Friction stir welding (FSW) is a relatively new solid-state joining process. This joining technique is energy efficient, environment friendly, and versatile. In particular, it can be used to join high-strength aerospace aluminum alloys and other metallic alloys that are hard to weld by conventional fusion welding. FSW is considered to be the most significant development in metal joining in a de...

Friction stir welding (FSW) is now well established as a welding process capable of joining some different types of metallic materials, as it was (1) found to be a reliable and economical way of producing high quality welds, and (2) considered a "clean" welding process that does not involve fusion of metal, as is the case with other traditional welding processes. The aim of this study was to de...

OBJECTIVE Traditional retainers (both metal and fiber-reinforced composite [FRC]) have limitations, and a retainer made from more flexible ligature wires might be advantageous. We aimed to compare an experimental design with two traditional retainers. METHODS In this prospective preliminary clinical trial, 150 post-treatment patients were enrolled and randomly divided into three groups of 50 ...

OBJECTIVES To estimate the prevalence and associated risk factors of hepatitis B virus (HBV) serological markers in female sex workers (FSW) in Mexico City. METHODS The study population consisted of 1498 FSW who attended a detection centre for human immunodeficiency virus (HIV) in Mexico City, between January and October 1992. Study participants responded to a standardised questionnaire and p...

To overcome limitations of fusion welding of the AA7050-T7451aluminum alloy friction stir welding (FSW) has become a prominent process which uses a non-consumable FSW tool to weld the two abutting plates of the workpiece. The FSW produces a joint with advantages of high joint strength, lower distortion and absence of metallurgical defects. Process parameters such as tool rotational speed, tool ...

For decades, models have been developed for predicting the size of the weld nugget and heat affected zones in fusion welded structures. The basis for these models is the welding heat input, which is fairly well understood for most arc welding processes. However, this traditional approach is not as straightforward for friction stir welding (FSW). To date, no definitive relationship exists to qua...

Friction stir welding (FSW) is considered one of the most significant developments in joining technology over the last half century. Its industrial applications are growing steadily and so are the number of workers using this technology. To date, there are no reports on airborne exposures during FSW. The objective of this study was to investigate possible emissions of nanoscale (<100 nm) and fi...

The prevalence of Mycoplasma genitalium is high in vulnerable populations of women in low-resource settings. However, the epidemiology of infection in these populations is not well established. To determine the prevalence of Mycoplasma genitalium and its association with cervical cytology and other correlates, we recruited 350 female sex workers (FSW) who were 18 to 50 years old in Nairobi, Ken...

We compared HIV-1 strains in incident and prevalent infections in a cohort of men having sex with men (MSM) and female sex workers (FSW) near Mombasa, Kenya and conducted a cross-sectional study of viral isolates from a sample of HIV-1-infected MSM and FSW in Kilifi, Coast Province, Kenya. RNA extracted from plasma of 13 MSM, 9 FSW, and one heterosexual male was amplified by nested RT-PCR and t...

Friction Stir Welding (FSW) is considered to be the most significant development in metal joining technologies to join high strength aerospace aluminum alloys. In order to improve the reliability and quality of the products manufactured by FSW process input process parameters such as tool rotational speed, welding speed and axial force are to be optimized. This study deals with the optimization...