We discuss the effects of particle correlations on the spectral broadening due to the radiator motion (Doppler broadening) for a Ni-like XUV laser line pumped in two different regimes (transient and quasi-steady state regimes) of collisional excitation. In a medium with gain, radiative transport effects modify the observed profile and these modifications depend on the homogeneous or inhomogeneo...

Two microstrip fed ultra-wideband (UWB) antennas with different band rejection techniques are presented in this paper. The designed antennas consist of a defected ground plane with an elliptical slot and two different radiator shapes. The first design is composed of a half circular ring radiator element while the second one uses a crescent shaped radiator. The radiators are fed by a 50 Ω micros...

This chapter focuses on the design of compact planar multiband antennas intended for exist‐ ing wireless services including LTE, GPS, GSM, PCS, DCS, GPS, UMTS, WLAN and Wi‐ MAX bands. The present techniques available in the open literature include the modification of the main radiator via bending, folding, meandering and wrapping. Each approach offers different advantages, depending on the requ...

The profiles of spectral lines of a radiator (atom or ion) immersed in a plasma are a valuable diagnostic tool [1]. Under certain conditions [1, 2], the observed line shapes are closely related to the electric microfield distribution (MFD) at the position of the radiator [2]. Since the pioneering work of Holtsmark [2], various theoretical approaches to determine the MFD have been proposed. Most...

An antenna is a device that is used to transfer guided electromagnetic waves (signals) to radiating waves in an unbounded medium, usually free space, and vice versa (i.e., in either the transmitting or receiving mode of operation). Antennas are frequency-dependent devices. Each antenna is designed for a certain frequency band. Beyond the operating band, the antenna rejects the signal. Therefore...

We present experimental data towards the development of a low-order model for the jet noise source for predictions of isolated and installed noise. In the proposed scheme, the source is prescribed on a radiator surface defining the boundary between the inner rotational jet flow and the outer linear pressure field. The source consists of wavepacket-type partial fields whose noise emission can be...

We show that a periodic metal-metal multilayer nanostructure can serve as an efficient source of hard x-ray transition radiation. Our research effort is aimed at developing an x-ray source for medical applications, which is based on using low-energy relativistic electrons. The approach toward choosing radiator-spacer couples for the generation of hard x-ray resonant transition radiation by few-...

In our daily life, central heating systems are generally used in home and office heating. The majority of fuel used in these systems are either natural gas or coal. However, in some cases air-conditioners and electrical oil-radiators are preferred in the heating of small mediums. But, the cost of electrical based heating is much higher than the cost of natural gas or coal based heating. Conside...

High power and miniaturization of motors in an in-wheel drive system, which is installed inside the wheels of a vehicle, are required for directly driving the wheels. In addition, an efficient cooling system is required to ensure high driving performance and durability. This study experimentally evaluated the heat dissipation performance of a 35-kW-class large-capacity in-wheel motor equipped w...

The harmonic generation process in a harmonic cascade (HC) FEL is subject to noise degradation which is proportional to the square of the total harmonic order. In this paper, we study the shot noise evolution in the first-stage modulator and radiator of a HC FEL that produces the dominant noise contributions. We derive the effective input noise for a modulator operating in the low-gain regime, ...