In this research, fatigue behaviour of Ti-6Al-4V alloy was investigated for smooth and notched specimens with stress concentration factor(Kt) 3.6 and 4.1.This investigation was conducted for various diameter bars having different ultimate strength.Rotating bending fatigue test at R= -1 was emploied for this research. Notch sensitivity data was compared with those of steels. The result indicated that the presence of notch in this alloy has a different amount of sensitivity when the notch specimens were subjected to high cycle fatigue (HCF) and low cycle fatigue(LCF) tests.The notch sensitivity of this alloy was shown generally to be much lower than steel alloys with similar ultimate strength values. Therefore,considering the low sensitivity to notch of this alloy, can be recommended for applications with the presence of notch such as biomedical application

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Manganese steels have extensively application in industries due to good resistance to wear, high work hardening capability with high toughness and ductility. Heat treatment is the main process to obtain desired mechanical properties and microstructure in this steel. The austenitizing temperature, the austenitizing time and the rate of quenching are the main factors in heat treatment. In this research, Taguchi analysis was used to determine optimal heat treatment for minimizing grain boundary carbide content with optimum hardness. Experimental variable chosen for this study included austenitizing temperature and time and the rate of quenching. In the optimization by Taguchi approach, L9(3)3 array, employing nine experiments, with three levels for each factor, was chosen for DOE. The austeitizing temperature and the cooling rate by changing in quenched solution were seen to have greatest influence on hardness of these steels.

Background We aimed to assess potential associations of habitual dietary pattern scores in relation to the risk of pre-diabetes (Pre-DM) progression to type 2 diabetes mellitus (T2DM) or the chance of returning to normal glycemia. Methods This cohort study included 334 Pre-DM individuals (mean age of 49.4 years, and 51.5% men) who participated in the third phase of the Tehran Lipid and Glucose Study (2006–2008) and followed up for a median of 9 years. A validated food frequency questionnaire at baseline assessed usual intakes of the participants. Major dietary patterns were identified using principal component analysis. The DASH score and Mediterranean diet score (MDS) were also calculated. Multinomial logistic regression analysis was used to estimate the odds ratios (95% confidence intervals (CIs)) of developing T2DM and returning to normal glycemia in relation to dietary pattern scores. Results During the study follow-up, 39.8% progressed to T2DM, and 39.8% returned to normal glycemia. Three following major dietary patterns, including Western-style (with a higher load of red meats, hydrogenated fats, sodium, and total fat intakes), healthy pattern (with a higher load of whole grains, vegetables, and dairy products), and processed-foods pattern (with a higher load of processed-meats, fast-foods, salty snakes, and sweets and candies) were identified. The Western-style dietary pattern increased the risk of progressing to T2DM by 38% (OR = 1.38; 95% CI = 1.00 to 1.89, P = 0.050). Other dietary pattern scores were not related to regression or progression from Pre-DM. Conclusion The Western-style dietary pattern (characterized by higher load of red meats, hydrogenated fats, sodium intake, and high-GI foods) may accelerate the progression of Pre-DM to T2DM.