6,293 research outputs found
Manufacturing-as-a-Service (MaaS): state-of-the-art of up and running solutions and a framework to assess the level of development of a Cloud Manufacturing platform
During the last decades manufacturers tried to find new sources of flexibility because of the uncertainty of the market. Both practitioners and academics started to study new paradigms aiming to make companies more flexible up and downstream of their value chains leveraging on suppliers and customers. Cloud Manufacturing (CM) is certainly one of the most interesting concepts because it comes from the success of Cloud Computing and belongs to the complex fourth industrial revolution (i.e. Industry 4.0 paradigm). It has been introduced in 2010, defined as the âmanufacturing version of cloud computingâ where manufacturing resources are available to users on-demand, with outstanding flexibility. CM pursues the idea of creating Manufacturing as-a-Service (MaaS) leveraging on the benefits of the platform economy. In spite of its interest, after ten years debate there is not consensus on the essential characteristics of this paradigm because of the very limited number of real applications (prototypes excluded). In this paper we explore 6 cases of up and running platforms which resemble some of the characteristics of CM, define them as âCM Early adoptersâ and inductively propose a framework to assess the level of development of a CM platform. This study contributes to theory as it shows that CM is already arising in some businesses, the approach to the paradigm can vary significantly from one case to another, and different levels of development can be assessed. From a managerial point of view, this paper helps to understand the CM paradigm as it shows concrete examples of real companies pursuing the MaaS idea. In conclusion, MaaS seems ready to land on some industrial sectors and this can be either a new opportunity for competitiveness or a serious threat
Performance studies of scintillating ceramic samples exposed to ionizing radiation
Scintillating ceramics are a promising, new development for various
applications in science and industry. Their application in calorimetry for
particle physics experiments is expected to involve an exposure to high levels
of ionizing radiation. In this paper, changes in performance have been measured
for scintillating ceramic samples of different composition after exposure to
penetrating ionizing radiation up to a dose of 38 kGy.Comment: 6 pages, 8 figures, to be published in the 2012 IEEE Nuclear Science
Symposium Conference Recor
A visualization of the damage in Lead Tungstate calorimeter crystals after exposure to high-energy hadrons
The anticipated performance of calorimeter crystals in the environment
expected after the planned High-Luminosity upgrade of the Large Hadron Collider
(HL-LHC) at CERN has to be well understood, before informed decisions can be
made on the need for detector upgrades. Throughout the years of running at the
HL-LHC, the detectors will be exposed to considerable fluences of fast hadrons,
that have been shown to cause cumulative transparency losses in Lead Tungstate
scintillating crystals. In this study, we present direct evidence of the main
underlying damage mechanism. Results are shown from a test that yields a direct
insight into the nature of the hadron-specific damage in Lead Tungstate
calorimeter crystals exposed to 24 GeV/c protons.Comment: 8 pages, 6 figure
A FLUKA study towards predicting hadron-specific damage due to high-energy hadrons in inorganic crystals for calorimetry
Hadrons emerging from high-energy collisions, as it is the case for protons
and pions at the CERN Large Hadron Collider, can produce a damage to inorganic
crystals that is specific and cumulative. The mechanism is well understood as
due to bulk damage from fragments caused by fission. In this paper, the
existing experimental evidence for lead tungstate, LYSO and cerium fluoride is
summarised, a study using FLUKA simulations is described and its results are
discussed and compared to measurements. The outcome corroborates the confidence
in the predictive power of such simulations applied to inorganic scintillators,
which are relevant to their adoption as scintillators for calorimetry.Comment: 15 pages, 8 figure
A study of high-energy proton induced damage in Cerium Fluoride in comparison with measurements in Lead Tungstate calorimeter crystals
A Cerium Fluoride crystal produced during early R&D studies for calorimetry
