Articolele autorului Cristiana Sebu
Link la profilul stiintific al lui Cristiana Sebu

Conductivity Reconstructions Using Real Data from a New Planar Electrical Impedance Device

In this paper, we present results of reconstructions using real data from a new planar electrical impedance tomography device developed at the Institut für Physik, Johannes Gutenberg Universität, Mainz, Germany. The prototype consists of a planar sensing head of circular geometry, and it was designed mainly for breast cancer detection. There are 12 large outer electrodes arranged on a ring of radius R = 4.8 cm where the external currents are injected,

Read more
A new analytic integration of the rate equation for batch dissolution of salts in the presence of Common ion

Following a recent suggestion of a new rate equation specifically for the batch dissolution of salts in solutions containing a common ion, this paper describes an analytic solution to its integration. The equation has been tested by dissolving 250 lm gypsumrock particles in water (26.7 g l-1) containing various mixtures of sodium and calcium chlorides, all at an ionic strength of 0.060 M. The model fitted the experimental curves very well and showed

Read more
Conductivity imaging with interior potential measurements

In this article, we present two reconstruction methods intended to be used for conductivity imaging with data obtained from a planar electrical impedance tomography device for breast cancer detection. The inverse problem to solve is different from the classical inverse conductivity problem. We reconstruct the electrical conductivity of a two-dimensional domain from boundary measurements of currents and interior measurements of the potential. One

Read more
A regularized solution for the inverse conductivity problem using mollifiers

In this article, we present a reconstruction method for the inverse conductivity problem suitable for smooth conductivity distributions. The inverse problem is reformulated in terms of a pair of coupled integral equations, one of which is of the first kind which we regularize using mollifier methods. An interesting feature of this method is that the kernel of this integral equation is not given, but can be modified for the choice of mollifier. We

Read more
The asymptotic behaviour of weak solutions to the forward problem of electrical impedance tomography on unbounded three-dimensional domains
A mollifier method for the inverse conductivity problem
Stable Lagrange points of large planets as possible regions where WIMPs could be sought

In this paper we show that the physical properties of the Lagrange points of large planets could provide an effective mechanism for trapping dark matter, if dark matter really exists in our solar system. Certainly, the familiar trapping mechanism of a potential well combined with some dissipative processes is not a good candidate for particles like WIMPs which are supposed to be very slippery. However, in each of the Lagrange regions, L4 and L5,

Read more
Modular decomposition of metabolic systems via null-space analysis

We describe a method by which the reactions in a metabolic system may be grouped hierarchically into sets of modules to form a metabolic reaction tree. In contrast to previous approaches, the method described here takes into account the fact that, in a viable network, reactions must be capable of sustaining a steady-state flux. In order to achieve this decomposition we introduce a new concept—the reaction correlation coefficient, f, and show that

Read more
On the resolving power of electrical impedance tomography

The resolving power of data is an essential question in most inverse problems and in many cases it can be estimated by very simple, often well known, methods. In this paper the resolving power of measurements on the boundary of a domain is estimated for Electrical Impedance Tomography. The data used are the values of a single pair of injected electric current and the corresponding induced boundary potential, together with the boundary values of the

Read more
Integral Equation Methods in Electrical Impedance Tomography