Search

The use of low-carbon unalloyed steel with minimal silicon content is widespread in structural steel and automotive applications due to its ease of manipulation. The mechanical properties of this steel can be significantly enhanced through severe plastic deformation (SPD) techniques. Our study focuses on the practical benefits of the dual rolling equal channel extrusion (DRECE) method, which strengthens the steel and has implications for material hardness and the thickness of subsequently applied hot-dip zinc galvanizing. Furthermore, the steel's corrosion potential and current are investigated as a function of material hardness and thickness. The findings show a 20% increase in hardness HV 30 after the first run through the forming machine, with an additional 10% increase after the second run. Subsequent galvanizing leads to a further 1–12% increase in HV 30 value. Notably, the DRECE hardening demonstrates no statistically significant effect on the corrosion potential and current; however, the impact of galvanizing is as anticipated. [ABSTRACT FROM AUTHOR]

Machine learning is increasingly integrated into chemistry research by guiding experimental procedures, correlating structure and function, interpreting large experimental datasets, to distill scientific insights that might be challenging with traditional methods. Such applications, however, largely focus on gaining insights via big data and/or big computation, while neglecting the valuable chemical prior knowledge dwelling in chemists' minds. In this paper, we introduce an Electrochemistry‐Informed Neural Network (ECINN) by explicitly embedding electrochemistry priors including the Butler–Volmer (BV), Nernst and diffusion equations on the backbone of neural networks for multi‐task discovery of electrochemistry parameters. We applied the ECINN to voltammetry experiments of Fe2+/Fe3+ ${{\rm F}{{\rm e}}^{2+}/{\rm F}{{\rm e}}^{3+}}$ and RuNH362+/RuNH363+ ${{\rm R}{\rm u}{\left({\rm N}{{\rm H}}_{3}\right)}_{6}^{2+{\rm \ }}/{\rm R}{\rm u}{\left({\rm N}{{\rm H}}_{3}\right)}_{6}^{3+{\rm \ }}}$ redox couples to discover electrode kinetics and mass transport parameters. Notably, ECINN seamlessly integrated mass transport with BV to analyze the entire voltammogram to infer transfer coefficients directly, so offering a new approach to Tafel analysis by outdating various mass transport correction methods. In addition, ECINN can help discover the nature of electron transfer and is shown to refute incorrect physics if imposed. This work encourages chemists to embed their domain knowledge into machine learning models to start a new paradigm of chemistry‐informed machine learning for better accountability, interpretability, and generalization. [ABSTRACT FROM AUTHOR]

This work focuses on wetting two types of substrates (a platinum substrate and a polished graphite substrate) by molten polycomponent oxide system CaO–MgO–SiO2–Al2O3–B2O3 to test the level of interaction at high temperatures. The tested systems were subjected to high-temperature wetting tests in the temperature range from liquidus temperature to 1550 °C using the sessile drop method. A total of four oxide systems were tested with graded boron oxide contents ranging from 0 to 30 wt%. The experiments were conducted in a CLASIC high-temperature resistance observation furnace and an inert atmosphere of high-purity argon. Droplet silhouettes were obtained with a CANON EOS 550D high-resolution camera during heat treatment, with reactive and non-reactive wetting occurring depending on the substrate type. The dependence of the average wetting angles on temperature and time was evaluated, and it was found that boron oxide decreased the average wetting angles of molten oxide droplets. The analyses were accompanied by the SEM/EDX analysis of the substrate and FTIR analysis of the droplets after high-temperature experiments. The phase composition of the oxide systems was evaluated by XRD analysis. [ABSTRACT FROM AUTHOR]

