Integral Transforms for Conformal Field Theories with a Boundary

A new method is developed for solving the conformally invariant integrals that arise in conformal field theories with a boundary. The presence of a boundary makes previous techniques for theories without a boundary less suitable. The method makes essential use of an invertible integral transform, related to the radon transform, involving integration over planes parallel to the boundary. For successful application of this method several nontrivial hypergeometric function relations are also derived.Comment: 20 pagess, LateX fil

Anomalous thermal conductivity of NaV2O5 as compared to conventional spin-Peierls system CuGeO3

A huge increase of thermal conductivity k is observed at the phase transition in stoichiometric NaV2O5. This anomaly decreases and gradually disappears with deviation from stoichiometry in Na(1-x}V2O5 (x = 0.01, 0.02, 0.03, and 0.04). This behavior is compared with that of pure and Zn-doped CuGeO3 where only modest kinks in the k(T) curves are observed at the spin-Peierls transition. The change of k at critical temperature Tc could be partially attributed to the opening of an energy gap in the magnetic excitation spectrum excluding the scattering of thermal phonons on spin fluctuations. However, the reason for such a strong anomaly in the k(T) may lie not only in the different energy scales of CuGeO3 and NaV2O5, but also in the different character of the phase transition in NaV2O5 which can have largely a structural origin, e.g. connected with the charge ordering.Comment: PostScript 4 pages, 4 PostScript pictures. Submitted to Physical Review Letter

O(1/N_f) Corrections to the Thirring Model in 2<d<4

The Thirring model, that is, a relativistic field theory of fermions with a contact interaction between vector currents, is studied for dimensionalities 2<d<4 using the 1/N_f expansion, where N_f is the number of fermion species. The model is found to have no ultraviolet divergences at leading order provided a regularization respecting current conservation is used. Explicit O(1/N_f) corrections are computed, and the model shown to be renormalizable at this order in the massless limit; renormalizability appears to hold to all orders due to a special case of Weinberg's theorem. This implies there is a universal amplitude for four particle scattering in the asymptotic regime. Comparisons are made with both the Gross-Neveu model and QED.Comment: 22 pages in plain TeX, with 7 figs included using psfig.tex (Minor conceptual changes - algebra unaffected

УНИВЕРСАЛЬНЫЙ ВЕНТИЛЬНЫЙ РЕАКТИВНЫЙ ДВИГАТЕЛЬ С ПОСЛЕДОВАТЕЛЬНЫМ КОММУТАЦИОННЫМ БУФЕРОМ

In this paper, a power-supply circuit for a multipurpose switched reluctance motor with a series commutation buffer is presented. It is shown that a series buffer improves output characteristics of multipurpose switched reluctance motors under supply from a single-phase circuit and also lifts necessity of switching capacitors according to the motor power supply modes.В статье предложена схема питания универсального вентильного реактивного двигателя с последовательным коммутационным буфером. Показано, что использование последовательного коммутационного буфера улучшает выходные характеристики универсальных вентильных реактивных двигателей при питании от сети однофазного переменного тока, а так же устраняет необходимость переключения емкостей в зависимости от режима питания двигателя.У статті запропонована схема живлення універсального вентильного реактивного двигуна з послідовним комутаційним буфером. Показано, що використання послідовного комутаційного буфера покращує вихідні характеристики універсальних вентильних реактивних двигунів при живленні від мережі однофазного змінного струму, а також усуває необхідність переключення ємностей в залежності від режиму живлення двигуна

Relationships of nosological form of the primary and second neoplasms in oncological patients

ЗЛОКАЧЕСТВЕННЫЕ НОВООБРАЗОВАНИЯНОЗОЛОГИЧЕСКИЕ ФОРМЫ РАКАЗАБОЛЕВАЕМОСТЬ, ЧАСТОТА СЛУЧАЕВУКРАИНАЦель. Исследование зависимости между нозологическими формами первых и вторых раков у пациентов, которые проходили специальное лечение по поводу онкологического заболевания и у которых возникли вторые раки через 3 года и более после окончания лечения. Материал и методы. В исследовании проводилось сравнение между нозологической структурой вторых раков, которые возникли у 203 пациентов, проходивших лечение по поводу онкологической патологии, и официальными данными об удельном весе 10 основных нозологических форм злокачественных новообразований населения Украины. Статистическая значимость полученных результатов оценивалась с помощью доверительных интервалов, нормированных с учетом специфики контингента пациентов клиники, где проводилось исследование. Результаты. В соответствии с удельным весом нозологических форм первых раков, обусловленных, в первую очередь, специализацией клиники, обследуемые группы пациентов были разделены на 5 нозологических подгрупп: пациенты с раком молочной железы, щитовидной железы, тела матки, шейки матки, рак яичников и с иными формами рака. Для каждой из подгрупп была исследована нозологическая структура вторых раков и сопоставлена с общей структурой злокачественных новообразований по данным официальной статистики. Показано, что частота пяти выделенных нозологических форм, рассчитанных для клиники, достаточно хорошо соответствует популяционному среднему, при этом для двух наиболее представительных нозологических форм соответствие находится в пределах ожидаемой стохастической изменчивости. Таким образом, показано, что не существует статистически значимых различий между процентным составом 10 основных нозологических форм рака населения Украины и структурой нозологических форм вторых раков у исследуемой группы пациентов. Заключение. Нозологическая форма вторых раков не является следствием первого рака, а воспроизводит общую нозологическую структуру заболеваемости злокачественными новообразованиями.Objective. To investigate the relationship between nosological forms of the primary and second neoplasms in patients who have undergone special treatment for cancer, and who have developed second neoplasms three and more years after the end of treatment. Methods. The study has compared the nosological structure of second neoplasms that developed in 203 patients undergoing treatment for oncological pathology with the official data on the specific weight of 10 major nosological forms of malignant neoplasms in Ukraine. The statistical significance of the obtained results has been estimated using confidence intervals normalized taking into account the specificity of the patients of the clinic where the study was conducted. Results. In accordance with the specific weight of the nosological forms of the primary neoplasms, conditioned first by the specialization of the clinic, the study groups were divided into 5 nosological subgroups: patients with breast, thyroid, uterine, cervical, ovarian, and subgroup with other forms of cancer. For each of the subgroups, the nosological structure of the second neoplasms was investigated and compared with the overall structure of malignant neoplasms according to the official statistics. It is shown that the frequencies of five allocated nosological forms calculated for the clinic correspond fairly well to the population mean, while for two most representative nosological forms the correspondence is within the expected stochastic variability. Thus, it has been demonstrated that there are no statistically significant differences between the percentage composition of 10 major nosological forms of cancer in Ukraine and the structure of nosological forms of second neoplasms in the study group of patients. Conclusions. The nosological form of second neoplasms is not a consequence of the primary cancer, but reproduces the overall nosological structure of the incidence of malignant neoplasms

