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The increasingly high standards required in sheet metal forming industry, both geometrical and aesthetical, lead to continuous search of solutions to control the metal sheet flow during deformation. As alternative to traditional draw beads or hydraulically controlled segmented dies, the possibility of locally varying the material tangential speed by adapting the surface tribology at the interface between the blank and the blank holder represents a still unexplored scenario. The paper presents the feasibility analysis of the use of magneto-rheological (MR) fluids as lubricants in stamping, exploiting their ability to vary their rheological behaviour in response to external magnetic fields. To this aim, a new strip drawing test bench was developed to investigate the friction behaviour of MR fluids under different magnetic fields. The cold stamping of DC05 steel sheet was taken as reference case to investigate the influence of typical process parameters such as contact pressure, sliding speed and magnetic field.

Inter-ply friction plays a dominant role in inducing defects (e.g., wrinkling) during the hot stamping process of fibre metal laminates (FMLs). In particular, the metal/prepreg inter-ply friction is highly affected by the process parameters at elevated temperature as the molten matrix is significantly sensitive to possible changes in these parameters. In this paper, the metal/prepreg inter-ply friction was experimentally investigated at increasing relative sliding displacement and varying normal pressure. To do that, pull-through tests with a stop-start control strategy were conducted at elevated temperature. The obtained results showed the transition of the lubrication mode given by the Stribeck theory from a hydrodynamic to a mixed one as the relative sliding displacement rose at whatever normal pressure level. An increase in the inter-ply friction coefficient was found as well.

On the basis of the materials collected on site, the larvae of six species of Mexican Calosoma, namely Calosoma (Callitropa) porosifrons Bates, 1891, and five species of the subgenus Carabomimus Kolbe, 1895 are figured and described for the first time. Though these larvae are quite similar for most characters, some important differences can be found in the two subgenera Callitropa Motschulsky, 1865 and Carabomimus, confirming the distinctness of these taxa. Through an accurate study of the collected adult specimens and of the relevant literature, the distribution of the population afferent to each of these same species is clarified. With the occasion, the distribution of all Mexican Calosoma, is discussed, distinguishing between winged species, usually widely spread, and apterous species, linked to humid, temperate or semi-cold climates. In this context, the distribution of the subgenus Carabomimus, appears to be more sensitive to the influence of geographic barriers and the differentiation of the species was clearly helped by geographic isolation at high altitude in the volcanic massif of central Mexico

The last decade has seen several attempts to introduce bioresorbable prostheses in order to reduce the number of surgeries, but all the potentially interesting metallic alloys suffer of poor mechanical or chemical resistance. Zinc alloys are attracting more attention for producing temporary prosthesis devices thanks to their bioabsorbable characteristic in human environment, since they present a suitable corrosion resistance to human fluids. However, at the same time, they have extremely poor mechanical properties that make them still unsuitable for such applications. One possible way to increase mechanical performances is to refine the material grain using Severe Plastic Deformation (SPD) processes that can be traditionally used to obtain such refined microstructures through the application of high deformation rates under complex stress states. The paper focuses on the feasibility of using the backward tube flowforming process to obtain a significant grain refinement (below 1 µm) when applied to pure zinc alloy in order to increase its mechanical resistance to values suitable for load bearing temporary prostheses, starting from a 287 µm grain size material. A numerical FE simulation was adopted to understand the strain during the process while the influence of the process parameters, namely the reduction per pass, the mandrel speed and the feed rate, on the microstructural characteristics and related mechanical properties are shown and discussed.

В работе изучено влияние температуры на рост хрупких трещин и, соответственно, на изменение механических свойств стали марки 20Mn4. На термомеханической моделирующей установке Gleeble 3800™ проведены испытания на одноосное растяжение в диапазоне температур от 1000 до 1280°C. Термические обработки при разных температурах и времени выдержки осуществлялись в трубчатой печи. После проведенных испытаний на растяжение и термических обработок образцы были проанализированы при помощи растровой электронной микроскопии для оценки влияния эволюции микроструктуры на протекание горячеломкости. Явление горячеломкости в основном обусловливает скопление меди на поверхности раздела металл-окалина: в характерном диапазоне температуры жидкая фаза, обогащенная медью, проникает по всем границам зерен, способствуя образованию трещин и проявлению горячеломкости.

In this paper, we analyze the behavior of a family of solutions of a nonlinear elliptic equation with nonlinear boundary conditions, when the boundary of the domain presents a highly oscillatory behavior which is uniformly Lipschitz and nonlinear terms are concentrated in a region which neighbors the boundary domain. We prove that this family of solutions converges to the solutions of a limit problem in H^1 , an elliptic equation with nonlinear boundary conditions which captures the oscillatory behavior of the boundary and whose nonlinear terms are transformed into a flux condition on the boundary. Indeed, we show the upper semicontinuity of this family of solutions., Comment: 13 pages, 2 figures

The prediction of ductile fracture occurrence in hot forging processes is one of the main industrial issues, which needs damage models that have to be on one hand accurate and easily calibrated, but also easy enough to be industrially implemented an utilized. Tensile testing formability characterization, although experimentally easy, does not allow taking into account all the variables influencing the evolution of damage, making the calibration test-dependent. Besides the stress triaxiality factor effect, in hot forging processes, the stress deviatoric parameter, the temperature and strain rate must be taken into account to provide reliable and efficient models. In this work hot fracture characterization was performed on the dual-phase brass alloy CuZn40Pb2, typically used for hot forging and characterized by a narrow temperature window of formability. The values of true strain at fracture from tensile, torsion and tensiletorsion tests performed at various temperatures and strain rates are obtained. Numerical simulations of the above-cited tests were carried out in order to determine the threedimensional surfaces of the fracture locus as a function of the stress triaxiality and deviatoric parameter. The results are critically discussed and in particular the influence of the rheological behaviour of the material on the fracture locus shape is highlighted. Optical microscopy analysis was carried out in order to assess the testing parameters influence on the phase distribution and EDS-SEM analysis to evaluate the grain boundary composition, which was recognized critical as regards the formability characteristics of the investigated alloy.

