Simulation of Isothermal Nucleation of Austenite in Spheroidite Plain Carbon Steels

2013 ◽  
Vol 752 ◽  
pp. 201-208
Author(s):  
Gábor Karacs ◽  
András Roósz
Keyword(s):  
Solid Phase ◽  
Carbon Diffusion ◽  
Transformation Process ◽  
Carbon Steels ◽  
Free Enthalpy ◽  
Average Value ◽  
Nucleation Model ◽  
Solid Phase Transformation ◽  
The Difference ◽  
Model Structures

The austenitization is a solid phase transformation process accompanied by nucleation and nucleus growth controlled by long-range carbon diffusion. In the course of our work, a method was developed by which spheroidite model structures were constructed such a way that their different parameters (the size of ferrite grains, the average value of carbon concentration, the size of cementite spheroids) could be changed optionally. In addition, a nucleation model of free enthalpy base was created by which the difference between the two different places of nucleation can be distinguished on the basis of their free enthalpy. The effects of structure parameters, interface free enthalpies and temperature on the nucleation rate of austenite were investigated by cellular automaton simulations.

Trapping Effect on the Kinetic Critical Radius in Nucleation and Growth Processes

2014 ◽  
Vol 790-791 ◽  
pp. 97-102
Author(s):  
Zoltán Erdélyi ◽  
Zoltán Balogh ◽  
Gabor L. Katona ◽  
Dezső L. Beke
Keyword(s):  
Critical Nucleus ◽  
Solid Phase ◽  
Kinetic Monte Carlo ◽  
Mean Field ◽  
Transformation Process ◽  
Nucleus Size ◽  
Critical Nucleus Size ◽  
Acta Mater ◽  
Order Of Magnitude ◽  
The Difference

The critical nucleus size—above which nuclei grow, below dissolve—during diffusion controlled nucleation in binary solid-solid phase transformation process is calculated using kinetic Monte Carlo (KMC). If atomic jumps are slower in an A-rich nucleus than in the embedding B-rich matrix, the nucleus traps the A atoms approaching its surface. It doesn’t have enough time to eject A atoms before new ones arrive, even if it would be favourable thermodynamically. In this case the critical nucleus size can be even by an order of magnitude smaller than expected from equilibrium thermodynamics or without trapping. These results were published in [Z. Erdélyi et al., Acta Mater. 58 (2010) 5639]. In a recent paper M. Leitner [M. Leitner, Acta Mater. 60 (2012) 6709] has questioned our results based on the arguments that his simulations led to different results, but he could not point out the reason for the difference. In this paper we summarize our original results and on the basis of recent KMC and kinetic mean field (KMF) simulations we show that Leitner’s conclusions are not valid and we confirm again our original results.

The Effect of Jigsaw Methode and Motivation on Students’ of Learning Outcomes

2020 ◽  
Vol 3 (1) ◽  
pp. 20-30
Author(s):  
Yunita Yunita ◽  
Hidayat Hidayat ◽  
Harun Sitompul
Keyword(s):  
Cooperative Learning ◽  
Student Learning ◽  
Learning Outcomes ◽  
Student Learning Outcomes ◽  
Learning Motivation ◽  
Learning Approaches ◽  
High Learning ◽  
Average Value ◽  
The Difference ◽  
Low Motivation

This study aims to: (1) investigate the effect of Jigsaw cooperative learning on students learning outcomes; (2) find the difference in learning outcomes between high and low learning motivation and (3) find the interaction between learning approaches and learning motivation towards learning outcomes. The population of the study is students of grade IVa, IVb, IVc at SD Kasih Ibu Patumbak and the sample in this study is grade IVa with 35 students and grade IVb with 35 students. The results show that: (1) the average student learning outcomes of jigsaw cooperative learning is 28.40 while conventional is 24.14. Thus, students learning outcomes that get cooperative learning of jigsaw type are higher than conventional learning, (2) Students who have high motivation get an average value = 30.74, while low motivation is 22.72. Thus, it can be concluded that there are differences in student learning outcomes having high learning motivation and low learning motivation, and (3) students learning outcomes  taught by jigsaw cooperative learning are high learning motivation groups (32.94), and low learning motivation groups (24.58), while students taught with conventional learning are high learning motivation groups (28.40 ), and low motivation groups (20,95). Thus, there is no interaction between learning approaches and learning motivation towards learning outcomes.

