Thermoelectric performance of weakly coupled granular materials

We study thermoelectric properties of inhomogeneous nanogranular materials for weak tunneling conductance between the grains, g_t < 1. We calculate the thermopower and figure of merit taking into account the shift of the chemical potential and the asymmetry of the density of states in the vicinity of the Fermi surface. We show that the weak coupling between the grains leads to a high thermopower and low thermal conductivity resulting in relatively high values of the figure of merit on the order of one. We estimate the temperature at which the figure of merit has its maximum value for two- and three-dimensional samples. Our results are applicable for many emerging materials, including artificially self-assembled nanoparticle arrays.Comment: 4 pages, 3 figure

Thermoelectric performance of granular semiconductors

We study thermoelectric properties of granular semiconductors with weak tunneling conductance between the grains, g_t < 1. We calculate the thermopower and figure of merit taking into account the shift of the chemical potential and the asymmetry of the density of states in the vicinity of the Fermi surface due to n- or p-type doping in the Efros-Shklovskii regime for temperatures less than the charging energy. We show that for weakly coupled semiconducting grains the figure of merit is optimized for grain sizes of order 5nm for typical materials and its values can be larger than one. We also study the case of compensated granular semiconductors and show that in this case the thermopower can be still finite, although two to three orders of magnitude smaller than in the uncompensated regime.Comment: 4 pages, 4 figure

Improving the accuracy of determining the character saturation reservoirs on the results of log interpretation in the oil field "K"(Tomsk region)

Log interpretation has revealed a number of factors that have a significant impact on the determination of reservoir fluid content (oil saturation factor). The presented research paper is focused on the analysis of petrophysical properties of reservoir fluids considering laboratory studies of core samples. Based on core sample analysis, data of laboratory studies have been correlated to estimates of radioactive logging and high-frequency induction logging. To determine the oil saturation factor a method which considers the effect of mixed clay on reservoir fluid saturation has been proposed

The new multipurpose neutron generator MANK

A new multi-purpose hardware-software system based on high-frequency pulsed neutron generator (MANK) is described. The main differences between this device from other devices of pulsed neutron logging (PNL) include: two probes, with each probes consists of a three epicadmium and thermal neutron counters, an variable frequency and duration of the fast neutron pulses. The device can measure the slowing-down time of neutrons, and determine the porosity of the reservoir with high sensitivity and weak influence of lithology, mineralization of the borehole and formation fluids. It is also possible the measurement of macro cross-section of thermal neutron capture (Sigma). There was completed computer (Monte-Carlo) optimization of the device, obtained a series of modeling and borehole measurements, obtained a set of interpretation charts for main parameters. Copyright 2012, Society of Petroleum Engineers

Mentoring as a Predominant Factor Affecting Well-Being of Older People

The authors of the paper studied the state of well-being of older people who retired and stop working at the company they have worked for over 20 years. The survey provided some useful insights into the problem with the reference to three samples of 10 older people from each group: 1) older people who retired and keep in touch with the previous organisation; 2) older people who retired and continue working at the company as consultants, supervisors, experts, mentors etc.; 3) older people who retired and work in another enterprise and lost the touch with the previous organisation. Retired people took part in present research by completing a questionnaire survey. A set of data was examined by being compared to reveal the state of older people’s well-being criteria predominance in the various sample groups

Simulation of neutron transport for the purpose of neutron filters optimization in the pulsed neutron logging apparatus

© 2006-2015 Asian Research Publishing Network (ARPN). Numerical modeling of thermal neutron filters, which are an integral part of the apparatus of pulsed neutron logging (PNL), has been carried out. Many models of filters were created. The neutrons slowing down and absorption processes in filters was analyzed. Optimum structure and dimensions of neutron filters was offered

Subalkalic and calc-alcalic Early-Eifelian volcanicity and related pyrite-pollymetallic mineralization in the Magnitogorsk Megazone, the Southern Urals

