Infrared catastrophe in two-quasiparticle collision integral

Relaxation of a non-equilibrium state in a disordered metal with a spin-dependent electron energy distribution is considered. The collision integral due to the electron-electron interaction is computed within the approximation of a two-quasiparticle scattering. We show that the spin-flip scattering processes with a small energy transfer may lead to the divergence of the collision integral for a quasi one-dimensional wire. This divergence is present only for a spin-dependent electron energy distribution which corresponds to the total electron spin magnetization M=0 and only for non-zero interaction in the triplet channel. In this case a non-perturbative treatment of the electron-electron interaction is needed to provide an effective infrared cut-off.Comment: 6 pages, 3 figure

Analysis of the morbidity with temporary incapacity for work among workers at the ship building and ship repairing company

Aim: To analyse the yearly morbidity with temporary in capacity among workers at the ship building and ship-repairing company as compared to norm groups after Batkis-Lekarev, previously defined values according to groups of disease - standard and registered illnesses of the population aged 18 and above in general hospitals in Varna district for the period 2004-2006. The comparative analysis for the period 2004-2006 shows that the negative tendencies in the morbidity with temporary in capacity for work have decreased during the past year. The structure of morbidity shows that the basic reasons for temporary in capacity for work of the working team as a whole are mainly diseases of the respiratory, musculo-skeletal system and diseases of the peripheral nervous system, which can be explained with the specific type of work. Special attention should be paid to the fact that the frequency of absences from work be cause of malignant growths grows double each following year. The progression of the sickness related to the peripheral nervous system, neuroses and eye diseases is similar. The presence of some of these diseases could be related directly with the working conditions.Scripta Scientifica Medica 2009; 41(2): 191-194

CONCERNING THE CLINICAL SIGNIFICANCE OF THE SYNDROME OF PSYCHIC AUTOMATISM

No abstrac

Flow and Fates of Discarded Copper in Sofia, Bulgaria, and New Haven CT, USA

In order to better understand the fate of copper following its use, the discard flows of copper were analyzed in Sofia, Bulgaria, and New Haven, CT, USA. These cities were chosen to compare discard copper generation and recovery between a city in a developed country and a city in a developing country. The comparison between these two cities can be problematic due to their different relative sizes, and generalizing the results to other cities cannot be done without some error. However, as the first study of its kind, this study provides insights into the relative copper recovery rates indifferent socioeconomic contexts. The total yearly per capita copper discards from in-use stocks in Sofia were found to be about 1.9 kg/person (for year 2003), while New Haven has total yearly per capita copper discards from in-use stocks of about 4.7kg/person (for year 2000). The associated recovery rates for copper in both cities are quite high, at about 87% in New Haven, and 97% in Sofia. The higher per capita copper discards and the lower recovery rate in New Haven is thought to be attributable to the higher average income level relative to Sofia

Advances in surface EMG signal simulation with analytical and numerical descriptions of the volume conductor

Surface electromyographic (EMG) signal modeling is important for signal interpretation, testing of processing algorithms, detection system design, and didactic purposes. Various surface EMG signal models have been proposed in the literature. In this study we focus on 1) the proposal of a method for modeling surface EMG signals by either analytical or numerical descriptions of the volume conductor for space-invariant systems, and 2) the development of advanced models of the volume conductor by numerical approaches, accurately describing not only the volume conductor geometry, as mainly done in the past, but also the conductivity tensor of the muscle tissue. For volume conductors that are space-invariant in the direction of source propagation, the surface potentials generated by any source can be computed by one-dimensional convolutions, once the volume conductor transfer function is derived (analytically or numerically). Conversely, more complex volume conductors require a complete numerical approach. In a numerical approach, the conductivity tensor of the muscle tissue should be matched with the fiber orientation. In some cases (e.g., multi-pinnate muscles) accurate description of the conductivity tensor may be very complex. A method for relating the conductivity tensor of the muscle tissue, to be used in a numerical approach, to the curve describing the muscle fibers is presented and applied to representatively investigate a bi-pinnate muscle with rectilinear and curvilinear fibers. The study thus propose an approach for surface EMG signal simulation in space invariant systems as well as new models of the volume conductor using numerical methods