depend on the substitution content. The crystalline symmetry of all compositions was confirmed and a structural resolution study was conducted for two compositions (x = 0.05 and x = 0.20) of Ca2+ containing compound. By the direct method, EC responsivity is of about 0.30 K.mm/kV under 8 kV/cm applied electric field obtained from 5BCZT. Furthermore, we showed that a small amount insertion of Sn in BZT causes a decrease of the transition temperature towards room temperature, with remaining constant the EC responsivity. However, the combination of the two elements (Sn and Ca) in BZT improved EC coefficient and the broadening of the transition which allows maintaining a significant EC response over a wide range of temperature, desirable for applications

Capitoli di libri sul tema "Pyroelectric coefficient":

Sakhnenko, V. P., Yu N. Zakharov, I. A. Parinov, A. G. Lutokhin, E. V. Rozhkov, N. S. Filatova, I. P. Raevski et al. "Electric Response to Bending Vibrations and Pyroelectric Effect in Unpolarized Ferroelectric Ceramic Plates with Electrodes, Differing in the Magnitude of the Coefficient of Thermal Expansion on Opposite Surfaces". In Springer Proceedings in Physics, 161–69. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-78919-4_13.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Newnham, Robert E. "Pyroelectricity". In Properties of Materials. Oxford University Press, 2004. http://dx.doi.org/10.1093/oso/9780198520757.003.0010.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Abstract (sommario):

As the name implies, pyroelectricity is a first rank tensor property relating a change polarization P to a change in temperature δT. The defining relation can also be written in terms of the electric displacement D since no field is applied: . . . Pi = Di = piδT [C/m2]. . . Pyroelectricity is a first rank polar tensor because of the way it transforms. Being polar vectors, Pi and Di transform as . . . D'i = aijDj . . . whereas the temperature change transforms as a zero rank tensor, or a scalar: . . . δT' = δT. . . . Transforming the defining relation for pyroelectricity we get . . . D'i = aijDj = aijpjδT = aijpjδT' = p'iδT'. . . . Both the independent variable δT and the dependent variable Di have now been transformed to the new coordinate system. The property relating D'i to δT' is the transformed pyroelectric coefficient p'i = aijpj. Thus the pyroelectric coefficient is a polar first rank tensor property. In Sections 6.1 and 7.3 it was shown that the electrocaloric effect and the pyroelectric effect are governed by the same set of coefficients pi. The change in entropy per unit volume caused by an electric field is . . . δS = piEi [J/m3]. The pyroelectric (=electrocaloric coefficient) coefficient is usually expressed in units of μC/m2 K and can be either positive or negative in sign depending on whether the spontaneous (built-in) polarization is increasing or decreasing with temperature. Pyroelectricity disappears in all centrosymmetric materials. The proof follows. For a first rank tensor there are, in general, three nonzero coefficients p1, p2, and p3 representing the values of the pyroelectric coefficient along property axes Z1, Z2, and Z3, respectively. The principal axes are perpendicular to each other and are chosen in accordance with the IEEE convention (Section 4.3).

Atti di convegni sul tema "Pyroelectric coefficient":

Banet, L., J. Castellon, G. Malucelli, C. Vanga Bouanga, M. Frechette, A. Toureille e S. Agnel. "Determination of the pyroelectric coefficient within pyroelectric materials by using space charge measurements". In 2012 IEEE Conference on Electrical Insulation and Dielectric Phenomena - (CEIDP 2012). IEEE, 2012. http://dx.doi.org/10.1109/ceidp.2012.6378759.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Acosta, Krystal L., William K. Wilkie e Daniel J. Inman. "Pyroelectric Coefficient Enhancement of Macro-fiber Composites using Electric Fields". In AIAA Scitech 2020 Forum. Reston, Virginia: American Institute of Aeronautics and Astronautics, 2020. http://dx.doi.org/10.2514/6.2020-0151.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Hockley, M. J., H. H. S. Chang e Z. Huang. "Pyroelectric coefficient under open circuit condition and its enhacement through product property". In European Conference on the Applications of Polar Dielectrics (ECAPD). IEEE, 2010. http://dx.doi.org/10.1109/isaf.2010.5712230.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Xie, J., P. P. Mane, C. W. Green, K. M. Mossi e Kam K. Leang. "Energy Harvesting by Pyroelectric Effect Using PZT". In ASME 2008 Conference on Smart Materials, Adaptive Structures and Intelligent Systems. ASMEDC, 2008. http://dx.doi.org/10.1115/smasis2008-605.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Abstract (sommario):

