405 research outputs found

    Hajar bin កumeid , l'ultima capitale di Qataban

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    Hajar bin Humeid Indice 1. Hajar bin Humeid 1.1. Lo Wadi Beihan 1.2. Il tell 1.3. Le vie commerciali 2. Ricostruzione della storia del sito di D-Gylum 3. La missione americana nel Beihan 3.1. Storia della spedizione 3.1.1. La spedizione 3.1.2. Lo scavo di Hajar bin Humeid 3.2. Metodologia 3.2.1. Stratigrafia 3.2.2. Ceramica 4. 1969, pubblicazione dei risultati di Hajar bin Humeid 4.1. La cronologia in discussione 4.2. L’impatto accademico 4.2.1. I dubbi di J.Pirenne 4.2.2. Le recensioni specialistiche 5. Bibliografi

    Synchro-push: A new production control paradigm

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    The paper aims at proposing a new production control paradigm, the Synchro-push, that offers a step forward with respect to the traditional push and pull production paradigms as for plant re-configurability power and quick reaction to demand changes: in fact, theoretically, it offers the advantages of the two traditional approaches without suffering their drawbacks. This could be of advantage for any manufacturing company and especially for SMEs (Small-Medium Enterprises), acting as a support against worldwide competition. The paper presents a brief history of the evolution of the push and pull approaches, the comparison between them and among the different alternatives that have been proposed in literature for their implementation. It presents the new approach, its theory and the subsequent industrial implications. The new approach is now made possible by the development of innovative smart technologies that allow the close-to-real-time decision making in scheduling and a higher level of modularity in the plant

    Assessing Color Rendering in a 3d Setup

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    Abstract The Color-Rendering Index (CRI) for light source is a quantitative measure of the capability to preserve color appearance of illuminated objects. Recently, CRI has had a renewed interest because of the new LED systems, which usually have a CRI rather low, but a good preservation of color appearance and a pleasant visual appeal. This article presents an experiment performed by human observers to assess the appearance preservation of colors under a set of light sources. Results are then compared with a range of available color rendering indices, in order to assess CRIs variability relative to human judgment

    Egas Moniz: 90 years (1927-2017) from cerebral angiography

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    In June 2017 we celebrate the 90th anniversary of the pioneer discovery of cerebral angiography, the seminal imaging technique used for visualizing cerebral blood vessels and vascular alterations as well as other intracranial disorders. Egas Moniz (1874-1955) was the first to describe the use of this revolutionary technique which, until 1975 (when computed tomography, CT, scan was introduced in the clinical practice), was the sole diagnostic tool to provide an imaging of cerebral vessels and therefore alterations due to intracranial pathology. Moniz introduced in the clinical practice this fundamental and important diagnostic tool. The present contribution wishes to pay a tribute to the Portuguese neurosurgeon, who was also a distinguished neurologist and statesman. Despite his tremendous contribution in modern brain imaging, Egas Moniz was awarded the Nobel Prize in Physiology or Medicine in 1949 for prefrontal leucotomy, the neurosurgical intervention nowadays unacceptable, but should rather be remembered for his key contribution to modern brain imaging. KEYWORDS

    Platinum, Palladium and Rhodium deposition to the Prunus laurus cerasus leaf surface as an indicator of the vehicular traffic pollution in the city of Varese area. An easy and reliable method to detect PGEs released from automobile catalytic converters

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    Background, aim, and scope The widespread use of some Platinum Group Elements (PGE) as catalysts to minimize emission of pollutants from combustion engines produced a constantly growing increase of the concentration of these elements in the environment; their potential toxicological properties explain the increasing interest in routine easy monitoring. We have found that leaves of Prunus laurus cerasus are efficient collectors of particulate with a dimension < 60-80 \u3bcm, and a simple and reliable procedure was developed to reveal traces of platinum, palladium and rhodium released from automotive catalysts. The analysis of the dust deposited on the foliage is a direct indicator of traffic pollution. Materials and methods Leaves of prunus laurus cerasus were washed by sonication in a mixture of water and 2 propanol and the washings, to be discarded, were separated by centrifugation to yield typically 0.05-1.2 g of dust that, after mineralization, were directly submitted to Atomic Absorption analysis. Results Comparison of the 2007 and 2004-5 results showed a dramatic reduction of the platinum levels and revealed that palladium is now the main component of this traffic related pollution. Discussion The results are consistent with the increasing diffusion of cars with a diesel engine whose catalysts are made up of Pt and/or Pd alone, and gives a significant insight into the recent evolution in catalyst design that replaces platinum for palladium. Conclusion The proposed analytical procedure is simple, with short preparation times, and greatly reduces matrix effects so that atomic absorption spectroscopy can easily detect the three noble metals at the ng/g level in the dust. Recommendation and perspectives The results clearly show that Pd concentrations have increased over time, and must be cause of concern
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