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Makanjuola O, Hashaikeh R. Assessing thermoelectric membrane distillation performance: An experimental design approach. MethodsX 2024; 12:102604. [PMID: 38357635 PMCID: PMC10864625 DOI: 10.1016/j.mex.2024.102604] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2023] [Accepted: 02/05/2024] [Indexed: 02/16/2024] Open
Abstract
Thermoelectric membrane distillation has shown promise as a new membrane distillation technique capable of improving energy consumption metrics. This study features an experimental design approach to investigating the performance of a thermoelectric membrane distillation system. Screening and full factorial designs were implemented in Minitab 16 to determine the optimal process conditions for minimizing the specific energy consumption of the system. The process parameter with the most significant impact on the specific energy consumption of thermoelectric membrane distillation systems was determined and a mathematical model for predicting the specific energy consumption was derived. The study showed that adjusting the feed flowrate, the most influential continuous parameter, from a sub-optimal level to an optimal level, while keeping other process variables at their optimal levels, could lead to a 34% reduction in the system's specific energy consumption. At the optimized process parameters of the thermoelectric membrane distillation system, the minimized specific energy consumption fell about 35% below the threshold value of 1,000 kWh/m3 found among the efficient membrane distillation systems in the literature.•Thermoelectric heat exchanger provides the driving force for the membrane distillation process•Seven process variables are assumed to influence the energy consumption of the distillation process•The variables are screened before being analyzed in a full factorial experimental design.
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Affiliation(s)
- Olawale Makanjuola
- Mechanical Engineering, New York University, Tandon School of Engineering, NY 11201, USA
- NYUAD Water Research Center, New York University Abu Dhabi, P.O. Box 129188, Abu Dhabi, UAE
| | - Raed Hashaikeh
- NYUAD Water Research Center, New York University Abu Dhabi, P.O. Box 129188, Abu Dhabi, UAE
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2
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Liu Y, Wang A, Du Q, Wu L, Zhu Y, Petrovic C. Nanoscale inhomogeneity and the evolution of correlation strength in FeSe[Formula: see text]S[Formula: see text]. Nano Converg 2023; 10:59. [PMID: 38133699 PMCID: PMC10746694 DOI: 10.1186/s40580-023-00405-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2023] [Accepted: 11/26/2023] [Indexed: 12/23/2023]
Abstract
We report a comprehensive study of the nanoscale inhomogeneity and disorder on the thermoelectric properties of FeSe[Formula: see text]S[Formula: see text] ([Formula: see text]) single crystals and the evolution of correlation strength with S substitution. A hump-like feature in temperature-dependent thermpower is enhanced for x = 0.12 and 0.14 in the nematic region with increasing in orbital-selective electronic correlations, which is strongly suppressed across the nematic critical point and for higher S content. Nanoscale Se/S atom disorder in the tetrahedral surroundings of Fe atoms is confirmed by scanning transmission electron microscopy measurements, providing an insight into the nanostructural details and the evolution of correlation strength in FeSe[Formula: see text]S[Formula: see text].
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Affiliation(s)
- Yu Liu
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, NY 11973 USA
- Center for Correlated Matter and School of Physics, Zhejiang University, Hangzhou, 310058 China
| | - Aifeng Wang
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, NY 11973 USA
- Present Address: College of Physics, Chongqing University, Chongqing, 401331 China
| | - Qianheng Du
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, NY 11973 USA
- Department of Materials Science and Chemical Engineering, Stony Brook University, Stony Brook, NeY 11790 USA
- Present Address: Material Science Division, Argonne National Laboratory, Lemont, IL 60439 USA
| | - Lijun Wu
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, NY 11973 USA
| | - Yimei Zhu
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, NY 11973 USA
| | - Cedomir Petrovic
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, NY 11973 USA
- Department of Materials Science and Chemical Engineering, Stony Brook University, Stony Brook, NeY 11790 USA
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3
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Brandalise JN, Guidoni LLC, Martins GA, Lopes ER, Nardino M, Bobrowski VL, Nadaleti WC, da Silva FMR, Lucia T, Corrêa ÉK. Environmental implications of combustion of rice husk at high temperatures and for an extended period for energy generation. Environ Sci Pollut Res Int 2023; 30:102222-102230. [PMID: 37667116 DOI: 10.1007/s11356-023-29588-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2023] [Accepted: 08/25/2023] [Indexed: 09/06/2023]
Abstract
The most common alternative for the management and valorization of rice processing waste is the combustion of rice husk (RH) for energy generation. The environmental risk assessment of the ash generated during the combustion of the RH to obtain energy has remained understudied. Disposal of rice husk ash (RHA) on agricultural land is the most common outcome, which could pose a risk to both natural ecosystems and human health. The objective of this study was to characterize the physicochemical composition and the phytotoxicity, cytotoxicity, and genotoxicity of RHA obtained from three distinct combustion processes. The evaluation processes were 800-900 °C in up to 5 min (I), 800-900 °C in 15-20 min (II), and 600-700 °C in 15-20 min (III). Furthermore, the content, pH, and concentrations of Al, Cd, Cu, Fe, Mg, Mn, Mo, Na, Ni, and Ti present in the ashes were determined. The germination index for two vegetable seeds was subsequently evaluated. By measuring the mitotic index and frequency of chromosomal aberrations, the cytotoxicity and genotoxicity were determined. It was observed that RHA produced by combustion of RH at higher combustion temperatures for an extended period exhibited different physicochemical properties, in addition to higher levels of phytotoxicity, cytotoxicity, and genotoxicity.
