STUDIO SULLA FLUIDITÀ DELLE LEGHE DI ALLUMINIO

La motivazione di questo studio nasce dall’esigenza di capire meglio i vari fattori che influenzano la fluidità delleleghe di alluminio da fonderia, in particolare la lega alluminio-silicio (Al-Si). I parametri studiati sono stati latemperatura di colata, il raffinamento del grano, il contenuto di idrogeno e di ossidi. Gli esperimenti sono statisvolti a Trondheim (Norvegia) presso l’università NTNU e il centro di ricerche SINTEF. I risultati hannoevidenziato che la temperatura di colata ha un ruolo determinante nell’aumentare la fluidità, mentre non è statoriscontrato nessun effetto significativo dovuto alla presenza di raffinante di grano o ad un alto livello di idrogeno.Un alto livello di ossidi riduce la fluidità. Inoltre, il riciclaggio di materiali da lavorazioni non influenza lafluidità se si presta attenzione al mantenimento più basso possibile del livello di ossidi

Chronic pelvic pain: comorbidity between chronic musculoskeletal pain and vulvodynia.

Chronic pelvic pain (CPP) is a common condition that has a major impact on the quality of life of both men and women. Male CPP is usually attributable to well-defined urogenital conditions (most frequently infectious/non infectious prostatic diseases) or musculoskeletal or bowel diseases, whereas the features of female CPP are much more complex and are of particular clinical and epidemiological importance. It is a multifactorial syndrome that can be due to diseases of the urogenital, gastrointestinal, or musculoskeletal systems, or to neurological or neuropsychiatric disorders. It is not always easy to identify its predominant pathogenesis, although it often occurs as a central sensitization syndrome triggered by an initial stimulus which is no longer detectable and only manifests itself clinically through pain. In this respect, there are some very interesting relationships between vulvodynia and fibromyalgic syndrome, as identified in a preliminary study of women with chronic musculoskeletal pain in which it was demonstrated that vulvar pain plays an important role, although it is often overlooked and undiagnosed

A review on the fluidity of al based alloys

Fluidity of molten metals is of significant importance in producing sound castings, particularly thin-walled castings.To meet the industrial demands of complex shaped castings, the knowledge of the parameters affecting fluidity is required in order to have a better control of the production processes.Since fluidity is one of the measures by which the castability of metals can be quantified, a definition and a description of castability are presented in this study.A definition of fluidity follows. Fluidity depends on many factors and this study reports the influence of the main factors: alloy composition, heat of fusion, superheat, grain refinement, modifying agents, mould material and temperature, melt cleanliness, coating and viscosity

Focal Cerebral Infarction in Newborn: Description of Three Cases:

We observed 3 full-term newborns with focal ischemic injury of the middle cerebral artery (MCA), in which diagnosis of MCA stroke was suspected by US and confirmed by CT scan and MRI. A four-year follow-up was carried out to study the effect of neonatal stroke on neurodevelopmental outcome. All children had a history of pre-perinatal risk factors: neonatal cerebral infarction in term infants, in fact, has many possible causes, including bacterial meningitis, inherited or acquired coagulopathies, trauma and hypoxia-ischemia. The prognosis of neonatal MCA infarction depends on early diagnosis, on the CNS plasticity mechanism and, finally, on medical therapy and neuropsychological rehabilitation

State-of-the-art characterization tools for Al foundry alloys

In this manuscript we review some characterization toolsfor Al foundry alloys. Castability is the ability of an alloyto be cast without formation of defects such as cracks,pores or misruns. Being able to measure, hence to control,these defects is fundamental and plays a critical role forthe development of numerical models for castability.Also melt quality influences these defects formation.Alloy dependent phenomena that determine castabilityare, among others, fluidity and porosity. This manuscriptfocuses on the main characterization tools for measuringfluidity, porosity and melt quality

Simulation of fluidity in AL-SI alloys

In this study, MAGMA soft® commercial software package was used to simulate the fluidity of A356 alloy. Established an optimum mesh generation, the influence of important metallurgical parameters, such as heat transfer coefficient, casting temperature and coherency temperature, on fluidity were simulated. The simulation results were compared with fluidity laboratory tests carried out with spiral-shaped sand moulds and the results from the simulations were found to be consistent with the experiments. Therefore, this study sets a basis for more extensive use of simulations as a means for predicting and optimizing the fluidity of aluminium alloys. In addition, the results from the spiral-shaped mould tests were compared with vacuum fluidity tests carried out using an A356 alloy and the two techniques showed consistent results

The Influence of Boron (B), Tin (Sn), Copper (Cu), and Manganese (Mn) on the Microstructure of Spheroidal Graphite Irons