Copyright of Pediatrie pro Praxi is the property of SOLEN sro and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The principal objective of this project was to investigate the rheological properties of Fe–C–Cr and Fe–C–Ni-based low-alloy steels using an Anton Paar high-temperature rotational viscometer up to 1550 °C. The emphasis was placed on determining the liquidus temperatures and evaluating the flow and viscosity curves and the temperature dependence of dynamic viscosity. All were studied depending on the change in the content of chromium (0.010–4.863 wt%), nickel (0.001–4.495 wt%), and carbon (0.043–1.563 wt%). It was shown that the dynamic viscosity decreases with increasing nickel content and increases with increasing carbon and chromium content. The experimental data of the flow curves were fitted using the Herschel–Bulkley model with a good agreement between the measured and calculated values. Characterization of the internal structure was performed by SEM and EDX analyses, confirming non-significant changes in the microstructure of the original and remelted samples. The phase composition of the selected samples was also determined using JMatPro 12.0 simulation software (Sente Software Ltd., Guildford, UK). [ABSTRACT FROM AUTHOR]

This work aims to describe the interfacial interaction at the interface between refractory material and high-manganese (XT 720) and structural (11 523) steel using a wetting test up to 1600 °C. The contact angles were determined through the sessile drop method, and the results were put into context through degradation testing and the characterization of the interfacial interface by Energy Dispersive X-Ray (EDX), X-Ray Diffraction (XRD) analyses, and Scanning Electron Microscopy (SEM). The lowest resistance to molten steel was observed for chamotte materials, while the highest was observed for materials based on electrofused corundum. High-manganese steel was strongly erosive to the materials tested, with the wetting angle decreasing significantly from 10 to 103° with decreasing Al2O3 content (an increase of 2.4 to 59.4% corundum) in the refractories. Structural steel showed wetting angles from 103 to 127° for identical refractories. These results were consistent with the average erosion depth for Mn steel (0.2–7.8 mm) and structural steel (0–2.4 mm). [ABSTRACT FROM AUTHOR]

The article titled "Inside Cover: Discovering Electrochemistry with an Electrochemistry-Informed Neural Network (ECINN)" by Richard G. Compton et al. introduces a festive electrochemistry-informed neural network (ECINN). The ECINN consists of three subnets, each with three layers of "Chinese lantern" neurons, which incorporate various electrochemical knowledge to solve experimental voltammograms and parameter estimation. The cover of the journal features auspicious clouds and China's earliest dragon from Neolithic Hongshan Culture, celebrating the Year of the Dragon. The authors of the article are Haotian Chen, Minjun Yang, Bedřich Smetana, Vlastimil Novák, Vlastimil Matějka, and Richard G. Compton. [Extracted from the article]

The article titled "Discovering Electrochemistry with an Electrochemistry-Informed Neural Network (ECINN)" by Richard G. Compton et al. introduces a festive electrochemistry-informed neural network (ECINN). The ECINN consists of three subnets, each with three layers of "Chinese lantern" neurons, which incorporate various electrochemical knowledge to solve experimental voltammograms and parameter estimation. The cover of the journal features auspicious clouds and China's earliest dragon from Neolithic Hongshan Culture, celebrating the Year of the Dragon. The authors of the article are Haotian Chen, Minjun Yang, Bedřich Smetana, Vlastimil Novák, Vlastimil Matějka, and Richard G. Compton. [Extracted from the article]

Ottoman coins have been registered in the Czech Lands since the beginning of the 18th century and have been systematically documented since the mid-19th century. The latest actualization comes from 1996, but the following massive use of metal detectors showed a serious need for a new summarization. Up until 2018, some 151 hoards/single finds with the Ottoman coins, forgeries, and jetons have been registered in the territory of the Czech Republic. These coins came to the mentioned territory via the Ottoman European expansion since the 16th century, and their flow reached its peak in the 17th century. The massive appearance of the Ottoman coins in Bohemia, partly in Moravia and Silesia, in the 17th century represents a phenomenon connected with the Thirty Years War. In south and central Moravia, it is explained by the direct military impact of the Ottoman armies. The later import of these coins is associated with the Napoleonic Wars and with the Austro-Hungarian period through its Balkan connection. [ABSTRACT FROM AUTHOR]

