Joining of Polyethylene Using a Non-Conventional Friction Stir Welding Tool.

The objective of the current study was to butt-weld 6 mm-thick polyethylene (PE) plates by friction stir welding (FSW) using a non-conventional stationary shoulder tool. The welds were performed with an unheated shoulder and with a shoulder temperature of 85 °C. Additionally, rotational speeds of 870, 1140 and 1500 rpm; welding speeds of 60 and 120 mm/min; and plunge depths of 5.5 and 5.7 mm were used. The influence of these parameters on morphology, hardness, ultimate tensile strength, elongation at break and fracture modes was evaluated. Shoulder heating proved to be crucial for the optimization of PE joints by FSW, as it clearly improved joint efficiency. Furthermore, shoulder heating promoted the reduction in internal and external defects, such as porosity and surface burning. Defect-free weld seams were obtained with higher rotational speeds and a lower welding speed. A maximum joint efficiency of about 97% was achieved with a shoulder temperature of 85 °C, a rotational speed of 1500 rpm, a welding speed of 60 mm/min and a plunge depth of 5.7 mm. A weld with the average joint efficiency of 92% was produced at 120 mm/min, which based on the literature found is the highest welding speed reported that achieved a joint efficiency above 90%.

Influence of Tool Geometry and Process Parameters on Torque, Temperature, and Quality of Friction Stir Welds in Dissimilar Al Alloys.

In the current investigation, the influence of the tool geometry, the position of the materials in the joint, the welding speed on the temperature and torque developed, and on the quality of the welds in dissimilar and tri-dissimilar T joints were analysed. The aluminium alloys used were AA2017-T4, AA6082-T6, and AA5083-H111 and the friction stir welds were performed with identical shoulder tools, but with either a pin with simple geometry or a pin with progressive geometry. Progressive pin tools proved to be a viable alternative in the production of dissimilar and tri-dissimilar welds, as they provide a larger tool/material friction area and a larger volume of dragged material, which promotes an increase in the heat generated and a good mixing of the materials in the stir zone, although they require a higher torque. Placing a stronger material on the advancing side also results in a higher temperature in the stir zone but requires higher torque too. The combination of these factors showed that tools with a progressive pin provide sound dissimilar and tri-dissimilar welds, unlike single-pin tools. The increase in the welding speed causes the formation of defects in the stir zone, even in tri-dissimilar welds carried out with a tool with a progressive pin, which impairs the fatigue strength of the welds.

Recent Developments in Non-Conventional Welding of Materials.

Welding is one of the technological fields with the greatest impact in many industries, such as automotive, aerospace, energy production, electronics, the health sector, etc. [...].

Nugget Formation and Mechanical Behaviour of Friction Stir Welds of Three Dissimilar Aluminum Alloys.

The aim of this research was to investigate the influence of the properties of the base materials and welding speed on the morphology and mechanical behavior of the friction stir welds of three dissimilar aluminum alloys in a T-joint configuration. The base materials were the AA2017-T4, AA5083-H111, and AA6082-T6 alloys in 3 mm-thick sheets. The AA6082-T6 alloy was the stringer, and the other alloys were located either on the advancing or retreating sides of the skin. All the T-joint welds were produced with a constant tool rotation speed but with different welding speeds. The microstructures of the welds were analyzed using optical microscopy, scanning electron microscopy with energy dispersive spectroscopy, and the electron backscatter diffraction technique. The mechanical properties were assessed according to micro-hardness, tensile, and fatigue testing. Good quality welds of the three dissimilar aluminum alloys could be achieved with friction stir welding, but a high ratio between the tool's rotational and traverse speeds was required. The welding speed influenced the weld morphology and fatigue strength. The positioning of the skin materials influenced the nugget morphology and the mechanical behavior of the joints. The joints in which the AA2017 alloy was positioned on the advancing side presented the best tensile properties and fatigue strength.

Monitoring of Newcastle disease in poultry at migratory birds landing sites: Mangue Seco and Cacha Pregos between 2013 and 2014 / Monitoramento da doença de Newcastle em aves domésticas nos sítios de pouso de aves migratórias: Mangue Seco e Cacha Pregos entre 2013 e 2014

