Journal articles: 'Grand spin'

1

Cohen, Marcus S. "Spin geometry and grand unification." Advances in Applied Clifford Algebras 11, no. 1 (June 2001): 129–63. http://dx.doi.org/10.1007/bf03042042.

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Villain, J. "Magnétisme des cristaux de molécules à grand spin." Annales de Physique 28, no. 1 (2003): 1–96. http://dx.doi.org/10.1051/anphys:2003003.

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Kühn, R., D. Grensing, and A. Huber. "Grand ensemble solution of a classical spin glass model." Zeitschrift für Physik B Condensed Matter 63, no. 4 (December 1986): 447–52. http://dx.doi.org/10.1007/bf01726192.

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Meier, David L. "Grand unification of AGN and the accretion and spin paradigms." New Astronomy Reviews 46, no. 2-7 (May 2002): 247–55. http://dx.doi.org/10.1016/s1387-6473(01)00189-0.

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Chester, David, Alessio Marrani, and Michael Rios. "Beyond the Standard Model with Six-Dimensional Spinors." Particles 6, no. 1 (January 28, 2023): 144–72. http://dx.doi.org/10.3390/particles6010008.

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Six-dimensional spinors with Spin(3,3) symmetry are utilized to efficiently encode three generations of matter. E8(−24) is shown to contain physically relevant subgroups with representations for GUT groups, spacetime symmetries, three generations of the standard model fermions, and Higgs bosons. Pati–Salam, SU(5), and Spin(10) grand unified theories are found when a single generation is isolated. For spacetime symmetries, Spin(4,2) may be used for conformal symmetry, AdS5→dS4, or simply broken to Spin(3,1) of a Minkowski space. Another class of representations finds Spin(2,2) and can give AdS3 with various GUTs. An action for three generations of fermions in the Majorana–Weyl spinor 128 of Spin(4,12) is found with Spin(3) flavor symmetry inside E8(−24). The 128 of Spin(12,4) can be regarded as the tangent space to a particular pseudo-Riemannian form of the octo-octonionic Rosenfeld projective plane E8(−24)/Spin(12,4)=(OsxO)P2.

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Goh, Segun, JunHyuk Woo, Jean-Yves Fortin, and MooYoung Choi. "Grand canonical description of equilibrium and non-equilibrium systems using spin formalism." Physica A: Statistical Mechanics and its Applications 558 (November 2020): 124983. http://dx.doi.org/10.1016/j.physa.2020.124983.

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MATERDEY, TOMAS B. "GRAND CANONICAL MIXED-STATE WIGNER FUNCTION IN A MAGNETIC FIELD: de HAAS–van ALPHEN OSCILLATIONS." International Journal of Modern Physics B 21, no. 06 (March 10, 2007): 829–55. http://dx.doi.org/10.1142/s0217979207036680.

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Kohn proved in 1961 that interactions between electrons did not change the de Haas–van Alphen (dHvA) oscillation frequency for single electrons in the nondegenerate ground-state [Phys. Rev.123(4), 1242 (1961)]. It was proved recently that the pure-state Wigner function for an electron in a magnetic field carries this quantum and physical oscillation, and a quantum dielectric function, so the conductance can be calculated from the Wigner function [Int. J. Mod. Phys. B17(25), 4555 (2003)], [Int. j. Mod. Phys. B17(26), 4683 (2003)]. We present the first complete proof that at a finite temperature, the mixed-state Wigner function also shows dHvA oscillations with the same frequency. The Wigner function is a fundamental quantity, the fact that it carries observable physical information shows a great potential in the design of new quantum materials at the nanoscale. The definition of the mixed-state Wigner function involves a grand canonical partition function (GCPF). Although dHvA is a well-known phenomenon, we present the first complete proof of it happening in degenerate mixed-states, based on a GCPF, which requires reconciliation between the dHvA experimental condition of a fixed number of particles and the GCPF's sum over number of particles. The GCPF is applied to one of the two spin species, while both the spin and spin-magnetic moment interaction are considered. We show that the contour integration in ω(ε) leads to a non-oscillatory term that is much larger than an oscillatory term, in the dHvA experimental conditions of high fields and low temperatures. This dominance of the non-oscillatory term explains the constancy of the chemical potential, allowing it to reduce to the Fermi energy in the limit of zero temperature. The obtained mixed-state Wigner function shows a fundamental period of oscillation with respect to B-1 that reduces to the Onsager's period for dHvA oscillations. This indicates that in mixed-states, dHvA oscillations depend on electrons of one spin species, this means the population of electrons of each spin species oscillates with the magnetic field. The temperature dependence in the Wigner function will allow a combination of phase-space and thermodynamics information for mesoscopic structures, and the study of phase-space density holes such as BGK modes in the quantum domain.

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AHLUWALIA, D. V., M. B. JOHNSON, and T. GOLDMAN. "MAJORANA-LIKE (j, 0) ⊕ (0, j) REPRESENTATION SPACES: CONSTRUCTION AND PHYSICAL INTERPRETATION." Modern Physics Letters A 09, no. 05 (February 20, 1994): 439–50. http://dx.doi.org/10.1142/s0217732394000460.

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We present a formalism that extends the Majorana-construction to arbitrary spin (j, 0) ⊕ (0, j) representation spaces. For the example case of spin-one, a wave equation satisfied by the Majorana-like (1, 0) ⊕ (0, 1) spinors is constructed and its physical content explored. The (j, 0) ⊕ (0, j) Majorana-construct is found to possess an unusual classical and quantum field theoretic structure. Relevance of our formalism to parity violation, hadronic phenomenologies, and grand unified field theories is briefly pointed out.

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Besprosvany, J. "Standard-Model Coupling Constants from Compositeness." Modern Physics Letters A 18, no. 27 (September 7, 2003): 1877–85. http://dx.doi.org/10.1142/s0217732303011642.

