Diagrammatic theory for Periodic Anderson Model: Stationary property of the thermodynamic potential

Diagrammatic theory for Periodic Anderson Model has been developed, supposing the Coulomb repulsion of $f-$ localized electrons as a main parameter of the theory. $f-$ electrons are strongly correlated and $c-$ conduction electrons are uncorrelated. Correlation function for $f-$ and mass operator for $c-$ electrons are determined. The Dyson equation for $c-$ and Dyson-type equation for $f-$ electrons are formulated for their propagators. The skeleton diagrams are defined for correlation function and thermodynamic functional. The stationary property of renormalized thermodynamic potential about the variation of the mass operator is established. The result is appropriate as for normal and as for superconducting state of the system.Comment: 12 pages, 10 figure

Diagrammatic theory for Anderson Impurity Model. Stationary property of the thermodynamic potential

A diagrammatic theory around atomic limit is proposed for normal state of Anderson Impurity Model. The new diagram method is based on the ordinary Wick's theorem for conduction electrons and a generalized Wick's theorem for gtrongly correlated impurity electrons. This last theorem coincides with the definition of Kubo cumulants. For the mean value of the evolution operator a linked cluster theorem is proved and a Dyson's type equations for one-particle propagators are established. The main element of these equations is the correlation function which contains the spin, charge and pairing fluctuations of the system. The thermodynamic potential of the system is expressed through one-particle renormalized Green's functions and the corelation function. The stationary property of the thermodynamic potential is established with respect to the changes of correlation function.Comment: 7 pages, 6 figures, Submitted to PR

Strong interaction of correlated electrons with phonons: Exchange of phonon clouds by polarons

We investigate the interaction of strongly correlated electrons with phonons in the frame of the Hubbard-Holstein model. The electron-phonon interaction is considered to be strong and is an important parameter of the model besides the Coulomb repulsion of electrons and band filling. This interaction with the nondispersive optical phonons has been transformed to the problem of mobile polarons by using the canonical transformation of Lang and Firsov. We discuss in particular the case for which the on-site Coulomb repulsion is exactly cancelled by the phonon-mediated attractive interaction and suggest that polarons exchanging phonon clouds can lead to polaron pairing and superconductivity. It is then the frequency of the collective mode of phonon clouds being larger than the bare frequency, which determines the superconducting transition temperature.Comment: 23 pages, Submitted to Phys. Rev.

Coronal radiation belts

The magnetic field of the solar corona has a large-scale dipole character, which maps into the bipolar field in the solar wind. Using standard representations of the coronal field, we show that high-energy ions can be trapped stably in these large-scale closed fields. The drift shells that describe the conservation of the third adiabatic invariant may have complicated geometries. Particles trapped in these zones would resemble the Van Allen Belts and could have detectable consequences. We discuss potential sources of trapped particles

THE STATE OF HYGIENE AND LOCAL IMMUNITY OF THE ORAL CAVITY IN PATIENTS WITH ANOREXIA NERVOSA

Aim: to study the state of local immunity and oral hygiene in patients with GP suffering from AN.Materials and methods: 35 patients with AN were examined at the age of 19-35 years. In the study we used immunological methods, an index assessment of the state of oral hygiene (PMA, API, GI).Results and discussion: in patients of I group poor oral hygiene was established. The amount of lysozyme in the oral fluid in I group was 0.014 ± 0.07 g/l. A decrease SIgA (11SIgA) was established in patients of I group: I, II and control (135.31 ± 23.17, 130.26 ± 24.21 and 300.34 ± 27.38 mg/l, respectively). A tendency to an increase in the level of IgG in the oral fluid in patients of group II compared with I and the control group (5.35 ± 0.36, vs. 4.57 ± 0.04 and 4.98 ± 0.23 g/l, respectively) was established.Conclusions: poor oral hygiene is an objective indicator which reflects low motivation to maintain oral health. The observed immunodeficiency (11SIgA) in patients with GP is a mirror image of changes occurring in the body of patients with AN.Aim: to study the state of local immunity and oral hygiene in patients with GP suffering from AN.Materials and methods: 35 patients with AN were examined at the age of 19-35 years. In the study we used immunological methods, an index assessment of the state of oral hygiene (PMA, API, GI).Results and discussion: in patients of I group poor oral hygiene was established. The amount of lysozyme in the oral fluid in I group was 0.014 ± 0.07 g/l. A decrease SIgA (11SIgA) was established in patients of I group: I, II and control (135.31 ± 23.17, 130.26 ± 24.21 and 300.34 ± 27.38 mg/l, respectively). A tendency to an increase in the level of IgG in the oral fluid in patients of group II compared with I and the control group (5.35 ± 0.36, vs. 4.57 ± 0.04 and 4.98 ± 0.23 g/l, respectively) was established.Conclusions: poor oral hygiene is an objective indicator which reflects low motivation to maintain oral health. The observed immunodeficiency (11SIgA) in patients with GP is a mirror image of changes occurring in the body of patients with AN

