scholarly journals The explosion energy of the type IIP supernova SN 2013fs with a confined dense circumstellar shell

2020 ◽  
Vol 494 (1) ◽  
pp. L86-L90
Author(s):  
N N Chugai

ABSTRACT The recent study of the SN 2013fs flash spectrum suggests an enormous explosion energy for SNe IIP, far beyond the possibilities of the neutrino mechanism. The issue of the explosion energy of SN 2013fs is revisited, making use of the effects of the early supernova interaction with the dense circumstellar shell. The velocity of the cold dense shell between reverse and forward shocks is inferred from the analysis of the broad He ii 4686 Å on day 2.4. This velocity, alongside other observables, provides us with an alternative energy estimate of ∼1.8 × 1051 erg for the preferred mass of ∼10 M⊙. The inferred value is within the range of neutrino-driven explosions.

2019 ◽  
Vol 2 (1) ◽  
pp. 8-16 ◽  
Author(s):  
P. A. Khlyupin ◽  
G. N. Ispulaeva

Introduction: The co-authors provide an overview of the main types of wind turbines and power generators installed into wind energy devices, as well as advanced technological solutions. The co-authors have identified the principal strengths and weaknesses of existing wind power generators, if applied as alternative energy sources. The co-authors have proven the need to develop an algorithm for the selection of a wind generator-based autonomous power supply system in the course of designing windmill farms in Russia. Methods: The co-authors have analyzed several types of wind turbines and power generators. Results and discussions: The algorithm for the selection of a wind generator-based autonomous power supply system is presented as a first approximation. Conclusion: The emerging algorithm enables designers to develop an effective wind generator-based autonomous power supply system.


Author(s):  
Mykhailo Kosmii ◽  
Vasyl. Kasiianchuk ◽  
Ruslan Zhyrak ◽  
Ivan Krykhovetskyi

The purpose of this paper is to analyze and research the legal mechanisms which make it possible to improve agroecology through the organization of cultivation of Jerusalem artichoke.Methodology. The methodology includes comprehensive analysis and generalization of available scientific, theoretical, practical and applied material and development of relevant conclusions and recommendations. During the research, the following methods of scientific cognition were used: dialectical, terminological, historical and legal, logical and normative, systemic and structural, functional, normative and dogmatic, generalization methods. Results. The process of analysis and research highlighted the possibilities of cultivating Jerusalem artichoke for improving agroecology, namely improving the ecological state of the atmosphere air and soil, preparing them for organic farming. The article contains examples of practical application of tubers of Jerusalem artichoke and herbage for the production of therapeutic and prophylactic products, alternative energy and highly efficient building materials. Scientific novelty. The study found that the authors summarized and systematized the levels of legal regulation in the field of using Jerusalem artichoke for improving agroecology, preparing soil for organic farming, in particular: the inter-sectoral level which covers the interaction of agricultural and environmental law in terms of cultivation and use of Jerusalem artichoke; the level of integrated environmental and legal regulation; level of individual resource (floristic) legal regulation; the level of environmental protection (anthropoprotection) legislation.Practical importance. The results of the study can be used in law-making and environmental protection activities related to issues of cultivating and using the Jerusalem artichoke as a means of improving agroecology.


2020 ◽  
Vol 7 (2) ◽  
pp. 72-78
Author(s):  
Adnan Al Farisi ◽  
Yopi Handoyo ◽  
Taufiqur Rokhman

The One of alternative energy that is environmentally friendly is by untilize water energy and turn it into a Microhydro power plant. Microhydro power plant usually made from utilize the waterfall with the head fell. While utilization for streams with a head small drop is not optimal yet. This is a reference to doing research on harnessing the flow of a river that has a value of head low between 0.7 m – 1.4 m with turning it into a Vortex flow (vortex). The purpose of this research is to know  the effect variation number of blade on power and efficiency in the vortex turbine. This research uses experimental methods to find current, voltage, torque and rpm using a reading instrument. The materials research vortex turbine used 6 blade, 8 blade and 10 blade with flat plate. The result showed the highest efficiency is 29,93 % with produce turbine power is 19,58 W, generated on turbine with variation 10 blade with load 3,315 kg and the capacity of water 10,14 l/s. Followed with an efficiency 24,17% and produce turbine power is 15,81 W, generated on turbine with the variation 8 blade with load 3,315 kg and the capacity of water is 10,14 l/s. The the lowest turbine efficiency 22,32% with produce tuebine power 14,60 W, generated on turbine with the variation 6 blade with load 3,315 kg, the capacity of water is 10,14 l/s.


2019 ◽  
Vol 3 (1) ◽  
pp. 1-12
Author(s):  
Lauren K. D’Souza ◽  
William L. Ascher ◽  
Tanja Srebotnjak

Native American reservations are among the most economically disadvantaged regions in the United States; lacking access to economic and educational opportunities that are exacerbated by “energy insecurity” due to insufficient connectivity to the electric grid and power outages. Local renewable energy sources such as wind, solar, and biomass offer energy alternatives but their implementation encounters barriers such as lack of financing, infrastructure, and expertise, as well as divergent attitudes among tribal leaders. Biomass, in particular, could be a source of stable base-load power that is abundant and scalable in many rural communities. This case study examines the feasibility of a biomass energy plant on the Cocopah reservation in southwestern Arizona. It considers feedstock availability, cost and energy content, technology options, nameplate capacity, discount and interest rates, construction, operation and maintenance (O&M) costs, and alternative investment options. This study finds that at current electricity prices and based on typical costs for fuel, O&M over 30 years, none of the tested scenarios is presently cost-effective on a net present value (NPV) basis when compared with an alternative investment yielding annual returns of 3% or higher. The technology most likely to be economically viable and suitable for remote, rural contexts—a combustion stoker—resulted in a levelized costs of energy (LCOE) ranging from US$0.056 to 0.147/kWh. The most favorable scenario is a combustion stoker with an estimated NPV of US$4,791,243. The NPV of the corresponding alternative investment is US$7,123,380. However, if the tribes were able to secure a zero-interest loan to finance the plant’s installation cost, the project would be on par with the alternative investment. Even if this were the case, the scenario still relies on some of the most optimistic assumptions for the biomass-to-power plant and excludes abatement costs for air emissions. The study thus concludes that at present small-scale, biomass-to-energy projects require a mix of favorable market and local conditions as well as appropriate policy support to make biomass energy projects a cost-competitive source of stable, alternative energy for remote rural tribal communities that can provide greater tribal sovereignty and economic opportunities.


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