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Affiliation(s)
| | - Lucas Lourenço Castiglioni Guidoni
- PPGB, Programa de Pós-Graduação em Biotecnologia, Universidade Federal de Pelotas, Rua Benjamin Constant, 989, sala 200-Porto, Pelotas, RS, 96010-450, Brazil.
| | | | - Emanoelli Restane Lopes
- Centro de Ciências Químicas, Farmacêuticas e de Alimentos, Universidade Federal de Pelotas, Pelotas, RS, Brazil
| | - Maicon Nardino
- Departamento de Agronomia, Universidade Federal de Viçosa, Viçosa, MG, Brazil
| | | | | | | | - Thomaz Lucia
- Fibra, Faculdade de Veterinária, Universidade Federal de Pelotas, Pelotas, RS, Brazil
| | - Érico Kunde Corrêa
- NEPERS, Centro de Engenharias, Universidade Federal de Pelotas, Pelotas, RS, Brazil
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Affiliation(s)
- Takao Mori
- International Center for Materials Nanoarchitectonics (WPI-MANA), National Institute for Materials Science, Tsukuba, Japan
- Graduate School of Pure and Applied Sciences, University of Tsukuba, Tsukuba, Japan
| | - Antoine Maignan
- Laboratoire de Cristallographie et Sciences des Matériaux (CRISMAT), Normandie Université, Caen, France
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Marchal N, da Câmara Santa Clara Gomes T, Abreu Araujo F, Piraux L. Large Spin-Dependent Thermoelectric Effects in NiFe-based Interconnected Nanowire Networks. Nanoscale Res Lett 2020; 15:137. [PMID: 32602034 PMCID: PMC7324447 DOI: 10.1186/s11671-020-03343-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Accepted: 05/06/2020] [Indexed: 06/09/2023]
Abstract
NiFe alloy and NiFe/Cu multilayered nanowire (NW) networks were grown using a template-assisted electrochemical synthesis method. The NiFe alloy NW networks exhibit large thermopower, which is largely preserved in the current perpendicular-to-plane geometry of the multilayered NW structure. Giant magneto-thermopower (MTP) effects have been demonstrated in multilayered NiFe/Cu NWs with a value of 25% at 300 K and reaching 60% around 100 K. A large spin-dependent Seebeck coefficient of -12.3 μV/K was obtained at room temperature. The large MTP effects demonstrate a magnetic approach to control thermoelectric properties of flexible devices based on NW networks.
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Affiliation(s)
- Nicolas Marchal
- Institute of Condensed Matter and Nanosciences, Université catholique de Louvain, Place Croix du Sud 1, Louvain-la-Neuve, 1348, Belgium
| | | | - Flavio Abreu Araujo
- Institute of Condensed Matter and Nanosciences, Université catholique de Louvain, Place Croix du Sud 1, Louvain-la-Neuve, 1348, Belgium
| | - Luc Piraux
- Institute of Condensed Matter and Nanosciences, Université catholique de Louvain, Place Croix du Sud 1, Louvain-la-Neuve, 1348, Belgium.
