Study of recrystallization kinetics of aluminium alloy 1565ch with low degree of cast structure conditioning

2021 ◽  
pp. 58-64
Author(s):  
V. V. Yashin ◽  
◽  
I. A. Latushkin ◽  
E. S. Chitnaeva ◽  
E. V. Aryshensky ◽  
...  
Keyword(s):  
Temperature Drop ◽  
High Rate ◽  
Recrystallization Temperature ◽  
Growth Speed ◽  
Recrystallization Process ◽  
Russian Science ◽  
Cast Structure ◽  
Recrystallization Kinetics ◽  
Low Degree

The present study addresses recrystallization process in Al – Mg 1565ch system alloy samples (Russian classification). The samples are taken from cast ingot, produced by continuous casting in DC mold and homogenized based on standard commercial mode. Then the samples were heated to 350–500 oC and rolled in lab mill with different process schedules to cover the entire range of temperature and strain rates, applied in rolling. After rolling the samples were annealed at 350, 400 and 450 oC, their resultant microstructure was examined by optic microscope. The rate of new grains nucleation, their growth speed, analytical notations, describing recrystallization kinetics, were obtained within the frames of the study to be applied during this alloy recrystallization modelling; the main alloy-specific recrystallization features were identified and compared with alloy АА5182 (classification of American Aluminum Association). It is demonstrated, that 1565ch recrystallization has a number of specific features in case of as-cast structure deformation with low strain levels (ε = 0.14÷0.56): first, high rate of new grains nucleation; second, low grain growth speed to the extent of complete process blocking. Optimal recrystallization temperature is identified as 400 oC, at this temperature the process is over 75% complete, the temperature drop (350 oC) causes incubation period extension, while recrystallization subsides at recrystallized structure volume of about 30%, in case of temperature rise (450 oC) the structure is saturated with fine new grains nuclei, probably, emerging during heating, but due to high intensity of recovery and polygonization, recrystallization driving force drops to zero, the process stops with mixed structure and max recrystallized grains volume of 20%. This research was funded through a grant by the Russian Science Foundation, Project 18-79-10099.

Species complexes and the generic classification of leaf-litter thrips of the tribe Urothripini (Phlaeothripidae)

1972 ◽  
Vol 20 (1) ◽  
pp. 83 ◽  
Author(s):  
LA Mound
Keyword(s):  
Leaf Litter ◽  
Morphological Difference ◽  
Distinct Species ◽  
High Rate ◽  
Incipient Speciation ◽  
Species Complexes ◽  
Low Degree ◽  
Complicated Pattern ◽  
Pattern Of Variation

Collections of the predominantly wingless urothripine Thysanoptera from leaf litter in Australia show little variation in external morphology within any one population, although the variation between populations is frequently very considerable. Morphological segregates in which winged individuals are known show little variation between populations, and these segregates can be regarded as distinct species. However, morphological segregates in which winged individuals are not known exist in the field as a complex of similar but distinctive local forms. Taxonomy is concerned with the interpretation in biological terms of morphological difference, but the significance of these distinctive populations cannot be determined at present, whether they are species, subspecies, or local variants. However, this high rate of incipient speciation of the Urothripini is evidently related, at least in part, to the low degree of dispersive activity of the wingless forms. The resulting complicated pattern of variation at the species level is reflected in the unsatisfactory generic classification, and several of the characters which have been used for distinguishing genera are here shown to be of little value. As a result four genera, Bournieria, Ramachandraiella, Transithrips, and Verrucothrips, are here placed in synonymy with Baenothrips, and a key is provided to the remaining 13 genera of Urothripini from the world. An account is given of the eight species in five genera known from Australia, including two new species: Baenothrips caenosus (Stannard), comb. nov. ; Baenothrips moundi (Stannard), comb. nov. ; Biconothrips reedi Stannard; Habrothrips curiosus Ananthakrishnan; Octurothrips pulcher Priesner; Stephanothrips occidentalis Hood & Williams; S. barretti, sp, nov.; S. ferrari, sp. nov. In addition, knechteli Priesner is transferred to Amphibolothrips, comb. nov., and erythrinus Pelikan is transferred to Baenothrips, comb. nov.

