9,243 research outputs found
Bottom production in Photon and Pomeron -- induced interactions at the LHC
In this paper we present a detailed comparison of the bottom production in
gluon -- gluon, photon -- gluon, photon -- photon, pomeron -- gluon, pomeron --
pomeron and pomeron -- photon interactions at the LHC. The transverse momentum,
pseudo -- rapidity and dependencies of the cross sections are calculated
at LHC energy using the Forward Physics Monte Carlo (FPMC), which allows to
obtain realistic predictions for the bottom production with one or two leading
intact protons. Moreover, predictions for the the kinematical range probed by
the LHCb Collaboration are also presented. Our results indicate that the
analysis of the single diffractive events is feasible using the Run I LHCb
data.Comment: 8 pages, 3 figures, 1 table. Version published in Physical Review
Squeezing generation and revivals in a cavity-ion system in contact with a reservoir
We consider a system consisting of a single two-level ion in a harmonic trap,
which is localized inside a non-ideal optical cavity at zero temperature and
subjected to the action of two external lasers. We are able to obtain an
analytical solution for the total density operator of the system and show that
squeezing in the motion of the ion and in the cavity field is generated. We
also show that complete revivals of the states of the motion of the ion and of
the cavity field occur periodically.Comment: 9 pages, 3 figure
Metallic hydrides: a hydrogen storage option?
The development of a safe and efficient way to store hydrogen that may exhibit good gravimetric and volumetric efficiencies is considered instrumental to hydrogen utilization as an alternative to fossil fuels. Furthermore, cost, safety and ease of production must be considered when evaluating storage options. Currently, no available system satisfies the requirements for wide scale acceptance. Some metallic systems allow reversible absorption/desorption of hydrogen, at temperatures and pressures suitable for practical applications. Currently, metallic hydrides based on intermetallic alloys are the most studied storage options for applications where weight is not an issue, representing more compact systems (by factor of 3x) when compared with high pressure compressed gas. In this work, the general mechanism of hydrogenation of metallic systems is discussed highlighting the potential for improvements and limitations. Examples of AB5 and AB type intermetallics will be given
A dynamic two phase flow model for a pilot scale sodium borohydride hydrogen generation reactor
A two-dimensional, non-isothermal, and dynamic model was developed to describe a sodium borohydride/hydrogen re-actor for stationary use. All relevant transport phenomena were treated in detail and the kinetic model developed previ-ously by the authors was introduced into the algorithm. In this paper the reactive solution was modeled as a two phase flow; with this approach the impact of the hydrogen production on the solution stirring could be observed and quantified. Results showed that not all ruthenium deposited on the nickel foam was used efficiently as catalyst. In fact, most of the reaction occurred in the surface of the catalyst foam and around 70% of the deposited catalyst was not used. It was also demonstrated the importance of the two phase flow approach for a correct simulation of the solution stirring and heat transfer
Synthesis of azole biophospanates presursors for proton-exchange membrane for application in high temperature PEM fuel cells
This work reports the synthesis and characterization of phosphonate-, hydroxybisphosphonate- and aminobisphosphonatebenzimidazole derivatives substituted at N-1 position and new regioisomers phosphonateand aminobisphosphonatebenzotriazole derivatives substituted at N-1 or N-2 positions. The compounds were characterized by NMR, IR spectroscopy and mass spectrometry (low and high resolution) allowing the assignment of their structure, including the identification of regioisomers. These azoles will be precursors of mesoporous silica host to produce novel membranes materials with high proton conductivity for intermediate temperature PEMFCs
Synthesis and characterization of new azaheterocyclic aromatic phosphonates for hybrid materials for fuel cell applications
ABSTRACT: This work reports the synthesis and characterization of new azaheterocyclic aromatic phosphonates derivated from benzimidazole and benzotriazole by nickel-catalyzed Arbuzov reaction of 4,7-dibromo-2,1,3-benzothiadiazole with triethyl phosphite, followed by reductive sulfur extrusion reaction and cyclization. The compounds were characterized by NMR and mass spectrometry (low and high resolution). These azoles will be incorporated into proton conductive inorganic-organic hybrid membranes of mesoporous silica to produce novel membranes materials with high proton conductivity for intermediate temperature PEMFCs.info:eu-repo/semantics/publishedVersio
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