In 2016, one half of a copper gilded coin was found single near the train station Louny předměstí (Louny district). Its prototype corresponds with an Ottoman gold denomination sultani struck under the Sultan Suleyman I (AH 926-974/AD 1520-1566). The name of the ruler and his father were identified, but the enthronization date and the mint-name are located out of the preserved area. The ED XRF analysis confirmed solid copper basis and process of gilding in fire. With high probability, the fake is connected with serious need of gold during the Thirty Years War (and the period closely after that), and it is very likely of the local (Central European) provenance. Bohemian, Moravian and Hungarian contexts of forging activities during the Thirty Years War are analyzed, relevant archaeological and numismatic evidence is summarized. [ABSTRACT FROM AUTHOR]

Copyright of Czech Radiology / Ceska Radiologie is the property of Czech Medical Association of JE Purkyne and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In 2016, one half of a copper gilded coin was found single near the train station Louny předměstí (Louny district). Its prototype corresponds with an Ottoman gold denomination sultáni struck under the Sultan Suleyman L (AH 926-974/ AD 1520-1566). The name of the ruler and his father were identified, but the enthronization date and the mint-name are located out of the preserved area. The ED XRF analysis confirmed solid copper basis and process of gilding in fire. With high probability, thefake is connected with serious need of gold during the Thirty Years War (and the period closely after that), and it is very likely of the local (Central European) provenance. Bohemian, Moravian and Hungarian contexts of forging activities during the Thirty Years War are analyzed, relevant archaeological and numismatic evidence is summarized. [ABSTRACT FROM AUTHOR]

Emissary veins create connections between intracranial and extracranial venous systems. The most commonly mentioned structures include parietal emissary vein, condylar emissary vein, occipital emissary vein, and clinically probably the most significant one -- mastoid emissary vein. These are anatomically overlooked structures with relatively low physiological significance in a healthy human. However, they may be of importance in intracranial hypertension, during inflammatory processes and may be a potential source of a number of complications associated with neurosurgical procedures. Awareness of the incidence, size and possible course of the mastoid emissary vein is important for the neurosurgeon, especially concerning the access to posterior cranial fossa through mastoid process. The aim of this work was to collect published findings regarding mastoid foramen, mastoid emissary vein with regard to retromastoid surgical approach and to acquaint with the clinical significance of these venous structures. It is clear from the literature that the reported frequency of venous junctions in mastoid foramen is influenced by the chosen method of investigation, there is high variability in its size and frequency of appearance, however the incidence is so high that precise preoperative location of emissary veins is necessary before neurosurgery. [ABSTRACT FROM AUTHOR]

In 2016, an Ottoman copper coin was studied by the authors in a private collection. It was reportedly found in Bohdanovce nad Trnavou (Trnava district, Slovakia). The coin was identified as the manghir struck under the Ottoman Sultan Murad III (AH 982-1003/ AD 1574-1595) in Miṣr (Cairo) in AH 982/ AD 1574 (in AD 1574-1595 respectively, because of the enthronement date). It is the earliest Ottoman copper issue discovered in Slovakia which was accidentally lost very likely in connection with the Ottoman raids against Hungary at the end of the 16th century. The remaining five Ottoman copper pieces found in Slovakia date back much later, to the end of the 17th century (Sulayman II, Ahmad II). [ABSTRACT FROM AUTHOR]

This work aims to assess the effect of an oxygen content graded in minimal quantities, on the order of hundreds of ppms, on the determination of surface tension of low-alloy FeCOCr and FeCONi steels in contact with a corundum substrate. Oxygen, as a surface-active element, was segregated at the surface where it interacted with the major components of the alloys, leading to a reduction in surface tension. The sessile drop method was used for wetting tests in the temperature range from steel liquidus temperatures to 1600 °C under nonoxidizing conditions. The effect of oxygen on surface tension and wetting angles was verified by statistical analysis using the Kruskal–Wallis test, which supported the results stating that the values of these quantities decreased with increasing oxygen content. Furthermore, liquidus temperatures, which are of practical importance, were determined by the optical and DTA methods and then compared with theoretically calculated temperature values. It turned out that the increased chromium content causes difficulties in determining surface tension up to 1550 °C due to the formation of a thin Cr2O3 layer. In addition, SEM and XRD analyses accompanied by calculations in the FactSage oxide database were performed to better understand the wetting mechanism. [ABSTRACT FROM AUTHOR]