STUDY ON CLINICAL CHARACTERISTICS AND RESULT OF TREATMENT BENIGN VOCAL CORD TUMOR WITH RIGID LARYNGEAL ENDOSCOPIC SURGERY

2012 ◽  
pp. 58-65
Author(s):  
Duy Thai Truong ◽  
Van Dung Phan ◽  
Tu The Nguyen
Keyword(s):  
Vocal Cord ◽  
Endoscopic Surgery ◽  
Clinical Characteristics ◽  
University Hospital ◽  
High Rate ◽  
Treatment Rate ◽  
Reinke’S Edema ◽  
Vocal Nodules ◽  
A Prospective Study

Objective: Study on clinical characteristics and result of treatment benign vocal cord tumor with suspensive laryngeal endoscopic surgery. Materials and Methods: A prospective study was undertaken in 43 patients who had benign vocal cord tumor and performed a suspensive laryngeal endoscopic surgery at ENT Dept. of Hue University Hospital, from 3/2010 to 5/2011. Results: The most common was group was 31 - 45 (44.2%). There was no difference of gender. Moderate hoarness was 67.4%. Classification of benign laryngeal tumor: vocal nodules (13 cases), vocal cyst (18 cases), vocal polyp (10 cases) and Reinke’s edema (2 cases). The successful treatment rate of vocal benign tumor was 88.4%. Conclusions: Suspensive laryngeal endoscopic surgery was the best method to cure benign vocal cord tumor. The surgeon had a clear operative field, easy manoeuver, high rate of cure and less complication.

scholarly journals RESEARCH OF RHEOLOGICAL PROPERTIES OF MEDICINAL SYRUP FOR ORAL USE

2020 ◽  
Vol 73 (4) ◽  
pp. 696-699
Author(s):  
Lena L. Davtian ◽  
Galyna P. Kukhtenko ◽  
Alona S. Voronkina ◽  
Viktoria V. Kudria
Keyword(s):  
Rheological Properties ◽  
Mechanical Stability ◽  
Rheological Parameters ◽  
Dynamic Flow ◽  
Shear Rates ◽  
Coaxial Cylinders ◽  
Low Degree ◽  
Newtonian Type ◽  
Rotary Viscometer

The aim of the present research was to investigate the rheological properties of the medicinal syrup for oral administration with glucosamine hydrochloride and levocarnitine. Matherials and methods: Coefficient of the dynamic flow (at shear rates of 3,49 and 10,3 s -1, as well as at shear rates of 27.2 and 149.0 s-1), mechanical stability, the index of destruction and restoration were studied. The rheological (structural-mechanical) properties of the samples were determined using a Rheolab QC rotary viscometer (AntonPaar, Austria) with coaxial cylinders CC27 / S-SN29766. The rheological parameters were studied at the temperature 20±0,5 °С. Results: It is established that the syrup has weakly expressed plastic viscous and thixotropic properties (the hysteresis area for the syrupis 1710.19 Pas/s). Such results characterize the system as a reopex. Conclusions: The results of the study enables classification of the research object as system with a low degree of fluidity. Such dependence is typical for systems of the Newtonian type of flow and characterizes the syrup under investigation as a weakly structured disperse system.

Differences in the lexical variation of reporting verbs in French, English and Czech fiction and their impact on translation

2020 ◽  
Vol 20 (2) ◽  
pp. 209-234
Author(s):  
Olga Nádvorníková
Keyword(s):  
Target Language ◽  
Lexical Variation ◽  
Amount Of Information ◽  
Low Degree ◽  
Multilingual Corpus ◽  
High Degree

Abstract The aims of this paper are to analyse differences in the degree of lexical variation (type/token ratio and hapax/token ratio) of reporting verbs in reporting clauses placed medially or in postposition in English, French and Czech fiction and to evaluate their consequences in translation, especially in regard to explicitation/implicitation. We expect that, in translations from a language with a low degree of lexical variation of reporting verbs into a language with a high degree of lexical variation, the frequency and the degree of explicitation will be higher than in translations involving languages less different with respect to lexical variation. The analysis, relying on data extracted from the InterCorp multilingual corpus, proposes a classification of reporting verbs based on the type and amount of information conveyed, which allows evaluating the degree of explicitation operated in translations. The results show that most shifts involve only the neutral reporting verb say/dire, replaced by a stylistically more specific synonym or by a verb explicitating information obvious from the context. This suggests that modifications of reporting verbs in translation are motivated primarily by respect for the stylistic norm of the target language and the degree of acceptability of the repetition of the neutral reporting verb.

