Critical behaviour of (2+12+1)-dimensional QED: 1/N_f-corrections in the Landau gauge

The dynamical generation of a fermion mass is studied within ($2+1$)-dimensional QED with $N$ four-component fermions in the leading and next-to-leading orders of the 1/N expansion. The analysis is carried out in the Landau gauge which is supposed to insure the gauge independence of the critical fermion flavour number, N_c. It is found that the dynamical fermion mass appears for N<N_c where N_c=3.29, that is only about $1\%$ larger than its value at leading order.Comment: (v2) Accepted for publication in PRD. Some references added. No change in results. 6 pages, 2 figures. (v1) LaTeX file with feynMF package. 6 pages, 2 figure

Monitoring of underground coal fires using thermal infrared data

The potential utility of thermal infrared and short wavelength infrared data for detecting and mapping sub-surface high temperature sources is analysed. In this study, NOAA-9 AVHRR data and Landsat-5 TM data were used to detect and map sub-surface coal fires. Brightness temperature depicted by AVHRR band 3 illustrated high thermal anomalies in the suspected area. Due to the relatively low spatial resolution of the AVHRR data, only TM data is used in detailed analysis. The short wavelength infrared sensors (bands 5 and 7) have been used to locate the positions of the most intense burning. The thermal band (band 6) has been useful in distinguishing gross thermal anomalies from the background of solar warming, The resultant surface temperature anomalies are compared to surface temperatures derived from thermal infrared aerial survey and ground measurements. Correlation of these data indicate that the relatively coarse resolution of the thermal TM data enabled the detection, delineation and quantifying of sub-surface coal fire zones. However, the capability of the short wavelength infrared bands to locate the position of the fire fronts is only preliminary. The research shows that the information gathered from the TM data could only be used as a basis for planning the detailed ground geothermal operation. The investigation also reveals the potential capability of the AVHRR band 3 to detect sub-surface high temperature sources such as coal fires

Hamiltonian anomalies of bound states in QED

The Bound State in QED is described in systematic way by means of nonlocal irreducible representations of the nonhomogeneous Poincare group and Dirac's method of quantization. As an example of application of this method we calculate triangle diagram $Para-Positronium \to \gamma\gamma$. We show that the Hamiltonian approach to Bound State in QED leads to anomaly-type contribution to creation of pair of parapositronium by two photon.Comment: 12 pages, 2 figures. Proceedings of the conference "Symmetry Methods in Physics XV", July 12-16, 2011, Dubna, Russi

Evaluation advanced lymph node dissection impact on long-term survival rate of gastric cancer patients. Journal of Education

Over a period of 2007-2011 188 stomach cancer (SC) patients have been included in the research in abdominal oncosurgical department of Odessa regional oncological dispensary. It was retrospective, one-center, nonrandomized research. Volume of lymph node dissections differed by quantity of lymph nodes to be removed. All patients were divided into three groups. Patients with D1 or D1+ lymph node dissections have been performed, totally 90 patients are included in group of historical control. The main group includes 33 patients to whom D3 lymph node dissections is executed and, finally, control group – 65 patients dissected up to the D2 volume. In all cases so-called lymph node dissections for principal reasons have been executed. The multifactorial analysis of patients survival is implemented depending on a type of a lymph node dissections, a stage of the cancer, number of involved lymph nodes, involvement of the tumoral microcirculatory net (ly is carried out, v) signs of a perinevral invasion (Nev), availability of residual tumoral tissue (R), degree of a differentiation (G). Regardless of a disease stage, SC at 60% of patients, represented with initially hematologicaly disseminated disease. 40% of SC`s had no signs of intratumoral microcirculatory net involvement even in case of more than 15 regional lymph nodes are involved. In the absence of a SC perinevral invasion appeared to be the most precise predictive marker. The conclusion is made some brand new additional53 prognostic factors could play a crucial role in more accurate patients selection for expanded lymph node dissections

The original formula for predicting the survival of gastric cancer patients undergoing surgical treatment

The purpose of this work was to find ways to predict the survival of gastric cancer patients. The study included 221 patients who were radically operated in the abdominal department of the Odessa Regional Oncology Center from 2007 to 2013. The life expectancy of this group of patients was measured in months. From the factors given in the article, only the age of the patient, the presence and invasion in neighboring organs and the number of organs resected during the operation were those factors that had a significant impact on the prognosis. A formula was obtained for the formal evaluation of the duration of patients. The results are preliminary. Conclusions. As a result of the regression analysis, a polynomial (formula) was obtained, which can be used to predict the survival of patients who underwent surgery for gastric cancer. There is a need to create clearer gradations of survival dependencies of cancer patients from different clinical and morphological situations. A mathematical apparatus with many variables can be used to create similar models for the analysis of survival in other types of pathology

The features of the vector pwm for two-section frequency converter

Статья посвящена вопросам анализа режимов работы двухсекционного преобразователя частоты (ДСПЧ) на основе двух последовательно включенных инверторов напряжения. Рассматривается вопрос реализации векторной широтно-импульсной модуляции для исследуемого преобразователя. Предложен алгоритм векторной ШИМ, позволяющий исключить необходимость компенсации 2-й и 4-й гармоник, возникающих в предложенном ранее подходе к синтезу системы управления двухсекционным преобразователем с использованием односторонних опорных сигналов в узле ШИМ.This paper deals with analysis of two-section frequency converter based on two series-connected voltage inverters operating modes. The implementation issue of the vector pulse-width modulation for analyzed convertor is considered. The presented algorithm of the vector PWM eliminates the necessity to compensate the 2nd and 4th harmonics that occurs when using traditional sinusoidal PWM with asymmetric reference signal