The Experts below are selected from a list of 1968 Experts worldwide ranked by ideXlab platform
Michael S Strano - One of the best experts on this subject based on the ideXlab platform.
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high Thermal Effusivity nanocarbon materials for resonant Thermal energy harvesting
Small, 2021Co-Authors: Ge Zhang, Volodymyr B. Koman, Tafsia Shikdar, Ronald J Oliver, Natalia Perezlodeiro, Michael S StranoAbstract:Carbon nanomaterials have extraordinary Thermal properties, such as high conductivity and stability. Nanocarbon combined with phase change materials (PCMs) can yield exceptionally high Thermal Effusivity composites optimal for Thermal energy harvesting. The progress in synthesis and processing of high Effusivity materials, and their application in resonant energy harvesting from temperature variations is reviewed.
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Ultra-high Thermal Effusivity materials for resonant ambient Thermal energy harvesting
Nature Communications, 2018Co-Authors: Anton L. Cottrill, Albert Tianxiang Liu, Yuichiro Kunai, Volodymyr B. Koman, Amir Kaplan, Sayalee G. Mahajan, Pingwei Liu, Aubrey R. Toland, Michael S StranoAbstract:Materials science has made progress in maximizing or minimizing the Thermal conductivity of materials; however, the Thermal Effusivity—related to the product of conductivity and capacity—has received limited attention, despite its importance in the coupling of Thermal energy to the environment. Herein, we design materials that maximize the Thermal Effusivity by impregnating copper and nickel foams with conformal, chemical-vapor-deposited graphene and octadecane as a phase change material. These materials are ideal for ambient energy harvesting in the form of what we call Thermal resonators to generate persistent electrical power from Thermal fluctuations over large ranges of frequencies. Theory and experiment demonstrate that the harvestable power for these devices is proportional to the Thermal Effusivity of the dominant Thermal mass. To illustrate, we measure persistent energy harvesting from diurnal frequencies, extracting as high as 350 mV and 1.3 mW from approximately 10 °C diurnal temperature differences. Ambient environmental Thermal fluctuations offer an abundant yet difficult to harvest renewable energy source, when compared to static Thermal gradients. Here, by tuning the Thermal Effusivity of composite phase change materials, the authors are able to harvest energy from diurnal ambient temperature changes.
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Ultra-high Thermal Effusivity materials for resonant ambient Thermal energy harvesting
Nature Communications, 2018Co-Authors: Anton L. Cottrill, Albert Tianxiang Liu, Yuichiro Kunai, Volodymyr B. Koman, Amir Kaplan, Sayalee G. Mahajan, Pingwei Liu, Aubrey R. Toland, Michael S StranoAbstract:Materials science has made progress in maximizing or minimizing the Thermal conductivity of materials; however, the Thermal Effusivity—related to the product of conductivity and capacity—has received limited attention, despite its importance in the coupling of Thermal energy to the environment. Herein, we design materials that maximize the Thermal Effusivity by impregnating copper and nickel foams with conformal, chemical-vapor-deposited graphene and octadecane as a phase change material. These materials are ideal for ambient energy harvesting in the form of what we call Thermal resonators to generate persistent electrical power from Thermal fluctuations over large ranges of frequencies. Theory and experiment demonstrate that the harvestable power for these devices is proportional to the Thermal Effusivity of the dominant Thermal mass. To illustrate, we measure persistent energy harvesting from diurnal frequencies, extracting as high as 350 mV and 1.3 mW from approximately 10 °C diurnal temperature differences.
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Ultra-high Thermal Effusivity materials for resonant ambient Thermal energy harvesting
Nature Publishing Group, 2018Co-Authors: Anton L. Cottrill, Albert Tianxiang Liu, Yuichiro Kunai, Volodymyr B. Koman, Amir Kaplan, Sayalee G. Mahajan, Pingwei Liu, Aubrey R. Toland, Michael S StranoAbstract:Ambient environmental Thermal fluctuations offer an abundant yet difficult to harvest renewable energy source, when compared to static Thermal gradients. Here, by tuning the Thermal Effusivity of composite phase change materials, the authors are able to harvest energy from diurnal ambient temperature changes
Volodymyr B. Koman - One of the best experts on this subject based on the ideXlab platform.
