background: radiosurgery is a focal brain irradiation technique that delivers, usually in a single session, high dose of ionizing radiation. the presence of lateral electronic disequilibrium and steep dose gradients in small fields demands special attention to the selection of a suitable detector with respect to its size, composition and response. materials and methods : small circular fields w...

Equatorial/axial conversion in piperidine and phosphorinane with different substituents wereinvestigated with great details. Three possible routes, i.e. heteroatom inversion and two ring inversiontype were considered. Ring conversion can occur via two pathways one starts with ring flatteningfrom the heteroatom site (nitrogen in piperidine and phosphorous in phosphorinane) and the otherinitiates...

The development of several fluid mechanics applications lead to inverse problems. Given a required distribution of flow variables one has to find the corresponding geometry which provides such distribution. Since the flow governing equations do not allow explicit inversion, iterative methods are used. A linear auxiliary equation, which is a simplified model of the flow governing equations, can ...

the application of energy absorbing systems in the structures are one of the main methods in attenuation of earthquake effects. in this paper, the vibration control of structures by using of tube inversion systems is considered. in this novel system, the energy is dissipated by the inversion of a metal tube. this energy dissipater has large energy absorbing capacity along with constant stiffnes...

In the present paper, the expressions for scalar and vector potentials in lossless isotropic chiral media are analyzed. Propagating eigenvalues of these potentials are then obtained. Furthermore by decomposition of sources and fields in a chiral medium, we introduce the auxiliary right-and left-handed potentials and find the associated fields. These potentials are used to solve the problem of a...

this paper presents results of applying a new approach on 2d inversion of magnetotelluric (mt) data in order to enhance resolution and stability of the inversion results. due to non-linearity and limited coverage of data acquisition in an mt field campaign, minimizing the error by linearization of the problem in least squares inversion usually leads to an ill-posed problem. in general, an inver...