Assessment of quality and safety of pork treated with low-temperature atmospheric-pressure plasma

It is known that processing methods ensuring partial or full microbial inactivation are quite limited. Therefore, it is of great interest to develop technique and technologies allowing the effective action on microorganisms without a significant influence on product properties. The use of cold plasma can be one of the promising methods of meat product treatment by cold sterilization. The present work examines a possibility of chilled meat treatment with low-temperature atmospheric-pressure plasma to increase its stability to microbial spoilage and extend shelf life. To obtain low temperature plasma, the equipment developed by the designing department “Plasmamed” was used. Chilled meat was treated with low-temperature atmospheric-pressure argon plasma for 5, 10, 20 and 30 min. Samples were stored at a temperature of 2–4 °C for 10 days. Organoleptic indices, moisture weight fraction, changes in pH and water activity were analyzed before treatment and during storage. Sanitary microbiological analyses were carried out by the following indicators: quantity of mesophilic aerobic and facultative anaerobic microorganisms (QMAFAnM), the presence and quantity of coliforms, Salmonella, Escherichia coli, Listeria monocytogenes, Proteus. It was shown that meat cold treatment with argon plasma inhibited the development of mesophilic microorganisms. The colony forming units detected in the samples after ten days of storage were determined by the duration of exposure to plasma. It was proved that meat treatment for 15 and 30 min had the bactericidal effect and facilitated an improvement in meat color during storage. The organoleptic indices of the samples treated with plasma corresponded to the requirements of standards and approved consumer characteristics

Single-particle states in spherical Si/SiO2_2 quantum dots

We calculate ground and excited electron and hole levels in spherical Si quantum dots inside SiO$_2$ in a multiband effective mass approximation. Luttinger Hamiltonian is used for holes and the strong anisotropy of the conduction electron effective mass in Si is taken into account. As boundary conditions for electron and hole wave functions we use continuity of the wave functions and the velocity density at the boundary of the quantum dots.Comment: 8 pages, 5 figure

On the Ginzburg-Landau Analysis of the Upper Critical Field Hc2 in MgB2

Temperature dependence of the upper critical field Hc2 (T) for the superconducting magnesium diboride, MgB2, is studied in the vicinity of Tc by using a two-band Ginzburg-Landau (G-L) theory. The temperature dependence of Hc2 (T) near Tc exhibits a positive curvature. In addition, the calculated temperature dependence and its higher order derivatives are also shown to be in a good agreement with the experimental data. In analogy with the multi-band character of Eliashberg microscopic theory, the positive curvature of Hc2 (T) is described reasonably by solving the two-band of G-L theory.Comment: 14 pages, 2 figures, submitted to SUST November 200

Estimation of probiotic and vitamine d efficiency in prophylactics of infectious diseases in premature infants

The objective: to study the efficacy of probiotic and vitamin D use in prophylaxis of infectious diseases in premature infants. Materials and methods. The reseach has been conducted on the base of the Odessa National Medical University – neonatal unit of the maternity hospital N 7 (Odessa). The I group consisted of 20 premature infants (PI) who got BioGiy drops. The II group conssted of 19 PI, who got BioGiy drops and vitamin D3. Control group- 23 PI who did not get the preparations mentioned above. At birth and at the age of 3–4 months complex immunological investigation was carried out. Every month the morbidity of PI was observed. Results. PI are more likely to suffer from infectious diseases, functional disorders of the gastrointestinal tract and hypovitaminosis D. The results obtained indicate a high effectiveness of probiotic with vitamin D3 use for the prevention of infectious diseases in PI. The greatest effect was observed in the prevention of skin infections and respiratory diseases of the upper respiratory tract as a reduction of respiratory episodes frequency, acceleration of recovery and lighter course of the disease. Also, the combination of probiotic and vitamin D has proven itself as a means of preventing hypovitaminosis D in PI

Diagrammatic analysis of the Hubbard model:Stationary property of the thermodynamic potential

Diagrammatic approach proposed many years ago for strong correlated Hubbard model is developed for analyzing of the thermodynamic potential properties. The new exact relation between such renormalized quantities as thermodynamic potential, one-particle propagator and correlation function is established. This relation contains additional integration of the one-particle propagator by the auxiliary constant. The vacuum skeleton diagrams constructed from irreducible Green's functions and tunneling propagator lines are determined and special functional is introduced. The properties of such functional are investigated and its relation to the thermodynamic potential is established. The stationary properties of this functional with respect to first order changing of the correlation function is demonstrated and as a consequence the stationary properties of the thermodynamic potential is proved.Comment: 6 pages, 4 figure