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A coupling-constant definition is given based on the compositeness property of some particle states with respect to the elementary states of other particles. It is applied in the context of the vector-spin-1/2-particle interaction vertices of a field theory, and the standard model. The definition reproduces Weinberg's angle in a grand-unified theory. One obtains coupling values close to the experimental ones for appropriate configurations of the standard-model vector particles, at the unification scale within grand-unified models, and at the electroweak breaking scale.

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10

Entin-Wohlman, O., Yuval Gefen, Yigal Meir, and Y. Oreg. "Effects of spin-orbit scattering in mesoscopic rings: Canonical- versus grand-canonical-ensemble averaging." Physical Review B 45, no. 20 (May 15, 1992): 11890–95. http://dx.doi.org/10.1103/physrevb.45.11890.

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11

Kühn, Reimer. "Critical Behavior of the Randomly Spin Diluted 2D Ising Model: A Grand Ensemble Approach." Physical Review Letters 73, no. 16 (October 17, 1994): 2268–71. http://dx.doi.org/10.1103/physrevlett.73.2268.

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12

ZÜCKERT, U., R. ALKOFER, H. REINHARDT, and H. WEIGEL. "THE SKYRMION LIMIT OF THE NAMBU–JONA-LASINIO SOLITON." Modern Physics Letters A 10, no. 01 (January 10, 1995): 67–78. http://dx.doi.org/10.1142/s0217732395000089.

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The special role of the isoscalar mesons (σ and ω) in the NJL soliton is discussed. Stable soliton solutions are obtained when the most general ansatz compatible with vanishing grand spin is assumed. These solutions are compared to soliton solutions of a purely pseudoscalar Skyrme type model which is related to the NJL model by a gradient expansion and the limit of infinitely heavy (axial-) vector mesons.

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13

van Enter, Aernout C. D., C. Külske, and C. Maes. "Comment on “Critical Behavior of the Randomly Spin Diluted 2D Ising Model: A Grand Ensemble Approach”." Physical Review Letters 84, no. 26 (June 26, 2000): 6134. http://dx.doi.org/10.1103/physrevlett.84.6134.

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14

Binder, Kurt. "The glass transition: How do complex craggy free energy landscapes emerge?" Europhysics News 53, no. 1 (2022): 11–14. http://dx.doi.org/10.1051/epn/2022104.

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Glass as a material was already known in ancient Egypt. Now its use for windows, bottles, etc. is very common; thus, it may sound surprising that the glassy state of matter and the transition from an undercooled melt to this state are grand challenge problems of physics. This article describes the basic concepts; then it points out how the discovery of “spin glasses” and the theory by Giorgio Parisi has given a new boost to the interest in these problems. The status of a theory of the glass transition will be critically discussed.

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Lamoureux, Johanne. "L’exposition comme produit dérivé." Intermédialités, no. 15 (October 13, 2010): 73–89. http://dx.doi.org/10.7202/044675ar.

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En 2008, les Galeries nationales du Grand Palais à Paris présentaient l’exposition Marie-Antoinette et en confiaient la scénographie au metteur en scène Robert Carsens. Ce blockbuster révisionniste nous propose Marie-Antoinette comme une figure dépolitisée, une espèce de célébrité contemporaine en manque de spin doctor et fatalement incapable de résoudre ses épineux problèmes d’image publique. Le présent essai réfléchit à deux usages de l’intermédialité dans la culture contemporaine en tant que ceux-ci se manifestent dans la scénographie de l’exposition. Chacun d’entre eux est exemplifié par un site précis de l’exposition : le kiosque Ladurée et la salle consacrée au Petit Trianon.

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Yee, Samuel W., Joshua N. Winn, Joel D. Hartman, Luke G. Bouma, George Zhou, Samuel N. Quinn, David W. Latham, et al. "The TESS Grand Unified Hot Jupiter Survey. II. Twenty New Giant Planets*." Astrophysical Journal Supplement Series 265, no. 1 (February 13, 2023): 1. http://dx.doi.org/10.3847/1538-4365/aca286.

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Abstract NASA’s Transiting Exoplanet Survey Satellite (TESS) mission promises to improve our understanding of hot Jupiters by providing an all-sky, magnitude-limited sample of transiting hot Jupiters suitable for population studies. Assembling such a sample requires confirming hundreds of planet candidates with additional follow-up observations. Here we present 20 hot Jupiters that were detected using TESS data and confirmed to be planets through photometric, spectroscopic, and imaging observations coordinated by the TESS Follow-up Observing Program. These 20 planets have orbital periods shorter than 7 days and orbit relatively bright FGK stars (10.9 < G < 13.0). Most of the planets are comparable in mass to Jupiter, although there are four planets with masses less than that of Saturn. TOI-3976b, the longest-period planet in our sample (P = 6.6 days), may be on a moderately eccentric orbit (e = 0.18 ± 0.06), while observations of the other targets are consistent with them being on circular orbits. We measured the projected stellar obliquity of TOI-1937A b, a hot Jupiter on a 22.4 hr orbit with the Rossiter–McLaughlin effect, finding the planet’s orbit to be well aligned with the stellar spin axis (∣λ∣ = 4.°0 ± 3.°5). We also investigated the possibility that TOI-1937 is a member of the NGC 2516 open cluster but ultimately found the evidence for cluster membership to be ambiguous. These objects are part of a larger effort to build a complete sample of hot Jupiters to be used for future demographic and detailed characterization work.

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Fossat, Pascale. "Un sité dédié aux grands-parents : Grand-Mercredi." Spirale N° 97, no. 1 (March 30, 2021): 43–45. http://dx.doi.org/10.3917/spi.097.0043.

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18

Zakharova, Marina Nikolaevna, and Lyudmila Vasilievna Rozhkova. "The effectiveness of autumn application of the herbicide Alistair Grand, MD depending on the consumption rates and phases of development of winter wheat on dark gray forest soils of the Ryazan region." Agrarian Scientific Journal, no. 8 (August 31, 2023): 28–35. http://dx.doi.org/10.28983/asj.y2023i8pp28-35.