This paper considers energy harvesting using pyroelectric materials such as PZT-5A and thin-films. A simple model is used to predict the power generated based on the measured temperature of the material as a function of time. The measured and predicted results are presented and compared. In particular, the measured peak power density for a PZT-5A sample was 0.23 μWcm−2 for a maximum temperature rate of approximately 15 °Cs−1. The predicted peak power density under the same boundary conditions for thin-film lead scandium tantalate was over 125 μWcm−2. The power density is shown to be highly dependent upon the surface area and the pyroelectric coefficient, underlining the importance of maximizing these parameters.

Lee, Soochan, Nishant Singh, Patrick E. Phelan e Carole-Jean Wu. "Harvesting CPU Waste Heat Through Pyroelectric Materials". In ASME 2015 International Technical Conference and Exhibition on Packaging and Integration of Electronic and Photonic Microsystems collocated with the ASME 2015 13th International Conference on Nanochannels, Microchannels, and Minichannels. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/ipack2015-48421.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Abstract (sommario):

Modern CPUs generate considerable wasted heat due to increased power dissipation from high-performance computation. Lots of research effort has extensively focused on using thermoelectric generators (TEGs) to harvest CPU waste heat to increase overall system energy efficiency. To harvest waste heat using TEGs requires a significant temperature differential between the processor as a heat source and the heat spreader/heat sink, as well as a high heat flow. However, the heat-to-electricity conversion efficiency is typically limited to 15 to 20 percent, due to large heat conductivity, low Seebeck coefficient, and low figure of merit of TEGs. In addition, TEGs on a CPU could significantly increase CPU junction temperature compared to the baseline CPU temperature due to its high thermal resistance. Contrary to using TEGs to harvest waste heat from a fixed, spatial temperature differential, this paper presents an approach to harvest CPU waste heat using pyroelectric (PE) materials from the time-varying, temporal temperature differential that is common in current processors. PE materials can generate electricity when subjected to a temporal temperature gradient. The operation of PE materials is distinctly different from TEGs and they have the following advantages. First, the theoretical efficiency is up to 50% using thin films. Second, the overall optimization of PE material is easier than thermoelectric material, since the conversion ratio, the ratio of net harvested energy divided by the heat taken from the hot reservoir, of PE material is independent of the material properties, whereas that of TEG is highly dependent on material properties. Although PE material is also a long-researched energy harvesting material, it is less explored by researchers compared to TEG in the application domain of processor waste heat management. In this paper, we review current PE materials in terms of pyroelectric coefficient and thermal conductivity, and also investigate the harvested power generation from CPU waste heat in a modern computing system.

Lee, Najae, Dae Won Ji, Sang-joo Kim e Yong Soo Kim. "Evolution of Linear Moduli and Nonlinear Responses of a PZT Wafer Under Electric Field at Room and High Temperatures". In ASME 2012 Conference on Smart Materials, Adaptive Structures and Intelligent Systems. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/smasis2012-8012.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Abstract (sommario):

A poled PZT wafer is subject to electric field loading of pulse type whose magnitude is increasing and then decreasing during a complete cycle of polarization reversal at four room and high temperatures. The PZT wafer is also subject to pure temperature increase from 20 to 110 Celsius degree at various initial states. During the two experiments, electric displacement and in-plane strain are measured. From the measured data, piezoelectric coefficient, permittivity, pyroelectric coefficient, and thermal expansion coefficient are evaluated and their distribution over remnant polarization and temperature is discussed. The dependency of linear moduli on temperature and remnant polarization is used to calculate reference remnant polarization and reference remnant in-plane strain responses to cyclic electric field loading at four different temperatures.

