Multicom onent design of rotor-stator-nozzle (RSN) propulsor on azipods

The paper offers design computation method of RSN propulsor fitted with post- swirl stator on AZIPODs. The method implemented as problem solution of non-linear optimization of objective functional with restrictions over the field of infinitely dimensional values (functions being sought for). Numerical solution of this problem is reduced to the finite dimensional problem The shape of internal and external nozzle surface, distribution of pitch, camber, width and thickness of rotor blades and post-swirl stator geometry at radius are unknown functions of RSN propulsor design. Computational accuracy was validated through CFD-aided calculation of designed propulsors. Comparative analysis with model test results was implemented as well. The AZIPOD XL propulsor concept has been developed by the present method

Network on Chip Optimization Based on Surrogate Model Assisted Evolutionary Algorithms

Network-on-Chip (NoC) design is attracting more and more attention nowadays, but there is a lack of design optimization method due to the computationally very expensive simulations of NoC. To address this problem, an algorithm, called NoC design optimization based on Gaussian process model assisted differential evolution (NDPAD), is presented. Using the surrogate model-aware evolutionary search (SMAS) framework with the tournament selection based constraint handling method, NDPAD can obtain satisfactory solutions using a limited number of expensive simulations. The evolutionary search strategies and training data selection methods are then investigated to handle integer design parameters in NoC design optimization problems. Comparison shows that comparable or even better design solutions can be obtained compared to standard EAs, and much less computation effort is needed

X-ray observations of RX J0822-4300 and Puppis-A

Based on observations with the X-ray observatories Chandra and XMM-Newton we present results from a detailed spectro-imaging and timing analysis of the central compact X-ray source RX J0822-4300 in the supernova remnant Puppis-A. The superior angular resolution of Chandra allows for the first time to pinpoint the point source nature of this object down to $0.59\pm0.01$ arcsec (FWHM) and to determine its position:{RA=$08^{\rm h}21^{\rm m}57.40^{\rm s}$, Dec=$-43^{\circ}00^{'}16.69^{''}$ (J2000)} with sub-arcsecond accuracy. Spectral fits based on Chandra and XMM-Newton data provide a tight constraint on the emission properties of RX J0822-4300. Most of its X-ray emission seems to be of thermal origin. A model spectrum consisting of two blackbody components with $T_{1}\simeq 2.6\times10^{6}$ K, $T_{2}\simeq 5.0\times10^{6}$ K and $R_{1}\simeq 3.3$ km, $R_2 \simeq 0.75$ km for the blackbody temperatures and the size of the projected emitting regions, respectively, provides the best model description of its spectrum. A search for X-ray pulsations from RX J0822-4300, revealed an interesting periodicity candidate which, if confirmed, does not support a scenario of steady spin-down.Comment: Accepted by A&A, 20 pages, 10 figures, 3 table

Jupiter's Moment of Inertia: A Possible Determination by JUNO

The moment of inertia of a giant planet reveals important information about the planet's internal density structure and this information is not identical to that contained in the gravitational moments. The forthcoming Juno mission to Jupiter might determine Jupiter's normalized moment of inertia NMoI=C/MR^2 by measuring Jupiter's pole precession and the Lense-Thirring acceleration of the spacecraft (C is the axial moment of inertia, and M and R are Jupiter's mass and mean radius, respectively). We investigate the possible range of NMoI values for Jupiter based on its measured gravitational field using a simple core/envelope model of the planet assuming that J_2 and J_4 are perfectly known and are equal to their measured values. The model suggests that for fixed values of J_2 and J_4 a range of NMOI values between 0.2629 and 0.2645 can be found. The Radau-Darwin relation gives a NMoI value that is larger than the model values by less than 1%. A low NMoI of ~ 0.236, inferred from a dynamical model (Ward & Canup, 2006, ApJ, 640, L91) is inconsistent with this range, but the range is model dependent. Although we conclude that the NMoI is tightly constrained by the gravity coefficients, a measurement of Jupiter's NMoI to a few tenths of percent by Juno could provide an important constraint on Jupiter's internal structure. We carry out a simplified assessment of the error involved in Juno's possible determination of Jupiter's NMoI.Comment: accepted for publication in Icaru

Production of unstable heavy neutrinos in proto-neutron stars

We discuss the production of a class of heavy sterile neutrinos nu(h) in proto-neutron stars. The neutrinos, of mass around 50 MeV, have a negligible mixing with the active species but relatively large dimension-5 electromagnetic couplings. In particular, a magnetic dipole moment mu approximate to 10(-6) GeV-1 implies that they are thermally produced through e(+)e(-) -> (nu) over bar (h)nu(h) in the early phase of the core collapse, whereas a heavy-light transition moment mu(tr) approximate to 10(-8) GeV-1 allows their decay nu(h) -> nu i gamma with a lifetime around 10(-3) s. This type of electromagnetic couplings has been recently proposed to explain the excess of electron-like events in baseline experiments. We show that the production and decay of these heavy neutrinos would transport energy from the central regions of the star to distances d approximate to 400 km, providing a very efficient mechanism to enhance the supernova shock front and heat the material behind it.Open Access funded by SCOAP³ - Sponsoring Consortium for Open Access Publishing in Particle Physics.This work has been supported by MINECO of Spain (FPA2013-47836, FIS2012-30926) and Consolider-IngenioMul-tidarkCSD2009-00064) and by Junta de Andalucía (FQM225, FQM101,3048)

Biodiversity of old-growth forests and its conservation in northwestern Russia

Kokoomajulkaisun viisi artikkelia käsittelevät Venäjän Karjalan Suomen vastaisen rajaseudun luonnon monimuotoisuutta ja sen suojelutarpeita. Tutkimuksissa käsitellään alueen geologiaa ja geomorfologiaa, putldiokasvi-, jäkälä-, sammal-, maksasammal- ja hyönteislajistoa sekä metsäja suoekosysteemien mosaflkkia. Alueelta löytyi lukuisia Karjalassa uhanalaisia ja Karjalalle uusia eläin- ja kasvilajeja. Myös eräät kasviyhdyskunnat olivat aiemmin Karjalassa tuntemattomia. Tutkimusten perusteella on tehty ehdotuksia Kostamuksen luonnonsuojelualueen laajentamiseksi, esitetyn Kalevala-kansallispuiston rajaukseksi sekä uusien pienten luonnonsuojelualueiden perustamiseksi. Tutkimukset osoittavat, että alueen monimuotoisuuden säilyttämiseksi tähänastiset suojelualueet ja suojelusuunnitelmat eivät ole täysin riittäviä