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As a leader in the development of high plant protection technologies, Bayer CropScience was the first in Russia to introduce the herbicide Alistair Grand, MD, specialized specifically for autumn use on winter grain crops. Experiments to study the effectiveness of the herbicide were laid in the fields of the ISA, a branch of the Federal State Budgetary Scientific Institution FNATS VIM in the Ryazan Region in 2020–2021 and 2021–2022. on dark gray forest heavy loamy soil. Under pre-sowing cultivation, 1.0 c/ha of azofos was applied. In the phase of spring tillering, winter wheat crops were fertilized with ammonium nitrate of 1.0 c/ha. Herbicide Alistair Grand, MD was applied in doses of 0.8 and 1.0 l / ha (spraying) in the phase of 1-3 leaves of the culture. In the same doses, Alistair Grand, MD (spraying) was used in the tillering phase of the crop. On the control variant, the herbicide was not used. Two-year tests of the autumn application of the herbicide Alistair Grand, MD in the phase of 1-3 leaves and in the tillering phase with a rate of application of 0.8 and 1.0 l / ha on winter wheat crops showed its high efficiency in the destruction of annual dicotyledonous and annual cereal (common broomstick) weeds. Annual dicots were inhibited to 97.9% in number and up to 96.6% by weight. tenacious bedstraw – by 11.5–12.5 pcs/m2, wild spin – by 17–19 pcs/m2, field and shepherd's purse violets – by 5.5–6.0 pcs/m2, common broom – by 14–15 pcs/m2. Surveys at the resumption of vegetation and before harvesting showed the complete destruction of the common broomstick. From the use of the drug, an additional grain yield of 106.9–114.7% was obtained.

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Carmelo, J. M. P., and T. Prosen. "Absence of high-temperature ballistic transport in the spin-1/2 XXX chain within the grand-canonical ensemble." Nuclear Physics B 914 (January 2017): 62–98. http://dx.doi.org/10.1016/j.nuclphysb.2016.10.021.

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20

Pardede, Indra, Daiki Yoshikawa, Tomosato Kanagawa, Nurul Ikhsan, Masao Obata, and Tatsuki Oda. "Anatomy of Magnetic Anisotropy and Voltage-Controlled Magnetic Anisotropy in Metal Oxide Heterostructure from First Principles." Crystals 10, no. 12 (December 8, 2020): 1118. http://dx.doi.org/10.3390/cryst10121118.

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Voltage control of magnetic anisotropy (VCMA) is one of the promising approaches for magnetoelectric control of magnetic tunnel junction (MTJ). Here, we systematically calculated the magnetic anisotropy (MA) and the VCMA energies in the well-known MTJ structure consisting of Fe/MgO interface with Cr buffer layer. In this calculation, we investigated an alloying between Fe and Cr and a strain effect. We used a spin density functional approach which includes both contributions from magnetocrystalline anisotropy energy (MCAE) originating from spin–orbit coupling and shape magnetic anisotropy energy from spin dipole–dipole interaction. In the present approach, the MCAE part, in addition to a common scheme of total energy, was evaluated using a grand canonical force theorem scheme. In the latter scheme, atom-resolved and k-resolved analyses for MA and VCMA can be performed. At first, we found that, as the alloying is introduced, the perpendicular MCAE increases by a factor of two. Next, as the strain is introduced, we found that the MCAE increases with increasing compressive strain with the maximum value of 2.2 mJ/m2. For the VCMA coefficient, as the compressive strain increases, the sign becomes negative and the absolute value becomes enhanced to the number of 170 fJ/Vm. By using the atom-resolved and k-resolved analyses, we clarified that these enhancements of MCAE and VCMA mainly originates from the Fe interface with MgO (Fe1) and are located at certain lines in the two dimensional Brillouin zone. The findings on MCAE and VCMA are fully explained by the spin-orbit couplings between the certain d-orbital states in the second-order perturbation theory.

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Karl, Robert M., Giulia F. Mancini, Joshua L. Knobloch, Travis D. Frazer, Jorge N. Hernandez-Charpak, Begoña Abad, Dennis F. Gardner, et al. "Full-field imaging of thermal and acoustic dynamics in an individual nanostructure using tabletop high harmonic beams." Science Advances 4, no. 10 (October 2018): eaau4295. http://dx.doi.org/10.1126/sciadv.aau4295.

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Imaging charge, spin, and energy flow in materials is a current grand challenge that is relevant to a host of nanoenhanced systems, including thermoelectric, photovoltaic, electronic, and spin devices. Ultrafast coherent x-ray sources enable functional imaging on nanometer length and femtosecond timescales particularly when combined with advances in coherent imaging techniques. Here, we combine ptychographic coherent diffractive imaging with an extreme ultraviolet high harmonic light source to directly visualize the complex thermal and acoustic response of an individual nanoscale antenna after impulsive heating by a femtosecond laser. We directly image the deformations induced in both the nickel tapered nanoantenna and the silicon substrate and see the lowest-order generalized Lamb wave that is partially confined to a uniform nanoantenna. The resolution achieved—sub–100 nm transverse and 0.5-Å axial spatial resolution, combined with ≈10-fs temporal resolution—represents a significant advance in full-field dynamic imaging capabilities. The tapered nanoantenna is sufficiently complex that a full simulation of the dynamic response would require enormous computational power. We therefore use our data to benchmark approximate models and achieve excellent agreement between theory and experiment. In the future, this work will enable three-dimensional functional imaging of opaque materials and nanostructures that are sufficiently complex that their functional properties cannot be predicted.

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CASTRO PERELMAN, CARLOS. "THE EXCEPTIONAL E8 GEOMETRY OF CLIFFORD (16) SUPERSPACE AND CONFORMAL GRAVITY YANG–MILLS GRAND UNIFICATION." International Journal of Geometric Methods in Modern Physics 06, no. 03 (May 2009): 385–417. http://dx.doi.org/10.1142/s0219887809003588.