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high Thermal Effusivity nanocarbon materials for resonant Thermal energy harvesting
Small, 2021Co-Authors: Ge Zhang, Volodymyr B. Koman, Tafsia Shikdar, Ronald J Oliver, Natalia Perezlodeiro, Michael S StranoAbstract:Carbon nanomaterials have extraordinary Thermal properties, such as high conductivity and stability. Nanocarbon combined with phase change materials (PCMs) can yield exceptionally high Thermal Effusivity composites optimal for Thermal energy harvesting. The progress in synthesis and processing of high Effusivity materials, and their application in resonant energy harvesting from temperature variations is reviewed.
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Ultra-high Thermal Effusivity materials for resonant ambient Thermal energy harvesting
Nature Communications, 2018Co-Authors: Anton L. Cottrill, Albert Tianxiang Liu, Yuichiro Kunai, Volodymyr B. Koman, Amir Kaplan, Sayalee G. Mahajan, Pingwei Liu, Aubrey R. Toland, Michael S StranoAbstract:Materials science has made progress in maximizing or minimizing the Thermal conductivity of materials; however, the Thermal Effusivity—related to the product of conductivity and capacity—has received limited attention, despite its importance in the coupling of Thermal energy to the environment. Herein, we design materials that maximize the Thermal Effusivity by impregnating copper and nickel foams with conformal, chemical-vapor-deposited graphene and octadecane as a phase change material. These materials are ideal for ambient energy harvesting in the form of what we call Thermal resonators to generate persistent electrical power from Thermal fluctuations over large ranges of frequencies. Theory and experiment demonstrate that the harvestable power for these devices is proportional to the Thermal Effusivity of the dominant Thermal mass. To illustrate, we measure persistent energy harvesting from diurnal frequencies, extracting as high as 350 mV and 1.3 mW from approximately 10 °C diurnal temperature differences. Ambient environmental Thermal fluctuations offer an abundant yet difficult to harvest renewable energy source, when compared to static Thermal gradients. Here, by tuning the Thermal Effusivity of composite phase change materials, the authors are able to harvest energy from diurnal ambient temperature changes.
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Ultra-high Thermal Effusivity materials for resonant ambient Thermal energy harvesting
Nature Communications, 2018Co-Authors: Anton L. Cottrill, Albert Tianxiang Liu, Yuichiro Kunai, Volodymyr B. Koman, Amir Kaplan, Sayalee G. Mahajan, Pingwei Liu, Aubrey R. Toland, Michael S StranoAbstract:Materials science has made progress in maximizing or minimizing the Thermal conductivity of materials; however, the Thermal Effusivity—related to the product of conductivity and capacity—has received limited attention, despite its importance in the coupling of Thermal energy to the environment. Herein, we design materials that maximize the Thermal Effusivity by impregnating copper and nickel foams with conformal, chemical-vapor-deposited graphene and octadecane as a phase change material. These materials are ideal for ambient energy harvesting in the form of what we call Thermal resonators to generate persistent electrical power from Thermal fluctuations over large ranges of frequencies. Theory and experiment demonstrate that the harvestable power for these devices is proportional to the Thermal Effusivity of the dominant Thermal mass. To illustrate, we measure persistent energy harvesting from diurnal frequencies, extracting as high as 350 mV and 1.3 mW from approximately 10 °C diurnal temperature differences.
