GEOFLOW: simulation of convection in a spherical shell under central force field

Time-dependent dynamical simulations related to convective motion in a spherical gap under a central force field due to the dielectrophoretic effect are discussed. This work is part of the preparation of the GEOFLOW-experiment which is planned to run in a microgravity environment. The goal of this experiment is the simulation of large-scale convective motion in a geophysical or astrophysical framework. This problem is new because of, on the one hand, the nature of the force field (dielectrophoretic effect) and, on another hand, the high degree of symmetries of the system, e.g. the top-bottom reflection. Thus, the validation of this simulation with well-known results is not possible. The questions concerning the influence of the dielectrophoretic force and the possibility to reproduce the theoretically expected motions in the astrophysical framework, are open. In the first part, we study the system in terrestrial conditions: the unidirectional Earth's force is superimposed on the central dielectrophoretic force field to compare with the laboratory experiments during the development of the equipment. In the second part, the GEOFLOW-experiment simulations in weightless conditions are compared with theoretical studies in the astrophysical framework's, in the first instance a fluid under a self-gravitating force field. We present complex time-dependent dynamics, where the dielectrophoretic force field causes significant differences in the flow compared to the case that does not involve this force field

Alcune proposte metodologiche per l’impiego di un GIS intra-site nella documentazione di un relitto: l’applicazione sul brick Mercurio (Punta Tagliamento, Italia)

The wreck of the ship Mercurio lies at a depth of 17 m, off Punta Tagliamento, between the Veneto and Friuli Venezia Giulia regions. It was discovered in 2001, and was excavated in 2001, and again between 2004 and 2011, by Carlo Beltrame (Università Ca’ Foscari) in collaboration with the local archaeological superintendency. It was a brigantine, belonging to an Italian-French squadron, sunk during the battle of Grado in the 1812. Problems typical of post-Medieval ships (especially when military), such as the complexity of the aspect because of the presence of metal concretions and a lot of items of different materials and typologies and the difficulties in documenting very small objects (such as the many buttons of uniforms) with the photogrammetrical system, were solved with the use of an intra-site GIS on a Quantum GIS open source application. The GIS allowed us not only to manage the large amount of information (site-plans, topological positions of the items, photos, etc.) produced during the excavations, but also to answer questions about the dynamics both of the sinking and the formation processes and, thanks to the use of a system of virtual frames, about the location of the nautical equipment, the links between the human skeletons and the personal objects and parts of the uniforms and the location of the caulker store-roo

Assets, Commodities and Biosocialities. Multiple Biovalues in Hybrid Biobanking Practices

This is the final version. Available on open access from STS Italia via the URL in this record.Biobanks are crucial institutions in the infrastructure of contemporary life sciences. They depend on the participation of donors who give tissues and data. Through their participa-tion, donors can build identities and form biosociality. Biobanks are key sites in the cur-rent bioeconomy, that enable the generation of value from those tissues and bioinfor-mation, transformed into assets or commodities. We define biobanks as hybrid zones of heterogeneous practices that blur the boundaries between institutional sectors and ways of producing economic values. On that basis we introduce a novel empirical, realist approach to the analysis of biobanking economies, explaining the different economic and social biovalues that emerge from the practices of valuing and interacting between the research-ers, biobank staff and donor participants in specific banking activities. We discuss why STS studies on biobanking should explore the concrete practices through which multiple biovalues as well as biosocialities are produced simultaneously and in configurations of mutual interdependence

A Power-Efficient Methodology for Mapping Applications on Multi-Processor System-on-Chip Architectures

This work introduces an application mapping methodology and case study for multi-processor on-chip architectures. Starting from the description of an application in standard sequential code (e.g. in C), first the application is profiled, parallelized when possible, then its components are moved to hardware implementation when necessary to satisfy performance and power constraints. After mapping, with the use of hardware objects to handle concurrency, the application power consumption can be further optimized by a task-based scheduler for the remaining software part, without the need for operating system support. The key contributions of this work are: a methodology for high-level hardware/software partitioning that allows the designer to use the same code for both hardware and software models for simulation, providing nevertheless preliminary estimations for timing and power consumption; and a task-based scheduling algorithm that does not require operating system support. The methodology has been applied to the co-exploration of an industrial case study: an MPEG4 VGA real-time encoder

Expected Sensitivity to Galactic/Solar Axions and Bosonic Super-WIMPs based on the Axio-electric Effect in Liquid Xenon Dark Matter Detectors

We present systematic case studies to investigate the sensitivity of axion searches by liquid xenon detectors, using the axio-electric effect (analogue of the photoelectric effect) on xenon atoms. Liquid xenon is widely considered to be one of the best target media for detection of WIMPs (Weakly Interacting Massive Particles which may form the galactic dark matter) using nuclear recoils. Since these detectors also provide an extremely low radioactivity environment for electron recoils, very weakly-interacting low-mass particles (< 100 keV/c^2), such as the hypothetical axion, could be detected as well - in this case using the axio-electric effect. Future ton-scale liquid Xe detectors will be limited in sensitivity only by irreducible neutrino background (pp-chain solar neutrino and the double beta decay of 136Xe) in the mass range between 1 and 100 keV/c^2. Assuming one ton-year of exposure, galactic axions (as non-relativistic dark matter) could be detected if the axio-electric coupling g_Ae is greater than 10^-14 at 1 keV/c^2 (or $10^-13 at 100 keV/c^2). Below a few keV/c^2, and independent of the mass, a solar axion search would be sensitive to a coupling g_Ae ~ 10^-12. This limit will set a stringent upper bound on axion mass for the DFSV and KSVZ models for the mass ranges m_A < 0.1 eV/c^2 and < 10 eV/c^2, respectively. Vector-boson dark matter could also be detected for a coupling constant alpha'/alpha > 10^-33 (for mass 1 keV/c^2) or > 10^-27 (for mass 100 keV/c^2).Comment: 17 pages, 10 figure

