Although the incidence of floor vibration problems appears to be on the rise, the use of mechanical damping devices to control vibrations is limited. In a recent survey of vibration control methods, Murray reports that passive-mechanical damping methods, including viscous damping, visco-elastic damping, and tuned-mass dampers, have often gone untried outside the laboratory or have had marginal ...

As proposed spacecraft and their associated thrusters have become smaller, technology has been developed to meet the demand for performance measurements for the extremely low force levels produced. For such thrusters, it is also desirable to measure the mass changes resulting from the utilization of propellant associated with either the steady state thrust or transient impulses. A thrust stand ...

We present a complete computation of the inflaton decay into very massive fermions during preheating, including back-reaction effects. We show that heavy fermions are produced very efficiently up to masses of order 10–10 GeV; the accessible mass range is thus even broader than the one for heavy bosons. We apply our findings to the leptogenesis scenario, proposing a new version of it, in which t...

We study Sogami’s generalized covariant derivative method for a SU(2)L × SU(2)R ×U(1)B−L × SU(3)c model that contains bi-doublet and triplet Higgs bosons. In particular, a detailed study is made on the minimization conditions of the Higgs potential. It is known that a minimization condition and certain phenomenology for a extra gauge boson mass derive a restriction on potential parameters, whic...

The formulae describing the radiative decays η ′ (η) → γγ in QCD beyond the chiral limit are derived. The modifications of the conventional PCAC formulae due to the gluonic contribution to the axial anomaly in the flavour singlet channel are precisely described. The decay constants are found to satisfy a modified Dashen formula which generalises the Witten–Veneziano formula for the mass of the ...

We suggest a simple grand unified theory where the fifth dimensional coordinate is compactified on an S1/(Z2 × Z ′ 2) orbifold. This model is based on the supersymmetric flipped SU(5) × U(1) grand unified theory, which can realize not only the triplet-doublet splitting but also the natural fermion mass hierarchies. The triplet-doublet splitting is realized by S1/(Z2 × Z ′ 2) orbifolding, which ...

We consider the Nelson model on some static space-times and investigate the problem of existence of a ground state. Nelson models with variable coefficients arise when one replaces in the usual Nelson model the flat Minkowski metric by a static metric, allowing also the boson mass to depend on position. We investigate the existence of a ground state of the Hamiltonian in the presence of the inf...

American mass media’s relation with the US government in foreign policy decision-making has been the subject of numerous studies in the interdisciplinary field of political communication. This paper reexamines the interaction between the media and the government in the US foreign policy decision-making process, analyzing the possible congruity and/or incongruity between The Washington Post...