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We continue to study the Chern–Simons E8 Gauge theory of Gravity developed by the author which is a unified field theory (at the Planck scale) of a Lanczos–Lovelock Gravitational theory with a E8 Generalized Yang–Mills (GYM) field theory, and is defined in the 15D boundary of a 16D bulk space. The Exceptional E8 Geometry of the 256-dim slice of the 256 × 256-dimensional flat Clifford (16) space is explicitly constructed based on a spin connection [Formula: see text], that gauges the generalized Lorentz transformations in the tangent space of the 256-dim curved slice, and the 256 × 256 components of the vielbein field [Formula: see text], that gauge the nonabelian translations. Thus, in one-scoop, the vielbein [Formula: see text] encodes all of the 248 (nonabelian) E8 generators and 8 additional (abelian) translations associated with the vectorial parts of the generators of the diagonal subalgebra [Cl(8) ⊗ Cl(8)] diag ⊂ Cl(16). The generalized curvature, Ricci tensor, Ricci scalar, torsion, torsion vector and the Einstein–Hilbert–Cartan action is constructed. A preliminary analysis of how to construct a Clifford Superspace (that is far richer than ordinary superspace) based on orthogonal and symplectic Clifford algebras is presented. Finally, it is shown how an E8 ordinary Yang–Mills in 8D, after a sequence of symmetry breaking processes E8 → E7 → E6 → SO(8, 2), and performing a Kaluza–Klein–Batakis compactification on CP2, involving a nontrivial torsion, leads to a (Conformal) Gravity and Yang–Mills theory based on the Standard Model in 4D. The conclusion is devoted to explaining how Conformal (super) Gravity and (super) Yang–Mills theory in any dimension can be embedded into a (super) Clifford-algebra-valued gauge field theory.

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Marsch, Eckart, and Yasuhito Narita. "Hadronic Isospin Helicity and the Consequent SU(4) Gauge Theory." Symmetry 15, no. 10 (October 23, 2023): 1953. http://dx.doi.org/10.3390/sym15101953.

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A new approach to the Dirac equation and the associated hadronic symmetries is proposed. In this approach, we linearize the second Casimir operator of the Lorentz Group, which is defined by the energy–momentum four-vector and the fermion spin, thereby using the spinor-helicity representation instead of the three-vector representation of the particle momentum and spin vector. We then expand the so-obtained standard Dirac equation by employing an inner abstract “hadronic” isospin, initially describing a SU(2) fermion doublet. Application of the spin-helicity representation of that isospin leads to the occurrence of a quadruplet of inner states, revealing the SU(4) symmetry via the isospin helicity operator. This further leads to two independent fermion state spaces, specifically, singlet and triplet states, which we interpret as U(1) symmetry of the leptons and SU(3) symmetry of the three quarks, respectively. These results indicate the genuinely very different physical nature of the strong SU(4) symmetry in comparison to the chiral SU(2) symmetry. While our approach does not require the a priori concept of grand unification, such a notion arises naturally from the formulation with the isospin helicity. We then apply the powerful procedures developed for the electroweak interactions in the SM, in order to break the SU(4) symmetry by means of the Higgs mechanism involving a scalar Higgs field as an SU(4) quadruplet. Its finite vacuum creates the masses of the three vector bosons involved, which can change the three quarks into a lepton and vice versa. Finally, we consider a toy model for calculation of the strong coupling constant of a Yukawa potential.

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Frodl, P., F. T. Sommer, K. Hau, and F. Wahl. "On the Effective Interaction of two Hydrogen Centres in Niobium." Zeitschrift für Naturforschung A 45, no. 7 (July 1, 1990): 857–66. http://dx.doi.org/10.1515/zna-1990-0704.

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AbstractWe derive an effective interaction between hydrogen impurities in Niobium using a microscopic theory of hydrogen in metals. Our model consists of an infinite bcc-crystal with two hydrogen centres occupying tetrahedral interstitial sites, neighbouring on the first to the fourth coordination shell. The elastic interactions are assumed to obey the classical harmonic approximation. The electronic interactions due to both the coulomb potentials and the overlap of the impurity induced electron densities in the vicinity of the interstitials also play an important role. These latter interactions are treated as two-body interactions in a zeroth order approximation of the New Tamm-Dancoffmethod. A separation ansatz results in an effective interaction which depends on the distance between the interstitials and upon the spin states of their excess electrons. We propose some improvements on our model, and to test our calculations, we construct the grand partition function of an appropriate lattice gas model.

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CHEN, LIANG, and A. M. S. TREMBLAY. "Determinant Monte Carlo for the Hubbard Model with Arbitrarily Gauged Auxiliary Fields." International Journal of Modern Physics B 06, no. 05n06 (March 1992): 547–60. http://dx.doi.org/10.1142/s0217979292000323.

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Monte Carlo methods for the Hubbard model rely on a Hubbard-Stratonovich (HS) decomposition (auxiliary field method) to perform importance sampling on classical variables. Freedom in the choice of the local HS fields can be formally seen as a gauge choice. While the choice of gauge does not influence observable quantities, it may influence intermediate quantities in the calculation, such as the famous “fermion sign”, and it may also influence the efficiency with which the algorithm explores phase space. The effect of arbitrary gauge choices on both aspects of the algorithm are investigated. It is found that in the single spin-flip determinantal approach, certain gauges lead to a better exploration of phase space. This improvement is demonstrated, in the intermediate coupling regime, by histograms which for the first time show the behavior expected from grand canonical simulations. It is also found that the improved phase space exploration can in practice offset the apparent disadvantage of a smaller fermion sign.

