Dr. Piotr Achinger of the PAS Institute of Mathematics talks about the job of a mathematician and the importance of basic research – explaining why some projects are like snakes, but others are like octopuses.
Copper slag differs by chemical composition and structure, depending on the type of processing. Copper slag typically contains about 1 wt.% copper and 40 wt.% iron depending upon the initial ore quality and type of furnace used. The aim is to produce a typical foundry pig iron with the chemical composition of C > 3.40 wt.%, Si 1.40 to 1.80 wt.%, Mn 0.30 to 0.90 wt.%, P < 0.03 wt.% and S < 0.03 wt.% from copper slag. But foundry pig iron manufactured from copper slag contains a high sulphur content. Therefore, this study examines how to conduct desulphurization. Desulphurization roasting and reduction smelting with desulphurization additives used to remove sulphur from the copper slag. The results showed that desulphurization effect of desulphurization roasting is poor but when combined with reduction smelting with CaO addition is possible to manufacture low sulphur pig iron from copper smelting slag.
The Christian laity is called to the ministry of evangelization in the Church and for the Church. In this work, basic ecclesial communities play an important role, because they are forming disciples of Christ and preparing them to bear testimony to the Gos-pel in the world. The communities have been initiated in the Church of South America and are centres of evangelization as a true expression of ecclesial communion (ChL no. 26). They also express the preferential option of the Church for the poor, because they are often created by people deprived of fair access to material goods and live on the margins of society. In the activities of basic ecclesial communities, the poor evan-gelize themselves first, feeding on the Word of God, to make it a source of inspiration for life and action. At that time, the poor are becoming subjects of evangelization, when they recognize the proclamation of the Good News of salvation as their task, not only with words but also through the testimony of life. The transmission of the Gospel occurs in interpersonal encounters in which the attitude of believers in Christ urges people to adopt Christian values and imbue in them the culture created by them.
This experimental study reveals the effects of CaF2, FeMn and NiO additions to the base fluxes on tensile strength and percentage elongation of the weld metal. The aim of this study is to develop suitable flux for mild steel for high tensile strength, impact strength and ductility. Bead on plate welds were made using submerged arc welding process. Mathematical model for percentage elongation and UTS of mild steel welds were made. The elements transfer to the welds have been correlated with the above mechanical performance characteristics. The effect of oxygen content on weld elongation and UTS also has been deduced. This study shows that CaF2 and NiO are the significant factors for tensile strength while FeMn is not significant for tensile strength. However, for elongation besides CaF2, the interaction of CaF2 and FeMn was also found significant. The effects of basicity index of the flux and carbon equivalent of the welds on tensile strength and percentage elongation of the welds have also been evaluated.
In this paper, a study of the lightning phenomenon and its harmful effect on Aqaba Thermal Power Station (ATPS), located in the south-western border of Jordan, is presented using the Electromagnetic Transients Program – Alternative Transients Program (EMTP- ATP). This study has been arisen due to an installation need of appropriate lightning arresters (LAs) for the 15/410 kV step-up transformers of the ATPS to eliminate the destructive effect of lightning. The simulation is carried out for two cases, once without using LAs and once more with using them. Two scenarios are applied for each of these cases, once when lightning strikes the primary side of the transformer and once more when it strikes the secondary side. The results obtained by the simulation indicate the necessity of LAs installation. This study, with using the EMTP-ATP program, is done for the first time with additional details that help researchers, designers, and engineers to get a broad overview of the ATPS in order to protect it against lightning.
The aim of the paper is to provide climatic data from the basic elements and characteristics of the energy balance in terms of the current state and in terms of trends and assumptions of their future changes in Slovakia. Climate change affect agriculture and its procedures. Changes in vegetation period in Slovakia of selected vegetables are presented in this study. We used for agro-climatic analysis one hundred climatological stations, which were selected to cover all agricultural re-gions up to 800 m a.s.l. Actual data and predictions were compared with time period 1961–2010. Due to homogeneity in data measurements, was chosen this period. We obtained climate trends and assumed map outputs of future climate chang-es by mathematical-statistical methods for horizons of years 2011–2020, 2041–2050, 2071–2080 and 2091–2100. We ana-lysed vegetation period changes of selected fruit vegetables, Brassica vegetables and root vegetable in field conditions with prediction to year 2100. In our results is shown the earlier beginning of vegetation period in a spring and later end in an autumn in last 30 years. The vegetation period is getting longer about 15–20 days for Capsicum annuum; 15–20 days for Brassica oleracea var. capitate; 10–15 days for Beta vulgaris subsp. vulgaris with comparation of nowadays situation and period 2091–2100.
While working on the oeuvre of P.F. Strawson (1919–2006), and especially on his metaphysics, I had a unique opportunity to exchange ideas with this eminent exponent of Oxford philosophy. Those exchanges, of which some have been reflected in private correspondence and in a published reply to one of my papers, were focussed on various interpretative questions. Three threads of those discussions seem especially pertinent for grasping the gist of Strawson’s philosophy and its general orientation. The first one concerned the nature of philosophical analysis, or to be more precise, the connective model of it, favoured by Strawson, and its relationship with the idea of concept presupposition. The second thread had to do with the position taken by the Oxford philosopher in the realism debate on three levels: semantic, epistemological, and metaphysical. Strawson made every effort to take a realist stand in this debate and avoid antirealism in any of its forms; however, his realism is in many respects very moderate and not so distant from antirealism. Similarly moderate was his stand in the traditional debate about universals, constituting the topic of the third thread of the exchanges with Strawson. He claimed that universals exist, but at the same time emphasized that they are objects of pure thought alone and as such do not form a part of the spatiotemporal world in which we live. One cannot also say much about the relation of exemplification in virtue of which universals manifest themselves in the world as particular instances. Presentation and elaboration of these three threads has led to the conclusion that although Strawson was a deeply systematic thinker, he avoided wide-ranging and ambitious statements and radical views. In characteristically minimalist way he dispelled some questions, and the ultimate resolution of many crucial and fundamental issues were for him choice and taking a particular attitude or stance.
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