44 research outputs found
Анализ эффективности зарезки боковых стволов на скважинах Катыльгинского нефтегазового месторождения (Томская область)
Работа посвящена анализу эффективности зарезки боковых стволов как самому эффективному методу по увеличению нефтеотдачи на Катыльгинском месторождении и рекомендована к применению в дальнейшем. В paбoте пpиведены cведения o геoлoгo-физичеcкoй и геoлoгo-пpoмыcлoвoй хapaктеpиcтике меcтopoждения, aнaлиз paзpaбoтки меcтopoждения, пoкaзaтели текущегo cocтoяния paзpaбoтки и востоновления скважин разными методами. Пpедcтaвленa cтpуктуpa фoндa cквaжин, oбopудoвaнных электpoцентpoбежными нacocaми. Пpoделанные paбoты пoкaзaли, чтo внедpение данного метода (закрезки боковых стволов) пoзвoляет увеличить дoбычу нефти из бездействующих скважин пpи cнижении ее cебеcтoимocти.The work is devoted to the analysis of the effectiveness of sidetracking as the most effective method for increasing oil recovery at the Katylginskoye field and is recommended for use in the future. The work contains information on the geological, physical, and geochemical properties of the site, the analysis of the location of the site, the indicators of the current state of the development and the development of wells in various ways. The structure of the wells is presented, which are equipped with electric centrifugal pumps. The completed works showed that the introduction of this method (sidetracking) allows increasing the oil output from idle wells while reducing its self-sufficiency
Sputtering yields exceeding 1000 by 80keV Xe irradiation of Au nanorods
Using experiments and computer simulations, we find that 80 keV Xe ion irradiation of Au nanorods can produce sputtering yields exceeding 1000, which to our knowledge are the highest yields reported for sputtering by single ions in the nuclear collision regime. This value is enhanced by more than an order of magnitude compared to the same irradiation of flat Au surfaces. Using MD simulations, we show that the very high yield can be understood as a combination of enhanced yields due to low incoming angles at the sides of the nanowire, as well as the high surface-to-volume ratio causing enhanced explosive sputtering from heat spikes. We also find, both in experiments and simulations, that channeling has a strong effect on the sputtering yield: if the incoming beam happens to be aligned with a crystal axis of the nanorod, the yield can decrease to about 100
Notes on entropic characteristics of quantum channels
One of most important issues in quantum information theory concerns
transmission of information through noisy quantum channels. We discuss few
channel characteristics expressed by means of generalized entropies. Such
characteristics can often be dealt in line with more usual treatment based on
the von Neumann entropies. For any channel, we show that the -average output
entropy of degree is bounded from above by the -entropy of the
input density matrix. Concavity properties of the -entropy exchange are
considered. Fano type quantum bounds on the -entropy exchange are
derived. We also give upper bounds on the map -entropies in terms of the
output entropy, corresponding to the completely mixed input.Comment: 10 pages, no figures. The statement of Proposition 1 is explicitly
illustrated with the depolarizing channel. The bibliography is extended and
updated. More explanations. To be published in Cent. Eur. J. Phy
Spatial representation for navigation in animats
This article considers the problem of spatial representation for animat navigation systems. It is proposed that the global navigation task, or "wayfinding, " is best supported by multiple interacting subsystems, each of which builds its own partial representation of relevant world knowledge. Evidence from the study of animal navigation is reviewed to demonstrate that similar principles underlie the wayfinding behavior of animals, including humans. A simulated wayfinding system is described that embodies and illustrates several of the themes identified with animat navigation. This system constructs a network of partial models of the quantitative spatial relations between groups of salient landmarks. Navigation tasks are solved by propagating egocentric view information through this network, using a simple but effective heuristic to arbitrate between multiple solutions
Galaxy bulges and their massive black holes: a review
With references to both key and oft-forgotten pioneering works, this article
starts by presenting a review into how we came to believe in the existence of
massive black holes at the centres of galaxies. It then presents the historical
development of the near-linear (black hole)-(host spheroid) mass relation,
before explaining why this has recently been dramatically revised. Past
disagreement over the slope of the (black hole)-(velocity dispersion) relation
is also explained, and the discovery of sub-structure within the (black
hole)-(velocity dispersion) diagram is discussed. As the search for the
fundamental connection between massive black holes and their host galaxies
continues, the competing array of additional black hole mass scaling relations
for samples of predominantly inactive galaxies are presented.Comment: Invited (15 Feb. 2014) review article (submitted 16 Nov. 2014). 590
references, 9 figures, 25 pages in emulateApJ format. To appear in "Galactic
Bulges", E. Laurikainen, R.F. Peletier, and D.A. Gadotti (eds.), Springer
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Mathematical modeling of heat transfer in Pu-238 ion exchange columns
The safety of increased Pu-238 loading on the larger ion exchange columns to be installed in the H-Canyon Frames was examined from the standpoint of the temperature increase of a fully-loaded column, following a flow interruption. A mathematical model incorporating self-heating and resin degradation was developed. Transient temperature profiles generated by this model indicate that the column loading limits may be safely scaled up in proportion to the column diameters. This model was also used to demonstrate that a short agitation period following an incomplete product elution step will appreciably decrease the maximum temperature rise of the resin bed