Superconductivity in heavily vacant diamond

Using first principle electronic structure calculations we investigated the role of substitutional doping of B, N, P, Al and vacancies (V) in diamond (X_αC_1-α). In the heavy doping regime, at about ∼1-6% doping an impurity band appears in the mid gap. Increasing further the concentration of the impurity substitution fills in the gap of the diamond host. Our first principle calculation indicates that in the case of vacancies, a clear single-band picture can be employed to write down an effective one band microscopic Hamiltonian, which can be used to further study various many-body and disorder effects in impurity band (super)conductors.     

Sensitivity analysis of the equal angle divider mechanism kinematics with the synthesis of the joint gap tolerances

Tolerance analysis of mechanical components and assemblies is a key element in the industry for improving product quality and reducing overall cost. This paper is an attempt to propose a methodology to formulate and compute the kinematic assembly variations with respect to the critical dimensions (joint clearances) by calculating the homogeneous matrix of loops with considering the transforming and rotation matrix, the tolerance sensitivities, the geometrical responses to assembly variations, and the tolerance sensitivity of mechanism for clearance in the joints in different motion phases. The analysis is performed by the systematic methodology which is extended for kinematic sensitivity and positional error analysis with published results.