Characterization of the Hamamatsu R11410-10 3-Inch Photomultiplier Tube for Liquid Xenon Dark Matter Direct Detection Experiments

To satisfy the requirements of the next generation of dark matter detectors based on the dual phase TPC, Hamamatsu, in close collaboration with UCLA, has developed the R11410-10 photomultipler tube. In this work, we present the detailed tests performed on this device. High QE (>30%) accompanied by a low dark count rate (50 Hz at 0.3 PE) and high gain (10^7) with good single PE resolution have been observed. A comprehensive screening measurement campaign is ongoing while the manufacturer quotes a radioactivity of 20 mBq/PMT. These characteristics show the R11410-10 to be particularly suitable for the forthcoming zero background liquid xenon detectors.Comment: 19 pages, 18 figure

Thin film evolution equations from (evaporating) dewetting liquid layers to epitaxial growth

In the present contribution we review basic mathematical results for three physical systems involving self-organising solid or liquid films at solid surfaces. The films may undergo a structuring process by dewetting, evaporation/condensation or epitaxial growth, respectively. We highlight similarities and differences of the three systems based on the observation that in certain limits all of them may be described using models of similar form, i.e., time evolution equations for the film thickness profile. Those equations represent gradient dynamics characterized by mobility functions and an underlying energy functional. Two basic steps of mathematical analysis are used to compare the different system. First, we discuss the linear stability of homogeneous steady states, i.e., flat films; and second the systematics of non-trivial steady states, i.e., drop/hole states for dewetting films and quantum dot states in epitaxial growth, respectively. Our aim is to illustrate that the underlying solution structure might be very complex as in the case of epitaxial growth but can be better understood when comparing to the much simpler results for the dewetting liquid film. We furthermore show that the numerical continuation techniques employed can shed some light on this structure in a more convenient way than time-stepping methods. Finally we discuss that the usage of the employed general formulation does not only relate seemingly not related physical systems mathematically, but does as well allow to discuss model extensions in a more unified way

Modelagem bioeconômica da transferência de embriões em bovinos.

O objetivo deste trabalho foi desenvolver um modelo matemático orientado a eventos de simulação, para auxiliar tomadas de decisão relativas à transferência de embriões em bovinos, considerando-se as dinâmicas de dois componentes da transferência de embriões: receptoras e embriões. Na simulação, não se avaliaram respostas individuais de doadoras a coletas consecutivas e eventos correspondentes na transferência de embriões. Simulou-se o mesmo protocolo para superovulação a todas as doadoras. Receptoras foram sincronizadas simulando-se o uso de prostaglandina. O número de embriões viáveis produzido por doadora e sua variabilidade tiveram como base um processo aleatório de simulação de Monte Carlo, que pressupôs uma distribuição exponencial negativa de densidade de probabilidade. Custos e receitas foram inseridos no modelo por meio de um cenário-base para calcular indicadores econômicos de rentabilidade. A análise sugeriu a impraticabilidade da atividade, se realizada diante do cenário proposto (VPL ? R$: 57.596,69). A partir do cenário proposto, o custo médio estimado foi de R$ 1.178,19, e de R$ 980,03, para se obter uma prenhez a partir de uma situação otimizada, sugerida pelo modelo (5/100; 5/190)

Human resilience to Holocene climate changes inferred from rodent middens in drylands of northwestern Patagonia (Argentina)

We reconstruct the Holocene vegetation, climate, and archaeological history for drylands of northwestern Patagonia, Argentina, based on multiproxy analysis (plant macrofossil, pollen, and parasites) of rodent middens integrated with a database of {14}^C dates associated with human occupations. The local scale corresponds to the Huenul paleoecological and archaeological locality, emplaced in north-western Patagonia (Neuquén Province, Argentina). The rodent midden record from the Huenul series reflects subtle vegetation changes driven by climatic variability at millennial timescale. Drier than present environmental conditions prevailed during the early Holocene (10,500–9400 cal yr BP), peaking during the mid-Holocene (9200–5500 cal yr BP), when wetter than present conditions established during the late Holocene (4400–2500 cal yr BP). These environmental and climatic dynamics agree with other paleoclimatic records from northern Patagonia, suggesting the winter precipitation dynamics related to the Southern Westerlies as a common driver. The diachronic distribution of anthropogenic radiocarbon dates from the western area of the South American Arid Diagonal between 32°–40°S conforms to a fitted exponential model of steady background population growth, not suggesting significant demographic changes that may have been the result of the impact of climate change. This record indicates that these human populations coped successfully with aridity, particularly during the mid-Holocene. These findings reinforce the need to integrate multi-scalar interdisciplinary analyses to assess the impact of climate change in human societies