Quantum gravity effect in torsion driven inflation and CP violation

Journal of High Energy Physics - In this paper we study the production of a heavy charged Higgs boson in association with heavy quarks at the LHC in the two-Higgs-doublet model. We present for the...     

Vibration control of a transversely excited cantilever beam with tip mass

The problem of controlling the vibration of a transversely excited cantilever beam with tip mass is analyzed within the framework of the Euler–Bernoulli beam theory. A sinusoidally varying transverse excitation is applied at the left end of the cantilever beam, while a payload is attached to the free end of the beam. An active control of the transverse vibration based on cubic velocity is studied. Here, cubic velocity feedback law is proposed as a devise to suppress the vibration of the system subjected to primary and subharmonic resonance conditions. Method of multiple scales as one of the perturbation technique is used to reduce the second-order temporal equation into a set of two first-order differential equations that govern the time variation of the amplitude and phase of the response. Then the stability and bifurcation of the system is investigated. Frequency–response curves are obtained numerically for primary and subharmonic resonance conditions for different values of controller gain. The numerical results portrayed that a significant amount of vibration reduction can be obtained actively by using a suitable value of controller gain. The response obtained using method of multiple scales is compared with those obtained by numerically solving the temporal equation of motion and are found to be in good agreement. Numerical simulation for amplitude is also obtained by integrating the equation of motion in the frequency range between 1 and 3. The developed results can be extensively used to suppress the vibration of a transversely excited cantilever beam with tip mass or similar systems actively.     

Study of the topology of metal-containing granular films by light scattering and atomic force microscopy

The correlation properties of films consisting of granular structures with granules smaller than 6 nm prepared by the laser electrodispersion method are investigated. The correlation functions of the nanoparticle distribution on a transparent substrate are calculated from the angular structure of scattered radiation using the single-scattering approximation, as well as from the data of atomic force microscopy for copper, nickel, and palladium structures with different packing density. The size of coarse particles in nanostructures is estimated.     

Incorporation of generalized uncertainty principle into Lifshitz field theories

In this paper, we will incorporate the generalized uncertainty principle into field theories with Lifshitz scaling. We will first construct both bosonic and fermionic theories with Lifshitz scaling based on generalized uncertainty principle. After that we will incorporate the generalized uncertainty principle into a non-abelian gauge theory with Lifshitz scaling. We will observe that even though the action for this theory is non-local, it is invariant under local gauge transformations. We will also perform the stochastic quantization of this Lifshitz fermionic theory based generalized uncertainty principle.     

Non-linear response of a magneto-elastic translating beam with prismatic joint for higher resonance conditions

The non-linear response of a magneto-elastic translating beam having prismatic joint for higher resonance conditions is studied. A periodically varying transverse magnetic field is applied to the system. Two frequencies of prismatic motion and oscillating transverse magnetic field are implemented to the system. The method of multiple scales as one of the perturbation techniques is used to derive two first order ordinary differential equations that govern the time variation of the amplitude and phase of the response. Then a stability analysis is conducted for subharmonic resonance and simultaneous resonance conditions. A parametric study is performed to investigate the effect of magnetic field strength, amplitude of prismatic motion, damping and payload mass on the frequency response curves for both the resonance conditions. The catastrophic failure of the system may occur due to the presence of saddle-node and pitchfork bifurcations. The results obtained by method of multiple scales are compared with those obtained by numerically integrating the reduced equations and are found to be in good agreement. The developed results can be applied to control the vibration of a beam with prismatic joint subjected to magnetic field for third order subharmonic resonance and simultaneous resonance conditions.     

Spectrophotometric system for measuring the characteristics of light scattered by biological tissues and humoral media

The structure, assembly, and physical capabilities of a spectrophotometric system intended for studying biotissues and humoral fluids are described. It can be used to investigate all the characteristics of scattered light at wavelengths of 400–1000 nm that are of interest for various problems in biomedical optics. Examples of these problems include noninvasive diagnostics of the structural and biophysical parameters of human skin tissue, analysis of the hemoglobin composition, sizes and degree of aggregation of erythrocytes, and evaluating the depth of penetration of light into biotissue. Pilot experiments on measuring the characteristics of scattered light are conducted in order to select an optimum operating mode for the system, estimate its errors, and develop ways of minimizing these errors.     

Light reflection spectra as a diagnostic tool for the structural and biophysical parameters of skin

The calculation scheme and the diagnostic algorithm for diagnosing the structural and biophysical parameters of skin from the spectrum of reflected radiation are constructed. The sought parameters are determined from the solution of the spectroscopic problem under conditions of multiple scattering. The method presented is based on the previously proposed model of the spectral properties of a tissue and on the engineering approaches to the solution of the transfer equation. The sought parameters are the volume concentrations of melanin and capillaries, the thickness of epidermis, the average diameter of capillaries, and the degree of blood oxygenation. In order to optimize the algorithm with respect to wavelength and to elaborate the experimental diagnostic scheme, the sensitivity of the reflection spectrum to the sought parameters is studied. The procedure of their successive restoration is proposed.     

Imaging spectroscopy: Origin and future trends

Imaging spectroscopy, a useful tool for modern spectroscopic studies, can embed both spatial and spectral information to a set of images and derive the spectra from that. Such techniques are implemented to diversified fields like space observation and laboratory studies of solid materials. The present article intends to highlight the less noticed but significant fact that today's imaging spectroscopy in physical science originates from hyperspectral remote sensing, a technique for earth science that acquired maturity during the last three decades. It introduces several applications of spectral imaging for terrestrial and extraterrestrial objects and anticipates some future trends in this technique. Implementation of imaging spectroscopy to atomic and molecular physics is hoped to provide an indication of future research in this direction.