19 research outputs found

    Predicting paid service adoption in a large social network

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    A comparative study of optical properties and X-ray induced luminescence of octahedral molybdenum and tungsten cluster complexes

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    © 2017 The Royal Society of Chemistry. Octahedral metal cluster complexes have high potential for biomedical applications. In order to evaluate the benefits of these moieties for combined CT/X-ray luminescence computed tomography, this paper compares photoluminescence, radiodensity and X-ray induced luminescence properties of eight related octahedral molybdenum and tungsten cluster complexes [{M 6 I 8 }L 6 ] n (where M is Mo or W and L is I - , NO 3 - , OTs - or OH - /H 2 O). This article demonstrates that despite the fact that molybdenum cluster complexes are better photoluminescence emitters, tungsten cluster complexes, in particular (Bu 4 N) 2 [{W 6 I 8 }I 6 ], demonstrate significantly higher X-ray induced luminescence due to a combination of relatively good photoluminescence properties and high X-ray attenuation. Additionally, photo-degradation of [{M 6 I 8 }(NO 3 ) 6 ] 2- was evaluated

    F2F computing as a base for network games

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    https://www.ester.ee/record=b5377950*es

    Lepton Pair Production By a High Energy Photon in a Strong Electromagnetic Field

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    Using impact--factor representation, we consider the lepton pair production by an incident high--energy photon in a strong electromagnetic field of a nucleus. By summing leading terms of perturbation series, we obtain a simple formula for the amplitude, valid to all orders in O(ffZ) and arbitrary field of the nucleus. Using these results, we derive, in a simple manner, the results for the lepton pair production by a virtual incident photon in a Coulomb field. For real incident photon our results coincide with the known ones. Also, a particular example of a non--Coulomb potential is discussed in some detail. 1 Introduction QED processes in the strong Coulomb field attracted considerable attention recently. The understanding of such processes is important for accurate background estimates in heavy ion collisions. Moreover, their analysis is also interesting from pure theoretical point of view. Indeed, the accuracy of perturbative calculations in this case is determined by a parameter..

    Pushkin, Melnikov, and Shevtsova Reply

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    A reply to the Comment by H. .C. Kuhlmann and F. H. Muldoon.Following article "Particle self-ordering in periodic flows"info:eu-repo/semantics/publishe

    Synchronization of finite-size particles by a traveling wave in a cylindrical flow

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    Motion of small finite-size particles suspended in a cylindrical thermocapillary flow with an azimuthally traveling wave is studied experimentally and numerically. At certain flow regimes the particles spontaneously align in dynamic accumulation structures (PAS) of spiral shape. We find that long-time trajectories of individual particles in this flow fall into three basic categories that can be described, borrowing the dynamical systems terminology, as the stable periodic, the quasiperiodic, and the quasistable periodic orbits. Besides these basic types of orbits, we observe the "doubled" periodic orbits and shuttle-like particle trajectories. We find that ensembles of particles having periodic orbits give rise to one-dimensional spiral PAS, while ensembles of particles having quasiperiodic orbits form two-dimensional PAS of toroidal shape. We expound the reasons why these types of orbits and the emergence of the corresponding accumulation structures should naturally be anticipated based on the phase locking theory of PAS formation. We give a further discussion of PAS features, such as the finite thickness of PAS spirals and the probable scenarios of the spiral PAS destruction. Finally, in numerical simulations of inertial particles we observe formation of the spiral structures corresponding to the 3:1 "resonance" between the particle turnover frequency and the wave oscillations frequency, thus confirming another prediction of the phase locking theory. In view of the generality of the arguments involved, we expect the importance of this structure-forming mechanism to go far beyond the realm of the laboratory-friendly thermocapillary flows. © 2013 AIP Publishing LLC.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

    Combining propensity and influence models for product adoption prediction

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    This paper studies the problem of selecting users in an online social network for targeted advertising so as to maximize the adoption of a given product. In previous work, two families of models have been considered to address this problem: direct targeting and network-based targeting. The former approach targets users with the highest propensity to adopt the product, while the latter approach targets users with the highest influence potential – that is users whose adoption is most likely to be followed by subsequent adoptions by peers. This paper proposes a hybrid approach that combines a notion of propensity and a notion of influence into a single utility function. We show that targeting a fixed number of high-utility users results in more adoptions than targeting either highly influential users or users with high propensity

    Evolution of the crater lake of Maly Semyachik volcano, Kamchatka (1965–2020)

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    Significant variations in temperature, water chemistry and volume of the lake in the crater of Maly Semyachik volcano, Kamchatka, in 1965–2020 can be divided in three main stages. The first stage, until about the mid-1980s, was characterized by intense volcanic-hydrothermal activity, high (above 40 °C) temperature, high salinity (up to 40 g/l) and an increase in the level (and volume) of the lake. During the second stage, which lasted 25–30 years, since the mid-1980s until the mid-2000s, the lake cooled down, until freezing in winter, the mineralization decreased (up to 1.6 g/l), and the volume of the lake remained almost constant. After the mid-2000s until present, there is a period of activation of the Maly Semyachik volcano, which is expressed in an increase in temperature, mineralization and a sharp increase in the volume of the crater lake. The water balance of the lake and the input and composition of the thermal acid chloride solution are estimated based on the analysis of changes in chemical and physical parameters over time, using a box model
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