incremental sheet forming of a composite made of thermoplastic matrix and glass fiber reinforcement

Abstract Incremental Sheet Forming (ISF) has been widely investigated in the last twenty years, highlighting advantages as low-cost, higher formability and greater process flexibility if compared to traditional processes. Recent works have proven the ISF feasibility for polymer processing whereas limited investigations exist on composite materials. In the proposed study, an experimental research was carried out with the aim to investigate the influence of process factors on the workability of composite parts. The attention was focused on extruded Reinforced Polyamide-6 sheets. The material is made of thermoplastic matrix and 15% of glass fibers as reinforcement. The processed material is characterized by a glass temperature higher than 50°C and, therefore, ISF was performed with the addition of an external heating source. More in detail, the experiments were carried out on a three axis CNC milling machine equipped with an additional chamber designed for the material heating. In this paper, the influence of the main process factors (i.e. wall slope angle, step depth and process temperature) on the manufactured parts and on the process feasibility was investigated

spif of tailored sheets to optimize thickness distribution along the shaped wall

Abstract Tailored blanks are widely used in industry for reducing the parts' weight without affecting stiffness. In this study, the authors proposed the use of the tailored blanks with an alternative aim. Specifically, the attention has been focused on the use of an initial blank with variable thickness for overcoming one of the main drawback of Single Point Incremental Forming process (SPIF), i.e. the material thinning. More in detail, blanks with variable thickness have been designed and experimentally tested for compensating the thinning phenomenon, which characterizes SPIF. An experimental and numerical research has been planned to consider the geometrical variables of the problem. Briefly, an artificial localised variable thickness has been imposed to the original blank with the aim to modify the overall strength of the sheet affecting its deformation. The idea has been analysed changing the depth and the position of the machined pockets on the sheet surface. The application of subtractive step, instead of forming or additive processes, was now preferred for time and cost saving. However, the outcomes of the experimentation can be easily transposed to any combination of processes. The feasibility of the proposed approach will be detailed in the paper

Numerical Analysis of the ISF Process on Sheet with Locally Modified Material Flow Stress

n/

Ophiolitic sequences from the central sector of the Catena Costiera (Calabria): stratigraphy, petrology and structural analyses