Alternative methods of alcohol consumption have recently emerged among adolescents and young adults, including the alcohol "eyeballing", which consist in the direct pouring of alcoholic substances on the ocular surface epithelium. In a context of drug and behavioural addictions change, "eyeballing" can be seen as one of the latest and potentially highly risky new trends. We aimed to analyze the existing medical literature as well as online material on this emerging trend of alcohol misuse.Literature on alcohol eyeballing was searched in PsychInfo and Pubmed databases. Results were integrated with a multilingual qualitative assessment of the database provided by The Global Public Health Intelligence Network (GPHIN) and of a range of websites, drug fora and other online resources between March 2013 and July 2013.Alcohol eyeballing is common among adolescents and young adults; substances with high alcohol content, typically vodka, are used for this practice across the EU and internationally. The need for a rapid/intense effect of alcohol, competitiveness, novelty seeking and avoidance of "alcoholic fetor" are the most frequently reported motivations of "eyeballers". Local effects of alcohol eyeballing include pain, burning, blurred vision, conjunctive injection, corneal ulcers or scarring, permanent vision damage and eventually blindness.Alcohol eyeballing represents a phenomenon with potential permanent adverse consequences, deserving the attention of families and healthcare providers. Health and other professionals should be informed about this alerting trend of misuse. Larger observational studies are warranted to estimate the prevalence, characterize the effects, and identify adequate forms of interventions for this emerging phenomenon.

The Authors intend to guide the choice of surgical treatment for mammary asymmetry, according to specific form of asymmetry.Possible types of symmetryzation surgery are listed. First Author's personal technique is described and some clinical cases are presented.Regardless to specific surgical needs for the single case, a generally valid concept is the necessity of a surgical moulding meant to obtain the same volume for both breasts before positioning of implants. This allows a longer lasting symmetry between breasts, as aging modifications bilaterally occur at equal speed if the adipo-glandular structures obtained have the same volume.

Il saggio analizza il tema della formazione iniziale e del reclutamento dei docenti, nell'ambito del miglioramento della qualità del servizio di istruzione, a garanzia del diritto sociale all'istruzione.

Modern aeronautical and aerospace industries must face the demanding challenge of reducing operational consumption and production costs coming from materials and labor. Current trend of engineering is oriented to meet both requirements increasing the use of materials characterized by high specific resistance as titanium alloys. Hot forging can be used to reduce the production costs of titanium components: forging in closed dies of billets or semi-finished forms, at different temperatures above or below the β-transus temperature, allows the production of complex shapes with limited amount of edge trim removal and machining rework after forging. Unfortunately, as far as Ti–6Al–4V titanium alloy is regarded, several material peculiarities have to be properly taken into account in order to produce defect free Ti–6Al–4V alloy components. In the paper, an experimental and numerical campaign, focused on a typical case study for aeronautical engines, is carried out. The aim of this research is to investigate the process mechanics and the causes for the final microstructure observed through micrographic analysis. Once set-up and tested against experimental loads, the model was used to predict phases distributions after both forging and cool down.

The rate of margins involvement and the associated recurrence risk in basal cell carcinomas (BCCs) varies widely in published works (7%-25% and 26%-67%, respectively). This study investigated the risk factors associated with incomplete excision and their relevance in surgical management when positive margins occur in 3957 BCCs excised in 2358 patients. This study performed a multivariate analysis on the database collected from all patients operated for BCCs in the Plastic Surgery Department between 1 January 1992 and 1 September 2007. All data collected (3957 excisions; 2358 individuals) were divided into complete and incomplete excisions groups and analyzed according to 14 variables. The overall rate of incomplete excisions was 14%. Mean age (68), size of the lesion (< 0.5 cm), BCC subtype (nodular with sclerosant aspects, sclerosant and basosquamous), location (face), infiltration depth (hypodermis and deep tissues), recurrent BCC and re-excised BCC were significantly associated with a higher rate of incomplete excision. The recurrence rate for incompletely excised tumours was 26.8%, while only 5.9% for completely excised tumours. Most of the risk factors associated to incomplete excision can be identified before surgery (by simple anamnesis and clinical examination) and successfully overcome by appropriate surgical margins. The high recurrence rate after incomplete excision and the low patient compliance towards follow-up should lead the surgeon to early re-excise residual cancer.

The physics objectives of SuperB, an asymmetric electron-positron collider with a luminosity above 10^36/cm^2/s are described, together with the conceptual design of a novel low emittance design that achieves this performance with wallplug power comparable to that of the current B Factories, and an upgraded detector capable of doing the physics in the SuperB environment.