at the CERN Large Hadron Collider was exposed to a 24 GeV/c proton fluence
Phi_p=(2.78 +- 0.20) x 10EE13 cm-2 and, after one year of measurements tracking
its recovery, to a fluence Phi_p=(2.12 +- 0.15) x 10EE14 cm-2. Results on
proton-induced damage to the crystal and its spontaneous recovery after both
irradiations are presented here, along with some new, complementary data on
proton-damage in Lead Tungstate. A comparison with FLUKA Monte Carlo simulation
results is performed and a qualitative understanding of high-energy damage
mechanism is attempted.Comment: Submitted to Elsevier Science on May 6th, 2010; 11 pages, 8 figure
Proof-of-principle of a new geometry for sampling calorimetry using inorganic scintillator plates
A novel geometry for a sampling calorimeter employing inorganic scintillators
as an active medium is presented. To overcome the mechanical challenges of
construction, an innovative light collection geometry has been pioneered, that
minimises the complexity of construction. First test results are presented,
demonstrating a successful signal extraction. The geometry consists of a
sampling calorimeter with passive absorber layers interleaved with layers of an
active medium made of inorganic scintillating crystals. Wavelength-shifting
(WLS) fibres run along the four long, chamfered edges of the stack,
transporting the light to photodetectors at the rear. To maximise the amount of
scintillation light reaching the WLS fibres, the scintillator chamfers are
depolished. It is shown herein that this concept is working for cerium fluoride
(CeF) as a scintillator. Coupled to it, several different types of
materials have been tested as WLS medium. In particular, materials that might
be sufficiently resistant to the High-Luminosity Large Hadron Collider
radiation environment, such as cerium-doped Lutetium-Yttrium Orthosilicate
(LYSO) and cerium-doped quartz, are compared to conventional plastic WLS
fibres. Finally, an outlook is presented on the possible optimisation of the
different components, and the construction and commissioning of a full
calorimeter cell prototype is presented.Comment: Submitted to Proceedings CALOR 2014, the 16th International
Conference on Calorimetry in High-Energy Physics, Giessen (Germany) 6 - 11
April 2014. To be published in Journal of Physics: Conference Series (10
pages, 15 figures
Test beam results for an upgraded forward tagger of the L3 experiment at LEP II
We have tested new scintillator modules with silicon photodiode readout for the upgraded Active Lead Rings (ALR) of the L3 detector at LEP II. Results are presented from data recorded in muon and electron test beams with particular emphasis on the light production and collection as a function of the particle impact position on the scintillator modules. The results from the beam test data will be used for the design of the readout and trigger electronics in conjunction with the required ALR performance as an electron tagger and beam background monitor at LEP II
Performance of a Tungsten-Cerium Fluoride Sampling Calorimeter in High-Energy Electron Beam Tests
A prototype for a sampling calorimeter made out of cerium fluoride crystals
interleaved with tungsten plates, and read out by wavelength-shifting fibres,
has been exposed to beams of electrons with energies between 20 and 150 GeV,
produced by the CERN Super Proton Synchrotron accelerator complex. The
performance of the prototype is presented and compared to that of a Geant4
simulation of the apparatus. Particular emphasis is given to the response
uniformity across the channel front face, and to the prototype's energy
resolution.Comment: 6 pages, 6 figures, Submitted to NIM
Constraints on Parity-Even Time Reversal Violation in the Nucleon-Nucleon System and Its Connection to Charge Symmetry Breaking
Parity-even time reversal violation (TRV) in the nucleon-nucleon interaction
is reconsidered. The TRV -exchange interaction on which recent analyses
of measurements are based is necessarily also charge-symmetry breaking (CSB).
Limits on its strength relative to regular -exchange are
extracted from recent CSB experiments in neutron-proton scattering. The result
(95% CL) is considerably lower than limits
inferred from direct TRV tests in nuclear processes. Properties of
-exchange and limit imposed by the neutron EDM are briefly discussed.Comment: RevTex, 8 pages. Factor ten error in cited neutron EDM corrected,
discussion and two references adde
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