Most spheroidal graphite irons (SGIs) have a matrix consisting of ferrite, pearlite, or a mix of the two. To achieve the desired matrix composition, pearlite promoters such as Mn, Cu, or Sn, are added to the molten metal. Among these elements, Sn is the most potent pearlite promoter. However, each has a different impact on the solidification, graphite precipitation, eutectoid transformation, and ultimately the final structure of the material. Research has shown that B promotes ferrite in fully pearlitic grades where Cu and Mn were used to promote pearlite. The present work investigates the effect of B in SGI with additions of Sn, Cu, and Mn, and the effects of varying amounts of the different pearlite promoters on the matrix composition. The results show that Mn alone at levels of approximately 0.9 wt% is not enough to promote a fully pearlitic matrix, while 0.5 wt% Cu combined with 0.67 wt% Mn is sufficient. Likewise, a fully pearlitic microstructure can be obtained by alloying with 0.06 wt% Sn and 0.67 wt% Mn. B was found to promote ferrite in fully pearlitic SGI alloyed with Sn or Cu. However, in the absence of those elements, B promoted pearlite when alloyed with just Mn. Graphite protrusions were observed on the graphite nodule surface only for B-added alloys with Sn and Cu. In these cases, it is believed B promotes ferrite by changing the growth mechanism of graphite after solidification from spherical to lamellar. However, a different graphite morphology is observed when B is added with just Mn. Thermal analysis data is in agreement with the microstructural observations regarding the ferrite promoting effect of B

Spatial and seasonal distribution of invertebrates in Northern Apennine rheocrene springs

Four perennial rheocrene springs located between 919 and 1252 m a.s.l. on substrata characterized by different lithologies were studied. Water samples and invertebrates were collected seasonally for one year. The crenic fauna was collected using three sampling techniques: moss washing, drift tubes and benthic traps. Each sampling technique was particularly efficient for collecting specific taxa typical of the different habitats (crenophilous crustaceans and crenoxenic benthic insects were dominant in benthic traps and moss; crenophilic, stygophilic and stygobiotic crustaceans in drift tubes). A total of 3,284 invertebrates belonging to 54 taxa were collected. Ostracoda, Harpacticoida, and Diptera were the most abundant taxa. Species assemblages collected at each spring, in each season, in traps and mosses, differed among springs, and, based on invertebrate assemblages, the ordination of the investigated springs did not correspond to that based on environmental parameters. Of the environmental variables only pH and temperature explained the diversity pattern. Assemblages collected from different habitats also differed: benthic traps collected mainly Chironomidae, Ostracoda, other Diptera, crenophilous Harpacticoida, and Gastropoda; in moss assemblages, the fauna was mostly represented by crenophilic Harpacticoida, Ostracoda, Plecoptera, Chironomidae. Finally, the groundwater assemblages, collected with drift tubes, were dominated by crenophilous Harpacticoida, Chironomidae and Plecoptera. Variation in number of taxa over time was observed in traps and moss samples, whereas drift tubes showed no seasonality. Meiofauna (i.e., permanent meiofauna, represented by Nematoda, Copepoda, Ostracoda, and Hydrachnidia, and temporary meiofauna, represented by early instars of insect larvae) dominated all habitats, probably because of constant flow and favourable habitats such as moss. The presence of mosses was a factor that increased the species diversity of the investigated springs; drift tubes allowed most of the stygobiotic taxa to be collected, although this technique did not necessarily increase the total number of taxa collected. In addition to the array of habitats, other factors, such as geology, might influence the structure of invertebrate communities. The diversity of the investigated springs was strictly dependent on the presence of different microhabitats and local environmental conditions

Ultrasound in the diagnosis of calcium pyrophosphate dihydrate deposition disease. A systematic literature review and a meta-analysis

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Impact on Glucose Homeostasis: Is Food Biofortified with Molybdenum a Workable Solution? A Two-Arm Study

Diabetes is expected to increase up to 700 million people worldwide with type 2 diabetes being the most frequent. The use of nutritional interventions is one of the most natural approaches for managing the disease. Minerals are of paramount importance in order to preserve and obtain good health and among them molybdenum is an essential component. There are no studies about the consumption of biofortified food with molybdenum on glucose homeostasis but recent studies in humans suggest that molybdenum could exert hypoglycemic effects. The present study aims to assess if consumption of lettuce biofortified with molybdenum influences glucose homeostasis and whether the effects would be due to changes in gastrointestinal hormone levels and specifically Peptide YY (PYY), Glucagon-Like Peptide 1 (GLP-1), Glucagon-Like Peptide 2 (GLP-2), and Gastric Inhibitory Polypeptide (GIP). A cohort of 24 people was supplemented with biofortified lettuce for 12 days. Blood and urine samples were obtained at baseline (T0) and after 12 days (T2) of supplementation. Blood was analyzed for glucose, insulin, insulin resistance, β-cell function, and insulin sensitivity, PYY, GLP-1, GLP-2 and GIP. Urine samples were tested for molybdenum concentration. The results showed that consumption of lettuce biofortified with molybdenum for 12 days did not affect beta cell function but significantly reduced fasting glucose, insulin, insulin resistance and increased insulin sensitivity in healthy people. Consumption of biofortified lettuce did not show any modification in urine concentration of molybdenum among the groups. These data suggest that consumption of lettuce biofortified with molybdenum improves glucose homeostasis and PYY and GIP are involved in the action mechanism