High frequency ESR investigation on dynamical charge disproportionation and spin gap excitation in NaV_2O_5

A significant frequency dependence of the ESR line width is found in NaV_2O_5 between 34-100 K and the line width increases as the resonance frequency is increased from 95 GHz to 760 GHz. The observed frequency dependence is qualitatively explained in terms of the dynamical charge disproportionation. The present results show the essential role of the internal charge degree of freedom in a V-O-V bond. We have also proposed the existence of the Dzyaloshinsky-Moriya interaction in the low temperature charge ordered phase considering the breaking of the selection rule of ESR realized as the direct observation of the spin gap excitation.Comment: 9 figures submitted to J. Phys.Soc. Jp

Solution combustion synthesis of α-Al2O3 using urea

The processes involved in the solution combustion synthesis of α-Al2O3 using urea as an organic fuel were investigated. The data describing the influence of the relative urea content on the characteristic features of the combustion process, the crystalline structure and the morphology of the aluminium oxide are presented herein. Our data demonstrate that the combustion of stable aluminium nitrate and urea complexes leads to the formation of α-alumina at temperatures of approximately 600-800 °C. Our results, obtained using differential thermal analysis and IR spectroscopy methods, reveal that the low-temperature formation of α-alumina is associated with the thermal decomposition of an α-AlO(OH) intermediate, which was crystallised in the crystal structure of the diaspore. © 2012 Elsevier Ltd and Techna Group S.r.l

Influence of helicity on scaling regimes in the extended Kraichnan model

We have investigated the advection of a passive scalar quantity by incompressible helical turbulent flow in the frame of extended Kraichnan model. Turbulent fluctuations of velocity field are assumed to have the Gaussian statistics with zero mean and defined noise with finite time-correlation. Actual calculations have been done up to two-loop approximation in the frame of field-theoretic renormalization group approach. It turned out that space parity violation (helicity) of turbulent environment does not affect anomalous scaling which is peculiar attribute of corresponding model without helicity. However, stability of asymptotic regimes, where anomalous scaling takes place, strongly depends on the amount of helicity. Moreover, helicity gives rise to the turbulent diffusivity, which has been calculated in one-loop approximation.Comment: 16 pages, talk given by M. Hnatich at "Renormalization Group 2005", Helsinki, Finland 30 August - 3 September 2005. To apear in J. Phys. A: Math. Ge

Gravitational Couplings of Intrinsic Spin

The gravitational couplings of intrinsic spin are briefly reviewed. A consequence of the Dirac equation in the exterior gravitational field of a rotating mass is considered in detail, namely, the difference in the energy of a spin-1/2 particle polarized vertically up and down near the surface of a rotating body is $\hbar\Omega\sin\theta$. Here $\theta$ is the latitude and $\Omega = 2GJ/(c^2 R^3)$, where $J$ and $R$ are, respectively, the angular momentum and radius of the body. It seems that this relativistic quantum gravitational effect could be measurable in the foreseeable future.Comment: LaTeX file, no figures, 16 page

Stratification of the orbit space in gauge theories. The role of nongeneric strata

Gauge theory is a theory with constraints and, for that reason, the space of physical states is not a manifold but a stratified space (orbifold) with singularities. The classification of strata for smooth (and generalized) connections is reviewed as well as the formulation of the physical space as the zero set of a momentum map. Several important features of nongeneric strata are discussed and new results are presented suggesting an important role for these strata as concentrators of the measure in ground state functionals and as a source of multiple structures in low-lying excitations.Comment: 22 pages Latex, 1 figur