Influence of recrystallization annealing on the properties and structure of low-carbon ferritic steel if

This paper shows results of researches of a structure and mechanical properties of metal sheets of IF steels subjected to recrystallization annealing. The annealing was held in the scope of the temperature of 600-900 degrees C over 25 min time. The impact of heat treatment on changes of properties and structure of the researches steel has been analysed. During annealing typical processes of rebuilding of the structure deformed as a result of cold deformation in the form of forming new recrystallized grains and their growth were observed. As the temperature of annealing increases the hardness of the material gradually decreases.Web of Science6341961195

Influence of the drece process of severe plastic deformation on the mechanical properties of the ultra-low carbon interstitial free steel

This research paper shows the influence of a repeated SPD (Severe Plastic Deformation) plastic forming with the DRECE technique (Dual Rolls Equal Channel Extrusion) on hardening of low carbon IF steel. The influence of number of passes through the device on change of mechanical properties, such as tensile strength TS and yield stress YS, of tested steel was tested. The developed method is based on equal channel extrusion with dual rolls and uses a repeated plastic forming to refinement of structure and improve mechanical properties of metal bands [1-2]. For the tested steel the increase of strength properties after the DRECE process was confirmed after the first pass in relation to the initial material. The biggest strain hardening is observed after the fourth pass.Web of Science6342100209

Usuwanie tlenków azotu metodą SCR : praca przeglądowa

W pracy omówiono źródła powstawania tlenków azotu, wpływ NOx na środowisko i życie człowieka, jak również katalityczne reakcje ich usuwania. W szczególności omówiono technologię procesu selektywnej katalitycznej redukcji NO amoniakiem (proces NH3-SCR), w tym stosowane w procesie komercyjne katalizatory oparte na tlenku tytanu oraz mieszane tlenki pochodzenia hydrotalkitowego. Uzyskane wyniki jednoznacznie wskazują na duży potencjał materiałów hydrotalkitowych jako katalizatorów technologii SCR.Nowadays, NOx reduction has become one of the major issues in environmental protection. Looking for an active and selective catalyst is one of the challenges. Up to now, tungsten and molybdenum promoted V2O5/TiO2 catalysts exhibit the best performance in the NOx reduction process, and these catalysts have already been industrialized. For the vehicle applications there is a trend for considering other catalysts due to some drawbacks of titania-supported catalysts. Application of Cu-containing mixed metal oxides obtained from hydrotalcite-like materials as catalysts for this process could be a potential solution; however, further research in real operating conditions is needed

Total oxidation of methanol low temperatures on (Cu, Mn)-Mg-Al mixed metal oxides derived from hydrotalcites

A series of (Cu, Mn)-Mg-Al hydrotalcite-like layered double hydroxides (HTs) was synthesized by a co-precipitation method.The incorporation of Mn into the Mg-Al and Cu-Mg- Al HTs structure was investigated by employing powder X-ray diffraction. Calcination of the precursors resulted in destruc- tion of the layered structure and led to low-crystalline MgO. Ob- tained mixed metal oxides were tested as catalysts for the process of total oxidation of methanol.The catalytic performance of the Cu-containing samples was better comparing to the Mn-based catalysts and decreased in the following order: Cu-Mg-Al > Cu- Mn-Mg-Al > Mn-Mg-Al > Mg-Al. Quantitative total oxidation of methanol was achieved at 325 C with Cu-Mg-Al mixed oxides

The Release of Trace Elements in the Process of Coal Coking

In order to assess the penetration of individual trace elements into the air through their release in the coal coking process, it is necessary to determine the loss of these elements by comparing their contents in the charge coal and in coke obtained. The present research covered four coke oven batteries differing in age, technology, and technical equipment. By using mercury analyzer MA-2 and the method of ICP MS As, Be, Cd, Co, Hg, Mn, Ni, Se, Sr, Tl, V, and Zn were determined in samples of charge coal and yielded coke. Basing on the analyses results, the release coefficients of selected elements were determined. Their values ranged from 0.5 to 94%. High volatility of cadmium, mercury, and thallium was confirmed. The tests have shown that although the results refer to the selected case studies, it may be concluded that the air purity is affected by controlled emission occurring when coke oven batteries are fired by crude coke oven gas. Fugitive emission of the trace elements investigated, occurring due to coke oven leaks and openings, is small and, is not a real threat to the environment except mercury

Technological Aspects of Production and Processing of Functional Materials Based on Intermetallic Fe-Al

