Grain refinement of aluminium 4032 alloy with the impact of vibration using Taguchi technique and analysis of variance (ANOVA)

2021 ◽  
Author(s):  
Akash Korgal ◽  
Shravan Upadhyaya ◽  
Anilkumar T
Keyword(s):  
Grain Refinement ◽  
Analysis Of Variance ◽  
Taguchi Technique ◽  
The Impact

scholarly journals Influence of Vanadium on the Microstructure and Mechanical Properties of Medium-Carbon Steels for Wheels

Metals ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 978 ◽  
Author(s):  
Pengfei Wang ◽  
Zhaodong Li ◽  
Guobiao Lin ◽  
Shitong Zhou ◽  
Caifu Yang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Impact Toughness ◽  
Grain Refinement ◽  
Carbon Steels ◽  
Precipitation Strengthening ◽  
Austenite Grain Size ◽  
Medium Carbon ◽  
Microstructure And Mechanical Properties ◽  
Medium Carbon Steels ◽  
The Impact

Steels used for high-speed train wheels require a combination of high strength, toughness, and wear resistance. In 0.54% C-0.9% Si wheel steel, the addition of 0.075 or 0.12 wt % V can refine grains and increase the ferrite content and toughness, although the influence on the microstructure and toughness is complex and poorly understood. We investigated the effect of 0.03, 0.12, and 0.23 wt % V on the microstructure and mechanical properties of medium-carbon steels (0.54% C-0.9% Si) for train wheels. As the V content increased, the precipitation strengthening increased, whereas the grain refinement initially increased, and then it remained unchanged. The increase in strength and hardness was mainly due to V(C,N) precipitation strengthening. Increasing the V content to 0.12 wt % refined the austenite grain size and pearlite block size, and increased the density of high-angle ferrite boundaries and ferrite volume fraction. The grain refinement improved the impact toughness. However, the impact toughness then reduced as the V content was increased to 0.23 wt %, because grain refinement did not further increase, whereas precipitation strengthening and ferrite hardening occurred.

scholarly journals Methods and techniques of research motivation and satisfaction of employees

2021 ◽  
Vol 9 (2) ◽  
pp. 53-63
Author(s):  
Dragana Pešić-Jenačković
Keyword(s):  
Analysis Of Variance ◽  
Employee Motivation ◽  
Test Point ◽  
Coefficient Of Determination ◽  
Business Success ◽  
Chi Square ◽  
Methods And Techniques ◽  
Chi Square Test ◽  
Using Data ◽  
The Impact

Motivation and employee satisfaction are very important precondition for the effectiveness of work and the achievement of set goals for individuals and organizations. Consequently, continuous measurement of employee motivation and satisfaction is essential to improve company's efficiency and improve human resource use. The results of a well-planned, detailed and adequate methods and techniques of research on employee motivation and satisfaction can be applied to the design of various schemes in order to reduce absenteeism and employee turnover and overall business success. In this paper, the emphasis is on the methodology of researching employee motivation and satisfaction. In addition to the elaboration of questionnaires with scales for measuring the motivation and satisfaction of employees, it is explained in which situations, in which types of questions and answers, respectively, types of data, and how certain statistical techniques are applied, such as: T-test, One-factor analysis of variance (ANOVA), Chi-square test, Point-two-series correlations. Also, the importance of using the subsequent post hoc test (LSD comparison) in the analysis of variance, as well as the indicators of correlation, the strength of the impact, such as: phi correlation coefficient, Kramer's coefficient and contingency coefficient, is pointed out in the Chi-square test. In addition to the mentioned techniques and indicators from SPSS, the role of certain indicators (eta squared and coefficient of determination) is calculated, which are calculated using data from research results and with the help of certain formulas

Investigation of mb and MS formulas for the Western United States and their impact on the MS/mb discriminant

1987 ◽  
Vol 77 (3) ◽  
pp. 987-995
Author(s):  
Marvin D. Denny ◽  
Steven R. Taylor ◽  
Eileen S. Vergino
Keyword(s):  
United States ◽  
Systematic Error ◽  
Analysis Of Variance ◽  
Magnitude Estimate ◽  
Peak Amplitude ◽  
Western United States ◽  
Station Correction ◽  
Simple Analysis ◽  
The Impact ◽  
Distance Correction

Abstract The impact of regional mb and MS formulas on regional MS/mb discrimination is investigated using a large number of Western United States earthquakes and explosions. Comparison of NEIS mb values with regional mb values shows a systematic error of 1.2. Additionally, a simple analysis of variance shows that the variance of the magnitude estimate is reduced when log(A) replaces log(A/T). These changes, along with a refinement of the distance correction, yield a new regional mb for the Western United States given by mb = log(A) + 2.4 log(Δ) − 3.95 + cj, where A = 0 to peak amplitude in nanometers, Δ is the distance in kilometers, and ci is a station correction. Usage of this formula improves the performance of regional MS/mb discrimination by a factor of 2 to 6.