Matveev, Nikolay, Viktor Saushkin, Natalya Evsikova, Nina Kamalova e Viktor Lisitsyn. "Formalized modeling of pyroelectric coefficient dependence on the kinematic viscosity during the first order phase transitions in oligodimethylsiloxanes". In PROCEEDINGS OF THE XV INTERNATIONAL CONFERENCE «PHYSICS OF DIELECTRICS». AIP Publishing, 2020. http://dx.doi.org/10.1063/5.0033266.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Kweon, G., G. Beadie e N. M. Lawandy. "Pyroelectric detection of light beams using a phase transition in guest–host compounds". In OSA Annual Meeting. Washington, D.C.: Optica Publishing Group, 1992. http://dx.doi.org/10.1364/oam.1992.mhh7.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Abstract (sommario):

Because of their relative ease of fabrication, β-quinol clath-rates are one of the most studied among non- stoichiometric inclusion compounds. (quinol)3(CH3OH) x with x close to 1 has shown1 spontaneous polarization at a critical temperature near 66 K accompanying induced voltage across the sample. During the phase transition, the enclathrated methanol undergoes a sudden cooperative re-orientation during which the angle between the methanol C–O bond and the crystallographic C-axis changes discontinuously. This produces a large pyroelectric coefficient for high occupancy methanol clathrates, which suggests the possibility for a sensitive bolometer. We report on experiments where a clathrate connected by two electrical leads inside a He Dewar and held just below the transition temperature is exposed to laser radiation. By observing the voltage change, we can detect a wide range of IR and FIR wavelengths by using CO2-pumped superradiated FIR and Nd:YAG lasers. By keeping the sample size and the temperature gap small, the detector can be made very sensitive to incoming radiation.

Lee, Ho-Jun, e Dimitris A. Saravanos. "Thermal Shape Control of Active and Sensory Piezoelectric Composite Plates". In ASME 1997 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 1997. http://dx.doi.org/10.1115/imece1997-0726.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Abstract (sommario):

Abstract Previously developed mechanics for piezoelectric composite materials are extended to account for thermal effects. The updated mechanics accounts for thermal effects which arise due to: (1) coefficient of thermal expansion mismatch between the various composite and piezoelectric layers, (2) pyroelectric effects on the piezoelectric plies, and (3) the temperature dependence of the composite and piezoelectric properties. The coupled mechanical, electrical, and thermal response of piezoelectric composite materials is captured at the material level. A layerwise laminate theory is formulated with the inherent capability to model both the active and sensory response of piezoelectric composite materials. Finite element equations are developed and implemented for a bilinear plate element. Numerical studies are conducted on a simply supported graphite/epoxy plate with attached piezoceramic patches to investigate thermal shape control applications and to study the resultant stress state.

Ju, Y. Sungtaek. "Theoretical Analysis of Pyroelectric Harvesting of Low-Grade Exhaust Waste Heat". In ASME 2015 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/imece2015-53042.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Abstract (sommario):

Efficient and cost-effective harvesting of exhaust waste heat represents significant opportunities for improving the overall energy efficiency of combined heat and power cycles, transportation vehicles, and industrial processes. Pyroelectric thermal energy harvesting is interesting for its potentially high efficiency. We report a design concept and related thermal models for harvesting of exhaust waste heat based on the pyroelectric effect. The design concept utilizes switchable thermal interfaces formed on duct walls of exhaust gas and liquid coolants to achieve temporal thermal cycling of pyroelectric materials. Our thermal model explicitly accounts for spatial variations in the exhaust gas and coolant temperatures for practical waste heat harvesting systems, for example, those that can be incorporated into micro-CHP (combined heat and power) units. Model prediction results for example cases are presented to illustrate the impact of design parameters, including the heat capacity rate and the convective heat transfer coefficients.

Rapporti di organizzazioni sul tema "Pyroelectric coefficient":

Ivill, Mathew, Eric Ngo e Melanie W. Cole. Method and Characterization of Pyroelectric Coefficients for Determining Material Figures of Merit for Infrared (IR) Detectors. Fort Belvoir, VA: Defense Technical Information Center, dicembre 2013. http://dx.doi.org/10.21236/ada592778.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri