Origin of the complex radio structure in BAL QSO 1045+352

We present new more sensitive high-resolution radio observations of a compact broad absorption line (BAL) quasar, 1045+352, made with the EVN+MERLIN at 5 GHz. They allowed us to trace the connection between the arcsecond structure and the radio core of the quasar. The radio morphology of 1045+352 is dominated by a knotty jet showing several bends. We discuss possible scenarios that could explain such a complex morphology: galaxy merger, accretion disk instability, precession of the jet and jet-cloud interactions. It is possible that we are witnessing an ongoing jet precession in this source due to internal instabilities within the jet flow, however, a dense environment detected in the submillimeter band and an outflowing material suggested by the X-ray absorption could strongly interact with the jet. It is difficult to establish the orientation between the jet axis and the observer in 1045+352 because of the complex structure. Nevertheless taking into account the most recent inner radio structure we conclude that the radio jet is oriented close to the line of sight which can mean that the opening angle of the accretion disk wind can be large in this source. We also suggest that there is no direct correlation between the jet-observer orientation and the possibility of observing BALs.Comment: 8 pages, 3 figures, accepted for publication in Ap

Corrosion Behavior of SiMo Cast Iron under Controlled Conditions

The resistance of cast iron to chemical and electrochemical corrosion depends on the exposure conditions, chemical composition and the distribution of alloying elements in the microstructure. The article presents an attempt to describe the formation of a corrosion layer under controlled chemical corrosion conditions for SiMo ductile iron. In the experiment, a (HT-HRD) chamber for heating the samples with a controlled atmosphere was used, at the same time providing the possibility of testing the sample surface using the XRD method. The analysis was both qualitative and quantitative. It allowed us to capture the sequence of the oxide layer growth on the tested samples. The beneficial effect of molybdenum on the corrosion resistance of SiMo cast iron has been proven. For all cases under analysis, the phenomenon of an increase in the share of hematite (Fe2O3) and magnetite (Fe3O4) was observed in the subsequent sample heating cycles. It turned out that the addition of molybdenum helps to create a tight oxide coating that inhibits the further growth of corrosion processes. Increasing the share of molybdenum in the alloy also reduces the thickness of the oxide layer

Effect of Mo Addition on the Chemical Corrosion Process of SiMo Cast Iron

The study was carried out to evaluate five SiMo cast iron grades and their resistance to chemical corrosion at elevated temperature. Corrosion tests were carried out under conditions of an actual cyclic operation of a retort coal-fired boiler. The duration of the study was 3840 h. The range of temperature changes during one cycle was in the range of 300–650 °C. Samples of SiMo cast iron with Si content at the level of 5% and variable Mo content in the range 0%–2.5% were used as the material for the study. The examined material was subjected to preliminary metallographic analysis using scanning microscopy and an Energy dispersive spectroscopy (EDS) system. The chemical composition was determined on the basis of a Leco spectrometer and a Leco carbon and sulfur analyzer. The examination of the oxide layer was carried out with the use of Scanning electron microscope (SEM), EDS, and X-ray diffraction (XRD) methods. It was discovered that, in the analyzed alloys, oxide layers consisting of Fe2O3, Fe3O4, SO2, and Fe2SiO4 were formed. The analyzed oxide layers were characterized by high adhesion to the substrate material, and their total thickness was about 20 μm

COVID-19 pandemic and stability of stock market-A sectoral approach.

The COVID-19 pandemic seems to be the most important phenomenon observed from March 2020 in virtually all countries of the world. The necessity to prevent the spread of COVID-19 and keep health care systems efficient resulted in the forced, drastic limitation of economic activity. Many service sectors were hit particularly hard with this but industry and agriculture were also affected. In particular, the pandemic substantially influenced financial markets and we can observe that some markets or instruments vary in stability since they have been affected in the different degree. In the paper, we present the problem of stability of stock markets during the COVID-19 pandemic. Due to the low number of works related to CEE countries during the pandemic, we analyze the Warsaw Stock Exchange, which is one of the most important markets in the CEE. Our main goal was to find how various industries represented by stock market indices have reacted to the COVID-19 shock and consequently which sectors turned out to keep stability and remained resistant to the pandemic. In our investigation, we use two clustering methods: the K-means and the Ward techniques with the criterion of maximizing the silhouette coefficient and six indicators describing stability in terms of profitability, volume, overbought/oversold conditions and volatility. The results of the research present that during the pandemic it was possible to identify 5 clusters of sector indices in the short term and 4 in the medium term. We found that the composition of the clusters is quite stable over time and that none of the obtained clusters can be univocally considered the most or the least stable taking into account all the analyzed indicators. However, we showed that the obtained clusters have different stability origins, i.e. they vary from each other in terms of the investigated indicators of stability

Selected Phenomena of the In-Mold Nodularization Process of Cast Iron That Influence the Quality of Cast Machine Parts

