| 1. |
- Bandyopadhyay, Triparno, et al.
(författare)
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Notes on a Z′
- 2021
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Ingår i: XXIII DAE High Energy Physics Symposium - Select Proceedings. - Singapore : Springer Nature Singapore. - 1867-4941 .- 0930-8989. - 9789813344075 ; 261, s. 175-180
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Konferensbidrag (refereegranskat)abstract
- We reexamine anomaly free U(1) extensions of the standard model in the light of LHC Drell-Yan data, constraints from unitarity, and neutrino-electron scattering to put model-independent bounds in the parameter space populated by MZ′, the Z- Z′ mixing angle (αz ), and the extra U(1) effective gauge coupling (gx′ ). We propose a formalism where any model dependence is absorbed into these three parameters.
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| 2. |
- Provino, Alessia, et al.
(författare)
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Stability, Crystal Chemistry, and Magnetism of U2+xN21-xB6 and Nb3-yNi20+yB6 and the Role of Uranium in the Formation of the Quaternary U2-zNbzNi21B6 and U delta Nb3-delta Ni20B6 Systems
- 2019
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Ingår i: Inorganic Chemistry. - : American Chemical Society (ACS). - 0020-1669 .- 1520-510X. ; 58:22, s. 15045-15059
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Tidskriftsartikel (refereegranskat)abstract
- We investigated the U-Ni-B and Nb-Ni-B systems to search for possible new heavy fermion compounds and superconducting materials. The formation, crystal chemistry, and physical properties of U2Ni21B6 and Nb3-yNi20+yB6 [ternary derivatives of the cubic Cr23C6-type (cF116, Fm3m)] have been studied; the formation of the hypothetical U3Ni20B6 and Nb2Ni21B6 has been disproved. U2Ni21B6 [a = 10.6701(2) angstrom] crystallizes in the ordered W2Cr21C6-type, whereas Nb3-yNi20+yB6 [a = 10.5842(1) angstrom] adopts the Mg3Ni20B6-type. Ni in U2Ni21B6 can be substituted by U, leading to the solid solution U2-xNi21+yB6 (0 <= x <= 0.3); oppositely, Nb in Nb3Ni20B6 is partially replaced by Ni, forming the solution Nb3-yNi20+yB6 (0 <= y <= 0.5), none of them reaching the limit corresponding to the hypothetically ordered U3Ni20B6 and Nb2Ni21B6. These results prompted us to investigate quaternary compounds U2-zNbzNi21B6 and U6Nb3-delta Ni20B6: strong competition in the occupancy of the 4a and 8c sites by U, Nb, and Ni atoms has been observed, with the 4a site occupied by U/Ni atoms only and the 8c site filled by U/Nb atoms only. U2Ni21B6, U2.3Ni20.7B6, and Nb3Ni20B6 are Pauli paramagnets. Interestingly, Nb2.5Ni20.5B6 shows ferromagnetism with T-c approximate to 11 K; the Curie-Weiss fit gives an effective magnetic moment of 2.78 mu(B)/Ni, suggesting that all Ni atoms in the formula unit contribute to the total magnetic moment. The M(H) data at 2 K further corroborate the ferromagnetic behavior with a saturation moment of 10 mu(B)/fu (approximate to 0.49 mu(B)/Ni). The magnetic moment of Ni at the 4a site induces a moment in all of the Ni atoms of the whole unit cell (32f and 48h sites), with all atoms ordering ferromagnetically at 11 K. Density functional theory (DFT) shows that the formation of U2Ni21B6 and Nb3Ni20B6 is energetically preferred. The various electronic states generating ferromagnetism on Nb2.5Ni20.5B6 and Pauli paramagnetism on U2Ni21B6 and Nb3Ni20B6 have been identified.
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| 3. |
- Seetharam, A., et al.
(författare)
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Estimation of node density for an energy efficient deployment scheme in wireless sensor network
- 2007
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Ingår i: 3rd IEEE/Create-Net International Conference on Communication System Software and Middleware, COMSWARE. - : IEEE. - 9781424417971 ; , s. 95-98
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Konferensbidrag (refereegranskat)abstract
- Wireless sensor network is a collection of nodes which can communicate with each other without any prior infrastructure along with the ability to collect data autonomously, effectively and robustly after being deployed in an ad-hoc fashion to monitor a given area. Since these nodes communicate in wireless sensor network one major problem often encountered in this network is obtaining an optimal balance among the number of nodes deployed, energy efficiency and lifetime. In this paper we propose an effective method to estimate the number of nodes to be deployed in a given area for a predetermined lifetime so that total energy utilization and 100% connectivity are ensured. This scheme also guarantees that during each data collection cycle, each node dissipates the requisite minimum amount of energy, which also minimizes the number of nodes required to achieve a desired network lifetime. Extensive simulations have been carried out to establish the effectiveness of the scheme.
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