Search

The Aluminium alloy 6061 and Magnesium alloy AZ31 plates of 6 mm thickness are welded in circular butt joint geometry by friction stir welding (FSW) process, using CNC vertical milling machine. Process parameters such as welding speed and tool rotational speed play an important role to obtain a better weld joint for dissimilar metals/materials. The friction stir welding tool is one of the critical components to the success of this process. It consists of a cylindrical shoulder and a pin with different geometry. In the experimental work, the said tool has been designed with cylindrical pin having four different geometries for friction stir welding of the dissimilar circular metal plates. Friction stir welding has been carried out at welding speed varying from 10 to 40 mm/min and tool rotational speed from 800 to 2000 rpm. Effects of process parameters on butt welded circular joint were investigated for weld strength. In this research work, it is found that welded joint between dissimilar metals alloys Al 6061 and Mg AZ31 can be formed using friction stir welding by selecting proper tool pin profile and welding parameters. It is suggested that friction stir welding of Aluminium alloy and Magnesium alloy with circular butt joint geometry would be useful in the future for automobile applications by getting the benefits from each material in a functional way. [ABSTRACT FROM AUTHOR]

Sudden unexplained deaths (SUD) in apparently healthy individuals, for which the causes of deaths remained undetermined after comprehensive forensic investigations and autopsy, present vexing challenges to medical examiners and coroners. Cardiac channelopathies, a group of inheritable diseases that primarily affect heart rhythm by altering the cardiac conduction system, have been known as one of the likely causes of SUD. Adhering to the recommendations of including molecular diagnostics of cardiac channelopathies in SUD investigation, the Molecular Genetics Laboratory of the New York City (NYC) Office of Chief Medical Examiner (OCME) has been routinely testing for six major channelopathy genes (KCNQ1, KCNH2, SCN5A, KCNE1, KCNE2, and RyR2) since 2008. Presented here are the results of cardiac channelopathy testing in 274 well-characterized autopsy negative SUD cases, all with thorough medicolegal death investigation including complete autopsy by NYC OCME between 2008 and 2012. The cohort consisted of 141 infants (92.9% younger than six-month old) and 133 non-infants (78.2% were between 19 and 58 years old). Among the ethnically diverse cohort, African American infants had the highest risks of SUD, and African American non-infants died at significantly younger age (23.7 years old, mean age-at-death) than those of other ethnicities (30.3 years old, mean age-at-death). A total of 22 previously classified cardiac channelopathy-associated variants and 24 novel putative channelopathyassociated variants were detected among the infants (13.5%) and non-infants (19.5%). Most channelopathy-associated variants involved the SCN5A gene (68.4% in infants, 50% in non-infants). We believe this is the first study assessing the role of cardiac channelopathy genes in a large and demographically diverse SUD population drawn from a single urban medical examiner's office in the United States. Our study supports that molecular testing for cardiac channelopathy is a valuable tool in SUD investigations and provides helpful information to medical examiners/coroners seeking cause of death in SUD as well as potentially life-saving information to surviving family members. [ABSTRACT FROM AUTHOR]