283 research outputs found
On maximal immediate extensions of valued division algebras
No full textWe show an extension theorem for strictly contracting bilinear mappings into a spherically complete valued vector space and we apply this result to prove that every maximal valued division algebra having the same characteristic as its residue division algebra is spherically complete
Detailed Chemistry Promotes Understanding of Octane Numbers and Gasoline Sensitivity
No full textDetailed kinetic models of pyrolysis and combustion of hydrocarbon fuels are now reliable tools which can aid the design of internal combustion engines required to meet the increasingly stringent pollutant formation and engine efficiency standards. The aim of this paper is to discuss and verify the potential of these kinetic models in analyzing the knock related combustion behavior of hydrocarbon fuels with particular regard to octane numbers and octane sensitivity. Detailed chemistry not only helps to explain the different reactivities of alkanes and alkenes but also the combustion behavior of hydrocarbon mixtures. A two-zone model of a spark ignition engine, coupled with the detailed chemistry of combustion processes, was developed and utilized for the predictions of octane numbers. This model explains the effect of various components on the knocking behavior of the fuel under different operating conditions and is thus a useful tool both in formulating new fuels and designing new engines
International Cooperation and Intra-Industrial Transactions
No full textThe paper examines theoretically the empirical observation or increasing levels of intra-industrial trade flows. The relationship between intra-industrial trade and consumer preferences in addition to product differentiation advanced by internationally active firms are discussed within the framework of a simple model of international trade in differentiated goods. In an international free trade scenario, ranking high in product differentiation and monopolistic market structures, the intensity of international trade activities steadily rises as the structure of consumer preferences exhibits demand pattern similarity: export and import levels rise simultaneously. Intra-industrial commodities exchanges as well as investment cross-hauling of multinational enterprises prove to be important vehicles international cooperation among nation.intra-industrial trade; consumer preferences; product differentiation; international trade; multinational enterprises
P. Biagi, E. Starnini 2016 The Origin and Spread of the Late Mesolithic Blade and Trapeze Industries in Europe: Reconsidering J. G. D. Clark’s Hypothesis Fifty Years After
No full textAlready in the late 1950s J. G. D. Clark outlined the important changes that took place at the end of the Mesolithic period in many regions of Europe, North Africa and the Near East, which led to the production of chipped stone assemblages characterized by parallel-sided blades and different types of trapezoidal arrowheads. This paper discusses the origin, chronology, eventual spread, and distribution of the new assemblages that suddenly, almost contemporaneously made their appearance in many different territories of the Old World in the light of the discoveries made during the last fifty years
The Italian Electricity Prices in Year 2025: an Agent-Based Simulation
No full textIn this paper, we build a realistic large-scale agent-based model of the Italian dayahead-electricity market based on a genetic algorithm and validated over several weeks of 2010, on the basis of exact historical data about supply, demand and network characteristics. A statistical analysis confirms that the simulator well replicates the observed prices. A future scenario for the year 2025 is then simulated, which takes into account market’s evolution and energy vectors’ price dynamics. The future electricity prices are contrasted with the ones that might arise considering also the possible (yet unlikely) construction of new nuclear power (NP) plants. It is shown that future prices will be higher than the actual ones. NP production can reduce the prices and their volatility, but the size of the impact depends on the pattern of the expected demand load, and can be negligible.Electricity market, PUN, Agent-based computational economics, Nuclear power.
The ”mind or no-mind” dilemma in agents behaving in a market
No full textABSTRACT: In computer simulation models based upon agents, what is the degree of sophistication that we have to put into the agents? Should we provide them or not with a “mind”? The answer ranges from Axelrod’s simplicity principle to the use of full BDI (Beliefs, Intentions, Desires) cognitive agents. To discuss the subject we introduce here three models: one with “no-mind ” agents that operate in an unstructured market, the second with “minded ” agents assuring some stability to an emerging unstructured market and, finally, the third with no mind agents, that show a sophisticated outcome in a structured market. No generalised results come from this presentation, but many useful doubts. RÉSUMÉ: Quel degré de complexité faut-il introduire dans un modèle de simulation fondé sur des agents? Doivent-ils disposer d'un "esprit"? Nous présentons ici trois modèles qui utilisent des agents, avec et sans "esprit", et ou les résultats obtenus sont très différents suivant la structure du marché dans lequel opèrent les agents
Shape preserving piecewise rational interpolation
No full textThis thesis was submitted for the degree of Doctor of Philosophy and was awarded by Brunel University.For abstract see full text
Siting Evaluations for the Ignitor Experimental Reactor
No full textIgnitor is a proposed compact high-magnetic field tokamak aimed at studying plasma burning conditions in Deuterium-Tritium plasmas. Localisation of this experimental reactor in Italy has seen growing attention during the last years. The determination to carry out this project in Italy has driven to taking into account several candidate sites. Recently, due to several technical reasons, it was identified a new site, the ENEL - TERNA plant in Rondissone (TO). The main positive characteristics of the ENEL - TERNA site are described. The non-site dependent accidental analysis of the machine has been recently completely re-evaluated. For instance, a new design of the machine Tritium Handling System (TRT) has brought to a reduction of the tritium inventory in Ignitor from about 6 g to about 3 g. As a consequence, many of the environmental source terms considered in previous accidental analyses have been reduced. Accidental sequences defined as DBA (Design Basis Accidents) bring to a maximum dose for the Most Exposed Individual (MEI) of the public of about 1 mSv. Also Beyond DBA (BDBA) accidents have been considered, bringing to maximum doses for MEI of about 3 mSv. All the above results show that the Ignitor machine can be effectively located in the ENEL-TERNA site, satisfying all the requirements from the environmental and safety viewpoin
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