Creep of binary Fe-Al alloys with ultrafine lamellar microstructures

On the Al-rich side of the Fe-Al binary system, the eutectoid decomposition of Fe5Al8 into B2-ordered FeAl and triclinic FeAl2 in the composition range of 55–65 at.% Al produces an ultrafine lamellar microstructure. The compression creep behavior of such two-phase intermetallic materials was investigated in the temperature range 600–800 °C under constant stress. In addition to the fully lamellar Fe-61Al alloy, Fe-58Al and Fe-62Al that included, pro-eutectoid FeAl and FeAl2, respectively, were characterized in terms of their microstructure and creep response. For all microstructures, the strain rate as a function of time and strain exhibits a distinct minimum instead of a steady state creep regime. Microstructure instability, primarily in the vicinity of colony boundaries, is identified as the main reason for the increase in strain rate beyond the minimum. In contrast, lamellar coarsening is shown to be only a secondary factor influencing creep response for the conditions investigated. In comparison to single phase FeAl, the fully lamellar FeAl-FeAl2 shows enhanced creep resistance while the presence of either pro-eutectoid phase leads to a relative deterioration of the creep resistance

Facile synthesis of an ambient stable pyreno[4,5-b]pyrrole monoanion and pyreno[4,5-b:9,10-b ']dipyrrole dianion: from serendipity to design

The stability of singly or multiply negatively charged π-conjugated organic compounds is greatly influenced by their electronic delocalization. Herein, we report a strategic methodology for isolation of a mysterious compound. The isolated compounds, a pyreno[4, 5-b]pyrrole monoanion and pyreno[4, 5-b:9, 10-b′]dipyrrole dianion, were highly stable under ambient conditions due to high delocalization of the negative charge over multiple electron deficient C[triple bond, length as m-dash]N groups and pyrene π-scaffolds and allowed purification by column chromatography. To our knowledge, this is the first report on TCNE type reductive condensation of malononitrile involving pyrene di- and tetraone and formation of pyrenopyrrole. All compounds were characterized by spectroscopic methods and X-ray crystallography. A UV-vis spectroscopic study shows an intense low energy absorption band with a large absorption coefficient (ε)

Creep of binary Fe-Al alloys with ultrafine lamellar microstructures

On the Al-rich side of the Fe-Al binary system, the eutectoid decomposition of Fe5Al8 into B2-ordered FeAl and triclinic FeAl2 in the composition range of 55–65 at.% Al produces an ultrafine lamellar microstructure. The compression creep behavior of such two-phase intermetallic materials was investigated in the temperature range 600–800 °C under constant stress. In addition to the fully lamellar Fe-61Al alloy, Fe-58Al and Fe-62Al that included, pro-eutectoid FeAl and FeAl2, respectively, were characterized in terms of their microstructure and creep response. For all microstructures, the strain rate as a function of time and strain exhibits a distinct minimum instead of a steady state creep regime. Microstructure instability, primarily in the vicinity of colony boundaries, is identified as the main reason for the increase in strain rate beyond the minimum. In contrast, lamellar coarsening is shown to be only a secondary factor influencing creep response for the conditions investigated. In comparison to single phase FeAl, the fully lamellar FeAl-FeAl2 shows enhanced creep resistance while the presence of either pro-eutectoid phase leads to a relative deterioration of the creep resistance

Substantiating Precise Analysis of Data to Evaluate Students Answer Scripts

<p>Handwriting recognition refers to interpreting and analyzing handwritten text. In rece-nt years, there have- been notable advance-ments in this field, espe-cially in the context of computerize-d assessments. As online e-xams and digital education platforms continue to gain  popularity, handwriting recognition plays a crucial role- in evaluating students' written answers. Our proposed  system automatically recognizes and scores handwritten responses on answer sheets by comparing them to the correct answers provided by a moderator. To achieve this, the system utilizes Optical Character Recognition (OCR) to convert the handwritten text images into computer-readable text. Additionally, BERT is employed to convert the text into embeddings, and cosine similarity is utilized to take these embeddings as input and provide a final matching confidence score.</p><p>Keywords:- OCR, Google Vision OCR, BERT, Cosine similarity.</p&gt

Recent Advances in Organic Radicals and Their Magnetism

The review presents an overview of the organic radicals that have been designed and synthesized recently, and their magnetic properties are discussed. The π-conjugated organic radicals such as phenalenyl systems, functionalized nitronylnitroxides, benzotriazinyl, bisthiazolyl, aminyl-based radicals and polyradicals, and Tetrathiafulvalene (TTF)-based H-bonded radicals have been considered. The examples show that weak supramolecular interactions play a major role in modulating the ferromagnetic and antiferromagnetic properties. The new emerging direction of zethrenes, organic polyradicals, and macrocyclic polyradicals with their attractive and discrete architectures has been deliberated. The magnetic studies delineate the singlet-triplet transitions and their corresponding energies in these organic radicals. We have also made an attempt to collate the major organic neutral radicals, radical ions and radical zwitterions that have emerged over the last century