Frequency intermittency and energy pumping by linear attachments

Cataloged from PDF version of article.The present paper considers the problem of realizing an effective targeted energy pumping from a linear oscillator to a set of ungrounded linear resonators attached to it. Theoretical as well as numerical results demonstrate the efficacy of using a complex attachment as a passive absorber of broadband energy injected into the primary structure. The paper unveils also the existence of an instantaneous frequency associated with the master response characterized by intermittency: a rather surprising result for a linear autonomous system. Comparison with nonlinear energy sinks demonstrates that the two systems have some analogies in this respect and that the linear complex attachment is a very efficient energy trap. (C) 2014 Elsevier Ltd. All rights reserved

Alternative scenarios for the LHC based electron-proton collider

Construction of the ERLC (twin LC) collider tangential to LHC will give opportunity to investigate ep collisions at essentially higher center-of-mass energies than ERL50 and LHC based ep collider. Luminosity estimations show that values well exceeding 10^{34} cm^{-2}s^{-1} can be achieved for ERLC and HL-LHC based ep colliders. Certainly, proposed ep colliders have great potential for clarifying QCD basics and new physics search in addition to providing precise PDFs for adequate interpretation of LHC experimental data. Another alternative to the ERL50 is to construct an e-ring with the same energy and length. In this case, 4.2x10^{33} cm^{-2}s^{-1} luminosity can be reached. The advantage of this option is that the {\mu}-ring can be installed instead of the e-ring as a next stage, which will allow it to reach a much higher center of mass energy.Comment: 8 pages, 1 figure, 8 tables. Section on physics search potential is added. Conclusion part is enlarged. New references are added. arXiv admin note: text overlap with arXiv:2107.0485

Review of Linac-Ring Type Collider Proposals

There are three possibly types of particle colliders schemes: familiar (well known) ring-ring colliders, less familiar however sufficiently advanced linear colliders and less familiar and less advanced linac-ring type colliders. The aim of this paper is two-fold: to present possibly complete list of papers on linac-ring type collider proposals and to emphasize the role of linac-ring type machines for future HEP research.Comment: quality of figures is improved, some misprints are correcte

Vibration absorption using non-dissipative complex attachments with impacts and parametric stiffness

Studies on prototypical systems that consist of a set of complex attachments, coupled to a primary structure characterized by a single degree of freedom system, have shown that vibratory energy can be transported away from the primary through use of complex undamped resonators. Properties and use of these subsystems as by energy absorbers have also been proposed, particularly using attachments that consist of a large set of resonators. These ideas have been originally developed for linear systems and they provided insight into energy sharing phenomenon in large structures like ships, airplanes, and cars, where interior substructures interact with a master structure, e.g., the hull, the fuselage, or the car body. This paper examines the effects of nonlinearities that develop in the attachments, making them even more complex. Specifically, two different nonlinearities are considered: (1) Those generated by impacts that develop among the attached resonators, and (2) parametric effects produced by time-varying stiffness of the resonators. Both the impacts and the parametric effects improve the results obtained using linear oscillators in terms of inhibiting transported energy from returning to the primary structure. The results are indeed comparable with those obtained using linear oscillators but with special frequency distributions, as in the findings of some recent papers by the same authors. Numerically obtained results show how energy is confined among the attached oscillators. © 2009 Acoustical Society of America

Energy equipartition and frequency distribution in complex attachments

As reported in several recent publications, an undamped simple oscillator with a complex attachment that consists of a set of undamped parallel resonators can exhibit unusual energy sharing properties. The conservative set of oscillators of the attachment can absorb nearly all the impulsive energy applied to the primary oscillator to which it is connected. The key factor in the ability of the attachment to absorb energy with near irreversibility correlates with the natural frequency distribution of the resonators within it. The reported results also show that a family of optimal frequency distributions can be determined on the basis of a variational approach, minimizing a certain functional related to the system response. The present paper establishes a link between these optimal frequency distributions and the energy equipartition principle: optimal frequency distributions are those that spread the injected energy as uniformly as possible over the degrees of freedom or over the modes of the system. Theoretical as well as numerical results presented support this point of view. © 2009 Acoustical Society of America

Model validation for a noninvasive arterial stenosis detection problem

Copyright @ 2013 American Institute of Mathematical SciencesA current thrust in medical research is the development of a non-invasive method for detection, localization, and characterization of an arterial stenosis (a blockage or partial blockage in an artery). A method has been proposed to detect shear waves in the chest cavity which have been generated by disturbances in the blood flow resulting from a stenosis. In order to develop this methodology further, we use both one-dimensional pressure and shear wave experimental data from novel acoustic phantoms to validate corresponding viscoelastic mathematical models, which were developed in a concept paper [8] and refined herein. We estimate model parameters which give a good fit (in a sense to be precisely defined) to the experimental data, and use asymptotic error theory to provide confidence intervals for parameter estimates. Finally, since a robust error model is necessary for accurate parameter estimates and confidence analysis, we include a comparison of absolute and relative models for measurement error.The National Institute of Allergy and Infectious Diseases, the Air Force Office of Scientific Research, the Deopartment of Education and the Engineering and Physical Sciences Research Council (EPSRC)

Production of ZnO thin films used in solar cell with a sol-gel homemade dip coater technique and investigated of their structural, morphological and optical properties

We designed a homemade dip coater controlled by an Arduino microcontroller to produce semiconductor metal oxide films such as ZnO, CoO, and NiO. The developed device was successfully used to deposit ZnO film on a glass substrate. The structural, surface, and optical properties of the film were investigated. XRD patterns showed that the film is predominantly a hexagonal wurtzite crystalline structure. Scanning electron microscopy (SEM) images showed that the ZnO film was uniformly and homogeneously coated on the glass substrate. EDX analysis confirmed the presence of Zn and O in the film structure. Optical characterization by UV-visible spectrometry showed that the ZnO film has a high transmittance of over 85% in the visible region and absorbs wavelengths in the range of 300–400 nm. Moreover, the band gap of the ZnO film calculated by the Tauc equation was determined as 3.398 eV