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The paper presents an innovative approach implemented in QForm UK Extrusion FEM software to analyse one of the core defects encountered in profile extrusion known as billet skin defect. The validation of the algorithm has been performed based on a number of experimental case studies taken from the literature [1,2]. Additionally, the sensitivity of the accuracy of the results to the variation in initial parameters has been analysed for both types of profile shapes: solid and hollow. Based on this, practical recommendations have been formalised for the successful industrial use of the presented algorithm.

The microstructure of Al-Mg-Si alloys is gaining nowadays an increasing industrial interest because it influences the strength, crash, corrosion and esthetic properties of the extruded profiles. In order to investigate and predict the recrystallization behaviour in the extrusion of 6XXX aluminum alloys, experimental and numerical activities are still needed. In this work, the extrusion of an industrial-scale AA6060 aluminum alloy hollow profile was carried out. An innovative recrystallization model was developed and optimized by comparing the microstructural data experimentally acquired with the outputs of the simulation performed using the Finite Element commercial code Qform Extrusion. A good correlation between numerical prediction and experimental data was found, thus proving the reliability of the proposed AA6060 recrystallization model.

During the extrusion process, high temperatures are generated, due to friction and deformation works, potentially leading to profile and die defects. Among the suggested solutions aimed at controlling the thermal field of the process, the most accredited one involves the manufacturing of cooling channels at the mating face between the die and a third plate. Despite the proven efficiency of well-designed channels, the main drawback lies in the managing of the many variables involved that strongly affect the cooling efficiency and balancing. In this frame, aim of the work is to investigate the applicability of the topological optimization tool, proposed by COMSOL Multiphysics software, for the design of cooling channels in extrusion dies. To validate the tool, an industrial case study has been selected and results compared between not optimized and optimized cooling solutions.

The rupture of an intracranial Arteriovenous Malformation (AVM) in pregnancy is a rare occurrence, but may have fatal consequences. A link between AVM rupture and pregnancy has been proposed; it may be caused by the increased cardiac output or circulatory effects of the elevated estrogen levels. Surgical intervention for ruptured AVM during pregnancy could prevent rebleeding, and allow for determination of the delivery method based on the obstetrical indications. Cooperation between neurosurgeons, obstetricians, and anesthesiologists and sufficient information about the treatment strategy given to the patients are essential. Here, we report the case of a 27-weekpregnant woman who presented with a symptomatic ruptured cerebral AVM, treated by cesarean section followed surgical resection.

During a multicentric pilot screening program for congenital hypothyroidism a comparison between the results obtained from Urbino, an area characterized by low iodine supply and endemic goiter, and Rome, a non-endemic area, has been made. The evaluation of neonatal urinary iodine excretion in the two areas showed significantly lower iodine urinary excretion levels in Urbino than in Rome. A shift of TSH at screening toward higher values as well as a higher percentage of recall in Urbino area than in Rome was observed. This finding, which well correlates with a low environmental iodine supply, emphasizes the importance of screening for congenital hypothyroidism as a suitable index of the presence and action of goitrogenic factors in the environment.

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A case of angiofollicular lymph node hyperplasia (Castleman's disease) characterized by nionotypic (1gG + , 1arnbda-t) plasrnacytosis is described. I'resh tissue was available and a thorough iiiiunohistocheniical analysis of lymphoid and noiilyniphoid cells was performed on cryostat sections. Although lyrnphoid follicles were nurnerous and exhibited sonie abnormal features they did not appear part of the nionocloiial cell proliferatiun. Follicular lymphocytes were niixtures of Kappai and 1arnbda-t cells. Vessels penetrating within these abnormal follicles expressed reduced levels of FVlll and Leu-M5 antigens and exhibited thicker layer oí collagen type IV. The analysis of T-cell subsets showed a normal (3:l) T4/T8 ratio. This case extends to the mixed variant of hyaline-vascular Castleman's disease, the neoplastic potential previously associated to the plasrria cell variant of the disease.

Eight cases of human thymoma have been analyzed on cryostat sections with the monoclonal antibody Ki67, which reacts with cells in the proliferative phases of the cell cycle. The aim was to assess the proportion of proliferating thymocytes among lymphoid cells in the thymoma samples. In all cases a large number of cells (mean, 58.75%; range, 35-80%), recognized as thymocytes by morphology and lack of cytokeratin expression in a combined immunohistochemical assay, exhibited nuclear Ki67 staining. These findings differ from the reactivity pattern observed in age-matched nonneoplastic thymuses where lower growth activity of cortical thymocytes was observed (15-20% Ki67+ cells). Intensive thymocyte proliferation in thymomas may represent one of the factors which lead to autoimmunity in myasthenia gravis and thymomas.