Study of recrystallization kinetics in AA5182 aluminium alloy after deformation of the as-cast structure

2019 ◽  
Vol 6 (6) ◽  
pp. 066552 ◽  
Author(s):  
Vasiliy Yashin ◽  
Evgenii Aryshenskii ◽  
Juergen Hirsch ◽  
Sergey Konovalov ◽  
Ilya Latushkin
Keyword(s):  
Aluminium Alloy ◽  
Cast Structure ◽  
Recrystallization Kinetics

scholarly journals Strong Interactions between Austenite and the Matrix of Medium-Mn Steel during Intercritical Annealing

Materials ◽  
2020 ◽  
Vol 13 (15) ◽  
pp. 3366 ◽  
Author(s):  
Tianpeng Zhou ◽  
Cunyu Wang ◽  
Chang Wang ◽  
Wenquan Cao ◽  
Zejun Chen
Keyword(s):  
Grain Size ◽  
Annealing Temperature ◽  
Ferrite Matrix ◽  
Strong Interactions ◽  
Recrystallization Process ◽  
Austenite Grain Size ◽  
Recrystallization Kinetics ◽  
Average Grain Size ◽  
The Matrix ◽  
Austenite Grains

The effects of heat treatment on the microstructure evolution was studied in regards to austenite nucleation and grain growth. It was found that the austenite nucleation and matrix recrystallization kinetics of samples annealed at 675 °C for different times were revealed, implying a strong interaction between the ferrite matrix and austenite. The recrystallization of the matrix during annealing provided favorable conditions for austenite nucleation and growth, and the formation of austenite during this process reduced the matrix recrystallization kinetics, thus delaying the recrystallization process of the matrix around the austenite grains. The statistical results for the austenite grain size under different annealing temperatures indicated that the average grain size of the austenite slightly increases with increasing of the annealing temperature, but the austenite with the largest grain size grows faster at the same temperature. This difference is attributed to the strict Kurdjumov Sachs (KS) orientation relationship (OR) between the austenite grains and the matrix, because the growth of austenite with a strict KS OR with the matrix is often inhibited during annealing. In contrast, the austenite maintains a non-strict KS OR with the matrix and can grow preferentially with increasing annealing temperature and time.

Recrystallization of 304SS during and after High Strain Rate Deformation

2013 ◽  
Vol 753 ◽  
pp. 403-406
Author(s):  
Adam S. Taylor ◽  
Peter D. Hodgson
Keyword(s):  
Dynamic Recrystallization ◽  
Strain Rate ◽  
Austenitic Stainless Steels ◽  
Avrami Equation ◽  
Recrystallization Process ◽  
Hollomon Parameter ◽  
Softening Mechanism ◽  
Recrystallization Kinetics ◽  
Kinetics Of ◽  
Shape Changes

During the hot working of austenitic stainless steels the shape of the flow curve is strongly influenced by the strain rate. Low strain rate deformation results in flow curves typical of dynamic recrystallization (DRX) but as the strain rate increases the shape changes to a ‘flat-top’ curve. This has traditionally been thought to indicate no DRX is taking place and that dynamic recovery (DRV) is the only operating softening mechanism. Examining the work-hardening behaviour and corresponding deformation microstructures showed this is not the case for austenitic stainless steel, as clear evidence of dynamic recrystallization process can be seen. The post-deformation recrystallization kinetics can be modelled using a standard Avrami equation with an Avrami exponent, n, of 1.15. With an increasing value of the Zener-Hollomon parameter it was found that the kinetics of recrystallization become less strain rate sensitive until at the highest values (highest strain rates/lowest temperatures) the recrystallization kinetics become strain rate insensitive.