The problems of this paper relate to a possibility to affect the structure and properties of new alloys with an intermetallic phase matrix of the Fe-Al system by improvements in casting and hot plastic working processes. The studies were focused on selection of an optimum chemical composition and parameters of the casting and heat treatment processes for further hot plastic working process. The primary goal was to obtain semifinished products in the forms of sheets and bars with specified set of mechanical and physical properties. The works included several selected alloys with various Al content and variable contents of alloying elements influencing the formation of intermetallic phases. A series of characteristics of mechanical, physical, and chemical properties of alloys containing 28 and 38% of Al were developed. The result of the work consists in the development of a technology for hot forming of flat and round products

Application of Hyphenated Techniques in Speciation Analysis of Arsenic, Antimony, and Thallium

Due to the fact that metals and metalloids have a strong impact on the environment, the methods of their determination and speciation have received special attention in recent years. Arsenic, antimony, and thallium are important examples of such toxic elements. Their speciation is especially important in the environmental and biomedical fields because of their toxicity, bioavailability, and reactivity. Recently, speciation analytics has been playing a unique role in the studies of biogeochemical cycles of chemical compounds, determination of toxicity and ecotoxicity of selected elements, quality control of food products, control of medicines and pharmaceutical products, technological process control, research on the impact of technological installation on the environment, examination of occupational exposure, and clinical analysis. Conventional methods are usually labor intensive, time consuming, and susceptible to interferences. The hyphenated techniques, in which separation method is coupled with multidimensional detectors, have become useful alternatives. The main advantages of those techniques consist in extremely low detection and quantification limits, insignificant interference, influence as well as high precision and repeatability of the determinations. In view of their importance, the present work overviews and discusses different hyphenated techniques used for arsenic, antimony, and thallium species analysis, in different clinical, environmental and food matrices

Study of hot deformation behavior of CuFe2 alloy

Nil strength temperature of 1062 degrees C and nil ductility temperature of 1040 degrees C were experimentally set for CuFe2 alloy. The highest formability at approx. 1020 degrees C is unusable due to massive grain coarsening. The local minimum of ductility around the temperature 910 degrees C is probably due to minor formation of gamma-iron. In the forming temperatures interval 650-950 degrees C and strain rate 0.1-10 s(-1) the flow stress curves were obtained and after their analysis hot deformation activation energy of 380 kJ.mol(-1) was achieved. Peak stress and corresponding peak strain values were mathematically described with good accuracy by equations depending on Zener-Hollomon parameter.Web of Science64270670

When genome-based approach meets the “Old but Good”: revealing genes involved in the antibacterial activity of Pseudomonas sp. P482 against soft rot pathogens

Dickeya solani and Pectobacterium carotovorum subsp. brasiliense are recently established species of bacterial plant pathogens causing black leg and soft rot of many vegetables and ornamental plants. Pseudomonas sp. strain P482 inhibits the growth of these pathogens, a desired trait considering the limited measures to combat these diseases. In this study, we determined the genetic background of the antibacterial activity of P482, and established the phylogenetic position of this strain. Pseudomonas sp. P482 was classified as Pseudomonas donghuensis. Genome mining revealed that the P482 genome does not contain genes determining the synthesis of known antimicrobials. However, the ClusterFinder algorithm, designed to detect atypical or novel classes of secondary metabolite gene clusters, predicted 18 such clusters in the genome. Screening of a Tn5 mutant library yielded an antimicrobial negative transposon mutant. The transposon insertion was located in a gene encoding an HpcH/HpaI aldolase/citrate lyase family protein. This gene is located in a hypothetical cluster predicted by the ClusterFinder, together with the downstream homologs of four nfs genes, that confer production of a non-fluorescent siderophore by P. donghuensis HYS(T). Site-directed inactivation of the HpcH/HpaI aldolase gene, the adjacent short chain dehydrogenase gene, as well as a homolog of an essential nfs cluster gene, all abolished the antimicrobial activity of the P482, suggesting their involvement in a common biosynthesis pathway. However, none of the mutants showed a decreased siderophore yield, neither was the antimicrobial activity of the wild type P482 compromised by high iron bioavailability. A genomic region comprising the nfs cluster and three upstream genes is involved in the antibacterial activity of P. donghuensis P482 against D. solani and P. carotovorum subsp. brasiliense. The genes studied are unique to the two known P. donghuensis strains. This study illustrates that mining of microbial genomes is a powerful approach for predictingthe presence of novel secondary-metabolite encoding genes especially when coupled with transposon mutagenesis