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Du R, Sun X, Zhang Z. Development and application of a mathematical model to design the venting system for corridors in nuclear power plants. NUCLEAR ENGINEERING AND DESIGN 2020. [DOI: 10.1016/j.nucengdes.2019.110369] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Pourovskii LV. Electronic correlations in dense iron: from moderate pressure to Earth's core conditions. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2019; 31:373001. [PMID: 31167170 DOI: 10.1088/1361-648x/ab274f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
We discuss the role of dynamical many-electron effects in the physics of iron and iron-rich solid alloys under applied pressure on the basis of recent ab initio studies employing the dynamical mean-field theory (DMFT). We review in detail two particularly interesting regimes: first, a moderate pressure range up to 60 GPa and, second, the ultra-high pressure of about 360 GPa expected inside the solid inner core of Earth. Electronic correlations in iron under the moderate pressure of several tens GPa are discussed in the first section. DMFT-based methods predict an enhancement of electronic correlations at the pressure-induced body-centered cubic α to hexagonal close-packed [Formula: see text] phase transition. In particular, the electronic effective mass, scattering rate and electron-electron contribution to the electrical resistivity undergo a step-wise increase at the transition point. One also finds a significant many-body correction to the [Formula: see text]-Fe equation of state, thus clarifying the origin of discrepancies between previous DFT studies and experiment. An electronic topological transition is predicted to be induced in [Formula: see text]-Fe by many-electron effects; its experimental signatures are analyzed. The next section focuses on the geophysically relevant pressure-temperature regime of the Earth's inner core (EIC) corresponding to the extreme pressure of 360 GPa combined with temperatures up to 6000 K. The three iron allotropes ([Formula: see text], [Formula: see text] and face-centered-cubic [Formula: see text]) previously proposed as possible stable phases at such conditions are found to exhibit qualitatively different many-electron effects as evidenced by a strongly non-Fermi-liquid metallic state of [Formula: see text]-Fe and an almost perfect Fermi liquid in the case of [Formula: see text]-Fe. A recent active discussion on the electronic state and transport properties of [Formula: see text]-Fe at the EIC conditions is reviewed in details. Estimations for the dynamical many-electron contribution to the relative phase stability are presented. We also discuss the impact of a Ni admixture, which is expected to be present in the core matter. We conclude by outlining some limitation of the present DMFT-based framework relevant for studies of iron-base systems as well as perspective directions for further development.
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Affiliation(s)
- Leonid V Pourovskii
- CPHT, CNRS, Ecole Polytechnique, IP Paris, F-91128 Palaiseau, France. Collège de France, 11 place Marcelin Berthelot, 75005 Paris, France
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Simulation-aided design of the negative-pressure exhaust system in HTGR nuclear power plants. NUCLEAR ENGINEERING AND DESIGN 2019. [DOI: 10.1016/j.nucengdes.2018.12.023] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Xu J, Zhang P, Haule K, Minar J, Wimmer S, Ebert H, Cohen RE. Thermal Conductivity and Electrical Resistivity of Solid Iron at Earth's Core Conditions from First Principles. PHYSICAL REVIEW LETTERS 2018; 121:096601. [PMID: 30230853 DOI: 10.1103/physrevlett.121.096601] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2018] [Indexed: 06/08/2023]
Abstract
We compute the thermal conductivity and electrical resistivity of solid hcp Fe to pressures and temperatures of Earth's core. We find significant contributions from electron-electron scattering, usually neglected at high temperatures in transition metals. Our calculations show a quasilinear relation between the electrical resistivity and temperature for hcp Fe at extreme high pressures. We obtain thermal and electrical conductivities that are consistent with experiments considering reasonable error. The predicted thermal conductivity is reduced from previous estimates that neglect electron-electron scattering. Our estimated thermal conductivity for the outer core is 77±10 W m^{-1} K^{-1} and is consistent with a geodynamo driven by thermal convection.