In the first part of the paper, experimental trials performed in the extrusion of 4 L-shaped profiles made by AA6082 aluminium alloy were presented and analyzed in order to investigate the effect of different pockets concepts on process results like extrusion load, profile lengths, die and profile temperature. The trials were performed at 0,5 and 5 mm/sec ram speed thus producing unexpected differences especially in term of profile lengths. Then two FE codes, COMSOL® Multiphysics and DEFORMTM 3D, were applied in the simulation of the problem in order to validate FEM simulations by comparison with the experimental trials. In particular the two codes adopt different formulations for process analysis: eulerian the first updated lagrangian the second, thus producing also an interesting comparison of the solving methods for the prediction of process outputs like loads, final profiles speeds and exit temperatures.

Visioplasticity represent a powerful technique for Investigating material flow during bulk metal forming processing and particularly In extrusion where complex metal flows occur. In particular, gridded billets or rod Insertion techniques are used for characterize metal flow In direct and Indirect hot aluminium extrusion. In the paper reduced scale experiments were innovatively proposed in order to analyze the process tribology by means of visioplasticity of coated tools (TIN layer by means of Physical Vapor Deposition (PVD) Technique, TiC-TiN-AI2O3 layer through Chemical Vapor Deposition (CVD) Technique) comparing the results to classical uncoated tools. Reduced scale experiments provides friction conditions comparable to real scale extrusion as revealed by the comparison with a real scale extrusion of a round profile. The deformed grids were measured In order to estimate the friction effect throughout the billet length In coated and uncoated tools conditions. Numerical investigations for the qualitative and quantitative determination of friction models were carried out by means of the Deform code with different friction formulations and coefficients. It was found that uncoated tools realize a fully sticking behaviour, while die coatings allowed reducing process friction; CVD coating better fits extrusion requirements because PVD coating lost its effect after a limited number of billets.

In a previous works [1] an innovative technological test has been presented developed by this research group. Analytical models available in the literature to describe the material behaviour in the creep-fatigue regime are currently under investigation to be validated against this experimental campaign. Aim of the present work is to present the first step of this investigation in which the thermal distribution of the specimen has been replicated by means of thermo-electrical simulations. Preliminary comparison between experimental and numerical results on the creep behaviour are also presented.

The authors report their experience of echocardiography performed on a group of 736 pregnancies with specific risk-factors for congenital heart disease (CHD). The aim of the study was to evaluate the influence of specific risk-factors (established through the genetic counselling) in detecting fetal cardiac anomalies and diagnostic accuracy of extended fetal echocardiographic examination in high-risk pregnancies. Twenty-seven heart defects were observed (3.6%), of these 24 were detected at ultrasound. Specificity and sensitivity were 99% and 90% respectively. These results suggest the importance of an early detection of pregnancies at increased risk for CHD and confirm the good diagnostic accuracy of a multiple cardiac examination.

The wedge and bulge expansion tests were compared in the assessment of the seam welds strength in a tubular profile extruded at two ram speeds. In the wedge test, the expansion was determined by moving a conical punch into the tube until the specimen fracture. In the bulge test, a hydrostatic tensile stress state was applied by expanding the specimen with an internal rubber plug. The two methodologies were compared in terms of load and hoop strain at fracture and by detecting the fracture morphology and location. Then, the effect of a number of design parameters was investigated in order to evaluate the robustness of the standard testing conditions. For both tests, ductile fractures appeared in the seam welds location, but the bulge test was more robust and conservative with respect to the wedge test, showing less scattered data. Thus, the performances of a second die for the tube profile, designed to optimize the seam welds quality, have been successfully assessed by the bulge test and results compared to those achieved by a novel numerical quality index, coming to a final good matching.

A wide range of volatile organic compounds (VOCs) is released during plant-pathogen interactions both by the pathogens and the hosts. Some of these VOCs may have an effect on plant signal transduction pathways, thus contributing to pathogenicity or plant defence responses. Strains of the virulent biovar 3 of Pseudomonas syringae pv. actinidiae emit ethylene, both from axenic cultures in a growth medium obtained from Actinidia deliciosa leaf extract, and from infected plants. Accordingly, the infection stimulates the ethylene signal cascade in the host. Other compounds, either emitted by the bacterium (such as 1-undecene, linear ketones and benzyl alcohol), or strongly induced in plants after infection, such as decane, may present a biological activity. Healthy plants react to VOCs from infected neighbours, by activating the phenylpropanoid pathway and several PR genes. However, after the infection, P. syringae pv. actinidiae is able to selectively depress the induced plant defences, possibly by stimulating the oxylipin pathway. Ethylene and oxylipin derivatives, such as jasmonates, may counteract salicylic acid-mediated defences, thus allowing bacterial growth in the host plant. Our research demonstrates that VOCs from infected plants may promote both plant defences and disease development. The further characterization of the signalling pathways involved in such mechanisms may result useful to design plant protection strategies.