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Chakraborty S, Maiti SK. Possible Routes for Efficient Thermo-Electric Energy Conversion in a Molecular Junction. Chemphyschem 2019; 20:848-860. [PMID: 30690808 DOI: 10.1002/cphc.201900030] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2019] [Revised: 01/28/2019] [Indexed: 11/09/2022]
Abstract
In the context of designing an efficient thermoelectric energy-conversion device at nanoscale level, we suggest several important tuning parameters to enhance the performance of thermoelectric converters. We consider a simple molecular junction, which is always helpful to understand the basic mechanisms in a deeper way, where a benzene molecule is coupled to two external baths having unequal temperatures. The key component responsible for achieving better performance is associated with the asymmetric nature of transmission function, and in the present work, we show that it can be implemented in different ways by regulating the physical parameters involving the system. Employing a tight-binding framework we calculate electrical and thermal conductances, thermopower, and figure of merit (FOM) by using Landauer integrals, and thoroughly examine the critical roles played by molecule-to-lead (ML) interface geometry, magnetic field, chemical substituent group, ML coupling, and the direct coupling between the two leads. Our results show that a reasonably large FOM (≫1) can be obtained and lead to a possibility of regulating the efficiency by selectively tuning the physical parameters. We believe that the present analysis will enhance the understanding of designing efficient thermoelectric devices, and can be verified in a laboratory.
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Affiliation(s)
- Suvendu Chakraborty
- Physics and Applied Mathematics Unit, Indian Statistical Institute, 203, Barrackpore Trunk Road, Kolkata-, 700 108, India
| | - Santanu K Maiti
- Physics and Applied Mathematics Unit, Indian Statistical Institute, 203, Barrackpore Trunk Road, Kolkata-, 700 108, India
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7
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Dutta B, Majidi D, García Corral A, Erdman PA, Florens S, Costi TA, Courtois H, Winkelmann CB. Direct Probe of the Seebeck Coefficient in a Kondo-Correlated Single-Quantum-Dot Transistor. Nano Lett 2019; 19:506-511. [PMID: 30566839 DOI: 10.1021/acs.nanolett.8b04398] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
We report on the first measurement of the Seebeck coefficient in a tunnel-contacted and gate-tunable individual single-quantum dot junction in the Kondo regime, fabricated using the electromigration technique. This fundamental thermoelectric parameter is obtained by directly monitoring the magnitude of the voltage induced in response to a temperature difference across the junction, while keeping a zero net tunneling current through the device. In contrast to bulk materials and single molecules probed in a scanning tunneling microscopy (STM) configuration, investigating the thermopower in nanoscale electronic transistors benefits from the electric tunability to showcase prominent quantum effects. Here, striking sign changes of the Seebeck coefficient are induced by varying the temperature, depending on the spin configuration in the quantum dot. The comparison with numerical renormalization group (NRG) calculations demonstrates that the tunneling density of states is generically asymmetric around the Fermi level in the leads, both in the cotunneling and Kondo regimes.
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Affiliation(s)
- Bivas Dutta
- Université Grenoble Alpes, CNRS, Grenoble INP*, Institut Néel , 38000 Grenoble , France
| | - Danial Majidi
- Université Grenoble Alpes, CNRS, Grenoble INP*, Institut Néel , 38000 Grenoble , France
| | - Alvaro García Corral
- Université Grenoble Alpes, CNRS, Grenoble INP*, Institut Néel , 38000 Grenoble , France
| | - Paolo A Erdman
- NEST, Scuola Normale Superiore and Istituto Nanoscienze-CNR , 56127 Pisa , Italy
| | - Serge Florens
- Université Grenoble Alpes, CNRS, Grenoble INP*, Institut Néel , 38000 Grenoble , France
| | - Theo A Costi
- Peter Grünberg Institut , Forschungszentrum Jülich , 52425 Jülich , Germany
| | - Hervé Courtois
- Université Grenoble Alpes, CNRS, Grenoble INP*, Institut Néel , 38000 Grenoble , France
| | - Clemens B Winkelmann
- Université Grenoble Alpes, CNRS, Grenoble INP*, Institut Néel , 38000 Grenoble , France
