36 research outputs found
Evolution of microstructure and crystallographic texture in severely cold rolled high entropy equiatomic CoCrFeMnNi alloy during annealing
An equiatomic FCC CoCrFeMnNi high entropy
alloy (HEA) was heavily cold rolled
up to 9
0
% reduction
in
thickness followed by isochronal annealing for 1 hour at temperatures
ranging between
70
0ºC to 1
1
00ºC. A strong brass texture was observed in the cold
-
roll
ed
condition indicating the low stacking fault energy of the material. A fine stable microstructure
was observed during annealing at low temperatures. The recrystallization texture was
characterized by the presence of deformation texture components, in pa
rticula
r, the α
-fiber
(ND//), S ({123} ) and
the typical brass recrystallization texture component ({236}
). Annealing twins were shown to have important effect on the formation of annealing
texture
Gene encoder: a feature selection technique through unsupervised deep learning-based clustering for large gene expression data
© 2020, Springer-Verlag London Ltd., part of Springer Nature. Cancer is a severe condition of uncontrolled cell division that results in a tumor formation that spreads to other tissues of the body. Therefore, the development of new medication and treatment methods for this is in demand. Classification of microarray data plays a vital role in handling such situations. The relevant gene selection is an important step for the classification of microarray data. This work presents gene encoder, an unsupervised two-stage feature selection technique for the cancer samples’ classification. The first stage aggregates three filter methods, namely principal component analysis, correlation, and spectral-based feature selection techniques. Next, the genetic algorithm is used, which evaluates the chromosome utilizing the autoencoder-based clustering. The resultant feature subset is used for the classification task. Three classifiers, namely support vector machine, k-nearest neighbors, and random forest, are used in this work to avoid the dependency on any one classifier. Six benchmark gene expression datasets are used for the performance evaluation, and a comparison is made with four state-of-the-art related algorithms. Three sets of experiments are carried out to evaluate the proposed method. These experiments are for the evaluation of the selected features based on sample-based clustering, adjusting optimal parameters, and for selecting better performing classifier. The comparison is based on accuracy, recall, false positive rate, precision, F-measure, and entropy. The obtained results suggest better performance of the current proposal
Evolution of Microstructure and Texture during Warm Rolling Of a Duplex Steel
The effect of warm rolling on the evolution of microstructure and texture in a duplex stainless steel (DSS) was investigated. For this purpose, a DSS steel was warm rolled up to 90 pct reduction in thickness at 498 K, 698 K, and 898 K (225 °C, 425 °C, and 625 °C). The microstructure with an alternate arrangement of deformed ferrite and austenite bands was observed after warm rolling; however, the microstructure after 90 pct warm rolling at 498 K and 898 K (225 °C and 625 °C) was more lamellar and uniform as compared to the rather fragmented and inhomogeneous structure observed after 90 pct warm rolling at 698 K (425 °C). The texture of ferrite in warm-rolled DSS was characterized by the presence of the RD (〈011〉//RD) and ND (〈111〉//ND) fibers. However, the texture of ferrite in DSS warm rolled at 698 K (425 °C) was distinctly different having much higher fraction of the RD-fiber components than that of the ND-fiber components. The texture and microstructural differences in ferrite in DSS warm rolled at different temperatures could be explained by the interaction of carbon atoms with dislocations. In contrast, the austenite in DSS warm rolled at different temperatures consistently showed pure metal- or copper-type deformation texture which was attributed to the increase in stacking fault energy at the warm-rolling temperatures. It was concluded that the evolution of microstructure and texture of the two constituent phases in DSS was greatly affected by the temperature of warm rolling, but not significantly by the presence of the other phas
Patient navigation across the cancer care continuum: An overview of systematic reviews and emerging literature
OnlinePublPatient navigation is a strategy for overcoming barriers to reduce disparities and to improve access and outcomes. The aim of this umbrella review was to identify, critically appraise, synthesize, and present the best available evidence to inform policy and planning regarding patient navigation across the cancer continuum. Systematic reviews examining navigation in cancer care were identified in the Cochrane Central Register of Controlled Trials (CENTRAL), PubMed, Embase, Cumulative Index of Nursing and Allied Health (CINAHL), Epistemonikos, and Prospective Register of Systematic Reviews (PROSPERO) databases and in the gray literature from January 1, 2012, to April 19, 2022. Data were screened, extracted, and appraised independently by two authors. The JBI Critical Appraisal Checklist for Systematic Review and Research Syntheses was used for quality appraisal. Emerging literature up to May 25, 2022, was also explored to capture primary research published beyond the coverage of included systematic reviews. Of the 2062 unique records identified, 61 systematic reviews were included. Fifty‐four reviews were quantitative or mixed‐methods reviews, reporting on the effectiveness of cancer patient navigation, including 12 reviews reporting costs or cost‐effectiveness outcomes. Seven qualitative reviews explored navigation needs, barriers, and experiences. In addition, 53 primary studies published since 2021 were included. Patient navigation is effective in improving participation in cancer screening and reducing the time from screening to diagnosis and from diagnosis to treatment initiation. Emerging evidence suggests that patient navigation improves quality of life and patient satisfaction with care in the survivorship phase and reduces hospital readmission in the active treatment and survivorship care phases. Palliative care data were extremely limited. Economic evaluations from the United States suggest the potential cost‐effectiveness of navigation in screening programs.Raymond J. Chan, Vivienne E. Milch, Fiona Crawford, Williams, Ria Joseph, Jolyn Johal, Narayanee Dick, Matthew P. Wallen, Julie Ratcliffe, Anupriya Agarwal, Larissa Nekhlyudov, Matthew Tieu, Manaf Al, Momani, Scott Turnbull, Rahul Sathiaraj, Dorothy Keefe, Nicolas H. Har
