Prevalence and intensity of depression in mothers of children with beta-thalassemia major in Talghani Hospital of Gorgan, Iran

Background: Thalassemia is a chronic disease that it leads to psychological and social problems for parents. Mothers are at markedly increased risk of suffering from psychological distress and depression because they usually take on a considerable part of extra care that their children need.This study was designed to determine prevalence and intensity of depression in mothers with a thalassemic child. Material and Methods: In this cross - sectional study, 65 mothers of children with thalassemia major (case group) and 65 mothers of children without thalassemia major (control group) were assessed using the Beck Depression Inventory (BDI). Data were analyzed by using SPSS (v 16.0) for windows. Results: Prevalence of depression was significantly higher in case group than that in control group (84.6%vs. 56.9%, p <0.05). Moderate depression had a highest prevalence in the both groups (33.4% in case group and 30.8% in control group). Prevalence of severe depression in case group was markedly higher than that in control group (29.2% vs. 3.1% p<0.05). There was a significant difference between intensity of depression in mothers of case group that had another child with beta-thalassemia major (p<0.05). Conclusion: Mothers of children with thalassemia major are vulnerable to depression. They need psychosocial support to promote their health. © Journal of Krishna Institute of Medical Sciences University

Application of cellular automata method to simulate the hot deformation behavior of a dual phase titanium alloy

A mathematical model based on the Eshelby theory and using the cellular automata method (CA) is developed to study microstructure evolution during forging of two-phase alloys. Specifically, the method is applied to the case of near alpha titanium alloy, IMI834, mainly used in the high-pressure parts of axial compressors of the most recent gas turbine engines. Viscoplastic laws are used to describe the flow behavior of this alloy for equixed&nbsp; microstructures. The results obtained by CA models can reasonably well describe the material behavior both in the high temperature beta phase and in the two phase alpha + beta region. Experimental data of hot compression in the pure beta field are exploited in order to quantify the thermomechanical behavior of this phase, then processing in the alpha + beta field are used to calculate a phase behavior. Comparisons between the numerical modelling results and the experimental ones indicates that the CA method has a good capability for predicting the influence of forging conditions on the local and global mechanical characteristics of IMI834 alloy

New Analyses of Pressure Filtration Curves of Al Alloys: A Case Study

NRC publication: Ye

Linear Friction Welding of Ti-6Al-4V: Processing, Microstructure and Mechanical Property Inter-relationships

The linear friction welding behavior of Ti-6Al-4V was investigated using varying processing conditions of frequency (15 to 70 Hz), amplitude (1 to 3 mm), pressure (50 to 90 MPa), and axial shortening (1 to 2 mm). Examination of linear friction welded Ti-6Al-4V using microscopic techniques indicated that the process requires certain critical conditions at the interface and its adjacent region to be reached for producing joints without structural defects along the weld centerline, such as voids or oxide inclusions. Characterization of the weldments included analysis of the microstructural features of the weld and thermomechanically affected zones (TMAZs) in relation to the parent material. It was observed that in the weld region, exposure to supertransus temperatures (>995 \ub0C) combined with hot-deformation working and rapid cooling after joining produced recrystallization of the beta grain structure that had a Widmanst\ue4tten alpha-beta transformation microstructure. In the TMAZ, the bimodal microstructure of the parent material was deformed and the presence of elongated alpha grains with broken beta-phase particles was established. Through examination of the mechanical properties, using microhardness and tensile testing, the integrity of the joints was determined in order to assess the impact of the various processing parameters and to define the optimum welding conditions.NRC publication: Ye

Effect of tool rotational speed and probe length on lap joint quality of a friction stir welded magnesium alloy

The effects of tool rotational speed and probe length on lap joint quality of friction stir welded 2-mm AZ31B-H24 magnesium alloy were investigated in terms of welding defects, microstructure and mechanical properties. Tensile shear load initially increases with increasing tool rotational speed but decreases with further increase. However, the tensile shear load always increases with increasing probe length. The highest shear strength is obtained using a set of welding parameters resulting in a downward hooking defect at the maximum stress location of the top sheet. Sound lap joints with low distortion, lack of cavity, minor kissing bond and preferable hooking defects, and high tensile shear strength were successfully obtained, indicating the great potential of friction stir welding technique for magnesium alloys. \ua9 2010.Peer reviewed: YesNRC publication: Ye

Application of shear punch testing to study microstructure-property relationships in electron beam welded 17-4 PH stainless steel

Electron beam (EB) weldments of 17-4 precipitation hardening (PH) martensitic stainless steel (SS) consisted of a series of distinct yet very narrow heat-affected zones (HAZ) with different microstructural characteristics (composition, fraction and/or size of precipitates, phases and grains). Considering the limited size of each HAZ, shear punch testing (SPT) offers a practical solution for evaluating the mechanical and fracture properties of individual regions within the weldment. This paper describes the use of SPT to determine the variation in the tensile strength (yield and maximum), ductility and strain hardening properties of different regions of the weldment and relate them to the microstructural gradient observed in each of them.Des soudures au faisceau \ue9lectronique (EB) de l'acier inoxydable (SS) martensitique 17-4 \ue0 durcissement par pr\ue9cipitation (PH) consistaient en une s\ue9rie de zones affect\ue9es par la chaleur (HAZ) distinctes bien que tr\ue8s \ue9troites avec des caract\ue9ristiques diff\ue9rentes de microstructure (composition, fraction et/ou taille de pr\ue9cipit\ue9s, de phases et de grains). Consid\ue9rant la taille limit\ue9e de chaque HAZ, l'essai au poin\ue7on de cisaillement (SPT) offre une solution pratique \ue0 l'\ue9valuation des propri\ue9t\ue9s m\ue9caniques et de fracture de r\ue9gions individuelles dans la soudure. Cet article d\ue9crit l'utilisation du SPT pour d\ue9terminer la variation de la r\ue9sistance \ue0 la traction (limite d'\ue9lasticit\ue9 et maximum), de la ductilit\ue9 et des propri\ue9t\ue9s d'\ue9crouissage de diff\ue9rentes r\ue9gions de la soudure, et les associe au gradient de microstructure observ\ue9 dans chacune d'elles.Peer reviewed: YesNRC publication: Ye

Estimation of the Resistance of the Filter Media Used for the Prefil Footprinter Tests of Liquid Aluminium Alloys

NRC publication: Ye

Effect of Welding Speed on 2-mm Thick Butt Joint Quality of Friction Stir Welded AZ31B-H24 Magnesium Alloy

NRC publication: Ye

Electron Beam Freeform Fabrication on Stainless Steel

The use of electron beam technology for freeforming 321 SS was investigated using 347 SS solid wire and BNi-2 brazing paste as filler materials. The electron beam freeforming (EBFF) studies involved examining the effect of processing parameters on the characteristics of the line build-ups. Specifically, the effective growth rate and the dimensional features (height-to-width ratio) of the build-ups were found to be dependent on the beam energy and the filler material conditions (e.g. wire feed rate and the number of re-melting passes). The EBFF work indicated that build-ups with either filler material could be deposited on 321 SS using an optimized processing window that resulted in properties comparable to technical data available for 347 SS and BNi-2.NRC publication: Ye

Overview of Friction Stir and Laser Welding Techniques for Lightweight Alloys

NRC publication: Ye