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Affiliation(s)
- Junqing Xu
- Department of Earth and Environmental Sciences, LMU Munich, Theresienstrasse 41, 80333 Munich, Germany
| | - Peng Zhang
- School of Science, Xi'an Jiaotong University, Xi'an, Shaanxi, 710049, China
| | - K Haule
- Department of Physics, Rutgers University, Piscataway, New Jersey 08854, USA
| | - Jan Minar
- University of West Bohemia, New Technologies-Research Centre, Pilsen, Czech Republic
| | - Sebastian Wimmer
- Department Chemie, Physikalische Chemie, University of Munich, D-81377 Munich, Germany
| | - Hubert Ebert
- Department Chemie, Physikalische Chemie, University of Munich, D-81377 Munich, Germany
| | - R E Cohen
- Department of Earth and Environmental Sciences, LMU Munich, Theresienstrasse 41, 80333 Munich, Germany
- Extreme Materials Initiative, Geophysical Laboratory, Carnegie Institution for Science, Washington, D.C. 20015-1305, USA
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Vidal AF, Ribeiro-Dos-Santos AM, Vinasco-Sandoval T, Magalhães L, Pinto P, Anaissi AKM, Demachki S, de Assumpção PP, Dos Santos SEB, Ribeiro-Dos-Santos Â. The comprehensive expression analysis of circular RNAs in gastric cancer and its association with field cancerization. Sci Rep 2017; 7:14551. [PMID: 29109417 PMCID: PMC5673933 DOI: 10.1038/s41598-017-15061-w] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2017] [Accepted: 10/18/2017] [Indexed: 12/12/2022] Open
Abstract
Circular RNAs comprise a new class of long noncoding RNAs characterized by their 5' and 3' ends covalently joined. Previous studies have demonstrated that some circular RNAs act as microRNA sponges, and are associated with cellular proliferation in cancer. We were the first to analyze the global expression of circular RNAs in samples of patients without gastric cancer, gastric cancer, and matched tumor-adjacent gastric tissue. Among the samples, we identified 736 previously annotated circular RNAs by RNA-Seq. The tumor-adjacent tissue presented the higher abundance of circular RNAs and could not be considered as a normal tissue, reinforcing the notion of field effect in gastric cancer. We identified five differentially expressed circular RNAs that may be potential biomarkers of this type of cancer. We also predicted candidate microRNAs targets of the highest expressed circular RNAs in gastric tissues and found five miRNAs. Overall, our results support the hypothesis of circular RNAs representing a novel factor in the dynamic epigenetic network of gene regulation, which involves the microRNAs, its mRNAs targets, and the circular RNAs-derived genes. Further studies are needed to elucidate the roles and the functional relevance of the circular RNAs in human diseases.
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Affiliation(s)
- Amanda Ferreira Vidal
- Laboratory of Human and Medical Genetics, Federal University of Pará, Belém, Pará, Brazil
| | | | | | - Leandro Magalhães
- Laboratory of Human and Medical Genetics, Federal University of Pará, Belém, Pará, Brazil
| | - Pablo Pinto
- Laboratory of Human and Medical Genetics, Federal University of Pará, Belém, Pará, Brazil
| | - Ana K M Anaissi
- Center of Oncology Research, Federal University of Pará, Belém, Pará, Brazil
| | - Samia Demachki
- Center of Oncology Research, Federal University of Pará, Belém, Pará, Brazil
| | | | - Sidney Emanuel Batista Dos Santos
- Laboratory of Human and Medical Genetics, Federal University of Pará, Belém, Pará, Brazil
- Center of Oncology Research, Federal University of Pará, Belém, Pará, Brazil
| | - Ândrea Ribeiro-Dos-Santos
- Laboratory of Human and Medical Genetics, Federal University of Pará, Belém, Pará, Brazil.
- Center of Oncology Research, Federal University of Pará, Belém, Pará, Brazil.
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