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Nguyen VQ, Nguyen TH, Duong VT, Lee JE, Park SD, Song JY, Park HM, Duong AT, Cho S. Thermoelectric Properties of Hot-Pressed Bi-Doped n-Type Polycrystalline SnSe. Nanoscale Res Lett 2018; 13:200. [PMID: 29980879 PMCID: PMC6035122 DOI: 10.1186/s11671-018-2500-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Accepted: 03/21/2018] [Indexed: 05/29/2023]
Abstract
UNLABELLED ᅟ: We report on the successful preparation of Bi-doped n-type polycrystalline SnSe by hot-press method. We observed anisotropic transport properties due to the (h00) preferred orientation of grains along the pressing direction. The electrical conductivity perpendicular to the pressing direction is higher than that parallel to the pressing direction, 12.85 and 6.46 S cm-1 at 773 K for SnSe:Bi 8% sample, respectively, while thermal conductivity perpendicular to the pressing direction is higher than that parallel to the pressing direction, 0.81 and 0.60 W m-1 K-1 at 773 K for SnSe:Bi 8% sample, respectively. We observed a bipolar conducting mechanism in our samples leading to n- to p-type transition, whose transition temperature increases with Bi concentration. Our work addressed a possibility to dope polycrystalline SnSe by a hot-pressing process, which may be applied to module applications. HIGHLIGHTS 1. We have successfully achieved Bi-doped n-type polycrystalline SnSe by the hot-press method. 2. We observed anisotropic transport properties due to the [h00] preferred orientation of grains along pressing direction. 3. We observed a bipolar conducting mechanism in our samples leading to n- to p-type transition.
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Affiliation(s)
- Van Quang Nguyen
- Department of Physics and Energy Harvest Storage Research Center, University of Ulsan, Ulsan, 44610, Republic of Korea
| | - Thi Huong Nguyen
- Department of Physics and Energy Harvest Storage Research Center, University of Ulsan, Ulsan, 44610, Republic of Korea
| | - Van Thiet Duong
- Department of Physics and Energy Harvest Storage Research Center, University of Ulsan, Ulsan, 44610, Republic of Korea
| | - Ji Eun Lee
- Thermoelectric Conversion Research Center, Creative and Fundamental Research Division, Korea Electrotechnology Research Institute (KERI), Changwon, 51543, Republic of Korea
| | - Su-Dong Park
- Thermoelectric Conversion Research Center, Creative and Fundamental Research Division, Korea Electrotechnology Research Institute (KERI), Changwon, 51543, Republic of Korea
| | - Jae Yong Song
- Materials Genome Center, Korea Research Institute of Standards and Science, Daejeon, 305-340, Republic of Korea
| | - Hyun-Min Park
- Materials Genome Center, Korea Research Institute of Standards and Science, Daejeon, 305-340, Republic of Korea
| | - Anh Tuan Duong
- Phenikaa Research and Technology Institute, A&A Green Phoenix Group, 167 Hoang Ngan, Hanoi, 10000, Vietnam.
| | - Sunglae Cho
- Department of Physics and Energy Harvest Storage Research Center, University of Ulsan, Ulsan, 44610, Republic of Korea.
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Apreutesei M, Debord R, Bouras M, Regreny P, Botella C, Benamrouche A, Carretero-Genevrier A, Gazquez J, Grenet G, Pailhès S, Saint-Girons G, Bachelet R. Thermoelectric La-doped SrTiO 3 epitaxial layers with single-crystal quality: from nano to micrometers. Sci Technol Adv Mater 2017; 18:430-435. [PMID: 28740558 PMCID: PMC5507149 DOI: 10.1080/14686996.2017.1336055] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Revised: 05/24/2017] [Accepted: 05/25/2017] [Indexed: 06/07/2023]
Abstract
High-quality thermoelectric La0.2Sr0.8TiO3 (LSTO) films, with thicknesses ranging from 20 nm to 0.7 μm, have been epitaxially grown on SrTiO3(001) substrates by enhanced solid-source oxide molecular-beam epitaxy. All films are atomically flat (with rms roughness < 0.2 nm), with low mosaicity (<0.1°), and present very low electrical resistivity (<5 × 10-4 Ω cm at room temperature), one order of magnitude lower than standard commercial Nb-doped SrTiO3 single-crystalline substrate. The conservation of transport properties within this thickness range has been confirmed by thermoelectric measurements where Seebeck coefficients of approximately -60 μV/K have been recorded for all films. These LSTO films can be integrated on Si for non-volatile memory structures or opto-microelectronic devices, functioning as transparent conductors or thermoelectric elements.
