On the Effect of Hot Rolling on Inclusion Size and Distribution in a Cast AISI 1070 Steel Railroad Wheel

The goal of this work is to examine the effect of hot deformation on shrinkage porosity and nonmetallic inclusions in an AISI 1070 grade steel industrially produced wheel casting. Steel cleanliness is an important consideration as it influences the mechanical properties of the final product. A high density of porosity and inclusions have been shown to be detrimental for mechanical properties, especially during hot rolling. Using a laboratory-scale rolling mill, cast preforms were subjected to a 66% cumulative reduction to determine the effect of thermomechanical processing on void closure and inclusions that may produce anisotropy in mechanical properties. Quantitative automated feature analysis, AFA, of inclusion type, size, morphology, and distribution was conducted utilizing an Aspex PICA 1020 scanning electron microscope to determine differences in inclusions and shrinkage porosity in the as-cast and as-rolled conditions. The results were compared with previously reported impact toughness values which indicated a trend with MnS projected length and average impact toughness in the T-L orientation. Reduction in shrinkage porosity was also verified utilizing 3D micro-X-ray CT scans. The AFA results showed a decrease in shrinkage porosity from 177 ppm in the as-cast condition to less than 35 ppm after rolling. Pores were in general much smaller and widely distributed after hot rolling and this would suggest improved impact properties. Analysis of nonmetallic inclusions revealed three primary categories of inclusions that included MnS, Al2O3, and complex inclusions that mainly consisted of MnS with an Al2O3 core, with small quantities of mixed silicates of Mn and Al and calcium aluminates (CaAl2O4)

Transmission Patterns of HIV and Hepatitis C Virus among Networks of People Who Inject Drugs

The risk-related behaviours and practices associated with injection drug use remain a driver of HIV and hepatitis C virus (HCV) transmission throughout the world. Here we evaluated HIV and HCV transmission patterns in the context of social networks of injection drug users (IDU) recruited from a higher incidence region in order to better understand factors that contribute to ongoing transmission among IDU.IDU recruited through a chain-referral method provided biological specimens for analysis. HIV and HCV positive specimens were sequenced and analyzed using phylogenetic methods (Neighbour-joining and Bayesian) and transmission patterns of HIV and HCV evaluated in the context of the recruitment networks.Among the 407 recruited IDU, HCV and HIV prevalence were 60.6% and 10.1%, respectively; 98% of HIV positive individuals were co-infected with HCV. Thirty-six percent of HCV sequences were associated with clusters, compared to 67% of HIV sequences. Four (16.7%) of the 24 HCV clusters contained membership separated by 2 or fewer recruitment cycles, compared to 10 (41.6%) derived from more than one recruitment component. Two (28.6%) of the 7 HIV clusters contained membership separated by 2 or fewer recruitment cycles while 6 (85.7%) were composed of inter component membership.Few HIV and HCV transmissions coincided with the recruitment networks, suggesting that they occurred in a different social context or a context not captured by the recruitment network. However, among the complete cohort, a higher degree of HIV clustering indicates many are recent infections originating from within current social networks, whereas a larger proportion of HCV infections may have occurred earlier in injecting history and in the context of a different social environment

Le site gaulois et antique de « La Carie », entre oppidum et ville romaine à Entrammes (Mayenne)

À mi-chemin entre oppidum gaulois et thermes antiques, le site de « La Carie » à Entrammes, installé près d’un gué sur un affluent de la Mayenne, a livré une succession stratigraphique débutant vers le milieu de La Tène moyenne, prenant son ampleur au Haut-Empire et finissant par une petite nécropole mérovingienne. Ces éléments s’organisent au sud, puis des deux côtés d’une large voie gauloise puis antique. L’habitat gaulois, peu dense, va en se complexifiant avant un abandon vers la fin de La Tène D1. Sur les mêmes bases, le site est réoccupé à partir de Tibère, des fours de potiers marquant la création d’une zone artisanale périphérique au nouveau chef-lieu du pagus gallo-romain d’Entrammes. À la période flavienne, de nouvelles structures sont élevées et agrandies jusqu’au début de la période sévérienne. Au Bas-Empire, si l’habitat est abandonné, la voie continue d’être utilisée ; une petite nécropole mérovingienne atteste de la permanence de cette dernière au moins jusqu’au viiie siècle. Enfin, mentionnons qu’un abondant mobilier, peu diversifié, illustre l’occupation, essentiellement de la période gauloise à la fin du Haut-Empire.Midway between the Gallic oppidum and the ancient spa, just before a ford on a Mayenne tributary, the site of “La Carie” at Entrammes has yielded a stratigraphic succession dating from the mid Celtic (La Tène) period, reaching its zenith during the time of the early Roman Empire with its end denoted by a small Merovingian necropolis. These elements are all arranged firstly to the south and then on either side of a large ancient Gallic well. Gallic habitation, firstly insignificant, became more complex before being abandoned towards the end of La Tène D1. Using the same base, the site was reoccupied from the time of Tiberius; potter’s kilns indicating the installation of a craft area were found on the periphery of the new administrative town of Entrammes, the former pagus. During the Flavian period, further structures were erected and enlarged through to the beginning of the Severan period. During the Late Empire, although the habitation was abandoned, the road continued to be used; a small Merovingian necropolis ensuring its permanence up to at least the fifteenth century. Finally, we should mention that abundant furniture, not particularly varied, illustrates occupation primarily from the Gallic period to the end of the Early Empire

