1,456 research outputs found
Design of the Target Dump Injection Segmented (TDIS) in the framework of the High Luminosity Large Hadron Collider (HL-LHC) project
The High Luminosity Large Hadron Collider (HL-LHC) Project at CERN calls for increasing beam brightness and intensity. In this scenario, most equipment has to be redesigned and rebuilt. In particular, beam intercepting devices (such as dumps, collimators, absorbers and scrapers) have to withstand impact or scraping of the new intense HL-LHC beams without failure. Furthermore, minimizing the electromagnetic beam-device interactions is also a key design driver since they can lead to beam instabilities and excessive thermo-mechanical loading of devices. In this context, the present study assesses the conceptual design quality of the new LHC injection protection absorber, the Target Dump Injection Segmented (TDIS), from an electromagnetic and thermo-mechanical perspective. This contribution analyzes the thermo-mechanical response of the device considering two cases: an accidental beam impact scenario and another accidental scenario with complete failure of the RFcontacts.
In addition, this paper presents the preliminary results from the simulation of the energy deposited by the two counter-rotating beams circulating in the device
CFD Analysis of Biologically-Inspired Marine Propulsors
In the present work, the design and testing of two propulsion mechanisms which emulate fish swimming are presented. The motivation comes from the high effi ciency and maneuverality that
fi sh demonstrate over conventional rotary propellers. In order to know the fl uid fl ow pattern in detail, a 3D CFD model was developed. Details of the velocity and pressure fi elds were obtained,
as well as the hydrodynamic forces, cruising velocity, power and effi ciency. The results obtained using this CFD model were validated with the experimental prototypes, obtaining a reasonable agreement. Once validated, the CFD model was used to analyze several confi gurations of the propelling fi n, obtaining that thunniform swimming mode is the most effi cient
Mist and Edge Computing Cyber-Physical Human-Centered Systems for Industry 5.0: A Cost-Effective IoT Thermal Imaging Safety System
While many companies worldwide are still striving to adjust to Industry 4.0
principles, the transition to Industry 5.0 is already underway. Under such a
paradigm, Cyber-Physical Human-centered Systems (CPHSs) have emerged to
leverage operator capabilities in order to meet the goals of complex
manufacturing systems towards human-centricity, resilience and sustainability.
This article first describes the essential concepts for the development of
Industry 5.0 CPHSs and then analyzes the latest CPHSs, identifying their main
design requirements and key implementation components. Moreover, the major
challenges for the development of such CPHSs are outlined. Next, to illustrate
the previously described concepts, a real-world Industry 5.0 CPHS is presented.
Such a CPHS enables increased operator safety and operation tracking in
manufacturing processes that rely on collaborative robots and heavy machinery.
Specifically, the proposed use case consists of a workshop where a smarter use
of resources is required, and human proximity detection determines when
machinery should be working or not in order to avoid incidents or accidents
involving such machinery. The proposed CPHS makes use of a hybrid edge
computing architecture with smart mist computing nodes that processes thermal
images and reacts to prevent industrial safety issues. The performed
experiments show that, in the selected real-world scenario, the developed CPHS
algorithms are able to detect human presence with low-power devices (with a
Raspberry Pi 3B) in a fast and accurate way (in less than 10 ms with a 97.04%
accuracy), thus being an effective solution that can be integrated into many
Industry 5.0 applications. Finally, this article provides specific guidelines
that will help future developers and managers to overcome the challenges that
will arise when deploying the next generation of CPHSs for smart and
sustainable manufacturing.Comment: 32 page
Impedance measurements and simulations on the TCT and TDI LHC collimators
The LHC collimation system is a critical element for
the safe operation of the LHC machine and it is subject
to continuous performance monitoring, hardware upgrade
and optimization. In this work we will address the impact
on impedance of the upgrades performed on the injection
protection target dump (TDI), where the absorber material
has been changed to mitigate the device heating observed
in machine operation, and on selected secondary (TCS) and
