5,017 research outputs found

    Agglomeration, Networking and the Great Recession

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    This paper analyzes how and to what extent firms’ external relations, such as belonging to a local cluster or a business group, affect the probability of firm survival and economic performance after the 2008 Great Recession. Using a large data set of Italian manufacturing companies for the period 2005–12, it was found that belonging to a business group or a local cluster mitigates the selection effect determined by the real and financial shocks, while in the case of firms not belonging to groups, only the more efficient units survive. This means that firms belonging to a group or local cluster are expected to show a lower likelihood of failure and also lower performance compared with stand-alone firms

    Geomorphology of the lower Mesopotamian plain at Tell Zurghul archaeological site

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    The landscape of the Lower Mesopotamia Plain (LMP) has been moulded by water-related processes, consequently, its Holocene geomorphic evolution has been strictly connected to the fluvial process and the anthropogenic water management since 8000 BC. About 6000 years ago, during the maximum marine ingression, the modern cities of Nasiriyah and Al-Amara were close to the Persian Gulf shoreline. Successively, the Tigris and Euphrates developed two wide delta systems, that prograded south-eastward developing a complex fluvial network. Remote sensing investigations over the LMP using satellite imagery and topographic analysis revealed the surficial expression of deltaic bodies with a lobate planform and several terminal distributary channels (TDCs), classifiable as tidal-influenced river-dominated deltas. Tell Zurghul archaeological site, belonging to the ancient State of Lagash, expanded in the western part of the recognized TDC during the Mid- and Late Holocene. Indeed, the occurrence of a divergent multi-channel system supplied water for the early civilizations, which improved the water management and prevented floods through a canals network. Therefore, the multi-sensor remote sensing approach over an area of 2850 km2 allowed us to recognize several fluvial landforms, both still active and relict, attributable to the Holocene riverscape of the LMP, as well as anthropogenic features and aeolian deposits. The Main map is a geomorphological map at the scale of 1:120,000 centred on Tell Zurghul, focusing on the geometry, spatial distribution, and state of activity of erosional and constructional landforms

    Test beam measurement of the first prototype of the fast silicon pixel monolithic detector for the TT-PET project

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    The TT-PET collaboration is developing a PET scanner for small animals with 30 ps time-of-flight resolution and sub-millimetre 3D detection granularity. The sensitive element of the scanner is a monolithic silicon pixel detector based on state-of-the-art SiGe BiCMOS technology. The first ASIC prototype for the TT-PET was produced and tested in the laboratory and with minimum ionizing particles. The electronics exhibit an equivalent noise charge below 600 e- RMS and a pulse rise time of less than 2 ns, in accordance with the simulations. The pixels with a capacitance of 0.8 pF were measured to have a detection efficiency greater than 99% and, although in the absence of the post-processing, a time resolution of approximately 200 ps

    Modulation of amyloidogenic peptide aggregation by photoactivatable co-releasing ruthenium(II) complexes

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    Three Ru(II)-based CO-releasing molecules featuring bidentate benzimidazole and terpyridine derivatives as ligands were investigated for their ability to modulate the aggregation process of the second helix of the C-terminal domain of nucleophosmin 1, namely nucleophosmin 1 (NPM1)264–277, a model amyloidogenic system, before and after irradiation at 365 nm. Thioflavin T (ThT) binding assays and UV/Vis absorption spectra indicate that binding of the compounds to the peptide inhibits its aggregation and that the inhibitory effect increases upon irradiation (half maximal effective concentration (EC50) values in the high micromolar range). Electrospray ionization mass spectrometry data of the peptide in the presence of one of these compounds confirm that the modulation of amyloid aggregation relies on the formation of adducts obtained when the Ru compounds react with the peptide upon releasing of labile ligands, like chloride and carbon monoxide. This mechanism of action explains the subtle different behavior of the three compounds observed in ThT experiments. Overall, data support the hypothesis that metal-based CO releasing molecules can be used to develop metal-based drugs with potential application as anti-amyloidogenic agents

    Prototyping of an HV-CMOS demonstrator for the High Luminosity-LHC upgrade

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    HV-CMOS sensors can offer important advantages in terms of material budget, granularity and cost for large area tracking systems in high energy physics experiments. This article presents the design and simulated results of an HV-CMOS pixel demonstrator for the High Luminosity-LHC. The pixel demonstrator has been designed in the 0.35 ÎŒm HV-CMOS process from ams AG and submitted for fabrication through an engineering run. To improve the response of the sensor, different wafers with moderate to high substrate resistivities are used to fabricate the design. The prototype consists of four large analog and standalone matrices with several pixel flavours, which are all compatible for readout with the FE-I4 ASIC. Details about the matrices and the pixel flavours are provided in this article

    HV/HR-CMOS sensors for the ATLAS upgrade—concepts and test chip results

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    In order to extend its discovery potential, the Large Hadron Collider (LHC) will have a major upgrade (Phase II Upgrade) scheduled for 2022. The LHC after the upgrade, called High-Luminosity LHC (HL-LHC), will operate at a nominal leveled instantaneous luminosity of 5× 1034 cm−2 s−1, more than twice the expected Phase I . The new Inner Tracker needs to cope with this extremely high luminosity. Therefore it requires higher granularity, reduced material budget and increased radiation hardness of all components. A new pixel detector based on High Voltage CMOS (HVCMOS) technology targeting the upgraded ATLAS pixel detector is under study. The main advantages of the HVCMOS technology are its potential for low material budget, use of possible cheaper interconnection technologies, reduced pixel size and lower cost with respect to traditional hybrid pixel detector. Several first prototypes were produced and characterized within ATLAS upgrade R&D effort, to explore the performance and radiation hardness of this technology. In this paper, an overview of the HVCMOS sensor concepts is given. Laboratory tests and irradiation tests of two technologies, HVCMOS AMS and HVCMOS GF, are also given

    Radiation-hard active pixel sensors for HL-LHC detector upgrades based on HV-CMOS technology

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    Luminosity upgrades are discussed for the LHC (HL-LHC) which would make updates to the detectors necessary, requiring in particular new, even more radiation-hard and granular, sensors for the inner detector region. A proposal for the next generation of inner detectors is based on HV-CMOS: a new family of silicon sensors based on commercial high-voltage CMOS technology, which enables the fabrication of part of the pixel electronics inside the silicon substrate itself. The main advantages of this technology with respect to the standard silicon sensor technology are: low material budget, fast charge collection time, high radiation tolerance, low cost and operation at room temperature. A traditional readout chip is still needed to receive and organize the data from the active sensor and to handle high-level functionality such as trigger management. HV-CMOS has been designed to be compatible with both pixel and strip readout. In this paper an overview of HV2FEI4, a HV-CMOS prototype in 180 nm AMS technology, will be given. Preliminary results after neutron and X-ray irradiation are shown
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