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81.
82.
Agosteo S Cammi A Garlati L Lombardi C Padovani E 《Radiation protection dosimetry》2005,115(1-4):86-91
The International Reactor Innovative and Secure is a modular pressurised water reactor with an integral design. This means that all the primary system components, such as the steam generators, pumps, pressuriser and control rod drive mechanisms, are located inside the reactor vessel, which requires a large diameter. For the sake of better reliability and safety, it is desirable to achieve the reduction of vessel embrittlement as well as the lowering of the dose beyond the vessel. The former can be easily accomplished by the presence of a wide downcomer, filled with water, which surrounds the core region, while the latter needs the presence of additional internal shields. An optimal shielding configuration is under investigation, for reducing the ex-vessel dose due to activated internals and for limiting the amount of the biological shielding. MCNP 4C calculations were performed to evaluate the neutron and the gamma dose during operation and the 60Co activation of various shields configurations. The gamma dose beyond the vessel from activation of its structural components was estimated in a shutdown condition, with the Monte Carlo code FLUKA 2002 and the MicroShield software. The results of the two codes are in agreement and show that the dose is sufficiently low, even without an additional shield. 相似文献
83.
A well-known lemma of Suslin says that for a commutative ring if is unimodular where is monic and , then there exist such that the ideal generated by equals . This lemma played a central role in the resolution of Serre’s Conjecture. In the case where contains a set of cardinality greater than such that is invertible for each in , we prove that the can simply correspond to the elementary operations , , where . These efficient elementary operations enable us to give new and simple algorithms for reducing unimodular rows with entries in to using elementary operations in the case where is an infinite field. Another feature of this paper is that it shows that the concrete local–global principles can produce competitive complexity bounds. 相似文献
84.
Fabrizio Lombardi 《Microelectronics Reliability》1983,23(6):1055-1065
In this paper the application of software implemented voting (ring structures) to pipeline networks is presented. The TMR characterization of the ring is extended to various topologies such as trees, cascade and locally voted pipelines. Both the aspects of reliability and data flow are analyzed in detail. 相似文献
85.
Masoud Hashempour Zahra Mashreghian Arani Fabrizio Lombardi 《Journal of Electronic Testing》2009,25(1):25-37
In self-assembly, individual components (commonly referred to as tiles) have sufficient infor mation to build templates for
structures such as lat tices for two-dimensional scaffolds. Tile sets that can heal (fully or partially) an erroneous DNA
assembly have been proposed. Healing requires growth to be restarted such that erroneous tiles can be removed and the correct
tiles can bind to the aggregate. Punctures have been proposed for this purpose; in this paper, a puncture is intentionally
induced in the self-assembly to restart the growth process. The goal of this paper is to characterize an intentionally induced
puncture (and its relevant properties) on an erroneous tile site in the grown crystal as part of a healing process. This allows
to propagate any newly generated error away from the source of growth (i.e. the seed tile), such that self-assembly can continue
along specific directions. Different types of puncture are considered with respect to healing and related features, such as
growth direction, error and aggregate types. Punctures are analyzed using a new characterization and metric; different tile
sets are investigated in detail for healing of a DNA self-assembly.
相似文献
Fabrizio LombardiEmail: |
86.
Mariangela Lombardi Valentina Naglieri Jean-Marc Tulliani Laura Montanaro 《Journal of Porous Materials》2009,16(4):393-400
An improved gel-casting procedure was successfully exploited to produce porous ceramic bodies having controlled porosity features
in terms of mean pore size, total pore volume as well as pore geometry. The gel-casting process in which a natural gelatine
for food industry is used as gelling agent was firstly set-up to prepare dense alumina and zirconia components. Then, commercial
PE spheres, sieved to select proper dimensional ranges, were added to the starting slurries as pore-forming agent. Both alumina
and zirconia porous bodies were then produced, having a porosity ranging between 40 and 50 vol%. The fired components were
characterised by spherical pores surrounded by highly dense ceramic walls and struts, having a homogeneous and fine microstructure.
Their mean pore size was directly dependent on the sieved fraction of the starting PE spheres selected as pore-forming phase. 相似文献
87.
Christian Andrighetto Angiolella Lombardi Massimiliano Ferrati Angelo Guidi Chiara Corrain Giuseppe Arcangeli 《Food Control》2009,20(5):462-468
The aim of this research was to study the biodiversity of lactic acid bacteria (LAB) in marinated seafood salad (pH 5.0) and their interaction on the growth of Listeria monocytogenes. LAB were highly present in the samples considered in this study, reaching values of 8.0 log cfu/g at the end of product’s shelf-life. A high biodiversity in terms of LAB species and strains was detected by means of RAPD–PCR within the 171 bacterial isolates collected. Among them Lactobacillus curvatus, Lactobacillus sanfranciscensis and Enterococcus were present in all the salad batches considered. Three challenge tests against L. monocytogenes were carried out in order to assess the growth of this pathogen in the presence of dominant populations of LAB. L. monocytogenes tended to decrease in time, suggesting that a stable concentration of LAB inhibits the development of this pathogenic micro-organism. 相似文献
88.
A new technique for machine precision evaluation of singular and nearly singular potential integrals with 1/R singularities is presented. The numerical quadrature scheme is based on a new rational expression for the integrands, obtained by a cancellation procedure. In particular, by using library routines for Gauss quadrature of rational functions readily available in the literature, this new expression permits the exact numerical integration of singular static potentials associated with polynomial source distributions. The rules to achieve the desired numerical accuracy for singular and nearly singular static and dynamic potential integrals are presented and discussed, and several numerical examples are provided. 相似文献
89.
90.
Bernaschi Massimo Celestini Alessandro Cianfriglia Marco Guarino Stefano Lombardi Flavio Mastrostefano Enrico 《World Wide Web》2022,25(3):1287-1313
World Wide Web - Tor is an open source software that allows accessing various kinds of resources, known as hidden services, while guaranteeing sender and receiver anonymity. Tor relies on a free,... 相似文献