A multiple-objective grouping genetic algorithm for the cell formation problem with alternative routings
Analysis of microstructure and microtexture during grain growth in low stacking fault energy equiatomic CoCrFeMnNi high entropy and Ni–60 wt.%Co alloys
The evolution of microstructure, texture and fraction of annealing twin boundaries is studied in Ni–60 wt.%Co and equiatomic CoCrFeMnNi high entropy alloy (HEA) with similar low stacking fault energy (SFE). The two materials are cold-rolled to 90% reduction in thickness and subjected to different annealing treatments to achieve very similar average grain size. The twin boundary fraction in the two materials was found to be similar for the same average grain size. This indicated that twin boundary fraction depended on the final grain size. The two alloys revealed a strong brass type deformation texture typical of low SFE materials. However, the texture after grain growth in the two alloys was strikingly dissimilar. The Ni–Co alloy showed strong α-fiber (ND//〈1 1 0〉) components, namely, G ({1 1 0}〈0 1 1〉) and G/B ({1 1 0}〈1 1 5〉) due to the preferential growth of these components. In contrast, the microstructure of the HEA showed no preferential grain growth and texture components in HEA revealed only minor changes. These sharply different microstructure and texture formation mechanisms in the two alloys could be explained on the basis of sluggish diffusion in multicomponent HEA which greatly diminished grain boundary mobility and restricted preferential grain growth
Effect of cold-rolling strain on the evolution of annealing texture of equiatomic CoCrFeMnNi high entropy alloy
The effect of cold-rolling strain on the evolution of microstructure and texture during annealing was studied in an equiatomic CoCrFeMnNi high entropy alloy. For this purpose the alloy was cold-rolled to 60%, 80% and 95% reduction in thickness. The three cold-rolled materials were isochronally annealed for 1 h at temperatures ranging between 700 °C and 1200 °C. With increasing rolling reduction, the texture transition from pure metal type ( 80% reduction) was observed. The final recrystallized grain size was found to decrease systematically with increasing prior cold-rolling strain. However, the effect was much less pronounced below the annealing temperature of 1200 °C due to sluggish diffusion in the HEA. The recrystallization texture of different deformed materials showed the presence of similar texture components indicating that prior deformation had only limited effect on the formation of annealing texture. The typical annealing texture components of low SFE materials, such as {236} or {113} were not the dominant components. The volume fractions of different texture components also did not reveal significant dependence on the annealing temperature. The evolution of annealing texture in the HEA could be adequately explained by the absence of strong preferential nucleation and growth
Effect of starting grain size on the evolution of microstructure and texture during thermo-mechanical processing of CoCrFeMnNi high entropy alloy
The effect of starting grain size on the formation of microstructure and texture in heavily deformed equiatomic CoCrFeMnNi high entropy alloy (HEA) was investigated. For this purpose two alloys with average grain size ∼7 μm (fine grained starting material or FGSM) and 200 μm (coarse grained starting material or CGSM) were cold-rolled to 90% and 95% reduction in thickness and isochronally annealed for one hour at temperatures ranging from 700 °C to 1200 °C. Development of strong brass type texture, typical of low stacking fault energy (SFE) materials was noticed in both FGSM and CGSM. Near ultrafine microstructure formation was observed after annealing at 700 °C but extensive grain growth was observed only after annealing at 1200 °C. The FGSM showed finer grain size as compared to CGSM after heavy deformation and annealing. The annealing twin boundary fraction increased with increasing annealed grain size. The annealing textures of both FGSM and CGSM did not show strong dominance of the {236 or {113} components unlike low SFE brass. Furthermore, the volume fractions of different annealing texture components of the HEA were not significantly affected by starting grain size or annealing temperature in stark contrast to low SFE brass. These differences could be explained on the basis of homogenously deformed matrix and sluggish diffusion in HEA which greatly reduced the preferential nucleation and growth of components, respectively
Microstructure and texture of heavily cold-rolled and annealed fcc equiatomic medium to high entropy alloys
The evolution of microstructure and texture after heavy cold-rolling and annealing was investigated in FCC equiatomic medium to high entropy alloys. For this purpose medium entropy ternary CoFeNi and quaternary CoCrFeNi, and high entropy quinary CoCrFeMnNi alloys were cold-rolled to 90% reduction in thickness and annealed at different temperatures. The ternary alloy showed the development of lamellar microstructure and pure metal type texture after heavy cold-rolling. In contrast, the quaternary and quinary alloys showed heavily fragmented microstructure and brass dominated texture. After annealing, the ternary alloy showed abnormal grain growth at lower annealing temperatures and strengthening of the cube component ({001}) with increasing annealing temperature. In contrast, the quinary and quaternary alloys showed more homogenous grain growth and only minor changes in the volume fraction of different texture components during annealing. The observed differences in the microstructure and texture formation during cold-rolling could be understood considering the differences in the stacking fault energy of the three alloys. On the other hand, the evolution of microstructure and texture of the quarternary and quinary alloys was affected by the sluggish diffusion behavior