Field Theory reformulated without self-energy parts.Divergence-free classical electrodynamics

A manifestly gauge-invariant hamiltonian formulation of classical electrodynamics has been shown to be relativistic invariant by the construction of the adequate generators of the Poincare Lie algebra [Physica, 76, No. 3, 421-444 (1974)]. The original formulation in terms of reduced distribution functions for the particles and the fields is applied here to the case of two charges interacting through a classical electrodynamical field. On the other hand, we have been able in previous work to introduce irreversibility at the fundamental level of description [Ann. Phys., 311, 314-349 (2004)] by reformulating field theory without self-energy parts by integrating all processes associated with self-energy in a kinetic operator, while keeping the equivalence with the original description [Prog. Theor. Phys.,109, 881-909 (2003)]. In this paper, the two approaches are combined to provide a formalism that enables the use of methods of statistical physics to tackle the problem of the divergence of the self-mass. Our approach leads to expressions that are finite even for point-like charged particles: the limit of a infinite cutoff can be taken in an harmless way on self consistent equations. In order to check our theory, we recover the power dissipated by radiation in geometries where the usual mass divergence does not play a roleComment: 82 pages, submitted Annals of Physics, Interpretation revised completel

Analysis of Service Quality Management in the Materials Industry using the BCG Matrix Method

For each product or service, the area of the circle represents the value of its sales. The BCG (Boston Consulting Group) matrix thus offers a very useful map of the organization's service strengths and weaknesses, at least in terms of current profitability, as well as the likely cash flows. The criteria function concept consists of transforming the criteria function (CF) in a qualityeconomical matrix MQE. The levels of prescribing the criteria function were obtained by using a composition algorithm for three vectors:T vector – technical parameters’ vector (ti);E vector – economical parameters’ vector (ej) and P vector – weight vector (p1).quality management, services, BCG Matrix Method, materials industry

Simple relationship between the virial-route hypernetted-chain and the compressibility-route Percus--Yevick values of the fourth virial coefficient

As is well known, approximate integral equations for liquids, such as the hypernetted chain (HNC) and Percus--Yevick (PY) theories, are in general thermodynamically inconsistent in the sense that the macroscopic properties obtained from the spatial correlation functions depend on the route followed. In particular, the values of the fourth virial coefficient $B_4$ predicted by the HNC and PY approximations via the virial route differ from those obtained via the compressibility route. Despite this, it is shown in this paper that the value of $B_4$ obtained from the virial route in the HNC theory is exactly three halves the value obtained from the compressibility route in the PY theory, irrespective of the interaction potential (whether isotropic or not), the number of components, and the dimensionality of the system. This simple relationship is confirmed in one-component systems by analytical results for the one-dimensional penetrable-square-well model and the three-dimensional penetrable-sphere model, as well as by numerical results for the one-dimensional Lennard--Jones model, the one-dimensional Gaussian core model, and the three-dimensional square-well model.Comment: 8 pages; 4 figures; v2: slight change of title; proof extended to multicomponent fluid

Non-Equilibrium Time Evolution in Quantum Field Theory

The time development of equal-time correlation functions in quantum mechanics and quantum field theory is described by an exact evolution equation for generating functionals. This permits a comparison between classical and quantum evolution in non-equilibrium systems.Comment: 7 pages, LaTe

Are the energy and virial routes to thermodynamics equivalent for hard spheres?

The internal energy of hard spheres (HS) is the same as that of an ideal gas, so that the energy route to thermodynamics becomes useless. This problem can be avoided by taking an interaction potential that reduces to the HS one in certain limits. In this paper the square-shoulder (SS) potential characterized by a hard-core diameter $\sigma'$, a soft-core diameter $\sigma>\sigma'$ and a shoulder height $\epsilon$ is considered. The SS potential becomes the HS one if (i) $\epsilon\to 0$, or (ii) $\epsilon\to\infty$, or (iii) $\sigma'\to\sigma$ or (iv) $\sigma'\to 0$ and $\epsilon\to\infty$. The energy-route equation of state for the HS fluid is obtained in terms of the radial distribution function for the SS fluid by taking the limits (i) and (ii). This equation of state is shown to exhibit, in general, an artificial dependence on the diameter ratio $\sigma'/\sigma$. If furthermore the limit $\sigma'/\sigma\to 1$ is taken, the resulting equation of state for HS coincides with that obtained through the virial route. The necessary and sufficient condition to get thermodynamic consistency between both routes for arbitrary $\sigma'/\sigma$ is derived.Comment: 10 pages, 4 figures; v2: minor changes; to be published in the special issue of Molecular Physics dedicated to the Seventh Liblice Conference on the Statistical Mechanics of Liquids (Lednice, Czech Republic, June 11-16, 2006

Classical and Quantum Ensembles via Multiresolution. I. BBGKY Hierarchy

A fast and efficient numerical-analytical approach is proposed for modeling complex behaviour in the BBGKY hierarchy of kinetic equations. We construct the multiscale representation for hierarchy of reduced distribution functions in the variational approach and multiresolution decomposition in polynomial tensor algebras of high-localized states. Numerical modeling shows the creation of various internal structures from localized modes, which are related to localized or chaotic type of behaviour and the corresponding patterns (waveletons) formation. The localized pattern is a model for energy confinement state (fusion) in plasma.Comment: 5 pages, 3 figures, espcrc2.sty, Presented at IX International Workshop on Advanced Computing and Analysis Techniques in Physics Research, Section III "Simulations and Computations in Theoretical Physics and Phenomenology", ACAT 2003, December, 2003, KEK, Tsukub

Sentinel lymph node in early stage ovarian cancer; a literature review

Although sentinel lymph node mapping has been widely implemented in gynecological malignancies in order to minimize the number of unnecessary lymph node dissections and to diminish postoperative morbidity rate, little is known about ovarian cancer sentinel lymph node mapping. This article presents a literature review regarding the effectiveness, safety and benefits of this method. Sentinel lymph node detection in early stage ovarian cancer seems to be a safe and effective method, able to minimize the rate of patients submitted to unnecessary lymph node dissection. The second goal of the procedure, to minimize the risk of missing involved lymph nodes, seems also to have been achieved, most studies reporting a very small number of cases diagnosed with positive non-sentinel lymph nodes. Considering all these data we can note that this procedure is not yet included as part of the standard therapeutic protocol, so that further studies would be necessary to include it as a common therapeutic approach in the case of patients with early stage ovarian cancer

Indocyanine green utility in sentinel node detection for cervical cancer patients

With wide implementation of screening tests for the Human Papilloma Virus, the number of diagnosed cases of premalignant or early stages of cervical cancer has increased considerably. As a consequence, surgeons’ attention has focused on determining how best to limit the surgical procedure so the benefits of the procedure will not be surpassed by postoperative morbidity. In this respect, extended lymph node dissection, routinely associated so far with cervical cancer patients, has in the last decades been replaced with sentinel node detection and biopsy. Initially performed through radiocolloid injection, this method has undergone permanent changes in order to maximize its efficacy and safety. Although the laparoscopic approach had been widely used in the past, a new method has been proposed, i.e., the use of indocyanine green injection, which has yielded promising results for sentinel node detection in the early stages of cervical carcinoma. This paper reviews the literature of the most relevant studies conducted on this topic