The kinetics of carbide precipitation in silicon-aluminum steels

The kinetics of carbide precipitation in a fully processed 2.3 wt Pct silicon, 0.66 wt Pct aluminum electrical steel with carbon contents of 0.005 to 0.016 wt Pct were investigated over the temperature range from 150 to 760 °C and times from 30 seconds to 240 hours. The size, morphology, and distribution of the carbide phases, as functions of aging time and temperature, were determined by optical and transmission electron microscopy. The 1.5T core loss was also evaluated and correlated with the changes in precipitation. Distinct C curves were observed for the formation of grain-boundary cementite at temperatures above 350 °C and a transition carbide ({100} _α habit plane) at temperatures below 350 °C. Grain-boundary cementite had a relatively small effect on core loss. The large increases in core loss that accompanied transition carbide precipitation peaked at specific aging temperatures depending on the carbon content of the steel. Once a transition carbide dispersion was initially established at a given aging temperature, particle coarsening and core loss changes were generally insensitive to aging time. The influence of a combined addition of silicon and aluminum on the solubility of cementite and the transition carbide in iron was estimated and discussed. This paper is based on a presentation made at the symposium “Physical Metallurgy of Electrical Steels” held at the 1985 annual AIME meeting in New York on February 24–28, 1985, under the auspices of the TMS Ferrous Metallurgy Committee.     

Precontact 50-kHz vocalizations in male rats during acquisition of sexual experience.

50-kHz ultrasonic vocalizations emitted by male rats during a 5-min period before introduction of a female (precontact vocalizations [PVs]) were analyzed in the context of acquisition of sexual experience. Changes in the main copulatory parameters and their N-methyl-D-aspartate (NMDA) receptor dependence, the role of contact with either anestrous or estrous females, and conditioning to odor and background cues were also investigated. Mount latency (ML) and intromission latency (IL) decreased after the 1st copulatory session, but ejaculation latency (EL) changed significantly only starting from the 4th session onward. The number of PVs gradually increased during the first 3–4 sessions. Blocking of NMDA receptors affected PVs and EL but not ML or IL. After a 5-month break in copulatory sessions, ML remained unchanged, whereas EL increased and the number of PVs decreased significantly. PVs were most robustly elevated by contact with estrous females. Exposure to background cues resulted in a linear decrease in number of PVs during 10 subsequent sessions without exposure to a female. The results suggest that, in the course of acquisition of a sexual experience, PVs reflect a learning process that depends on a rewarding value of sociosexual contact. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Electrochemical behaviour of palladium electrode: Oxidation, electrodissolution and ionic adsorption

In electrochemistry, Pourbaix diagrams also known as potential-pH diagrams map out the regions of stability of metals as well as the regions of possible existence of stable compounds. The stable states other than the metallic one are macroscopic compounds, typically oxides and hydroxides, or their hydrated forms. Yet, several noble metals possess the ability to form thin surface oxides, to adsorb anions, and to adsorb or to absorb hydrogen in the potential range of water stability. Palladium is a unique noble metal owing to its ability to adsorbed and to absorb H, as well as to form compact and stable surface oxides. Anodic polarization of Pd results in the formation of a surface oxide. Thus, a great majority of anodic electrode processes takes place not at a metallic surface but at a surface covered with an oxide layer. Although thin surface oxides reveal metallic conductivity, the presence of O-containing species affects the electron transfer kinetics and the adsorption behaviour of reactants, intermediates, and products. Thus, the electrocatalytic properties of Pd electrodes, and the mechanism and kinetics of the reaction under consideration are strongly affected by the oxide layer, its thickness, chemical composition (Pd oxidation state and nature of O-containing species) and 3D structure, degree of oxide hydration, and electronic properties. This contribution presents an overview of the current understanding of electro-oxidation of Pd in aqueous acidic and basic electrolytes. In particular, it describes the formation of Pd oxides under various experimental conditions and discusses their chemical and physical nature. It examines the reduction of O-containing species present on Pd electrodes as well as the adsorption of anions and cations. Since Pd can undergo electrodissolution that results in material loss, the process is analyzed in relation to experimental parameters. Recent developments in the electrochemical behaviour of single-crystal Pd electrodes are discussed. Electrochemical parameters such as the potential of zero charge, potential of zero total charge and potential of zero free charge are of importance to the structure of the electric double layer; thus, their values are discussed in relation to the absence/presence of Pd surface oxides. Finally, various experimental procedures commonly used to determine the real surface area of Pd electrodes are outlined and compared.     

$$hbox {TG}^2$$ TG 2 : text-guided transformer GAN for restoring document readability and perceived quality

International Journal on Document Analysis and Recognition (IJDAR) - Most image enhancement methods focused on restoration of digitized textual documents are limited to cases where the text...     