Pengaruh Jumlah Pencucian Beras dengan Kadar Klorin

2017 ◽  
Vol 1 (1) ◽  
pp. 89
Author(s):  
Indah Purwaningsih ◽  
Supriyanto Supriyanto
Keyword(s):  
Mucous Membrane ◽  
Confidence Level ◽  
Iodometric Titration ◽  
Titration Method ◽  
Anova Test ◽  
Average Value ◽  
Significant Difference ◽  
The Difference

Abstract: Chlorine is a green halogen-shaped halogen gas at normal temperature and serves as bleach, stain remover and disinfectant. Chlorine is now widely used for bleaching rice so that less quality rice looks like quality rice. Chlorine is very toxic and causes mucous membrane irritation, highly reactive and very powerful oxidizer. The purpose of this research was to determine the difference of chlorine level in chlorinated rice washed once, twice and 3 times. The sample in this study amounted to 11 samples calculated by replication formula. Each sample was treated 3 times, ie 1 washed once, 2 washed twice and washed 3 times. The samples then examined by iodometric titration method. Based on the results of the study using ANOVA test, 11 samples obtained the average value of chlorine after washed once amount of 0.0176%, after washed twice amount of 0.0111%, and after washed 3 times amount of 0.0052% with the value significance p = 0.03 (p <0.05) at 95% confidence level which means there was a significant difference between chlorine levels in chlorinated rice washed once, twice and 3 times.Abstrak: Klorin merupakan unsur halogen berbentuk gas berwarna kuning kehijauan pada suhu normal danberfungsi sebagai pemutih, penghilang noda maupun desinfektan. Klorin sekarang banyak digunakan untuk bahan pemutih beras agar beras yang kurang berkualitas tampak seperti beras berkualitas. Klorin sangat toksik dan menyebabkan iritasi membran mukosa, sangat reaktif dan merupakan oksidator yang sangat kuat. Tujuan dari penelitian ini ialah untuk mengetahui perbedaan kadar klorin pada beras berklorin yang dicuci sebanyak 1 kali, 2 kali dan 3 kali. Sampel dalam penelitian ini berjumlah 11 sampel yang dihitung dengan rumus replikasi. Setiap sampel diberi perlakuan sebanyak 3 kali, yaitu 1 kali pencucian, 2 kali pencucian dan 3 kali pencucian. Sampel penelitian kemudian diperiksa dengan metode titrasi iodometri. Berdasarkan hasil penelitian menggunakan uji Anova secara komputerisasi terhadap 11 sampel diperoleh nilai rata-rata kadar klorin setelah 1 kali pencucian sebesar 0,0176 %, setelah 2 kali pencucian sebesar 0,0111 %, dan setelah 3 kali pencucian sebesar 0,0052 % dengan nilai signifkansi p = 0,03 (p<0,05) pada tingkat kepercayaan 95% yang artinya ada perbedaan yang bermakna antara kadar klorin pada beras berklorin yang dicuci sebanyak 1 kali, 2 kali dan 3 kali.

Results of studying the dimensional accuracy of the bases of complete removable prostheses made using 3D printing and traditional technologies

2020 ◽  
pp. 34-39
Author(s):  
Vokulova Yu.A. Vokulova ◽  
E.N. Zhulev
Keyword(s):  
3D Printing ◽  
Traditional Method ◽  
Laser Scanning ◽  
Laser Scanner ◽  
Digital Technologies ◽  
Dimensional Accuracy ◽  
3D Printer ◽  
Significance Level ◽  
Average Value ◽  
The Difference

This article presents the results of studying the dimensional accuracy of the bases of complete removable prostheses made using a 3D printer and the traditional method. Bases of complete removable prostheses were made using an intraoral laser scanner iTero Cadent (USA) and a 3D printer Asiga Max UV (Australia). To study the dimensional accuracy of the bases of complete removable prostheses, we used the DentalCAD 2.2 Valletta software. The Nonparametric Wilcoxon W-test was used for statistical analysis of the obtained data. We found that the average value of the difference with the standard for bases made using digital technologies is 0.08744±0.0484 mm. The average value of the difference with the standard for bases made by the traditional method is 0.5654±0.1611 mm. Based on these data, we concluded that the bases of complete removable prostheses made using modern digital technologies (intraoral laser scanning and 3D printer) have a higher dimensional accuracy compared to the bases of complete removable prostheses made using the traditional method with a significance level of p<0.05 (Wilcoxon's W-test=0, p=0.031). Keywords: digital technologies in dentistry, digital impressions, intraoral scanner, 3D printing, ExoCAD, complete removable dentures.

scholarly journals Changes in Phenols, Polysaccharides and Volatile Profiles of Noni (Morinda citrifolia L.) Juice during Fermentation

Molecules ◽  
2021 ◽  
Vol 26 (9) ◽  
pp. 2604
Author(s):  
Zhulin Wang ◽  
Rong Dou ◽  
Ruili Yang ◽  
Kun Cai ◽  
Congfa Li ◽  
...  
Keyword(s):  
Octanoic Acid ◽  
Solid Phase ◽  
Principal Component ◽  
Hexanoic Acid ◽  
Morinda Citrifolia ◽  
Gas Chromatography Mass Spectrometry ◽  
Aroma Characteristics ◽  
Volatile Profiles ◽  
The Difference ◽  
Aroma Components

