302 research outputs found
Numerical modeling for the evaluation of grout penetration in fractured rock masses
Grouting aims to reduce the permeability of rock mass below the required value and has been widely used in rock engineering field for a long time
The integrated prediction system for geological conditions ahead of tunnel faces
It is essential to employ the observational design and construction method to manage tunnel projects efficiently
Development of superconducting conductors for Large Helical Device
The superconducting helical coils of the Large Helical Device (LHD) require superconducting conductors with large current capacities (from 20 kA to 30 kA) and high current densities (55 A/mm2 at 8 T). An NbTi superconductor/bin with pool boiling is being used because of the large electromagnetic force and the complicated helical windings. Several conductors are designed to show how the difference of the position of pure aluminum in the conductors affects the stability and the mechanical properties. Scaled-down R&D conductors with operational currents from 7 kA to 10 kA were made on an experimental basis. The superconducting characteristics, stability, and mechanical properties of these scaled-down conductors were tested. The design and the test results concerning the superconducting characteristics are describe
Ferrimagnetic and Long Period Antiferromagnetic Phases in High Spin Heisenberg Chains with D-Modulation
The ground state properties of the high spin Heisenberg chains with
alternating single site anisotropy are investigated by means of the numerical
exact daigonaization and DMRG method. It is found that the ferrimagnetic state
appears between the Haldane phase and period doubled N\'eel phase for the
integer spin chains. On the other hand, the transition from the
Tomonaga-Luttinger liquid state into the ferrimagnetic state takes place for
the half-odd-integer spin chains. In the ferrimagnetic phase, the spontaneous
magnetization varies continuously with the modulation amplitude of the single
site anisotropy. Eventually, the magnetization is locked to fractional values
of the saturated magnetization. These fractional values satisfy the
Oshikawa-Yamanaka-Affleck condition. The local spin profile is calculated to
reveal the physical nature of each state. In contrast to the case of
frustration induced ferrimagnetism, no incommensurate magnetic superstructure
is found.Comment: 5 pages, 7 figure
Dependence of Heat Transfer from a Large Cu Plate to Liquid Helium on Surface Treatment and Orientation
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