Comparison of Four MANOVA Test Statistic for Pig Production in Delta State, Nigeria

2021 ◽  
Vol 6 (5) ◽  
pp. 43-49
Author(s):  
J. M. Aniesedo ◽  
C. N. Okoli
Keyword(s):  
Multivariate Analysis ◽  
Analysis Of Variance ◽  
Multivariate Normality ◽  
Secondary Source ◽  
Multivariate Analysis Of Variance ◽  
Test Statistic ◽  
Pig Production ◽  
Normality Test ◽  
Significant Difference ◽  
The Impact

This study used the multivariate analysis of variance (MANOVA) test statistic to examine the impact of three categories feed used in the production of pig in Delta State. The multivariate test statistic considered are the Pillai – Bartlett trace, Wilks’ Test Statistic, Roy’s Largest Root Test Statistic, and the Lawley- Hotelling (LH) Statistic. The objectives include to: evaluate the robustness of the four Multivariate Analysis of Variance test statistics to ensure that the best is employed in multivariate analysis to guarantee most useful result in pig production; determine the relatively efficient test statistic for pig production; and determine the test statistic that is consistent across the sample sizes. Secondary source of data collection was used to obtain the data required for the analysis. The outcome of the study showed that the obtained data was multivariate normally distributed based on the result of the asymmetry-based multivariate normality test and the multivariate normality test based on the kurtosis test which makes the data suitable parametric multivariate method such as multivariate analysis of variance (MANOVA). The results show that the Wilks and Roy tests found a significant difference for the intercept. While the Pillai and LH tests could not find any significance. The Roy test was also found to be significant for feed one, feed two, and feed three. The Wilks and Roy tests also turned out to be significant differences for the intercept. All test measures showed significance for feed one. The Wilks and Roy tests also showed a significant difference for feed two, while all test measures found a significance for feed one. Another result showed that none of the tests found significance for the interaction between feed one and two, while the Roy test found significance for the interaction between feed one and three, feed two and three and feed one, two and three. The performance of the test for evaluating the performance of feeds for pig production with/without considering interactions was found to be in the following order of magnitude: Roy, Wilks and Pilla = LH. This result implies that the Roy method, with or without consideration of the interaction, has a better performance of the test than the other methods considered in the study.

The Perception of Managers on the Impacts of the Internet in Brazilian Hotels

2003 ◽  
pp. 244-259 ◽  
Author(s):  
Luiz A.M.M. Filho ◽  
Anatália S.M. Ramos
Keyword(s):  
Analysis Of Variance ◽  
Internet Use ◽  
The Internet ◽  
Test Results ◽  
Communication Tool ◽  
Tukey Test ◽  
Significant Difference ◽  
The Impact ◽  
The City

The present study has an exploratory nature and aims to analyze the perception of managers on the efficiency, access importance, use as a communication tool, benefits and difficulties of Internet use in Brazilian hotels and also its effects according to the facilities rank and property size plus managers’ age and experience time. It has been used as a questionnaire to collect data from the managers of 35 hotels in the city of Natal, RN, Brazil. By using analysis of variance (ANOVA) and the Tukey test, results showed that there is almost no significant difference on the perception of managers on the impact of Internet use in hotels. However, those variables that were different show that for younger and less experienced managers and luxurious hotels with more than 50 rooms, there is a more favorable perception on the impacts of the Internet.

Design of Experiments to Study Slurry Erosive Wear Behavior of Inconel-718 Coatings on Copper

2014 ◽  
Vol 939 ◽  
pp. 459-464 ◽  
Author(s):  
C.S. Ramesh ◽  
Rupanagudi Suresh Kumar ◽  
Sikhakolli Ramakrishna ◽  
Venkatesh K.G. Kashyap
Keyword(s):  
Particle Size ◽  
Design Of Experiments ◽  
Analysis Of Variance ◽  
Inconel 718 ◽  
Wear Behavior ◽  
Erosive Wear ◽  
Taguchi Technique ◽  
Nacl Solution ◽  
Slurry Erosion ◽  
Wear Tests

The present work is aimed at investigating the effect of speed , slurry concentration and particle size on Inconel-718 coatings on copper subjected to slurry erosion with the help of DOE (design of experiments) tool among which the Taguchi technique is well known. The coatings are subjected to slurry erosive wear tests in 3.5% NaCl solution (35 gms NaCl/ ltr of water) with sand as erodent. On application of analysis of variance, it is found that all three parameters namely speed, sand concentration of the slurry and particle size are significant with speed being the most significant one.