Mesozoic ophiolites crop out in the Catena Costiera (Northern Calabrian Arc). The Northern Calabrian Arc is characterized by the superposition of three structural elements (OGNIBEN, 1973): the uppermost Hercynian continental section intruded by late- Variscan granitoids (Calabrian Nappe), the intermediate ophiolitic Nappe and the lowermost Mesozoic passive margin carbonate sequences (Apenninic Units). The studied area is located in the central Catena Costiera (fig. 1) where the ophiolitic sequences are characterized by both aphyric and porphyritic metabasalts with a T-MORB affinity (LIBERI et alii, 2006). They represent the basement of a peliticarenaceous metasedimentary sequence, previously interpreted as a pre-Mesozoic continental basement (Bagni Unit of AMODIO MORELLI et alii, 1976). In the metasedimentary cover, a remarkable increase in the carbonatic supply is noticed moving from south to north of the study area. According to this evidence two stratigraphic sequences have been defined for the southernmost Cozzo Cervello area and the northernmost San Martino di Finita area. The Cozzo Cervello area ophiolitic sequence is characterized by: metabasites, thin levels of volcanoclastic metasediments, rare metacarbonates, metapelites and metarenites. The San Martino di Finita area ophiolitic sequence is instead characterized by: metabasites, volcanoclastic metasediments and calcschists. The studied rocks underwent a polyphase deformation history and the meso- and microstructural analyses allowed distinguishing three main (D1-D3) deformation phases: – D1, this phase is characterized by a S1 foliation locally developed and preserved as microlithons inside the S2 main foliation; – D2, a N-S trending isoclinal folding event (F2; fig. 2 a,b) is responsible for the formation of the S2 foliation (fig. 2 d), that represent the main surface recognizable in the field; – D3, this phase is characterized by asymmetric folds (F3) developed at different scales and showing a WNW-ESE trending axes. An incipient foliation (S3) is locally developed in the phyllosilicate-rich levels (fig. 2 c,d). *Dipartimento di Scienze della Terra, Università della Calabria. ([email protected]) **Dipartimento di Scienze della Terra, Università di Pisa The petrographic analysis allows to define the mineralogical assemblage of the different lithotypes and to determine the relationships between deformation and blastesis. The metabasites are characterized by the mineralogical assemblage: Epidote + Na-amphibole + Lawsonite + Phengite + Chlorite + Albite Calcite Quartz + Magnetite. Metapelites and metarenites are characterized by: Epidote + Phengite + Stilpnomelane + Na-Amphibole + Pumpellyite + Chlorite + Albite + Quartz + Magnetite. The calcschist are constituted by: Calcite + Phengite + Chlorite + Albite + Quartz + Magnetite. The described mineralogical assemblages suggest that the studied rocks underwent P-T conditions typical of the blueschist facies as suggested by the blastesis of Na-amphiboles, lawsonite, stilpnomelane and phengite along the S2 foliation. The blastesis of white mica can be observed along the S3 foliation also. The following metamorphic retrogression developed within the prehnitepumpellyite facies and is characterized by a static recrystalization. Fig. 1 – Tectonic sketch map of central sector of the Catena Costiera, after LIBERI et alii (2006). 64 OPHIOLITIC SEQUENCES FROM THE CATENA COSTIERA 65 Fig. 2 – a) isoclinal folds (F2) in the metapelites of Cozzo Cervello area; b) isoclinal folds (F2) in the calcschists of San Martino di Finita area; c) crenulation F3 in the metabasites; d) microscopic view of the main foliation S2 deformed by the later D3 phase in the metapelites. The white line indicates white mica flakes along S3. The field study and the tectonometamorphic evolution reconstructed for the ophiolitic sequences cropping out in the central sector of the Catena Costiera of Calabria show that a subduction and exhumation history inside an accretionary wedge can be proposed. In particular, the characterization and the definition of the complex relationships existing within the ophiolitic metasedimentary cover allow us to propose: 1. the source area was composite, with both carbonatic and siliciclastic contributions; 2. the presence of terrigenous deposit, even in the lowermost part of the sedimentary sequence, seem to indicate that this part of oceanic crust was located close to the continental margin; 3. the San Martino di Finita type sedimentary cover can be correlated with that of the Malvito ophiolitic unit (sensu AMODIO MORELLI et alii, 1976), cropping out in the northernmost sector of the Catena Costiera; 4. the subdivision between the Bagni and Gimigliano-Monte Reventino Units, as proposed by DIETRICH & SCANDONE (1972) and AMODIO MORELLI et alii (1976) for the study area, is not supported by the data collected in this work. REFERENCES AMODIO MORELLI L., BONARDI G., COLONNA V., DIETRICH D., GIUNTA G., IPPOLITO F., LIGUORI V., LORENZONI S., PAGLIONICO A., PERRONE V., PICCARRETA G., RUSSO M., SCANDONE P., ZANETTIN-LORENZONI E. & ZUPPETTA A. (1976) - L’arco Calabro-peloritano nell’orogene appenninicomagrebide. Mem. Soc. Geol. It, 17, 1–60. DIETRICH D. & SCANDONE P. (1972) - The position of the basic and ultrabasic rocks in the tectonic units of the southern Apennines. Atti Acc. Pont., 21, 61–75. LIBERI F., MORTEN L. & PILUSO E. (2006) - Geodynamic significance of the ophiolites within the Calabrian Arc. Island Arc, 15, 26–43. OGNIBEN L. (1973) - Schema geologico della Calabria in base ai dati odierni. Geologia Romana, 12, 243

Crucial role of phospholamban phosphorylation and S-nitrosylation in the negative lusitropism induced by 17β-estradiol in the male rat heart.

Background/Aims: 17β-estradiol (17βE2) plays an important cardiovascular role by activating estrogen receptors (ER) α and ERβ. Previous studies demonstrated that the novel estrogen G protein-coupled receptor (GPR30/GPER) mediates estrogen action in different tissues. We have recently shown in the rat heart that 17βE2 elicits negative inotropism through ERα, ERβ and GPR30, by triggering activation of ERK1/2, phosphatidylinositol 3-kinase (PI3K), protein kinase A (PKA) and endothelial Nitric Oxide synthase (eNOS) signaling. Methods: In the present study, using the isolated and Langendorff-perfused rat heart as a model system we analyzed: i) whether and to which extent 17βE2 modifies mammalian ventricular myocardial relaxation (lusitropism); ii) the type of ERs and the signaling pathways involved in this effect. Results: We found that 17βE2 negatively modulated the ventricular lusitropic performance. This effect, which partially involved the vascular endothelium, recruited ERβ and occurred via PI3K, eNOS-NO-cGMP-protein kinase G (PKG) transduction cascade. Of note, 17βE2-mediated negative lusitropism associated with a modification of phospholamban (PLN) phosphorylation and S-nitrosylation (SNO) both in isolated Langendorff rat heart and in isolated cardiomyocytes. Conclusion: Taken together, our results allow including 17βE2 to the family of substances that control ventricular relaxation. This is of relevance in relation not only to the normal endocrine control of cardiac function, but also to physio-pathologic conditions characterized by an altered ventricular diastolic performance

New southernmost record of the European Brook Lamprey, Lampetra planeri (Bloch, 1784) (Agnatha, Petromyzontidae)

We report the occurrence of the European Brook Lamprey, Lampetra planeri (Bloch, 1784), in the Lao river in the Calabria region (southern Italy). This record extends the species’ known distribution limit southwards. Information regarding some morphometric and ecological data are provided and discussed

