Usage of experience of development of territories with similar socio-economic characteristics taken as a whole as an instrument of Kronshtadt sustainable development

This article gives an account of approach to design of sustainable regional development concept and presents the results of its usage on the Kronshtadt example. In the today?s world most of the regions are faced with a crucially important task, which is to take the way of sustainable development. There is a number of instruments, which could be successfully used in sustainable regional development concept design. One of then is a usage of experience of development of territories with similar socio-economic characteristics taken as a single whole. First of all, usage of this instrument allows to reveal economic industries that have been effectively developing in regions with similar characteristics and in the close economic conditions. Secondly, it allows to analyze measures that were taken to develop those industries and appraise their efficiency. This instrument gives an opportunity to ?learn by other people?s mistakes?. At the same time it requires to take into account internal conditions and the law-governed nature of the investigated region. Usage of this instrument could be demonstrated on Kronshtadt example. Kronshtadt is a town situated on the Kotlin Island in the Gulf of Finland, and presents an administrative district and municipal district of Saint-Petersburg. As the main socio-economic characteristics of the region were selected the following: -island territory; -favorable geographic position on the intersection of the sea and tourist routes; -naval dockyard and naval base town which lost its historic role and majority of government investments as the Cold War came to an end. The following regions were classified as territories similar to Kronshtadt according to socio-economic characteristics taken as a single whole: Kaliningrad region, Russia; Gibraltar island, Great Britain (one of the most important naval bases of Great Britain and key strong point of NATO at the Cold War time); Malta island (former English colony) and such historic naval dockyard and maritime towns as Medway/Chatham, Great Britain; Portsmouth, Great Britain; Rochefort, France; San-Fernando, Spain; Suomenlinna, Finland; Karlskrona, Sweden. The experience of development of these territories was systematized in the following directions: -most effectively developing economic industries; -projects that were financed by regional or federal government investments; -measures that were taken to attract commercial investments; -rules that were accepted to transfer the property rights on naval dockyards; -socio-economic effect from the implementation of the development programs. This article presents the results of the conducted research and provides recommendations for Kronshtadt sustainable development.

Explosion and nucleosynthesis of low redshift pair instability supernovae

Both recent observations and stellar evolution models suggest that pair-instability supernovae (PISNe) could occur in the local Universe, at metallicities below Z_Sun/3. Previous PISN models were mostly produced at very low metallicities in the context of the early Universe. We present new PISNe models at a metallicity of Z=0.001, which are relevant for the local Universe. We take the self-consistent stellar evolutionary models of pair-instability progenitors with initial masses of 150 and 250 solar masses at metallicity of Z=0.001 by Langer et al. (2007) and follow the evolution of these models through the supernova explosions, using a hydrodynamics stellar evolution code with an extensive nuclear network including 200 isotopes. Both models explode as PISNe without leaving a compact stellar remnant. Our models produce a nucleosynthetic pattern that is generally similar to that of Population III PISN models, which is mainly characterized by the production of large amounts of alpha-elements and a strong deficiency of the odd-charged elements. However, the odd-even effect in our models is significantly weaker than that found in Population III models. The comparison with the nucleosynthetic yields from core-collapse supernovae at a similar metallicity (Z=0.002) indicates that PISNe could have strongly influenced the chemical evolution below Z=0.002, assuming a standard initial mass function. The odd-even effect is predicted to be most prominent for the intermediate mass elements between silicon and calcium. With future observations of chemical abundances in Population II stars, our result can be used to constrain the number of PISNe that occurred during the past evolution of our Galaxy.Comment: 10 pages, 13 figures, 3 tables. Accepted by Astronomy & Astrophysic

How much radioactive nickel does ASASSN-15lh require?

The discovery of the most luminous supernova ASASSN-15lh triggered a shock-wave in the supernova community. The three possible mechanisms proposed for the majority of other superluminous supernovae do not produce a realistic physical model for this particular supernova. In the present study we show the limiting luminosity available from a nickel-powered pair-instability supernova. We computed a few exotic nickel-powered explosions with a total mass of nickel up to 1500 solar masses. We used the hydrostatic configurations prepared with the GENEVA and MESA codes, and the STELLA radiative-transfer code for following the explosion of these models. We show that 1500 solar masses of radioactive nickel is needed to power a luminosity of 2x10^45 erg/s. The resulting light curve is very broad and incompatible with the shorter ASASSN-15lh time-scale. This rules out a nickel-powered origin of ASASSN-15lh. In addition, we derive a simple peak luminosity - nickel mass relation from our data, which may serve to estimate of nickel mass from observed peak luminosities.Comment: accepted for publication in MNRAS Letter