Thermo-mechanical analysis of additively manufactured hybrid extrusion dies with conformal cooling channels

Profile overheating and surface defects during hot aluminum extrusion can occur when seeking higher productivity rates at increased ram speed velocities. The incorporation of cooling channels in the die-design allows overcoming this process limitation by keeping the profile temperature below the melting point of the alloy used [1]. Selective laser melting (SLM) of conformal cooling channels provides, in contrast to conventional manufacturing techniques, the opportunity to place the cooling circuit inside the mandrel of a porthole-die in a well-defined position to the critical bearing region [2]. In the framework of this study, a preliminary numerical investigation on the extrusion process under the assumption of liquid nitrogen cooling is analysed. The results show, that by combining conformal cooling channels with liquid nitrogen as a cooling media high cooling rates, which are well beyond the state of the art of conventional dies, can be achieved. In a hybrid extrusion die set-up, a part of the mandrel, that is additively manufactured, is either joined [3] or directly selective leaser melted onto the conventionally manufactured parts [4]. For a proper implementation in the extrusion process, material testing of the welded joint are needed. Thus, in the current study, tensile tests performed at room temperature for hybrid specimens, partially consisting of conventionally processed tool steel 1.2343 and partially additively manufactured 1.2709, will be presented. Moreover, four different heat treatment sequences of the hybrid specimens will be discussed. In addition, for each configuration, micro-structural images are taken to investigate failure at the bonding region. Finally, an optimal manufacturing sequence for a hybrid die with the described material combination is proposed

Malpractice risk and medical treatment selection

We study how legal and financial incentives affect medical decisions. Using patient-level data from Italy, we identify the effect of a change in medical liability pressure by exploiting the geographical distribution of hospitals across court districts, where some districts increase the predictability of expected damages per injury while others do not. Using a difference-in-differences identification strategy, we show that as certainty of compensation increases, c-sections increase by 6.5 percentage points. There is no statistically significant effect on secondary health outcomes of either mothers or newborns, but the increase is higher for low-risk than high-risk mothers. The increase is driven by hospitals that have lower quality, are governed by inefficient court districts, face lower expected damages, and are paid more per c-section

Automated synthesis of executable web service compositions from BPEL4WS processes

We propose a technique for the automated synthesis of new com-posite web services. Given a set of abstract BPEL4WS descriptions of component services, and a composition requirement, we auto-matically generate a concrete BPEL4WS process that, when exe-cuted, interacts with the components and satisfies the requirement. We implement the proposed approach exploiting efficient repre-sentation techniques, and we show its scalability over case stud-ies taken from a real world application and over a parameterized domain

MORPH: A Reference Architecture for Configuration and Behaviour Self-Adaptation

An architectural approach to self-adaptive systems involves runtime change of system configuration (i.e., the system's components, their bindings and operational parameters) and behaviour update (i.e., component orchestration). Thus, dynamic reconfiguration and discrete event control theory are at the heart of architectural adaptation. Although controlling configuration and behaviour at runtime has been discussed and applied to architectural adaptation, architectures for self-adaptive systems often compound these two aspects reducing the potential for adaptability. In this paper we propose a reference architecture that allows for coordinated yet transparent and independent adaptation of system configuration and behaviour

ПІДХІД ДЛЯ АВТОМАТИЗОВАНОЇ КОМПОЗИЦІЇ BPEL ПРОЦЕСІВ / ПЕРЕКЛАД СТАТТІ «AN APPROACH FOR THE AUTOMATED COMPOSITION OF BPEL PROCESSES» (ПЕРЕКЛАД РЕМАРОВИЧ С.)

Ми описуємо метод для автоматизованого синтезу нових композитних Веб-сервісів. Враховуючи набір компонентних сервісів, які описані як абстрактні BPEL4WS процеси, збагачені семантичними анотаціями, а також враховуючи вимогу композиції, ми автоматично генеруємо виконуваний BPEL4WS процес, який після розгортання здатний взаємодіяти з компонентами, щоб задовольнити вимогу. Ми орієнтуємося, зокрема, на опис анотацій, які ми повинні додати до \ud абстрактних BPEL4WS процесів для того, щоб охопити «семантичні» аспекти їх виконання, і на роль, яку ці семантичні анотації грають в завданні автоматизованої композиції

АВТОМАТИЗОВАНИЙ СИНТЕЗ КОМПОЗИТНИХ BPEL4WS ВЕБ-СЕРВІСІВ. ПЕРЕКЛАД СТАТТІ «AUTOMATED SYNTHESIS OF COMPOSITE BPEL4WS WEB SERVICES» (ПЕРЕКЛАД РЕМАРОВИЧ С.)