Plasma Electrolytic Oxidation (PEO) was applied to extruded ZM21 Mg alloys to improve their corrosion resistance in a chloride-containing environment. PEO was carried out in DC mode and voltage control in a fluoride-free electrolyte. Potentiodynamic polarization tests in 3.5 wt.% NaCl aqueous solution and neutral salt spray (NSS) tests were carried out. Microstructural and profilometric characterization, as well as NSS tests were performed in different conditions: (i) bare ZM21, (ii) PEO-treated ZM21, (iii) powder-coated ZM21 (without PEO interlayer), and (iv) PEO-treated ZM21 with powder coating top layer (carboxyl-functionalized polyester resin). The PEO + powder coating double layer was identified as the best-performing corrosion protection.

In the last decades a strong increase of use in Carbon Fibre Reinforced Polymers (CFRPs) in the production of structures and components occurred. In particular in the automotive and aeronautical sectors several manufacturers already replaced light alloy or high strength steel parts with composites but the use of composite materials is rapidly growing also in other industrial sectors. Composites offer great advantages not only in term of specific proprieties but also in term of “functionalization” of the products by means of the lay-up sequence optimization and consequently providing heterogeneous improved proprieties in the different three-dimensional directions. CFRPs with epoxy resin matrix, among the polymer composites, offer the highest mechanical proprieties in particular when combined with autoclave technology that represents the top standard. On the other side the production of composite materials parts, and particularly the autoclave processing, is still very far respect to conventional metal forming processes in term of production rates. For this reason a considerable effort is oriented towards research and development of the so called “out of autoclave” processing where a trade-off between mechanical proprieties and production rates are investigated. A real optimization of the whole process requires robust and efficient technologies also during those phases able to guarantee high production rates. Laser processing represents a typical technology able to guarantee high flexibility joined with high automation and high production rate not only for small but also for large series manufacturing. For all these reasons, a solid state continuous wave Laser has been used for machining thin sheets made by woven carbon fibre/epoxy resin Pre-preg of 160 g/mm2 (HR 3K 200 TEX carbon fibre with a 50% fibres in the warp and 50% in the weft directions). The aim was to investigate the interaction mechanism for removing the resin without damaging the fibres. Preliminary results in terms of process feasibility area were presented and discussed.

The paper reports information in term of simulation settings and output results related to the Industrial benchmark 2015: extrusion benchmark is an event where participants from software houses, industries and academia are requested to simulate an extrusion process case which main experimental data are initially unknown and disclosed only after the submission of simulation results. The industrial benchmark 2015 is focused on the extrusion of a multi-cavities hollow profile with EN AW-6063 aluminum alloy. Thermal field was monitored by means of contactless pyrometers installed on the press and five thermosensors were inserted in key positions in the die. Several extrusion data were continuously acquired including the profile speed, the puller force and the extrusion load. After extrusion the profiles are analyzed in order to determine the position of the seam weld and the microstructure inside the profile cross section after air or water quenching.

BACKGROUND: To evaluate the safety and efficacy of hylan G-F 20 in patients with ankle osteoarthritis. METHODS: A prospective, open study in patients with symptomatic (>or=50 mm and

In this work an experimental methodology to evaluate the prediction of recrystallized structures in aluminum extrusion was presented and validated. In the first part of the work an experimental procedure to investigate the evolution of recrystallization in aluminum alloys is presented and discussed. Several cups, obtained by means of inverse extrusion, were produced at different temperatures and process speeds. The specimens were analyzed in order to examine the grain size distribution. The coefficients for dynamic recrystallization models were obtained by regression analysis after thermo-mechanical FEM simulations of the experiments realized with the code Deform 3D. A complete set of coefficients was regressed for the available microstructure evolution models inside the code environment. The specimens were then heated in a furnace and cooled in order to reproduce static recrystallization of the material. The grain distribution was examined and the coefficients for the equation for static recrystallization prediction were regressed, too. In the second part of the work the extrusion of a round-shaped profile is described and the grain size distribution on the profile and on the billet rest is analyzed. The obtained models were applied to the real extrusion of a round profile and a comparison between experimental measurements and simulation results was performed. The simulated results were in very good agreement with experimental data, except in zones where peripheral coarse grain and grain growth appeared. Here, a further investigation effort and specific modeling equations are required.