tertiary (TCT) collimators, where beam position monitors
(BPM) have been embedded for faster jaw alignment. Con-
cerning the TDI, we will present the RF measurements per-
formed before and after the upgrade, comparing the result
to heating and tune shift beam measurements. For the TCTs,
we will study how the higher order modes (HOM) intro-
duced by the BPM addition have been cured by means of
ferrite placement in the device. The impedance mitigation
campaign has been supported by RF measurements whose
results are in good agreement with GdfidL and CST simula-
tions. The presence of undamped low frequency modes is
proved not to be detrimental to the safe LHC operation
A theoretical model for tellurite-sulfates NaCu(TeO)(SO)(OH) and KCu(TeO)(SO)(OH)
A theoretical model for two new tellurite-sulfates, namely
NaCu(TeO)(SO)(OH) and KCu(TeO)(SO)
(OH) is determined to be compatible with ab-initio calculations. The
results obtained in this work show that some previous speculations in the
literature about the couplings are correct, obtaining a model with a mixture of
ferromagnetic and antiferromagnetic couplings. We use a combination of
numerical techniques to study the magnetic properties of the model. Our
numerical calculations based on the density-matrix renormalization group method
reveal that the system presents Ising-like magnetization plateaux at rational
values of the saturation magnetization.Comment: 7 pages, 8 figure
CFD Analysis of Biologically-Inspired Marine Propulsors
In the present work, the design and testing of two propulsion mechanisms which emulate fish swimming are presented. The motivation comes from the high effi ciency and maneuverality that
fi sh demonstrate over conventional rotary propellers. In order to know the fl uid fl ow pattern in detail, a 3D CFD model was developed. Details of the velocity and pressure fi elds were obtained,
as well as the hydrodynamic forces, cruising velocity, power and effi ciency. The results obtained using this CFD model were validated with the experimental prototypes, obtaining a reasonable agreement. Once validated, the CFD model was used to analyze several confi gurations of the propelling fi n, obtaining that thunniform swimming mode is the most effi cient
Fermi surface instabilities at finite Temperature
We present a new method to detect Fermi surface instabilities for interacting
systems at finite temperature. We first apply it to a list of cases studied
previously, recovering already known results in a very economic way, and
obtaining most of the information on the phase diagram analytically. As an
example, in the continuum limit we obtain the critical temperature as an
implicit function of the magnetic field and the chemical potential
. By applying the method to a model proposed to describe reentrant
behavior in , we reproduce the phase diagram obtained
experimentally and show the presence of a non-Fermi Liquid region at
temperatures above the nematic phase.Comment: 10 pages, 10 figure
Quantum interference with photon pairs created in spatially separated sources
We report on a quantum interference experiment to probe the coherence between
two photons coming from non degenerate photon pairs at telecom wavelength
created in spatially separated sources. The two photons are mixed on a beam
splitter and we observe a reduction of up to 84% in the coincidence count rate
when the photons are made indistinguishable. This experiment constitutes an
important step towards the realization of quantum teleportation and
entanglement swapping with independent sources.Comment: 5 pages, 2 figures, changes according to referee's comments,
discussions partly rewritte
NUMERICAL ANALYSIS OF SEVERAL PORT CONFIGURATIONS IN THE FAIRBANKS-MORSE 38D8-1/8 OPPOSED PISTON MARINE ENGINE
The aim of the present paper is to analyze several port configurations in the Fairbanks-Morse 38D8-1/8 marine diesel engine. The motivation comes from the high number of intake and exhaust ports which characterizes this engine. The scavenging and trapping efficiency were studied by modifying several parameters related to the ports, such as the inclination, shape, pressure and number. To this end, a numerical model based on the commercial software ANSYS Fluent was employed. Numerical results were validated using experimental measurements performed on a Fairbanks-Morse 38D8-1/8 engine installed on a submarine. The results confirmed that the influence of the port shape is practically negligible; nevertheless, an adequate combination of the inclination, pressure and number of ports can modify the scavenging and trapping efficiency noticeably
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