Test particle acceleration by rotating jet magnetospheres

Abstract

Abstract. Centrifugal acceleration of charged test particles at the base of a rotating jet magnetosphere is considered. Based on an analysis of forces we derive the equation for the radial accelerated motion and present an analytical solution. It is shown that for particles moving outwards along rotating magnetic field lines, the energy gain is in particular limited by the breakdown of the bead-on-the-wire approximation which occurs in the vicinity of the light cylinder r L . The corresponding upper limit for the maximum Lorentz factor γ max for electrons scales ∝ B 2/3 r 2/3 L , with B the magnetic field strength at r L , and is at most of the order of a 10 2 − 10 3 for the conditions regarded to be typical for BL Lac objects. Such values suggest that this mechanism may provide pre-accelerated seed particles which are required for efficient Fermi-type particle acceleration at larger scales in radio jets.

A fundamental approach for the estimation of the mechanical glass transition temperature in gelatin

“…Instead, the emerging constant energy of activation reflects the need to overcome an energetic barrier for the occurrence of local rearrangements from one state to the other. The fundamental definition is an improvement on several empirical indices of the glass transition temperature that can be found in the literature [12,31]. The empirical nature of indicators does not allow for a physical interpretation of T g and, consequently, these have been reported to be entirely different estimates for the same preparation.…”

“…This method has not been extended, apparently because of the relative complexity of the formalism of the time-time superposition, and the separation of the variables of time and temperature in the mechanical properties of biomaterials [12]. Recently, we treated the case of polysaccharides at normal levels of industrial use (up to 2%) in the presence of high levels of sucrose and/or glucose syrup (60-90%) to a sinusoidal driving force on shear.…”

Gels from acrylic acid and hydroxypropyl cellulose via free radical polymerization

“…The change in the transitions is a clear indication of the changes in the viscoelastic properties of the gels. The discrepancies in T g between DSC and DMA are related to the different physical parameters measured with each procedure [15], as some authors suggest that DMA is more precise than DSC [16]. Since HPC can form liquid crystal phases and present a complex substitution pattern, it is not clear if the endothermic transition is due to a glass transition, the melting of the crystalline phase, or a liquid crystal isotropic transition.…”

Mechanical Properties of Soft Magnetic Composites at the Temperature of Liquid Nitrogen

“…Below glass transition temperature, an epoxy resin is hard but brittle and it increases bending and compressive strength of composites [19][20][21].…”