An Analysis of the Perception of Psoriasis Symptoms and the Impact on Willingness to Seek Medical Attention

2020 ◽  
Vol 5 (3) ◽  
pp. 109-113
Author(s):  
Jeremy K. Bray ◽  
Steven R. Feldman
Keyword(s):  
Medical Care ◽  
Analysis Of Variance ◽  
Daily Life ◽  
Severe Psoriasis ◽  
Mechanical Turk ◽  
Amazon Mechanical Turk ◽  
Medical Attention ◽  
Medical Visit ◽  
Daily Lives ◽  
The Impact

Background: Most people with psoriasis do not have a medical visit for psoriasis within a given year. Objective: To assess individuals’ perceptions of the impact of psoriasis symptoms and how this impact affects willingness to seek medical attention. Methods: A total of 302 subjects with self-reported psoriasis were recruited through Amazon Mechanical Turk and surveyed via Qualtrics to assess the impact of psoriasis on their daily lives and willingness to seek medical care. Comparisons were made between subjects presented with either an image of mild psoriasis or severe psoriasis. Outcome measures were evaluated on a 10-point Likert scale and compared using 1-way analysis of variance and 2-group t tests. Results: In the mild and severe psoriasis groups, those who rated the impact on their daily life ≥8 (1-10 scale) reported a greater willingness to seek medical attention for their psoriasis ( M = 9.1, SD = 1.5) compared to those who rated the impact between 6 and 7 ( M = 7.5, SD = 1.9, P < .01) and between 1 and 5 ( M = 6.4, SD = 2.4, P < .01). Those who rated the impact between 6 and 7 ( M = 7.5, SD = 1.9) reported a greater willingness to seek medical attention compared to those who rated the impact between 1 and 5 ( M = 6.4, SD = 2.4, P < .01). Conclusion: Patients with psoriasis may not visit a dermatologist in part due to not viewing their symptoms as severe enough to seek medical attention.

Numerical and Experimental Study on ECAP-Processing Parameters for Efficient Grain Refinement of AA5083 Sheet Metal

2019 ◽  
Vol 794 ◽  
pp. 315-323 ◽  
Author(s):  
Maximilian Gruber ◽  
Christian Illgen ◽  
Philipp Frint ◽  
Martin F.X. Wagner ◽  
Wolfram Volk
Keyword(s):  
Shear Strain ◽  
Grain Refinement ◽  
Sheet Metal ◽  
Electron Backscatter Diffraction ◽  
Superplastic Forming ◽  
Processing Parameters ◽  
Geometrical Parameters ◽  
Maximum Magnitude ◽  
Applied Model ◽  
The Impact

Equal-channel angular pressing (ECAP) is often used as effective tool for grain refinement for many different metallic materials. It is well known that grain size is an important microstructural feature influencing superplastic properties of fcc materials like aluminum alloys. The magnitude of introduced shear strain depends on geometrical parameters of the ECAP channel. In this contribution, the impact of different geometrical parameters of the ECAP channel on the resulting magnitude of introduced shear strain is analyzed. ECAP on AA5083 aluminum sheets with the dimensions of 200x200x1.8 mm3 is performed. Microhardness measurements reveal a considerable increase of hardness after ECAP and microstructural investigations by electron backscatter diffraction (EBSD) show the beginning formation of a deformation-induced substructure which is known to be a preliminary stage of the grain refinement process. It is assumed that this fine-grained microstructure results in an enhanced superplastic forming capability. Furthermore, a numerical model of the process based on the experimental results is established. The bending of the ECAP processed sheet metal as well as its microhardness are used for the validation of the model. The friction coefficient between the channel and the aluminum sheet significantly influences the results of the simulation. With the applied model different channel angles and inner corner radii are varied in order to determine a maximum magnitude of deformation resulting in sufficient grain refinement of the investigated material. With the help of the results gained in this study, suitable ECAP parameters for sheet metals can be derived that enable creating ultrafine-grained materials for superplastic forming operations.

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