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Bojana Radojković Bore Jegdić Jovanka Pejić Dunja Marunkić Anđela Simović Sanja Eraković Pantović 《工业材料与腐蚀》2024,75(4):444-459
The influence of welding current and nitrogen content in argon shielding gas on the resistance of the welded joint (weld metal and heat-affected zone [HAZ]) of the stainless steel X5CrNi18-10 to the formation and growth of pits was investigated. Also, the susceptibility of the welded joint to intergranular corrosion was examined. Pitting corrosion resistance indicators were determined based on anodic potentiodynamic polarization measurements in NaCl + Na2SO4 solution, while susceptibility to intergranular corrosion was determined by the potentiokinetic method with a double loop (DL EPR). SEM/EDS was used to analyze the microstructure. It has been shown that higher nitrogen content in shielding gas leads to an increase in the resistance of welded joints (weld metal and HAZ) to the pit formation. However, an improvement in the resistance to the pit formation leads to a decline in the resistance of the welded joint to pit growth. An explanation of this phenomenon is proposed. Also, it was shown that the increase of the welding current increases the susceptibility of the welded joint to intergranular corrosion, while the higher nitrogen content has no effect. 相似文献
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Dunja Šajn Gorjanc 《纺织学会志》2019,110(5):680-689
The purpose of presented research is to find out the influence of air-jet yarn from the mixture of CO/PA (50/50) and CO/PES (67/33) fibres on functionality of woven fabric in the plain weave.The first part of the study is directed to the mechanical and physical properties of air-jet yarns (16.7 tex) from CO/PA and CO/PES fibres, while the second part of the study focuses on permeability properties of fabrics with air-jet yarns in the weft. The results show that air-jet yarn in the weft direction influences on the water vapor transmission and thermal conduction increase and air permeability decrease.Incorporation of air-jet yarn in the weft direction also improves breaking extension level.The results of presented research also show that the incorporation of air-jet yarn in the weft has statistical important influence on thermal conduction, water-vapor and air permeability changes. 相似文献
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In debates about the positive effects of renewable and bioenergy projects the aspect of generating regional added value is discussed widely. But the real effects, generated by this regional added value stayed up to now on a non-measurable level. In order to expedite the calculation of these important figures, the author presents a field tested method for confidently arriving at useful values. This methodology takes into consideration the ecological, economical and social impact of a given biomass project's implementation. The model enables a comparison between the different renewable energy plants as well as between them and plants and technology of competing alternatives. Regional authorities are hereby enabled to count on a tool for confidently measuring the possible results of various bioenergy utilization technologies. With this knowledge at hand, they could then take qualified decisions towards positive effects for their region. The developed tool allows the definition of adjustable parameters, and therefore it is able to influence the regional framework regarding a more sustainable development. 相似文献
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The effect of reaction temperature, mixing speed and oxidant to catalyst volume ratio, including their interactions on the oxidative desulfurization of dibenzothiophene by using response surface methodology was studied. Hydrogen peroxide was used as oxidant and acetic acid as catalyst. The obtained model accurately predicts conversion of dibenzothiophene and the best conversion of 98.7% was observed at temperature 70°C, mixing speed of 1250 rpm and oxidant to catalyst volume ratio of 1:1. At high temperatures, a major limitation of the desulfurization process is the mass transfer and the high mixing speed is needed to achieve an efficient process. 相似文献
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The Web is a source of valuable information, but the process of collecting, organizing, and effectively utilizing the resources it contains is difficult. We describe CorpusBuilder, an approach for automatically generating Web search queries for collecting documents matching a minority concept. The concept used for this paper is that of text documents belonging to a minority natural language on the Web. Individual documents are automatically labeled as relevant or nonrelevant using a language filter, and the feedback is used to learn what query lengths and inclusion/exclusion term-selection methods are helpful for finding previously unseen documents in the target language. Our system learns to select good query terms using a variety of term scoring methods. Using odds ratio scores calculated over the documents acquired was one of the most consistently accurate query-generation methods. To reduce the number of estimated parameters, we parameterize the query length using a Gamma distribution and present empirical results with learning methods that vary the time horizon used when learning from the results of past queries. We find that our system performs well whether we initialize it with a whole document or with a handful of words elicited from a user. Experiments applying the same approach to multiple languages are also presented showing that our approach generalizes well across several languages regardless of the initial conditions. 相似文献
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U. V. Desnica B. Šantić Dunja I. Desnica M. Pavlović 《Journal of Electronic Materials》1993,22(4):403-407
Trapping and recombination of free carriers by deep level T3 has been studied. Occupancy of the level by electrons and dynamics of its filling and emptying as a function of illumination
with monoenergetic photons in 0.69–1.55 eV range has been monitored by the thermally stimulated currents method. We have found
that level T3 behaves more like a recombination center than like an ordinary electron trap. Besides trapping free electrons from conduction
band, this trap can also communicate with valence band, trapping holes. The capture cross section for trapping a hole is estimated
to be comparable or even larger than the capture cross section for trapping an electron. However, in many experimental conditions
free electrons are generated more abundantly than free holes, and free carrier mobility and thermal velocity are both much
higher for electrons than for holes. Therefore, electron trapping often prevails, so that this frequently detected defect,
has been up to now most often perceived as a deep electron trap. 相似文献