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Xiao, Hai, Hyeyoung Shin, and William A. Goddard. "Synergy between Fe and Ni in the optimal performance of (Ni,Fe)OOH catalysts for the oxygen evolution reaction." Proceedings of the National Academy of Sciences 115, no. 23 (May 21, 2018): 5872–77. http://dx.doi.org/10.1073/pnas.1722034115.

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The oxygen evolution reaction (OER) is critical to solar production of fuels, but the reaction mechanism underlying the performance for a best OER catalyst, Fe-doped NiOOH [(Ni,Fe)OOH], remains highly controversial. We used grand canonical quantum mechanics to predict the OER mechanisms including kinetics and thus overpotentials as a function of Fe content in (Ni,Fe)OOH catalysts. We find that density functional theory (DFT) without exact exchange predicts that addition of Fe does not reduce the overpotential much. However, DFT with exact exchange predicts dramatic improvement in performance for (Ni,Fe)OOH, leading to an overpotential of 0.42 V and a Tafel slope of 23 mV/decade (dec), in good agreement with experiments, 0.3–0.4 V and 30 mV/dec. We reveal that the high spin d4 Fe(IV) leads to efficient formation of an active O radical intermediate, while the closed shell d6 Ni(IV) catalyzes the subsequent O–O coupling, and thus it is the synergy between Fe and Ni that delivers the optimal performance for OER.

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STOCK, REINHARD. "HADRON FORMATION IN HIGH ENERGY ELEMENTARY AND NUCLEAR COLLISIONS." International Journal of Modern Physics E 16, no. 03 (April 2007): 687–714. http://dx.doi.org/10.1142/s0218301307006216.

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We consider the dynamical origin of the apparent statistical equilibrium that governs the yields, and yield ratios, of all hadron and resonance species (consisting of the three light quark flavours) produced in nucleus-nucleus collisions from AGS via SPS to RHIC energies [Formula: see text]. This hadro-chemical equilibrium state is well described, overall, by the grand canonical, quasi-classical Gibbs ensemble of all corresponding hadrons and resonances. In order to pin down the stochastic elements, featured by the dynamical evolution prior to hadron formation and hadronic "chemical" (i.e. species) freeze-out, and determining the eventual equilibrium state, we concentrate on the high energy domain, [Formula: see text], where a model of primordial perturbative QCD partonic shower evolution appears plausible. For guidance concerning a hadronization model we revisit the QCD description of jet-induced hadron formation in e+e- annihilation at LEP energy. At the end of the pQCD partonic shower evolution a stage of color neutralization and flavour recombination leads to transition into non perturbative QCD clusters or strings, that decay to hadrons/resonances under phase space dominance. The combination of stochastic shower multiplication and cluster decay to the phase space defined by the hadron/resonancemass and spin spectrum results in a hadronization output featuring statistical equilibrium of the species, which is well described by the canonical Gibbs ensemble. We then assume that hadronization in A + A collisions occurs from a similar stage of singlet cluster formation. However, owing to the extreme overall energy density these clusters should overlap spatially, giving rise to extended super-cluster formation, increasing with [Formula: see text], A and collision centrality. In the limit of an extended volume decaying coherently, hadronization is free of local quantum number conservation constraints. This leads to strangeness enhancement and explains the success of a grand canonical description.

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Mecci, Puke Lajaladita Litle, Annisa Monica, Iin Riananda Br Sinurat, Agustina Widiyani, Abdul Rajak, and Indra Pardede. "FIRST-PRINCIPLES STUDY OF MAGNETIC ANISOTROPY ENERGY IN TWO-DIMENSIONAL FERROMAGNETIC CrI3." Indonesian Physical Review 6, no. 1 (December 26, 2022): 60–84. http://dx.doi.org/10.29303/ipr.v6i1.191.

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First-principles calculations are increasingly crucial in searching for new materials with customized properties or new functionality. First-principles calculations are superior in speed and cost, and comparable to experiments in terms of accuracy. Two-dimensional (2D) ferromagnetism materials were successfully fabricated experimentally in atomic thin films of CrI3. 2D intrinsic ferromagnetism with perpendicular magnetic anisotropy energy (PMAE) is an encouraging applicant compatible with high-density magnetic storage applications. In this study, spin density functional calculations are investigated on the magnetic anisotropy energy (MAE) in 2D monolayer ferromagnetic CrI3 using a first-principles electronic structure calculation. We include the MAE part calculation from the magnetocrystalline anisotropy energy (MCAE) that comes from the spin-orbit coupling (SOC). In the present calculation, the MCAE part, in addition to a usual scheme of total energy (TE), was evaluated using a grand-canonical force theorem (GCFT) scheme. The MCAE of 2D monolayer ferromagnetic CrI3 is 1.7 meV/unit cell and verified it has an easy-axis perpendicular to the crystal plane, which is a good agreement with experimental measurement. In the latter scheme, employing GCFT, we evaluated atom-resolved, k-resolved, and atomic k-resolved analyses for MCAE can be performed. From the GCFT result, the Cr atom indicates that it is the primary origin of PMAE in the atom-resolved MCAE. The negative MCAE contribution is in points, and the positive MCAE is mainly placed at the line in the 2D first Brillouin zone. Our systematic calculation in this work may also help design an effective structure of monolayer CrI3 in new 2D material magnetic sensor and spintronic device designs.

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Čenčariková, H., and N. Tomašovičová. "Comparative Study of a Critical Behavior of a Coupled Spin-Electron Model on a Doubly Decorated Square Lattice in the Canonical and Grand-Canonical Ensemble." Acta Physica Polonica A 137, no. 5 (May 2020): 607–9. http://dx.doi.org/10.12693/aphyspola.137.607.

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ARNOWITT, R., and PRAN NATH. "NEUTRALINO EVENT RATES IN DARK MATTER DETECTORS." Modern Physics Letters A 10, no. 18 (June 14, 1995): 1257–67. http://dx.doi.org/10.1142/s021773239500137x.

