The Coincidence Limit of the Graviton Propagator in de Donder Gauge on de Sitter Background

We explicitly work out the de Sitter breaking contributions to the recent solution for the de Donder gauge graviton propagator on de Sitter. We also provide explicit power series expansions for the two structure functions, which are suitable for implementing dimensional regularization. And we evaluate the coincidence limit of the propagator.Comment: 41 pages, uses LaTeX 2e, version 2 has some typoes correcte

Vacuum energy induced by an impenetrable flux tube of finite radius

We consider the effect of the magnetic field background in the form of a tube of the finite transverse size on the vacuum of the quantized charged massive scalar field which is subject to the Dirichlet boundary condition at the edge of the tube. The vacuum energy is induced, being periodic in the value of the magnetic flux enclosed in the tube. Our previous study in J. Phys. A: Vol.43, 175401 (2010) is extended to the case of smaller radius of the tube and larger distances from it. The dependence of the vacuum energy density on the distance from the tube and on the coupling to the space-time curvature scalar is comprehensively analyzed.Comment: 11 pages, 8 figures, journal version, abstract extended. arXiv admin note: substantial text overlap with arXiv:0911.287

Core acid treatment influence on well reservoir properties in Kazan oil-gas condensate field

The research involves investigation of the influence of hydrochloric acid (HCI-12%) and mud acid ( mixture: HCl - 10 % and HF - 3 %) treatment on the Upper-Jurassic reservoir properties in Kazan oil-gas condensate field wells. The sample collection included three lots of core cylinders from one and the same depth (all in all 42). Two lots of core cylinders were distributed as following: first lot - reservoir properties were determined, and, then thin sections were cut off from cylinder faces; second lot- core cylinders were exposed to hydrochloric acid treatment, then, after flushing the reservoir properties were determined, and thin sections were prepared. Based on the quantitative petrographic rock analysis, involvin 42 thin sections, the following factors were determined: granulometric mineral composition, cement content, intergranular contacts and pore space structure. According to the comparative analysis of initial samples, the following was determined: content decrease of feldspar, clay and mica fragments, mica, clay and carbonate cement; increase of pore spaces while in the investigated samples- on exposure of rocks to acids effective porosity and permeability value range is ambiguous

Properties of resistive hydrogen sensors as a function of additives of 3d-metals introduced in the volume of thin nanocrystalline SnO2 films

Analysis of the results of studying electrical and gas sensitive characteristics of the molecular hydrogen sensors based on thin nanocrystalline SnO2 films coated with dispersed Au layers and containing Au+Ni and Au+Co impurities in the bulk showed that the characteristics of these sensors are more stable under the prolonged exposure to hydrogen in comparison with Au/SnO2:Sb, Au films modified only with gold. It has been found that introduction of the nickel and cobalt additives increases the band bending at the grain boundaries of tin dioxide already in freshly prepared samples, which indicates an increase in the density Ni of the chemisorbed oxygen. It is important that during testing, the band bending eφs at the grain boundaries of tin dioxide additionally slightly increases. It can be assumed that during crystallization of films under thermal annealing, the 3d-metal atoms in the SnO2 volume partially segregate on the surface of microcrystals and form bonds with lattice oxygen, the superstoichiometric tin atoms are formed, and the density Ni increases. If the bonds of oxygen with nickel and cobalt are stronger than those with tin, then, under the prolonged tests, atomic hydrogen will be oxidized not by lattice oxygen, but mainly by the chemisorbed one. In this case, stability of the sensors’ characteristics increases

Effect of oxygen on the electrical conductivity of Pt-contacted α-Ga2O2/ε(κ)-Ga2O3 MSM structures on patterned sapphire substrates

Electrical conductivity and gas sensitivity of α-Ga2O2/ ε(κ)-Ga2O3 structures were measured for oxygen concentrations ranging from 2 % to 100 % and temperatures ranging from 25 °C to 220 °C. It was found that the oxygen sensitivity of the structures depended on the donor dopant concentration. The alpha -Ga _{2}O_{3}/arepsilon ( kappa )-Ga 2 O 3 structures doped with sim 1.5 imes 10^{17} cm −3 of Sn showed high sensitivity to O 2 in the temperature range from 180 °C to 220 °C and at the bias voltage below 7.5 V. This effect can be attributed to the chemisorption of oxygen molecules on the surface of structures, which reduces energy barriers between ε(κ)-Ga2O3 grains

Using forecasting as part of the system of decision support for optimization of plant processes