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Affiliation(s)
- Mihai Apreutesei
- Institut des Nanotechnologies de Lyon (INL) – CNRS UMR 5270, Ecully, France
| | - Régis Debord
- Institut Lumière Matière (ILM) - CNRS UMR 5306, Villeurbanne, France
| | - Mohamed Bouras
- Institut des Nanotechnologies de Lyon (INL) – CNRS UMR 5270, Ecully, France
| | - Philippe Regreny
- Institut des Nanotechnologies de Lyon (INL) – CNRS UMR 5270, Ecully, France
| | - Claude Botella
- Institut des Nanotechnologies de Lyon (INL) – CNRS UMR 5270, Ecully, France
| | - Aziz Benamrouche
- Institut des Nanotechnologies de Lyon (INL) – CNRS UMR 5270, Ecully, France
| | - Adrian Carretero-Genevrier
- Institut des Nanotechnologies de Lyon (INL) – CNRS UMR 5270, Ecully, France
- Institut d’Electronique et des Systèmes (IES) - CNRS UMR 5214, Univ. Montpellier 2, Montpellier, France
| | - Jaume Gazquez
- Institut de Ciencia de Materials de Barcelona (ICMAB -CSIC), Bellaterra, Spain
| | - Geneviève Grenet
- Institut des Nanotechnologies de Lyon (INL) – CNRS UMR 5270, Ecully, France
| | - Stéphane Pailhès
- Institut Lumière Matière (ILM) - CNRS UMR 5306, Villeurbanne, France
| | | | - Romain Bachelet
- Institut des Nanotechnologies de Lyon (INL) – CNRS UMR 5270, Ecully, France
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Balout H, Boulet P, Record MC. Strain-induced electronic band convergence: effect on the Seebeck coefficient of Mg 2Si for thermoelectric applications. J Mol Model 2017; 23:130. [PMID: 28337677 DOI: 10.1007/s00894-017-3304-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2016] [Accepted: 02/27/2017] [Indexed: 10/19/2022]
Abstract
The present theoretical study, performed using density-functional theory and Boltzmann transport theory formalisms, shows that under 2.246 % isotropic tensile strain, the two energy-lowest conduction bands of Mg2Si overlap. The two, threefold-degenerated orbitals become a unique, sixfold-degenerated orbital. It is demonstrated that such degeneracy implies an increase of the Seebeck coefficient, of the electrical conductivity, of the power factor, and in fine of the figure of merit.
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11
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Chiarotti U, Moroli V, Menchetti F, Piancaldini R, Bianco L, Viotto A, Baracchini G, Gaspardo D, Nazzi F, Curti M, Gabriele M. Development of a Small Thermoelectric Generators Prototype for Energy Harvesting from Low Temperature Waste Heat at Industrial Plant. J Nanosci Nanotechnol 2017; 17:1586-1591. [PMID: 29693960 DOI: 10.1166/jnn.2017.13723] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
A 39-W thermoelectric generator prototype has been realized and then installed in industrial plant for on-line trials. The prototype was developed as an energy harvesting demonstrator using low temperature cooling water waste heat as energy source. The objective of the research program is to measure the actual performances of this kind of device working with industrial water below 90 °C, as hot source, and fresh water at a temperature of about 15 °C, as cold sink. The article shows the first results of the research program. It was verified, under the tested operative conditions, that the produced electric power exceeds the energy required to pump the water from the hot source and cold sink to the thermoelectric generator unit if they are located at a distance not exceeding 50 m and the electric energy conversion efficiency is 0.33%. It was calculated that increasing the distance of the hot source and cold sink to the thermoelectric generator unit to 100 m the produced electric energy equals the energy required for water pumping, while reducing the distance of the hot source and cold sink to zero meters the developed unit produces an electric energy conversion efficiency of 0.61%.
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Ioannou M, Delimitis A, Symeou E, Giapintzakis J, Kyratsi T. Effect of Silicon Nitride/Oxide on the Structure and the Thermal Conductivity of CoSi Nanocomposites. J Nanosci Nanotechnol 2017; 17:1555-1563. [PMID: 29693349 DOI: 10.1166/jnn.2017.13721] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
In this work, the fabrication of nanocomposites with silicon nitride/oxide into the thermoelectric matrix of cobalt silicide is presented. The different concentrations of nano-Si₃N₄ were intentionally introduced by mechanical grinding while it was found that the nanocomposites also included SiO₂ phase at micro- as well as at nano-scale. The structural and morphological modifications of the materials were studied by powder X-ray Diffraction, Scanning Electron Microscopy and Transmission Electron Microscopy. The nanocomposites were studied in terms of Hall Effect, Seebeck coefficient, electrical and thermal conductivity. Emphasis is given on the lattice thermal conductivity that was analyzed based on Effective Medium Theory and the contribution of each phase is taken into account.