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The expected event rates for [Formula: see text] dark matter for supergravity grand unified models are studied for a variety of dark matter detectors over the parameter space with tan β≤20 and a range of gluino masses where the maximum event rate can at least approach 10−2 event/kg.da. This is the maximum sensitivity that the dark matter detectors can hope to achieve in the forseeable future. Radiative breaking constraints are implemented and effects of the heavy neutral Higgs as well as loop corrections to the neutral Higgs sector are included. The parameter space is further restricted so that the [Formula: see text] relic density obeys the CHDM constraint [Formula: see text], consistent with the COBE data and astronomical determinations of the Hubble constant. It is found that the best detectors sensitive to coherent [Formula: see text] scattering (e.g. Pb) are about 5–10 times more sensitive than those based on incoherent spin-dependent scattering (e.g. CaF). In general, the dark matter detectors are most sensitive to the large tan β and small m0 and [Formula: see text] sectors of the parameter space.

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Delpy, Catherine-Juliet. "« Moi, ma grand-mère, moi, mon grand-père… »." Spirale N° 97, no. 1 (March 30, 2021): 26–29. http://dx.doi.org/10.3917/spi.097.0026.

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Aldufeery, Elham, and Maien Binjonaid. "Dark Matter Constraints and the Neutralino Sector of the scNMSSM." Universe 7, no. 2 (January 31, 2021): 31. http://dx.doi.org/10.3390/universe7020031.

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The neutralino sector of the semi-constrained next-to-minimal supersymmetric standard model is explored under recent experimental constraints, with special attention to dark matter (DM) limits. The effects of the upper and lower bounds of dark matter relic density and recent direct detection constraints on spin-independent and -dependent cross-sections are thoroughly analyzed. Particularly, we show which regions of the parameter space are ruled out due to the different dark matter constraints and the corresponding model-specific parameters: λ,κ,Aλ, and Aκ. We analyze all annihilation and co-annihilation processes (with heavier neutralinos and charginos) that contribute to the dark matter relic density. The mass components of the dark matter candidate, the lightest neutralino χ˜10, are studied, and the decays of heavy neutralinos and charginos, especially χ˜20 and χ˜1+, into the lightest neutralino are examined. We impose semi-universal boundary conditions at the Grand Unified Theory scale, and require a moderate range of tanβ≲10. We find that the allowed parameter space is associated with a heavy mass spectrum in general and that the lightest neutralino is mostly Higgsino with a mass range that resides mostly between 1000 and 1500 GeV. However, smaller mass values can be achieved if the DM candidate is bino-like or singlino-like.

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Laading, Camille. "Mon grand-père." Spirale N° 97, no. 1 (March 30, 2021): 40–42. http://dx.doi.org/10.3917/spi.097.0040.

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Spalart, P. R., and D. R. Bogue. "The role of CFD in aerodynamics, off-design." Aeronautical Journal 107, no. 1072 (June 2003): 323–29. http://dx.doi.org/10.1017/s0001924000013634.

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Abstract We discuss the status, trends and long-term ambitions of Computational Fluid Dynamics (CFD) when applied away from the design point or concept, and therefore in the historically weak areas of CFD. This includes both undesirable flight conditions, such as stall, and undesirable products of the flow, such as noise. All pose the great challenge of turbulence, and accuracy is as dependent on the ideas behind the turbulence treatment as it is on computing power. A measured shift from Reynolds-averaged representations to large-eddy simulations will take place. Empiricism, both turbulence and engineering related, will recede only step by step over many years. Yet, CFD will make full use of every increase in computer power of this century. Increasingly, CFD will compete with flight tests, not just with wind tunnels, and will be validated by flight tests. Integration with other disciplines will allow us to predict crucial phenomena such as flutter, sonic fatigue, and pilot-induced oscillations. A gap will remain at any time between the phenomena amenable to a ‘grand challenge’ calculation and those amenable to a fully CFD-based design process, because certification involves thousands of conditions. The highest demand currently is in community and cabin noise for which industrial-accuracy methods are non-existent. On the other hand, gratifying progress has occurred in the area of stall and spin.

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Iyer, Rajan, Christopher O’Neill, and Manuel Malaver. "Helmholtz Hamiltonian Mechanics Electromagnetic Physics Gaging Charge Fields Having Novel Quantum Circuitry Model." Oriental Journal of Physical Sciences 5, no. 1-2 (December 30, 2020): 30–48. http://dx.doi.org/10.13005/ojps05.01-02.06.

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This article shows novel model Pauli-Dirac-Planck-quantum-circuit-assembly-gage, consisting of the monopole quasiparticles and electron-positron particle fields, demonstrating power of Iyer Markoulakis Helmholtz Hamiltonian mechanics of point vortex and gradient fields general formalism. Transforming this general metrics to Coulombic gaging metrics and performing gage charge fields calculations, derivation of assembly eigenvector matrix bundle constructs of magnetic monopoles, and electron positron particle gage metrics were successfully compiled, like SUSY (?( 1 &?@?*&1 )) Hermitian quantum matrix., modified to asymmetric strings gage metrics to account for asymmetrical magnetic pole forces measurements recently in physics. Physical analysis with graphics discussing scenarios of electric tensor particles and magnetic tensor monopoles permutationally interacting, figures showing simulations of fermions’ spins with Clifford algebraic geometry, and the graphs explaining vortex sinusoidal pulsed signal output distribution profile of typical equivalent wave velocity of the related point fields partially verify this quantum circuity assembly model. Table shows estimated size of this assembly greater than 10-34 Planck unit and less than quasi-particle size of 10-26 metrics unit. Wide-ranging applications of this quantum circuitry assembly model exist for quantum supercomputing expertise antenna networks, alongside quantum astrophysical grand unifying genesis of electromagnetic gravitational matter antimatter systems. This quantum model can be verified by experimental techniques, such as spin-ice and Bose-Einstein condensate spinors.