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Ultra-high Thermal Effusivity materials for resonant ambient Thermal energy harvesting
Nature Publishing Group, 2018Co-Authors: Anton L. Cottrill, Albert Tianxiang Liu, Yuichiro Kunai, Volodymyr B. Koman, Amir Kaplan, Sayalee G. Mahajan, Pingwei Liu, Aubrey R. Toland, Michael S StranoAbstract:Ambient environmental Thermal fluctuations offer an abundant yet difficult to harvest renewable energy source, when compared to static Thermal gradients. Here, by tuning the Thermal Effusivity of composite phase change materials, the authors are able to harvest energy from diurnal ambient temperature changes
Anton L. Cottrill - One of the best experts on this subject based on the ideXlab platform.
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Ultra-high Thermal Effusivity materials for resonant ambient Thermal energy harvesting
Nature Communications, 2018Co-Authors: Anton L. Cottrill, Albert Tianxiang Liu, Yuichiro Kunai, Volodymyr B. Koman, Amir Kaplan, Sayalee G. Mahajan, Pingwei Liu, Aubrey R. Toland, Michael S StranoAbstract:Materials science has made progress in maximizing or minimizing the Thermal conductivity of materials; however, the Thermal Effusivity—related to the product of conductivity and capacity—has received limited attention, despite its importance in the coupling of Thermal energy to the environment. Herein, we design materials that maximize the Thermal Effusivity by impregnating copper and nickel foams with conformal, chemical-vapor-deposited graphene and octadecane as a phase change material. These materials are ideal for ambient energy harvesting in the form of what we call Thermal resonators to generate persistent electrical power from Thermal fluctuations over large ranges of frequencies. Theory and experiment demonstrate that the harvestable power for these devices is proportional to the Thermal Effusivity of the dominant Thermal mass. To illustrate, we measure persistent energy harvesting from diurnal frequencies, extracting as high as 350 mV and 1.3 mW from approximately 10 °C diurnal temperature differences. Ambient environmental Thermal fluctuations offer an abundant yet difficult to harvest renewable energy source, when compared to static Thermal gradients. Here, by tuning the Thermal Effusivity of composite phase change materials, the authors are able to harvest energy from diurnal ambient temperature changes.
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Ultra-high Thermal Effusivity materials for resonant ambient Thermal energy harvesting
Nature Communications, 2018Co-Authors: Anton L. Cottrill, Albert Tianxiang Liu, Yuichiro Kunai, Volodymyr B. Koman, Amir Kaplan, Sayalee G. Mahajan, Pingwei Liu, Aubrey R. Toland, Michael S StranoAbstract:Materials science has made progress in maximizing or minimizing the Thermal conductivity of materials; however, the Thermal Effusivity—related to the product of conductivity and capacity—has received limited attention, despite its importance in the coupling of Thermal energy to the environment. Herein, we design materials that maximize the Thermal Effusivity by impregnating copper and nickel foams with conformal, chemical-vapor-deposited graphene and octadecane as a phase change material. These materials are ideal for ambient energy harvesting in the form of what we call Thermal resonators to generate persistent electrical power from Thermal fluctuations over large ranges of frequencies. Theory and experiment demonstrate that the harvestable power for these devices is proportional to the Thermal Effusivity of the dominant Thermal mass. To illustrate, we measure persistent energy harvesting from diurnal frequencies, extracting as high as 350 mV and 1.3 mW from approximately 10 °C diurnal temperature differences.
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Ultra-high Thermal Effusivity materials for resonant ambient Thermal energy harvesting
Nature Publishing Group, 2018Co-Authors: Anton L. Cottrill, Albert Tianxiang Liu, Yuichiro Kunai, Volodymyr B. Koman, Amir Kaplan, Sayalee G. Mahajan, Pingwei Liu, Aubrey R. Toland, Michael S StranoAbstract:Ambient environmental Thermal fluctuations offer an abundant yet difficult to harvest renewable energy source, when compared to static Thermal gradients. Here, by tuning the Thermal Effusivity of composite phase change materials, the authors are able to harvest energy from diurnal ambient temperature changes
Hiromichi Ohta - One of the best experts on this subject based on the ideXlab platform.