This paper discusses a problem connected with the production process of ductile iron castings made using the in-mold method. The study results are presented showing that this method compromises the quality of the cast machine parts and of the equipment itself. Specifics of the nodularization process using the in-mold method do not provide the proper conditions for removal of chemical reaction products to the slag, i.e., the products stay in the mold cavity and they also decrease the quality of the casting. In this work, corrosion-type defects were diagnosed mostly on the surface of the casting and some compounds in the near-surface layer—i.e., fayalite (Fe2SiO4) and forsterite (Mg2SiO4)—which cause discontinuities in the metal matrix. The results presented here were selected based on experimental melts of ductile iron. The elements of the mold used in this study, the shape of the mixing chamber, charge materials, method of melting, temperature of liquid metal, etc. were directly related to the production conditions. An analysis was conducted of the chemical composition using a Leco GDS500A spectrometer and a carbon and sulfur Leco CS125 analyzer. Metallographic examinations were conducted using a Phenom-ProX scanning electron microscope with an EDS system

Method for Resistivity Measurement of Grainy Carbon and Graphite Materials

The article presents the issue of electrical resistivity measurement of carbon materials. The device that was developed by the authors is described and is the subject of a Polish patent. The innovative approach of the setup is based on the possibility of measuring the resistivity of grainy (powdered, dusty) materials without having to conduct their preliminary pressing. The material that is to be analyzed is placed inside the chamber made of electrically non-conducting material. The sample is then compacted with pneumatically driven pistons and the compaction force can be controlled by the air pressure. The device as proposed by the authors works at a pressure of 900 kPa, which is equal to the compaction force of 1.2 kN. Resistivity is calculated on the basis of the voltage drop recorded on the sample length. The research covers the analysis of the influence of carbon material grade and compaction force on the resistivity value. It was stated that the resistivity of the graphite materials that were analyzed here changed within the range of 43⁻172 µm: petroleum coke—360⁻780 µm; the anthracite—1900⁻3900 µm. The experimental method presented here can be used whenever carbon materials are present in the form of grains

The Importance of SiC in the Process of Melting Ductile Iron with a Variable Content of Charge Materials

The article presents issues related to melting ductile iron grade EN-GJS-400-15, with different proportions of feedstock (steel scrap and pig iron). The main attention was paid to determining the impact of silicon carbide on the structure and properties of melted cast iron. In the conducted melts, carbon and silicon deficiencies were supplemented with a suitably chosen carburizer, ferrosilicon, and SiC metallurgical silicon carbide. The percentage of silicon carbide in the charge ranged from 0 to 0.91%. The basic condition for the planning of melts was to maintain the repeatability of the chemical composition of the output cast iron and cast iron after the secondary treatment of liquid metal with various charge compositions. Based on the tests, calculations, and analyses of the results obtained, it was concluded that the addition of SiC may increase the number and size of graphite precipitates. Increasing the SiC content in the charge also caused a change in the solidification nature of the alloy and the mechanism of growth of spheroidal graphite precipitates, causing their surface to form a scaly shell. The influence of the addition of silicon carbide on the reduction of the temperature of liquidus in the alloys was also observed. Silicon carbide had a positive effect on the structure and properties of melted alloys. The introduction of SiC into the melting in the studied range caused an increase in the content of carbon and silicon without causing an increase in the amount of impurities in the alloy

Various Aspects of Application of Silicon Carbide in the Process of Cast Iron Melting

The article discusses benefits associated with the use of silicon carbide in the process of melting gray cast iron and ductile cast iron in induction electric furnaces. It presents the analysis of the impact of various charge materials and the addition of a variable amount of SiC and FeSi to the fixed charge when melting cast iron of grades GJS 400-15 and GJS 500-7 on mechanical properties and microstructure. Moreover, the article includes an analysis of the efficiency of carburization and the increase in the content of silicon during the application of SiC. The article also presents the results of the study of primary modification using silicon carbide at the minimum temperature of Temin eutectic and Tsol solidus. Based on analysis of the literature, conducted research, and calculations, it was found that the addition of silicon carbide has a beneficial impact on the properties of melted cast iron. The addition of SiC in the charge increases the content of C and Si without increasing the amount of contaminations. The addition of SiC at reduced pig iron presence in the charge decreases production costs, while the use of SiC as an inoculant increases both Temin and Tsol, which is beneficial from the point of view of cast iron nucleation

How to embed ethics into laboratory research

Health-related innovation in biotechnology requires anticipating potential bioethical implications. In this article, we present a strategy to embed ethics in a group of early-stage researchers performing research in gene therapy and regenerative medicine in the laboratory phase. We conducted a series of focus group meetings with early-stage researchers who work in biotechnology laboratories. The objective was to reflect on the bioethical challenges of their own work and to promote the integration of research ethics with laboratory practice. The activity was assessed with questionnaires completed by the researchers before and after the meetings, and the analyses of the focus groups’ content. As a result of the focus group series, all participants changed their perspectives about ethical issues regarding their planned research, developed the ability to reflect and debate on research ethics and had increased awareness of ethical issues in their own research activities. Half of them made changes in their research work. The study provides a concrete strategy to embed ethics and to strengthen responsibility in laboratory research. It is a strategy that allows to perform ethics reflection “on site” and in “real time” and complements the classic strategy of ethics assessment of the research protocol before starting the research procedure.</p