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Iyer, Rajan, Christopher O’Neill2, and Manuel Malaver. "Helmholtz Hamiltonian Mechanics Electromagnetic Physics Gaging Charge Fields Having Novel Quantum Circuitry Model." Oriental Journal of Physical Sciences 5, no. 1-2 (December 30, 2020): 30–48. http://dx.doi.org/10.13005/10.13005/ojps05.01-02.06.

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This article shows novel model Pauli-Dirac-Planck-quantum-circuit-assembly-gage, consisting of the monopole quasiparticles and electron-positron particle fields, demonstrating power of Iyer Markoulakis Helmholtz Hamiltonian mechanics of point vortex and gradient fields general formalism. Transforming this general metrics to Coulombic gaging metrics and performing gage charge fields calculations, derivation of assembly eigenvector matrix bundle constructs of magnetic monopoles, and electron positron particle gage metrics were successfully compiled, like SUSY (?( 1 &?@?*&1 )) Hermitian quantum matrix., modified to asymmetric strings gage metrics to account for asymmetrical magnetic pole forces measurements recently in physics. Physical analysis with graphics discussing scenarios of electric tensor particles and magnetic tensor monopoles permutationally interacting, figures showing simulations of fermions’ spins with Clifford algebraic geometry, and the graphs explaining vortex sinusoidal pulsed signal output distribution profile of typical equivalent wave velocity of the related point fields partially verify this quantum circuity assembly model. Table shows estimated size of this assembly greater than 10-34 Planck unit and less than quasi-particle size of 10-26 metrics unit. Wide-ranging applications of this quantum circuitry assembly model exist for quantum supercomputing expertise antenna networks, alongside quantum astrophysical grand unifying genesis of electromagnetic gravitational matter antimatter systems. This quantum model can be verified by experimental techniques, such as spin-ice and Bose-Einstein condensate spinors.

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37

Mignon, Pascale. "L’art d’être grand-mère." Spirale N° 97, no. 1 (March 30, 2021): 86–91. http://dx.doi.org/10.3917/spi.097.0086.

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Besson, Jacques, Mireille Galtier, and Isabelle Odier. "Petit parent deviendra grand." Spirale 29, no. 1 (2004): 25. http://dx.doi.org/10.3917/spi.029.0025.

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Duflos, Mathilde. "Grand-parentalité et nature." Spirale N° 102, no. 2 (October 28, 2022): 42–49. http://dx.doi.org/10.3917/spi.102.0042.

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40

Haponenko, K. M., and A. I. Sokolovsky. "Calculation of nonequilibrium thermodynamic potential of Bose system near the condensation point." Journal of Physics and Electronics 26, no. 2 (December 26, 2018): 7–16. http://dx.doi.org/10.15421/331817.

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Bose system of zero spin particles is considered in the presence of the Bose–Einstein condensate in the vicinity of the phase transition point. The system is investigated in the framework of the Bogolyubov model with the separated condensate. In this model an effective Hamiltonian of the system is introduced by replacing condensate creation and annihilation operators in system Hamiltonian by n01/2 where n0 is occupation number of the condensate state. According to Bogolyubov, the grand canonical thermodynamic potential related to the effective Hamiltonian is considered as nonequilibrium thermodynamic potential. In the present paper this potential is investigated as a function of the small variable n0. With the help of the thermodynamic perturbation theory it is shown that it is expanded in a series over integer powers of n0. This corresponds to the basic idea of the Landau theory of the phase transitions of the second kind. Coefficients at terms of the first and second orders in n0 in the expansion are calculated for Bose gas in the main approximation in small interaction. Calculation of the coefficients at terms of the third and fourth orders needs accounting contributions of the thermodynamic perturbation theory at least of the 4th order and will be done elsewhere. It is established that the results obtained for Bose gas do not fit into the Landau theory of phase transitions of the second kind. Some comments that discuss the situation are given.

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ALFORD, MARK G., and JOHN MARCH-RUSSELL. "DISCRETE GAUGE THEORIES." International Journal of Modern Physics B 05, no. 16n17 (October 1991): 2641–73. http://dx.doi.org/10.1142/s021797929100105x.

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In this review we discuss the formulation and distinguishing characteristics of discrete gauge theories, and describe several important applications of the concept. For the abelian (ℤN) discrete gauge theories, we consider the construction of the discrete charge operator F(Σ*) and the associated gauge-invariant order parameter that distinguishes different Higgs phases of a spontaneously broken U(1) gauge theory. We sketch some of the important thermodynamic consequences of the resultant discrete quantum hair on black holes. We further show that, as a consequence of unbroken discrete gauge symmetries, Grand Unified cosmic strings generically exhibit a Callan-Rubakov effect. For non-abelian discrete gauge theories we discuss in some detail the charge measurement process, and in the context of a lattice formulation we construct the non-abelian generalization of F(Σ*). This enables us to build the order parameter that distinguishes the different Higgs phases of a non-abelian discrete lattice gauge theory with matter. We also describe some of the fascinating phenomena associated with non-abelian gauge vortices. For example, we argue that a loop of Alice string, or any non-abelian string, is super-conducting by virtue of charged zero modes whose charge cannot be localized anywhere on or around the string (“Cheshire charge”). Finally, we discuss the relationship between discrete gauge theories and the existence of excitations possessing exotic spin and statistics (and more generally excitations whose interactions are purely “topological”).

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42

Sotty, Dominique. "Un très heureux grand-père." Spirale N° 97, no. 1 (March 30, 2021): 92–94. http://dx.doi.org/10.3917/spi.097.0092.

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Clerget, Joël. "Le coup du grand-père." Spirale N° 97, no. 1 (March 30, 2021): 76–85. http://dx.doi.org/10.3917/spi.097.0076.

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44

Iyer, Rajan. "Quantum Physical Observables with Conjectural Modeling: Paradigm shifting Formalisms II: A Review." Oriental Journal of Physical Sciences 7, no. 2 (January 10, 2023): 50–66. http://dx.doi.org/10.13005/ojps07.02.02.

