The two-dimensional (2-D) parabolic equation (PE) is widely used for making radiowave propagation predictions in the troposphere. The effects of transverse terrain gradients, propagation around the sides of obstacles, and scattering from large obstacles to the side of the great circle path are not modeled, leading to prediction errors in many situations. In this paper, these errors are addresse...

K. Badron , A.F. Ismail, , M.R. Islam , A.R Tharek and J. Din Electrical and Computer Department, Kulliyyah of Engineering, International Islamic University Malaysia Fakulti Kejuruteraan Elektrik, Universiti Teknologi Malaysia Abstract. Radiowave propagation plays a very important part in the design and eventually dictates performance of space communication systems. The requirements of today’s ...

The sudden growth of mobile communications, and more specifically the forthcoming new generations of mobile systems (such as UMTS) require the development of sophisticated tools for automatic and optimum planning and network design. Such systems must include accurate radiopropagation models, as well as efficient global optimizers. Due to the huge complexity of the task, the combined use of more...

We describe an experiment in satellite radiowave probing of the ionosphere, modi®ed by powerful waves from the HF heating facility at Tromsù (Norway) in May 1995. Amplitude scintillations and variations of the phase of VHF signals from Russian navigational satellites passing over the heated region were observed. We show that both large-scale electron density irregularities (several tens of kilo...

With the growth of wireless technology for an everincreasing range of devices, services, applications and users, the role of spectrum management is becoming more complex and difficult. National and international spectrum regulations define the use of frequencies from 9 kHz to 275 GHz, and most spectrum bands are allocated to two or more services. Furthermore, new technologies and growing techno...

The technology The explosion in the number of telemedicine projects is largely due to major advances in telecommunications technology, which have made it possible to transfer large amounts of data quickly. One of the most significant developments is the introduction of integrated services digital network (ISDN) lines to the telephone network of most western countries. These lines have the capac...

One of the main limitations for BNCT effectiveness is the insufficient intake of (10)B nuclei within tumour cells. This work was aimed at investigating the use of L-DOPA as enhancer for boronophenylalanine (BPA) uptake in the C6 glioma model. The investigation was first performed in vitro, and then extended in vivo to the animal model. BPA accumulation in C6 glioma cells was assessed, using rad...

The effects of energetic electron precipitation into the auroral region at a time of enhanced solar wind have been investigated during a continuous period of 24 h, using the European Incoherent Scatter (EISCAT) radar, an imaging riometer, and particle measurements on an orbiting satellite. The relative effects in the E region (120 km) and D region (90 km) are found to vary during the day, consi...