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13
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Soffientini A, Tredici IG, Boldrini S, Famengo A, Spinolo G, Anselmi-Tamburini U. Synthesis and Characterization of Bulk Nanostructured Thermoelectric Ca₃Co₄O₉. J Nanosci Nanotechnol 2017; 17:1668-1673. [PMID: 29697910] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Nanostructuring has been proposed as an effective strategy for the reduction of the phonon contribution to the thermal conductivity, resulting in an increase in the figure of merit of thermoelectric materials. However, obtaining bulk samples presenting high relative density and nanometric grain size can be quite challenging, particularly in the case of ceramic phases. Only few examples have been reported and none in the case of Ca₃Co₄O₉. In this work, we used a sol–gel synthesis coupled with ball milling to prepare powders of Ca₃Co₄O₉ presenting a grain size as small as 4 nm. These nanopowders were then sintered at different temperature and pressures using the High-Pressure Field-Assisted Sintering Technique (HP-FAST). Relative densities up to 95 vol% where obtained while maintaining a nanometric grain size. The microstructural and electrical properties of the sintered samples have been characterized. The results show that in this oxide a reduction to the nanometric grain size produces a drastic reduction in the electrical conductivity, which cannot be compensated by the reduction in the thermal conductivity. The Seebeck effect, on the other hand, appears to be affected only marginally by the grain size and porosity.
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Abstract
We have performed thermoelectric measurements of benzenedithiol (BDT) and C60 molecules with Ni and Au electrodes using a home-built scanning tunneling microscope. The thermopower of C60 was negative for both Ni and Au electrodes, indicating the transport of carriers through the lowest unoccupied molecular orbital in both cases, as was expected from the work functions. On the other hand, the Ni-BDT-Ni junctions exhibited a negative thermopower, whereas the Au-BDT-Au junctions exhibited a positive thermopower. First-principle calculations revealed that the negative thermopower of Ni-BDT-Ni junctions is due to the spin-split hybridized states generated by the highest occupied molecular orbital of BDT coupled with s- and d-states of the Ni electrode.
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Affiliation(s)
- See Kei Lee
- Graduate School of Engineering Science, Osaka University , 1-3 Machikaneyama, Toyonaka, Osaka, 560-8531, Japan
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15
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Culebras M, Torán R, Gómez CM, Cantarero A. La 1-x Ca x MnO 3 semiconducting nanostructures: morphology and thermoelectric properties. Nanoscale Res Lett 2014; 9:415. [PMID: 25206315 PMCID: PMC4148682 DOI: 10.1186/1556-276x-9-415] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/14/2014] [Accepted: 07/07/2014] [Indexed: 06/03/2023]
Abstract
Semiconducting metallic oxides, especially perosvkite materials, are great candidates for thermoelectric applications due to several advantages over traditionally metallic alloys such as low production costs and high chemical stability at high temperatures. Nanostructuration can be the key to develop highly efficient thermoelectric materials. In this work, La 1-x Ca x MnO 3 perosvkite nanostructures with Ca as a dopant have been synthesized by the hydrothermal method to be used in thermoelectric applications at room temperature. Several heat treatments have been made in all samples, leading to a change in their morphology and thermoelectric properties. The best thermoelectric efficiency has been obtained for a Ca content of x=0.5. The electrical conductivity and Seebeck coefficient are strongly related to the calcium content.
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Affiliation(s)
- Mario Culebras
- Materials Science Institute, University of Valencia, P. O. Box 22085, Paterna, Valencia, Spain
| | - Raquel Torán
- Materials Science Institute, University of Valencia, P. O. Box 22085, Paterna, Valencia, Spain
| | - Clara M Gómez
- Materials Science Institute, University of Valencia, P. O. Box 22085, Paterna, Valencia, Spain
| | - Andrés Cantarero
- Materials Science Institute, University of Valencia, P. O. Box 22085, Paterna, Valencia, Spain
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