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In continuation with the previous Review Force General Conjectural Modeling Transforms Formalism PHYSICS33 (Physics & Astronomy International Journal under publication), the current review article will try to develop quantum gravity gage transforms Algorithm Graphical Equation of micro-blackhole force to gauge fields-wavefunctions algorithm transforms equations. Theoretical derivations of experimental observable measurable parameters having scalar quantum gauge field as function in terms of Laplacian, Fourier, and the Legendre transform gaging the spin, rotation, revolution, and rotational angular velocity have been shown. These transforms appear only as a function of time, and that makes the formulation independent of assumptions of invariability of fundamental universally known constants. We consider examples of universal eonic parametric observables as well. The question of whether the time is a linear operator has been answered by employing Correspondence Principle’s linear operator four-vector time matrix spatial range algorithm equivalence and is estimated to be about ¼ mile. Theoretically derived algorithm physics designs enable prototype testing by utilizing experimental instrumentations measuring observables. A flowchart has been configured simplifying theoretical to experimental mathematical physical sciences to profile signal/noise intensity and the density matrix. Additionally, estimation of Hod PDP mechanistic probability, grand unifying physics operations, schematics of potential scalar gauge field alongside incorporating typical wavefunction general quantum computing signal/noise matrix graphing, simple lab-top prototype sound and light profiling intensity, and spectral density point-to-point matrix oscilloscopic observational measurement techniques have been schematically sketched out to enhance facilitation of future implementations of state-of-the-art physics techniques practically!!

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45

Marsch, Eckart, and Yasuhito Narita. "A New Route to Symmetries through the Extended Dirac Equation." Symmetry 15, no. 2 (February 13, 2023): 492. http://dx.doi.org/10.3390/sym15020492.

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A new route to the Dirac equation and its symmetries is outlined on the basis of the four-vector representation of the Lorentz group (LG). This way permits one to linearize the first Casimir operator of the LG in terms of the energy–momentum four-vector and enables one to derive an extended Dirac equation that naturally reveals the SU(2) symmetry in connection with an isospin associated with the LG. The procedure gives a spin-one-half fermion doublet, which we interpret as the electron and neutrino or the up-and-down quark doublet. Similarly, the second Casimir operator can be linearized by invoking an abstract isospin that is not connected with the LG, but with the two basic empirical fermion types. Application of the spinor helicity formalism yields two independent singlet and triplet fermion states—which we interpret as being related to U(1) and the lepton, respectively—to the SU(3) symmetry group of the three colors of the quarks. The way in which we obtain these results indicates the genuine yet very different physical natures of these basic symmetries. This new notion does not need the idea of grand unification. However, by still combining them in the product group SU(4)=SU(3)⊗U(1) and then further combining all groups into SU(2)⊗SU(4), one may get a symmetry scheme that perhaps supports the notion of unification by the group SU(8). We also argue that the simpler SO(4) group—instead of SU(4)—seems more appropriate for achieving unification.

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Bayot, Ingrid. "Comment être une grand-mère acceptable ?" Spirale N° 100, no. 4 (May 10, 2022): 85–88. http://dx.doi.org/10.3917/spi.100.0085.

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Nos enfants deviennent adultes et créent, avec leur conjoint ou conjointe, leur propre entité familiale, chacune avec ses codes, ses habitudes, ses manières de materner, d’éduquer le enfants. Ces petites personnes, qui parfois ressemblent tant à leurs parents, n’en sont pourtant pas la répétition. Les repères sont bousculés par la créativité de la vie. Quand un remariage apporte d’autres « petits-enfants » à fréquenter, il y a de nouvelles relations à tisser en même temps qu’avec les beaux-enfants. Il faut donc du temps, des vécus communs, tout ce qui tisse, fil par fil, ce quelque chose entre humains qui s’appelle une relation… quel que soit l’âge civil des humains rencontrés.

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Golse, Bernard. "Petit enfant deviendra grand, si ses parents." Spirale N° 73, no. 1 (2015): 136. http://dx.doi.org/10.3917/spi.073.0136.

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Tang, Man-Chung, Dennis J. Jang, and Kookjoon Ahn. "Seohae Grand Bridge." Transportation Research Record: Journal of the Transportation Research Board 1696, no. 1 (January 2000): 273–85. http://dx.doi.org/10.3141/1696-28.

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The Seohae Grand Bridge, located about 65 km south of Seoul, Korea, is currently under construction and, when complete, will be the longest bridge in Korea. The total length of the bridge is 9.4 km from Pyongtaek on the north to Dangjin on the south, carrying three lanes of traffic in each direction across the Asan Bay. The center span provides a 62-m-high navigation clearance above the high sea level of +4.65 m. The main bridge is composed of three cable-stayed spans of 200, 470, and 200 m and two 60-m-long side spans, one at each end. The center span will form the entrance to the harbor and will be built in the future. The bridge deck is supported by two longitudinal steel edge girders that are spaced 34 m apart and by transverse steel floor beams at 4.10 m on centers. The majority of the bridge deck is composed of precast panels and cast-in-place joints. The bridge superstructure is restrained in the transverse direction at the two pylons and end piers. The bridge longitudinal displacement due to live load, temperature variation, and creepshrinkage is restrained at one pylon with longitudinal shear keys. Lockup devices are installed on the other pylon and are mobilized only for longitudinal earthquake loading.

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Dequiré, Anne-Françoise. "Quand les minutes de silence au collège font grand bruit." Spirale - Revue de recherches en éducation N° 67, no. 1 (2021): 127. http://dx.doi.org/10.3917/spir.067.0127.

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Ibáñez, Margarita, Martin Iriondo, and Pilar Poo. "Attachement et compétences relationnelles chez le grand prématuré." Spirale 37, no. 1 (2006): 115. http://dx.doi.org/10.3917/spi.037.0115.

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Journal articles on the topic 'Grand spin'

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