У статті виконаний аналіз прогнозування як важливого елементу системи підтримки і прийняття рішень. Відмічено, що період оперативного прогнозування тісно пов'язаний з організацією передачі інформації про поїзди. Вказано, що для чіткого обліку даних і достовірності отриманих результатів в оперативному прогнозі, інформація про елементи системи, що становлять, повинна поступати на станцію не пізніше за початок періоду прогнозування. Встановлена актуальність використання прогнозування для оптимізації роботи станційних процесів в сучасній роботі залізничного транспорту.В статье выполнен анализ прогнозирования как важного элемента системы поддержки и принятия решений. В ходе изучения проблематики исследования в качестве основного критерия поиска решения в транспортных задачах выявлено создание и внедрение систем поддержки и принятия решений, и прогнозирование объема работы станций в свою очередь является важным элементом на станционном уровне. Информация, как основа прогнозирования, определяет качество прогноза и обладает рядом качественных характеристик. Отмечено, что период оперативного прогнозирования тесно связан с организацией передачи информации о поездах. Указано, что для четкого учета данных и достоверности полученных результатов в оперативном прогнозе, информация о составляющих элементах системы должна поступать на станцию не позднее начала периода прогнозирования. Установлена актуальность использования прогнозирования для оптимизации работы станционных про- цессов в современной работе железнодорожного транспорта.In this paper the analysis of forecasting as an important element on support systems and decision-making. In the course of studying the issues the study as the main search term solutions to the transport problems identified the creation and implementation on support systems and decision making, and forecasting the volume the work stations in turn is an important element at the plant level. Information, as a basis forecasting, determines the quality of the forecast and has a number of qualitative characteristics. It is noted that the period of operational forecasting is closely connected with the organization an information transfer trains. States that for a clear account the data and the reliability of the results in the operational forecast, information about the components of the system elements should arrive at the station no later than the beginning the projection period. Actuality use forecasting to optimize plant processes in the contemporary work on a railway transport

Sensitivity studies of beta-radiation detector based on small-crystalline scintillator ZnSe(Te)

A new large area β-detector has been designed and studied. The design includes wedge-shaped light transducers. A composite material based on a small crystalline ZnSe(Te) was applied onto the wide surface of light transducer. This design ensures optimum light collection from the large sensitive surface onto the output window of a much smaller size. An experimental specimen has been prepared, which showed a β-sensitivity Cβ=5.5 cm². The spectrograms of a ⁹⁰Sr+⁹⁰Y β-source obtained with the specimen under study make it possible to evaluate the age of the source by the ratio of low- and high-energy regions of the spectrum. Other designs are proposed for application of large-area detectors possessing wedge-shaped light transducers as elements of assembled constructions for high efficiency detectors operating under flow conditions

Interactions of a j=1j=1 boson in the 2(2j+1)2(2j+1) component theory

The amplitudes for boson-boson and fermion-boson interactions are calculated in the second order of perturbation theory in the Lobachevsky space. An essential ingredient of the used model is the Weinberg's $2(2j+1)$ component formalism for describing a particle of spin $j$, recently developed substantially. The boson-boson amplitude is then compared with the two-fermion amplitude obtained long ago by Skachkov on the ground of the hamiltonian formulation of quantum field theory on the mass hyperboloid, $p_0^2 -{\bf p}^2=M^2$, proposed by Kadyshevsky. The parametrization of the amplitudes by means of the momentum transfer in the Lobachevsky space leads to same spin structures in the expressions of $T$ matrices for the fermion and the boson cases. However, certain differences are found. Possible physical applications are discussed.Comment: REVTeX 3.0 file. 12pp. Substantially revised version of IFUNAM preprints FT-93-24, FT-93-3

Uniting cosmological epochs through the twister solution in cosmology with non-minimal coupling

We investigate dynamics of a flat FRW cosmological model with a barotropic matter and a non-minimally coupled scalar field (both canonical and phantom). In our approach we do not assume any specific form of a potential function for the scalar field and we are looking for generic scenarios of evolution. We show that dynamics of universe can be reduced to a 3-dimensional dynamical system. We have found the set of fixed points and established their character. These critical points represent all important epochs in evolution of the universe : (a) a finite scale factor singularity, (b) an inflation (rapid-roll and slow-roll), (c) a radiation domination, (d) a matter domination and (e) a quintessence era. We have shown that the inflation, the radiation and matter domination epochs are transient ones and last for a finite amount of time. The existence of the radiation domination epoch is purely the effect of a non-minimal coupling constant. We show the existence of a twister type solution wandering between all these critical points.Comment: 22 pages, 5 figs; (v2.) 27 pages, 12 figs, JCAP in pres