Until now, there is a problem of the stratigraphic position and the serial petrogenetic affiliation of the Dzhusinsky volcanic complex and the correlation of the section of the Dzhusa-Dombarovka pyrite-palevolcanic belt of the East Magnitogorsk zone (EMZ) with an similar to age section of the Tanalyk paleovolcanic uplift of the Western Magnitogorsk zone (WMZ). The urgency of this problem is justified by the fact that the Early-Eifelian South Irendyk paleovolcanic complex and the Sukrakovo subcomplex, which completes the section of the South Irendyk complex, contain the large Podolsk pyrite deposit of the Urals (Cu > Zn) type and the average barite-polymetallic East-Podolsk deposit (Zn-Cu-Pb-Ba), located in the Sukrakovo subcomplex. In the Djusa ore-bearing zone, average barite-polymetallic deposits (Dzhusinskoye and Barsuchiy Log) localized in the Dzhusinsky complex, according to our data, also is of Early-Eifelian age. The problem of the geological position of the Dzhusinsky pyrite-bearing complex is of great importance for the prognostic assessment of EMZ for pyrite mineralization. The paper is based on materials of geological survey and science studies, in which the authors took part, as well as on published and fund materials of other researchers. Geological and paleovolcanological materials were obtained by the authors in the process of creating a paleovolcanological map of the Southern Urals at a scale of 1 : 500,000 and compiling numerous more detailed maps for individual ore regions and pyrite ore fields at a scale of 1: 100,000 to 1 : 10,000. Samples for chemical analyzes were selected in Process of thematic works. The study of petrogenic, rare and rare-earth elements was carried out by methods of wet chemistry, atomic absorption, X-ray-fluorescent analysis, ICP-MS. The paper gives a brief facial and petrological-geochemical description of the Sukrakovo, Dzhusa and Lower Zingei paleovolcanic complexes and subcomplexes, provides information on the geology and composition of pyrite barite-polymetallic of East Podolsky, Dzhusinsky and Barsuchiy Log deposits and their stratigraphic position on the basis of conodont fauna materials. The Sukrakovo trachydacitic subcomplex (D2ef1ir5), containing the East-Podolsky barite-polymetallic deposit, belongs to the calc-alkaline transition to the shoshonite petrochemical series. The Dzhusa shoshonite-latite-trachyte trachyriolite complex (D2ef1dj), which contains the pyrite-barite polymetallic deposits (Dzhusinsky and Barsuchi Log), is located in the southern part of the East Magnitogorsk zone. In the middle and northern parts of the EMZ there are barren basalt-andesibasaltic Lower-Zingeisky and Irendyksky complexes of calc-alkaline series (D2ef1zg; D2ef1ir). Synchronous Early-Eifelian age of the Irendyksky Formation of the West-Magnitogorsk Zone, the Dzhusa and Lower Zingei Volcanic Complexes of the East-Magnitogorsk Zone, geodynamic reconstructions were established. The upper stratum of the Irendyk Formation WMZ, the Sukrakovo, the Dzhusa and the Lower Zingei (with the Irendyksky) complexes of the EMZ form the rear island arc, which split in the Late-Eifelian time. Dzhusa complex together with age analogs of the EMZ form a residual (split off) island arc

ЭЛЕКТРОМАГНИТНАЯ СОВМЕСТИМОСТЬ В СЕТЯХ ЭЛЕКТРОСНАБЖЕНИЯ

The authors propose engineering solutions ensuring electromagnetic compatibility of not traction power installations and electric supply networks with AC electrified railways. They take into account different characteristics of traction systems of power supply, conditioned by their respective categories.Предложены технические решения  по обеспечению электромагнитной  совместимости электроустановок  и сетей нетягового электроснабжения  с электрифицированными железными  дорогами переменного тока. При  этом учитываются особенности  функционирования тяговых систем  в зависимости от их категорийности