У цій статті ми пропонуємо метод для автоматизованого синтезу нових композитних Веб-сервісів. Враховуючи набір абстрактних BPEL4WS описів компонентних сервісів, а також вимогу композиції, ми автоматично генеруємо виконуваний BPEL4WS процес, який, після розгортання, здатний взаємодіяти з компонентами, щоб задовольнити вимогу. Ми реалізували запропонований підхід, використовуючи ефективні засоби синтезу, і експеримент з деякими тематичними дослідженнями, взятими з реальних застосувань і з параметризованим доменом. Ми показали, що метод може масштабуватися до випадків, в яких ручна розробка BPEL4WS композитних сервісів не є тривіальною і вимагає багато часу

Microglia in prion diseases: Angels or demons?

Prion diseases are rare transmissible neurodegenerative disorders caused by the accumulation of a misfolded isoform (PrPSc) of the cellular prion protein (PrPC) in the central nervous system (CNS). Neuropathological hallmarks of prion diseases are neuronal loss, astrogliosis, and enhanced microglial proliferation and activation. As immune cells of the CNS, microglia participate both in the maintenance of the normal brain physiology and in driving the neuroinflammatory response to acute or chronic (e.g., neurodegenerative disorders) insults. Microglia involvement in prion diseases, however, is far from being clearly understood. During this review, we summarize and discuss controversial findings, both in patient and animal models, suggesting a neuroprotective role of microglia in prion disease pathogenesis and progression, or\u2014conversely\u2014a microglia-mediated exacerbation of neurotoxicity in later stages of disease. We also will consider the active participation of PrPC in microglial functions, by discussing previous reports, but also by presenting unpublished results that support a role for PrPC in cytokine secretion by activated primary microglia

Recent Ostracod Fauna of the Western Ross Sea (Antarctica): A Poorly Known Ingredient of Polar Carbonate Factories

Ostracoda are a minor but recurrent component of Southern Ocean marine carbonate factories, and their low-Mg calcitic skeletal mineralogy helps in ensuring a noteworthy post-mortem resilience. Our study, based upon surface sediment occurrences, contributes to the better definition of their distribution vs. potential controlling factors in Antarctic waters. The ostracod fauna from the Western Ross Sea Shelf appears dominated by Australicythere polylyca, Australicythere devexa, Xestoleberis rigusa, Loxoreticulatum fallax, Cativella bensoni, Austrotrachyleberis antarctica and Patagonacythere longiducta, colonizing a variety of shelf environments along a wide bathymetric range. The abundance and richness values correlate well to nutrient distribution and sediment supply, primarily related to the circulation of different oceanographic regimes affecting the floor of the Ross Sea Shelf. Circumpolar Deep Water could represent the main factor controlling the distribution of ostracods. Similar results (high abundance and richness in ostracod values) were also recorded in the Terra Nova Bay and in a nearby area characterized by warm water rich in nutrients and composed of water of circumpolar origin flowing from the open ocean southwards onto the continental shelf. Particulate Fe (pFe), in suspended particulate matter (SPM), and other particulate trace metals in TNB could support the hypothesis that biogenic iron may significantly contribute to the bioavailable iron pool, sustaining both primary production and ostracod fauna richness in this area

Enhancing workflow-nets with data for trace completion

The growing adoption of IT-systems for modeling and executing (business) processes or services has thrust the scientific investigation towards techniques and tools which support more complex forms of process analysis. Many of them, such as conformance checking, process alignment, mining and enhancement, rely on complete observation of past (tracked and logged) executions. In many real cases, however, the lack of human or IT-support on all the steps of process execution, as well as information hiding and abstraction of model and data, result in incomplete log information of both data and activities. This paper tackles the issue of automatically repairing traces with missing information by notably considering not only activities but also data manipulated by them. Our technique recasts such a problem in a reachability problem and provides an encoding in an action language which allows to virtually use any state-of-the-art planning to return solutions

Reduced T-cell repertoire restrictions in abatacept-treated rheumatoid arthritis patients.

BACKGROUND: CD28(neg) T cells, which display functional characteristic of oligoclonally expanded cytotoxic memory T lymphocytes, are believed to be pathologically relevant in rheumatoid arthritis manifestation. The CD28 co-stimulation blockade by abatacept can prevent the generation of CD28(neg) T-cell populations in these patients. METHODS: Samples were obtained before and after 12 months of abatacept therapy. T-cell phenotype and T-cell receptor diversity were evaluated by flow cytometry and complementarity-determining region-3 spectratyping, respectively, while telomerase reverse-transcriptase gene level was measured by real-time PCR. RESULTS: Abatacept induces a decrease of the percentage and number of CD4(+)CD28(neg) T cells and a reduction of T-cell repertoire restrictions; these features are directly correlated. Thymic output and telomerase activity are not modified by the therapy. CONCLUSIONS: Abatacept-induced decrease of peripheral T-cell repertoire restrictions can due to a reduced generation of senescent, chronically stimulated CD4(+)CD28(neg) T cells