Quantification of the chemical reactivity of molten nitrate salts with heat treatable aluminum alloys

This work explores the conditions for safe heat treatment of aluminum alloys containing lithium and magnesium in molten sodium nitrate (NaNO3) bath furnaces, and conditions where industrial accidents may occur. Using calorimetry coupled to classical thermodynamics, the strength of classical thermodynamics when analyzing thermal curves was demonstrated through a series of small-scale thermal analyses of various aluminum alloys in contact with sodium nitrate. This system was selected to illustrate reactions that may lead to severe and violent heat effect phenomena. Using idealized binary alloys, severe oxidation of magnesium- and lithium-rich aluminum alloy samples were shown to occur near 500 °C, a temperature range dangerously close to the operating temperature of solution heat treatment furnaces in manufacturing processes of heat treatable aluminum alloy sheets used in the aerospace industry. Commercial aluminum alloys AW257, 2198, 2024, and 1050 were also assessed with the same tools. The temperature that needed to be reached for these commercial aluminum alloys to react with molten sodium nitrate was significantly higher than the normal operating temperature of a conventional solution heat treatment furnace

Patterns of Recovery from Severe Mental Illness: A Pilot Study of Outcomes

We performed a pilot study examining the patterns of recovery from severe mental illness in a model integrated service delivery system using measures from the Milestones of Recovery Scale (MORS), a valid and reliable measure of recovery outcomes which ranges from 1 to 8 (8 levels). For purposes of presentation, we constructed an aggregate MORS (6 levels) where the levels are described as follows: (1) extreme risk; (2) unengaged, poorly self-coordinating; (3) engaged, poorly self-coordinating; (4) coping and rehabilitating; (5) early recovery, and (6) self reliant. We analyzed MORS data on individuals followed over time from The Village in Long Beach, California (658 observations). Using Markov Chains, we estimated origin-destination transition probabilities, simulating recovery outcomes for 100 months. Our models suggest that after 12 months only 8% of “extreme risk” clients remain such. Over 40% have moved to “engaged, poorly self-coordinating.” After 2 years, almost half of the initial “extreme Risk” clients are “coping/rehabilitating”, “early recovery” or “Self reliant.” Most gains occur within 2 years

Portrait of blood-derived extracellular vesicles in patients with Parkinson's disease.

The production of extracellular vesicles (EV) is a ubiquitous feature of eukaryotic cells but pathological events can affect their formation and constituents. We sought to characterize the nature, profile and protein signature of EV in the plasma of Parkinson's disease (PD) patients and how they correlate to clinical measures of the disease. EV were initially collected from cohorts of PD (n = 60; Controls, n = 37) and Huntington's disease (HD) patients (Pre-manifest, n = 11; manifest, n = 52; Controls, n = 55) - for comparative purposes in individuals with another chronic neurodegenerative condition - and exhaustively analyzed using flow cytometry, electron microscopy and proteomics. We then collected 42 samples from an additional independent cohort of PD patients to confirm our initial results. Through a series of iterative steps, we optimized an approach for defining the EV signature in PD. We found that the number of EV derived specifically from erythrocytes segregated with UPDRS scores corresponding to different disease stages. Proteomic analysis further revealed that there is a specific signature of proteins that could reliably differentiate control subjects from mild and moderate PD patients. Taken together, we have developed/identified an EV blood-based assay that has the potential to be used as a biomarker for PD