Helical liquid of snake states

We derive an exact solution to the problem of spin snake states induced in a nonhomogeneous magnetic field by a combined action of the Rashba spin-orbit and Zeeman fields. In an antisymmetric magnetic field the spin snake states are nonlocal composite particles, originating from spatially separated entangled spins. Adding an external homogeneous magnetic field breaks the spin-parity symmetry gapping out the spectral branches, which results in a regular beating pattern of the spin current. These new phenomena in a helical liquid of snake states are proposed for an experimental realization.Comment: 5 pages, 3 figure

Standardization of insurance operations and risk assessment and edition of manual for recognition of management and natural disaster risks in shrimp farms, and feasibility study of insuring shrimp hatcheries

According to achieve sustainable production in shrimp farming industry, it is necessary to provide the relief of producers through insurance. Aquaculture faces various environmental conditions such as unpredictable climate changes, epidemic diseases, harsh water factors, that may affect the production cycle, and impact on producer's life. In this research, the effects of various factors on production of cultured shrimp have been studied. The project conducted through completion of questionaries by random selected of small scale farms, and all large farms which engaged in production in that years. In order to increase the accuracy of responses, special questionnaires provided to fill in by expertise experts. All data explained the share of management and natural factors on production process