4,853 research outputs found
Hidden Extra U(1) at the Electroweak/TeV Scale
We propose a simple extension of the Standard Model (SM) by adding an extra
U(1) symmetry which is hidden from the SM sector. Such a hidden U(1) has not
been considered before, and its existence at the TeV scale can be explored at
the LHC. This hidden U(1) does not couple directly to the SM particles, and
couples only to new SU(2)_L singlet exotic quarks and singlet Higgs bosons, and
is broken at the TeV scale. The dominant signals at the high energy hadron
colliders are multi lepton and multi b-jet final states with or without missing
energy. We calculate the signal rates as well as the corresponding Standard
Model background for these final states. A very distinctive signal is 6 high
p_T b-jets in the final state with no missing energy. For a wide range of the
exotic quarks masses the signals are observable above the background at the
LHC.Comment: 19 pages, 5 figure
A comparative study of a bio fuel cell with two different proton exchange membrane for the production of electricity from waste water
In the present study, electricity generation with waste water as substrate was investigated in a two compartment biofuel cell with two different combinations of electrodes and membrane. Two proton exchange membranes namely nafion and agar salt bridge and aluminum as electrode were used in the biofuel cell. It was found that biofuel cells operated with nafion produce maximum voltage 0.504 V with a current density of 0.1 A/m2 whereas in case of agar salt bridge maximum voltage of 0.145 V with a current density of 0.05 A/m2 was obtained. The more voltage produced in case of nafion is attributed to its low resistance for hydrogen ion transport
Development of high efficiency solar cells on silicon web
Web base material is being improved with a goal toward obtaining solar cell efficiencies in excess of 18% (AM1). Carrier loss mechanisms in web silicon was investigated, techniques were developed to reduce carrier recombination in the web, and web cells were fabricated using effective surface passivation. The effect of stress on web cell performance was also investigated
Economic Efficiency Measure of Induction Motors for Industrial Applications
This paper, introduced an expression of Economic Efficiency Measure (EEM) to permit quick evaluation for replacement of faulty induction motor with alternative (new or refurbished motor) for lowest life-cycle cost based on efficiency and rated-load conditions. This approach, simplifies the process for evaluating the energy efficiency to mere proportionate factor called as EEM. During the operating phase, the motor losses correspond to extra energy consumption, based on various parameters like motor operating conditions, operating hours, operating costs, fault factor, depreciation factor and fixed costs. The approach is effective in addressing the global issue on replacement of the faulty motor that needs a comprehensive analysis and mathematical expression. Compared to other alternatives the EEM provides a simple but effective and reliable means to asses, the feasibility of replacing or refurbishing the faulty motor. A detail analysis here would establish how much the present approach is effective in determining the replacement for a faulty induction motor either by a new one or refurbished one of corresponding rating
[3-(5-Nitro-2-furyl)-1-phenyl-1H-pyrazol-4-yl](phenyl)methanone
In the title pyrazole compound, C20H13N3O4, an intramolecular C—H⋯O hydrogen bond generates a seven-membered ring, producing an S(7) ring motif. The essentially planar furan and pyrazole rings [maximum deviations of 0.002 (1) and 0.007 (1) Å, respectively] are coplanar with each other, forming a dihedral angle of 3.06 (10)°. The pyrazole ring forms dihedral angles of 8.51 (9) and 56.81 (9)° with the two benzene rings. The nitro group is coplanar with the attached furan ring, as indicated by the dihedral angle of 2.5 (3)°. In the crystal packing, intermolecular C—H⋯O hydrogen bonds link adjacent molecules into two-molecule-wide chains along the a axis. The crystal packing is further stabilized by weak intermolecular C—H⋯π and π–π interactions [centroid–centroid distance = 3.4441 (10) Å]
Associated single photons and doubly charged scalar at linear e-e- colliders
Doubly charged scalars, predicted in many models having exotic Higgs
representations, can in general have lepton-number violating (LFV) couplings.
We show that by using an associated monoenergetic final state photon seen at a
future linear e-e- collider, we can have a clear and distinct signature for a
doubly-charged resonance. The strength of the Delta L=2 coupling can also be
probed quite effectively as a function of the recoil mass of the doubly-charged
scalar.Comment: Reference adde
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