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Thermal microscope measurement of Thermal Effusivity distribution in compositionally graded PbTe–Sb 2 Te 3 –Ag 2 Te alloy system
Thermochimica Acta, 2018Co-Authors: Tsuyoshi Nishi, Kimihito Hatori, Suguru Yamamoto, Mori Okawa, Teruyuki Ikeda, Hiromichi OhtaAbstract:Abstract A compositionally graded alloy in the PbTe–Sb2Te3–Ag2Te system was fabricated by the Bridgeman method. In the sample obtained for analysis, the length of the graded area was of the order of several tens of nanometers. Its Thermal Effusivity was measured with a Thermal microscope, which required sputtering of a Mo film on the surface of the sample. The measured values of Thermal Effusivity depended on the thickness of the Mo film. However, it was difficult to sputter the Mo film uniformly in the wide area. Even though a relatively large target was used in the sputtering apparatus on the laboratory scale, the thickness of the Mo film just under the center of the target was larger than that in other areas. In this study, the measured thickness of the Mo film was calibrated with a high degree of accuracy against the reference glass slide. The Thermal Effusivity of the PbTe–Sb2Te3–Ag2Te alloy was in the range of 400–800 Ws0.5 m−2 K−1.
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Thermal Effusivity measurement based on analysis of 3d heat flow by modulated spot heating using a phase lag matrix with a combination of Thermal Effusivity and volumetric heat capacity
Measurement Science and Technology, 2016Co-Authors: Hiromichi Ohta, Kimihito Hatori, Genzou Matsui, Takashi Yagi, Shugo Miyake, Takeo Okamura, Ryo Endoh, Ryo Okada, Keisuke Morishita, Shinichiro YokoyamaAbstract:The study goal was to establish a standard industrial procedure for the measurement of Thermal Effusivity by a Thermal microscope (TM), using a periodic heating method with a thermoreflectance (TR) technique. To accomplish this goal, a working group was organized that included four research institutes. Each institute followed the same procedure: a molybdenum (Mo) film was sputtered on the surface of Pyrex, yttria-stabilized zirconia (YSZ), alumina (Al2O3), Germanium (Ge), and silicon (Si) samples, and then the phase lag of the laser intensity modulation was measured by the resultant surface temperature. A procedure was proposed to calibrate the effect of 3D heat flow, based on the analytical solution of the heat conduction equation, and Thermal Effusivity was measured. The derived values show good agreement with literature values. As a result, the TM calibration procedure can be recommended for practical use in measuring the Thermal Effusivity in a small region of the materials.
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Measurement for Thermal Effusivity of AlxGa1-xN Alloys Using Thermoreflectance with Periodic Heating
High Temperature Materials and Processes, 2010Co-Authors: Hiroyuki Shibata, Hiromichi Ohta, Yoshio Waseda, Takashi Nemoto, Shun Nagayama, Katsushi Fujii, K. Thomas JacobAbstract:AlxGa1-xN alloys with x=0.375, 0.398, 0.401, 0.592 and 0.696 were deposited on sapphire substrate by the hydride-vapor-phase epitaxy (HVPE) method. Thermal Effusivity measurements were carried out on AlxGa1-xN alloys using a Thermal microscope at room temperature. The lag between sinusoidal heating laser wave and thermoreflectance wave was used to measure the Thermal diffusivity. Thermal conductivity values of the AlxGa1-xN alloys were also obtained as a function of AIN mole fraction in the alloy. The Thermal conductivity was found to decrease with increasing AIN fraction and the experimental data agree with values estimated using the virtual crystal model.
