The efficient reduction of the pulse length and the energy width of electron beams plays a crucial role in the generation of short pulses in the range of sub-picoseconds at future light sources. At the radiation source ELBE in DresdenRossendorf short pulses are required for coherent THz generation and laser-electron beam interaction experiments such as X-ray Thomson scattering. Energy dechirpin...

We propose an indirect approach to the generation of a two-dimensional quasiperiodic (QP) pattern in convection and similar nonlinear dissipative systems where a direct generation of stable uniform QP planforms is not possible. An eightfold QP pattern can be created as a broad transient layer between two domains filled by square cells (SC) oriented under the angle of 45 degrees relative to each...

Abstract. Observations indicate that the fortnightly fluctuations in mean amplitude of water level increase upstream direction along lower half a tide-dominated estuary (the Guadiana Estuary), with negligible river discharge, but remain constant upstream. Analytical solutions reproducing semi-diurnal wave propagation shows this pattern results from reflection effects at head. The phase differen...

An analysis is suggested to study the impact of Hall currents in Jeffrey fluid which is chemically reactive through a porous medium limited by a semi-infinite vertical permeable plate within the existence of heat generation. An evenly distributed magnetic field turns vertically on the porous surface which absorbs the Jeffrey fluid with a changed suction velocity with time. The analytical expres...

Abstract Proppant is one of the major elements a hydraulic fracture process that can influence productivity an oil or gas well. The permeability propped may be determined through laboratory measurements, utilizing experimental relationships, using analytical methods. All methods have their advantages and disadvantages, this study attempts to offers solution combines various achieve practical so...