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