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An application of Thermal microscopes to the measurement of Thermal Effusivity of films
Heat Transfer-Asian Research, 2009Co-Authors: Kimihito Hatori, Kei Suzuki, Hiroyuki Fukuyama, Hiromichi OhtaAbstract:The application of Thermal microscopes to the measurement of local Thermal properties has drawn considerable scientific interest. We report on the application of a Thermal microscope to the measurement of Thermal Effusivity for films comprising alumina deposited on a substrate, which were fabricated by an electrophoretic deposition method. The measured data was analyzed to consider the undulations on the sample surface The Thermal Effusivity of these samples was approximately 1×103 Js−0.5m−2K−1; this value is smaller than that for dense alumina because the alumina grain makes contact with a point. © 2008 Wiley Periodicals, Inc. Heat Trans Asian Res; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/htj.20227
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A simple calibration procedure to determine Thermal Effusivity values measured by using a Thermal microscope
Netsu Bussei, 2008Co-Authors: Kimihito Hatori, Hiromichi OhtaAbstract:A Thermal microscope is a useful tool for investigating the spatial distribution of the Thermal transport properties of materials. However, for materials with relatively high Thermal effusivities, it is well known that the values calculated on the basis of the conventional one-dimensional heat flow solution are higher than the values provided in the literature. In this study, we developed a simple calibration procedure for a Thermal microscope to measure the Thermal effusivities of materials by using several reference materials whose Thermal effusivities are known. It is expected that the temperature response will be influenced by not only the Thermal Effusivity but also the heat capacity per unit volume. However, reference samples with different heat capacities per unit volume were used. In comparison with the calculated values obtained with the conventional one-dimensional heat flow solution, the values for pure iron obtained with our calibration procedure, without considering the heat capacity per unit volume, were closer to the values provided in the literature. We found that this procedure is useful for calibrating a Thermal microscope easily for measuring Thermal Effusivity.
Michèle Queneudec - One of the best experts on this subject based on the ideXlab platform.
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Effect of moisture content on the Thermal Effusivity of wood cement-based composites
Journal of Physics D: Applied Physics, 1998Co-Authors: A Bouguerra, J P Laurent, M B Diop, M L Benmalek, Michèle QueneudecAbstract:The influence of moisture content on the Thermal Effusivity of wood cement-based composite was investigated. Measurements of Thermal Effusivity were performed inside a closely controlled climatic cell at ambient temperature (C) in conditions ranging from fully saturated to oven-dry. Shrotriya et al's model based on an Ohm's law approach was used for predicting the effective Thermal Effusivity of studied materials. The topological parameters of the model, such as sphericity of particles and resistivity formation factor, have been estimated as a first approximation from both Thermal conductivity measurements and formulae proposed in the literature. Test results confirm that moisture content tends to increase the Thermal Effusivity significantly. It is also found that the Shrotriya et al's model yields predictions which agree quite closely with experimental data for wood aggregates-clay-cement composites for different amounts of wood aggregates and degrees of saturation.
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Thermal Effusivity of two-phase wood cement-based composites
Journal of Physics D: Applied Physics, 1998Co-Authors: A Bouguerra, A Ledhem, J P Laurent, M B Diop, Michèle QueneudecAbstract:This study presents a method for estimating the Thermal Effusivity of wood cement-based composites used in the dry state. Two models, based on an Ohm's law approach, will be displayed herein: the unit cell of the parallel model and the model of Jackson and Black have both been used to predict the effective Thermal Effusivity of wood composites. Various topological parameters, such as the tortuosity factor and the stereological concept of contiguity, have been introduced in order to take into account the effect of the pore structure on the Thermal Effusivity. Furthermore, the porosity correction term and the correction term which accounts both for the effect of the randomization of particle distribution and for the effect of the ratio of Thermal effusivities have been determined empirically. Measurements of the Thermal Effusivity have been performed inside a closely controlled climatic cell at ambient temperature (C) using a heat plane source technique. Calculated values of the Thermal Effusivity of these materials have been compared with experimental results. The values predicted by the two models are all in very close agreement with experimental values.