The poultry industry has been considered one of the most efficient agricultural activities, placing Brazil in the ranking of the largest producers of chicken meat. However, a threat to the poultry production chain is the entrance of Newcastle disease virus (NDV) in the country, which would bring huge economic and social losses. Monitoring of the virus was conducted in domestic poultry (Gallus gallus domesticus) farms on the migratory birds landing sites Mangue Seco and Cacha Pregos between 2013 and 2014 to control Newcastle disease (NCD) in these locations. Activities in health education, filling the questionnaire to define the sanitary profile of the farms, georeferenced registration and collection of blood samples, cloacal and tracheal swabs of the backyard birds were the epidemiological surveillance actions performed. A total of 133 serum samples were analyzed in Mangue Seco and 81 in Cacha Pregos. The results showed that both Mangue Seco (63.4%) and Cacha Pregos (88.9%) presented reactive animals for the NDV. The results of real-time polymerase chain reaction (RT-PCR) and viral isolation analyses were negative, proving that the domestic poultry were not eliminating the virus at the time of sample collection. The high percentage of reactive animals by indirect ELISA test in both epidemiological units studied suggests the presence of NDV circulating lentogenic strain, since there was no death registration and the birds did not have characteristic symptoms of the disease.(AU)

A avicultura tem sido considerada uma das atividades agrícolas mais eficientes, colocando o Brasil no ranking dos maiores produtores de carne de frango. No entanto, uma ameaça à cadeia produtiva da avicultura é a entrada do vírus da doença de Newcastle (NDV) no país, o que acarretaria enormes prejuízos econômicos e sociais. O monitoramento do vírus foi realizado em granjas de aves domésticas (Gallus gallus domesticus) nos locais de desembarque de aves migratórias de Mangue Seco e Cacha Pregos entre 2013 e 2014 para controlar a doença de Newcastle (DCNT) nesses locais. Atividades de educação em saúde, preenchimento de questionário para definição do perfil sanitário das fazendas, cadastro georreferenciado e coleta de amostras de sangue e swabs cloacal e traqueal de aves de quintal foram as ações de vigilância epidemiológica realizadas. Um total de 133 amostras de soro foram analisadas em Mangue Seco e 81 em Cacha Pregos. Os resultados mostraram que tanto Mangue Seco (63,4%) quanto Cacha Pregos (88,9%) apresentaram animais reativos para o NDV. Os resultados da reação em cadeia da polimerase em tempo real (RT-PCR) e das análises de isolamento viral foram negativos, comprovando que as aves domésticas não estavam eliminando o vírus no momento da coleta das amostras. O alto percentual de animais reativos pelo teste ELISA indireto em ambas as unidades epidemiológicas estudadas sugere a presença de cepa lentogênica circulante de NDV, uma vez que não houve registro de óbito e as aves não apresentavam sintomas característicos da doença.(AU)

Isolated abdominal wall metastasis of endometrial carcinoma.

A woman in her mid-60s presented with a bulky mass on the anterior abdominal wall. She had a previous incidental diagnosis of endometrial adenocarcinoma FIGO stage IB following a vaginal hysterectomy. Physical exam and imaging revealed a well circumscribed bulging tumour at the umbilical region, measuring 10 × 9 × 9 cm, with overlying intact skin and subcutaneous tissue. Surgical resection was undertaken, and histological examination showed features of endometrial carcinoma. She began chemotherapy and is alive with no signs of recurrent disease one year after surgery. This case brings up to light an atypical location of a solitary metastasis of endometrial carcinoma.

Total and acute uterine inversion after delivery: a case report.

INTRODUCTION: Uterine inversion is a rare obstetric emergency that can lead to hypovolemic shock or even maternal death. There are many management strategies, but they are poorly described and dispersed in the medical literature. The purpose of this article is to describe a case of complete acute uterine inversion and a review of the literature. CASE PRESENTATION: The authors describe a case of complete uterine inversion after a normal delivery with fundal placenta and without cord traction, in a 33-year-old Caucasian woman. After the diagnosis was made and after several attempts of manual correction of the inversion, the patient was taken immediately to the operating room and a laparotomy was performed. With opposing pressures in the cervical ring through the abdominal cavity and on the uterus fundus through her vagina, the inversion was resolved. An incision on the cervical ring was unnecessary. Due to incomplete detachment of the placenta the bleeding was mild. She recovered without complications and the histological examination of placenta was unremarkable. In this case, the only risk factor for uterine inversion was the fundal implantation of the placenta. CONCLUSIONS: The low incidence of uterine inversion leads to sparse experience in resolving this obstetrical emergency. The best prognosis occurs in situations where the diagnosis and maneuvers for uterine reversal are made at an early stage. The authors concluded that opposing pressures in the cervical ring through the abdominal cavity and on the uterus fundus through the vagina can resolve the inversion without the need of other surgical techniques. It is essential to keep in mind this diagnosis, and be updated about the strategies required to solve this complication.