A novel sensitivity analysis on friction spot joining process performed on aluminum\polycarbonate sheets by simulation

The manufacturing research has been focusing on the improvement of product performance and lightweight design. The synergic effects between material properties and manufacturing solutions have been considered, extensively. Specifically, joining techniques have been developing with the aim to propose new suitable solutions considering dissimilarities in the properties of the materials that have to be combined. Setting of new manufacturing routes is, therefore, a demanding task. In this direction, there are several methods available in the scientific literature that are focused on sensitivity analysis or optimization/minimization techniques to reduce the necessary attempts or to find a solution/correlation among big data. In this work, the goal of obtaining high joint efficiency between Aluminum and Polycarbonate sheets by the Friction Spot Joining process is considered as a case study. This process must face two main issues, i.e., the mechanical, physical and chemical compatibilities between the parts and the integrity protection of the polymeric sheet near the joining area. The process parameters influences were analysed using numerical simulations performed by a commercial FE code. The number of executed analyses was reduced with a planned DoE. From these results, the Code2Vect algorithm was employed with the aim to visualize, efficiently, high-dimensional data and to evaluate the influences of some identified parameters on the process answer. Finally, a transfer function involving the input and output quantities of interest was derived in a compact representation by a Newton Raphson minimization technique

Left hemicolectomy and low anterior resection in colorectal cancer patients: Knight–griffen vs. transanal purse-string suture anastomosis with no-coil placement

BackgroundColorectal cancer (CRC) is considered one of the most frequent neoplasms of the digestive tract with a high mortality rate. Left hemicolectomy (LC) and low anterior resection (LAR) with minimally invasive laparoscopic and robotic approaches or with the open technique are the gold standard curative treatment.Materials and methodsSeventy-seven patients diagnosed with CRC were recruited between September 2017 and September 2021. All patients underwent a preoperative staging with a full-body CT scan. The goal of this study was to compare both types of surgeries, LC-LAR LS with Knight–Griffen colorectal anastomosis and LC-LAR open with Trans-Anal Purse-String Suture Anastomosis (the TAPSSA group), by positioning a No-Coil transanal tube (SapiMed Spa, Alessandria, Italy), in terms of postoperative complications such as prolonged postoperative ileus (PPOI), anastomotic leak (AL), postoperative ileus (POI), and hospital stay.ResultsThe patients were divided into two groups: the first with 39 patients who underwent LC and LAR in LS with Knight–Griffen anastomosis (Knight–Griffen group) and the second with 38 patients who underwent LC and LAR by the open technique with the TAPSSA group. Only one patient who underwent the open technique suffered AL. POI was 3.76 ± 1.7 days in the TAPSSA group and 3.07 ± 1.3 days in the Knight–Griffen group. There were no statistically significant differences in terms of AL and POI between the two different groups.ConclusionThe important point that preliminarily emerged from this retrospective study was that the two different techniques showed similarities in terms of AL and POI, and therefore, all the advantages reported in the previous studies pertaining to No-Coil also hold good in this study regardless of the surgical technique used. However, randomized controlled trials are needed to confirm these findings

Early Prediction of Response to Tyrosine Kinase Inhibitors by Quantification of EGFR Mutations in Plasma of NSCLC Patients.

IntroductionThe potential to accurately quantify epidermal growth factor receptor (EGFR) mutations in plasma from non–small-cell lung cancer patients would enable more rapid and more frequent analyses to assess disease status; however, the utility of such analyses for clinical purposes has only recently started to explore.MethodsPlasma samples were obtained from 69 patients with EGFR-mutated tumors and 21 negative control cases. EGFR mutations in plasma were analyzed by a standardized allele-specific polymerase chain reaction (PCR) test and ultra-deep next-generation sequencing (NGS). A semiquantitative index (SQI) was derived from dilutions of known EGFR mutation copy numbers. Clinical responses were evaluated by Response Evaluation Criteria in Solid Tumors 1.1 criteria and expressed as percent tumor shrinkage.ResultsThe sensitivity and specificity of the PCR test and NGS assay in plasma versus tissue were 72% versus 100% and 74% versus 100%, respectively. Quantitative indices by the PCR test and NGS were significantly correlated (p < 0.001). EGFR testing at baseline and serially at 4 to 60 days during tyrosine kinase inhibitor therapy revealed a progressive decrease in SQI, starting from day 4, in 95% of cases. The rate of SQI decrease correlated with percent tumor shrinkage at 2 months (p < 0.0001); at 14 days, it was more than 50% in 70% of patients (rapid responders). In two patients with slow response, an early increase in the circulating levels of the T790M mutation was observed. No early T790M mutations were seen in plasma samples of rapid responders.ConclusionsQuantification of EGFR mutations from plasma with a standardized PCR test is feasible. To our knowledge, this is the first study showing a strong correlation between the EGFR SQI in the first days of treatment and clinical response with relevant implications for patient management