The change in phenols, polysaccharides and volatile profiles of noni juice from laboratory- and factory-scale fermentation was analyzed during a 63-day fermentation process. The phenol and polysaccharide contents and aroma characteristics clearly changed according to fermentation scale and time conditions. The flavonoid content in noni juice gradually increased with fermentation. Seventy-three volatile compounds were identified by solid-phase microextraction coupled with gas chromatography–mass spectrometry (SPME-GC-MS). Methyl hexanoate, 3-methyl-3-buten-1-ol, octanoic acid, hexanoic acid and 2-heptanone were found to be the main aroma components of fresh and fermented noni juice. A decrease in octanoic acid and hexanoic acid contents resulted in the less pungent aroma in noni juice from factory-scale fermentation. The results of principal component analysis of the electronic nose suggested that the difference in nitrogen oxide, alkanes, alcohols, and aromatic and sulfur compounds, contributed to the discrimination of noni juice from different fermentation times and scales.

Solid-solid phase transformation of uniaxially oriented n-alkane crystals of high purity

1995 ◽  
Vol 355 (1) ◽  
pp. 95-104 ◽  
Author(s):  
Ryozo Kitamaru ◽  
Fumitaka Horii ◽  
Masaru Nakagawa ◽  
Kanichiro Takamizawa ◽  
Yoshiko Urabe ◽  
...  
Keyword(s):  
Phase Transformation ◽  
High Purity ◽  
Solid Phase ◽  
Solid Phase Transformation

Heat-Induced Solid–Solid Phase Transformation of TKX-50

2017 ◽  
Vol 121 (15) ◽  
pp. 8262-8271 ◽  
Author(s):  
Zhipeng Lu ◽  
Xianggui Xue ◽  
Liya Meng ◽  
Qun Zeng ◽  
Yu Chi ◽  
...  
Keyword(s):  
Phase Transformation ◽  
Solid Phase ◽  
Solid Phase Transformation

scholarly journals Dynamical simulations of an electronically induced solid-solid phase transformation in tungsten

2015 ◽  
Vol 92 (13) ◽  
Author(s):  
Samuel T. Murphy ◽  
Szymon L. Daraszewicz ◽  
Yvelin Giret ◽  
Matthew Watkins ◽  
Alexander L. Shluger ◽  
...  
Keyword(s):  
Phase Transformation ◽  
Solid Phase ◽  
Dynamical Simulations ◽  
Solid Phase Transformation

Electronic irradiation of TlInSxSe2−x (x = 1): Morphology, structure and raman scattering

2021 ◽  
Author(s):  
M. Yu. Tashmetov ◽  
F. K. Khallokov ◽  
N. B. Ismatov ◽  
I. I. Yuldashova ◽  
S. Kh. Umarov
Keyword(s):  
Surface Morphology ◽  
Single Crystal ◽  
Single Phase ◽  
Phase State ◽  
Monoclinic Structure ◽  
Average Value ◽  
Single Phase State ◽  
Before And After ◽  
Electronic Irradiation ◽  
The Difference

It is shown that the replacement of a part of sulfur atoms with selenium atoms in a TlInS2 single crystal stimulates the formation of a single-phase state with a monoclinic structure (space group [Formula: see text]/[Formula: see text] in TlInS[Formula: see text]Se[Formula: see text] ([Formula: see text]). Irradiation with 2 MeV electrons and a fluence of [Formula: see text] electron/cm2 of powder TlInS[Formula: see text]Se[Formula: see text] ([Formula: see text]) leads to an increase in the crystallite size from 56.5 nm to 65 nm, which is most likely associated with a decrease in the interface. The difference between the surface morphology of the synthesized TlInS[Formula: see text]Se[Formula: see text] ([Formula: see text]) single crystal and the surface morphology of the TlInS2 single crystal is established, which consists in a decrease in the height and width of the roughness in TlInS[Formula: see text]Se[Formula: see text] ([Formula: see text]). Irradiation of a TlInS[Formula: see text]Se[Formula: see text] ([Formula: see text]) single crystal with electrons with a fluence of [Formula: see text] electron/cm2 does not lead to a change in the height of the tubercle on its surface, and the average value of its width increases more than ten-fold. The identity of the peaks in the Raman spectra of the TlInS[Formula: see text]Se[Formula: see text] ([Formula: see text]) single crystal before and after its irradiation with electrons with an energy of 2 MeV and upto a fluence of [Formula: see text] electron/cm2, along with the absence of a shift of the peaks, indicates the radiation resistance of the TlInS[Formula: see text]Se[Formula: see text] ([Formula: see text]) single crystal.

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