Microstructure and Texture Evolution Law of Ti-IF Steel for Extra Deep Drawing during Batch Annealing Process

2013 ◽  
Vol 873 ◽  
pp. 42-47
Author(s):  
Zheng Bing Meng ◽  
Lang He ◽  
Guang Liang Wu ◽  
Xin Bin Liu ◽  
Chao Yang Zhou
Keyword(s):  
Deep Drawing ◽  
Early Stage ◽  
Texture Evolution ◽  
Annealing Process ◽  
Recrystallization Temperature ◽  
Recrystallization Annealing ◽  
Recrystallization Process ◽  
If Steel ◽  
Hardness Tester ◽  
Batch Annealing

The variation of microstructure of Ti-IF steel of extra deep drawing grade, which having a 83%cold-rolled deformation under simulated batch annealing process at temperature ranging from 480°C to 750°C, was studied by using optical microscopy, X-ray diffraction (XRD) and metallographic micro-hardness tester. The evolution of texture during the recrystallization process was analyzed by Orientation Density Function (ODF). The results show that, the recrystallization temperature of experimental steel is 620-630°C, and the recrystallization process can be accomplished within 1h at660°C. Four major textures after cold rolling are observed as follows,{001}<110>, {111}<110>, {111}<112> and {112}<110>, respectively. At the early stage of recrystallization annealing, texture evolves from {111} toγ-{111}, which is quite beneficial to achieve high deep drawing performance,the texture {001}<110> and {112}<110> change marginally. as the annealing temperature rises up to 720°C, texture {001}<110> and {112}<110> change into fiber textureγ-{111}. After annealing,{111}<112> and {111}<110> textures become the two main types.

scholarly journals Using Automated Detection and Classification of Interictal HFOs to Improve the Identification of Epileptogenic Zones in Preparation for Epilepsy Surgery

2019 ◽  
Author(s):  
Sina Farahmand ◽  
Tiwalade Sobayo ◽  
David J. Mogul
Keyword(s):  
Alternative Therapy ◽  
Brain Regions ◽  
Automated Detection ◽  
High Rate ◽  
Epileptogenic Zone ◽  
Analytical Methodology ◽  
Automated Algorithm ◽  
Energy Peak ◽  
Drug Resistant Epilepsy

AbstractObjectiveFor more than 25 million drug-resistant epilepsy patients, surgical intervention aiming at resecting brain regions where seizures arise is often the only alternative therapy. However, the identification of this epileptogenic zone (EZ) is often imprecise which may affect post-surgical outcomes (PSOs). Interictal high-frequency oscillations (HFOs) have been revealed to be reliable biomarkers in delineating EZ. In this paper, an analytical methodology aiming at automated detection and classification of interictal HFOs is proposed to improve the identification of EZ. Furthermore, the detected high-rate HFO areas were compared with the seizure onset zones (SOZs) and resected areas to investigate their clinical relevance in predicting PSOs.MethodsFIR band-pass filtering as well as a combination of time-series local energy, peak, and duration analysis were utilized to identify high-rate HFO areas in interictal, multi-channel intracranial electroencephalographic (iEEG) recordings. The detected HFOs were then classified into fast-ripple (FR), ripple (R), and fast-ripple concurrent with ripple (FRandR) events.ResultsThe proposed method resulted in sensitivity of 91.08% and false discovery rate of 7.32%. Moreover, it was found that the detected HFO-FRandR areas in concordance with the SOZs would have better delineated the EZ for each patient, while limiting the area of the brain required to be resected.ConclusionTesting on a dataset of 20 patients has supported the feasibility of using this method to provide an automated algorithm to better delineate the EZ.SignificanceThe proposed methodology may significantly improve the precision by which pathological brain tissue can be identified.

scholarly journals Study of Recrystallization Kinetics of 1565ch Aluminum Alloy during hot deformation

2020 ◽  
Vol 326 ◽  
pp. 05001
Author(s):  
Vasiliy Yashin ◽  
Alexander Drits ◽  
Evgenii Aryshenskii ◽  
Ilya Latushkin ◽  
Ekaterina Chitnaeva
Keyword(s):  
Growth Rate ◽  
Aluminum Alloy ◽  
Optical Microscope ◽  
Recrystallization Process ◽  
System Alloy ◽  
Industrial Practice ◽  
Cast Ingot ◽  
Recrystallization Kinetics ◽  
Different Temperatures ◽  
Kinetics Of

The present study addresses recrystallization process in Al-Mg-Mn-Zn-Zr system alloy samples. The samples are collected from cast ingot, produced by casting to industrial DC mold, and homogenized based on standard industrial practice. After that the samples were rolled with different hot rolling schedules. Rolled samples were annealed at different temperatures and their resultant microstructure was examined using optical microscope. During the study new grains nuclei generation rate and their growth rate were determined, analytical records, describing recrystallization kinetics, were obtained, main differences, specific to this alloy recrystallization in 350 ºС-450 ºС temperature range, were identified.

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