The influence of laser power on the interfaces of functionally graded materials fabricated by powder-based directed energy deposition

Journal of Materials Science - Powder-based directed energy deposition (DED) technology with separate feeders for different individual materials enables the deposition of functionally graded...     

The performance assessment framework (PPAFR) for RPA implementation in a loan application process using process mining

When a company decides to automate its business processes by means of RPA (Robotic Process Automation), there are two fundamental questions that need to be answered. Firstly, what activities should the company automate and what characteristics make them suitable for RPA. The aim of the presented research is to design and demonstrate a data-driven performance framework assessing the impact of RPA implementation using process mining (PPAFR). Firstly, we comment on and summarise existing trends in process mining and RPA. Secondly, we describe research objectives and methods following the Design Science Research Methodology. Then, we identify critical factors for RPA implementation and design process stages of PPAFR. We demonstrate the design on real data from a loan application process. The demonstration consists of a process discovery using process mining methods, process analysis, and process simulation with assessment of RPA candidates. Based on the research results, a redesign of the process is proposed with emphasis on RPA implementation. Finally, we discuss the usefulness of PPAFR by helping companies to identify potentially suitable activities for RPA implementation and not overestimating potential gains. Obtained results show that within the loan application process, waiting times are the main causes of extended cases. If the waiting times are generated internally, it will be much easier for the company to address them. If the automation is focused mainly on processing times, the impact of automation on the overall performance of the process is insignificant or very low. Moreover, the research identified several characteristics which have to be considered when implementing RPA due to the impact on the overall performance of the process.

     

Visualization of active biomass distribution in a BGAC fluidized bed reactor using GFP tagged Pseudomonas putida F1

A favorable microenvironment for biofilm growth on GAC particles was shown using green fluorescent protein (GFP) as a marker for a phenol degrading bacterium, Pseudomonas putida F1. The dispersion of P. putida F1 in a biofilm covering granulated activated carbon (GAC) particles was monitored and compared to a biofilm on non-activated granular carbon particles. Laser scanning confocal microscopy (LSCM) micrographs of the biofilms taken from two fluidized bed reactors operating under identical conditions, showed higher fluorescent green areas in the GAC biofilm, especially close to the GAC surface. Quantitative analysis of the biofilm by COMSTAT, a three-dimensional biofilm structure analysis program, showed higher biomass concentration and higher viability in the GAC covered biofilm vs. the non-activated carbon biofilm. In addition, better effluent quality was measured for the BGAC reactor, which strongly suggests a significantly larger biofilm surface area available to the substrate, as opposed to that of the non-activated carbon carrier reactor.     

A novel multiscale approach to brittle fracture of nano/micro‐sized components

Principles and advantages of a new concept based on the ab initio aided strain gradient elasticity theory are shown in comparison with the classical Barenblatt cohesive model. The method is applied to the theoretical prediction of the critical energy release rate and the crack tip opening displacement at the crack instability in nanopanels made of germanium and molybdenum crystals. The necessary length scale parameter l₁ is determined for germanium and molybdenum by the best gradient elasticity fits of ab initio computed screw dislocation displacements and phonon dispersions. Values of ab initio computed critical energy release rates and crack opening profiles revealed that the length l₁ is related to inflexion points of profiles. A novel ab initio method in combination with continuum mechanics was successfully tested to replace molecular statics dependent of availability of interatomic potentials. The asymptotic strain gradient elasticity solution for displacement components near the crack tip in materials with cubic lattice was also derived.     

Tight and uniform layer of covalently bound aminoethylophenyl groups perpendicular to gold surface for attachment of biomolecules

Strongly adhered layers of the compound with the primary amino group directed toward the solution were obtained at the gold surface by chronoamperometric electroreduction of 4-aminoethylobenzenodiazonium salt (AEBD) in acetonitrile solution at appropriately selected potential. The used techniques (EQCM, AFM, EIS, PM, IRRAS) showed that the nature and thickness of formed aminoethylophenyl layer strongly depend on the potential applied to the electrode. Electroreduction of AEBD salt at a potential more negative than -0.6 V (vs Ag/AgCl) leads to about monolayer on the gold surface. Additionally, such a layer was very tight and uniform. The electrochemical measurements indicate that the efficient and precise attachment of biomolecules to the aminoethylophenyl layer is only possible when this layer is formed at appropriate potential. This was shown for ss- and dsDNA.