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This study deals with the evaluation of the longitudinal and transverse coupling impedance of a charge travelling in a drift tube with a perfectly electric conductive angular strip. The problem is formulated in the particle frame as dual series equations, and efficiently solved through the representation of the unknown in terms of Neumann series. Then, the electric parameters are obtained in the pipe frame through the Lorentz transforms. The presented solution can be adopted as the general methodology in case of angular discontinuities in particle accelerators.

In this article we propose a general method for estimating the capacitance of a ring placed on a dielectric supported by a metal plane. The problem, formulated as three integral equations, valid in complementary regions, is resolved by adopting a new expansion, which we have called double Neumann series, according to which the unknown of the problem is expanded by adopting a series of two Bessel function products.

High power microwave applications can be considered an attractive and eco-compatibile solution for contrasting the diffusion of Rhynchophorus ferrugineus, one of the major threats to palm in the Mediterranean area. In this work we present the results of a research activity aimed to obtain by palm dielectric heating temperatures that are lethal for the insect without damaging the plant tissues. Laboratory and semi-field tests showed an high effectiveness of the techniques.

Passive microwave filters based on HTS films are very promising for telecommunication applications. We report on the design, obtained using a commercial 2.5D software, and the realization of filters, fabricated with double sided YBCO films grown on LaAlO 3 substrates, for both receiving and transmission systems. For the receiving side, planar multi-pole interdigital L-band filters with 75 MHz transmission bandwidths have been fabricated on 2" substrates. Up to 80 K this kind of filter, based on a Tchebischev response, shows an insertion loss lower than 0.5 dB with a ripple of 0.3 dB for a maximum input power of 2 Watts. For the transmitting side, dual-mode filters represent one of the main interesting configuration to exploit since they can combine a high power handling capability with miniaturization requirements. A novel kind of dual-mode C-band filter based on cross slotted square resonators is presented. The novelty of the proposed structure is to use a pair of unequal crossed slots that are formed on a square patch resonator such that its structure size can be significantly reduced. A prototypal device operating at 3.7 GHz is fabricated with different type of couplings on 10 × 10 mm 2 LaAlO 3 substrate to showcase our proposal. The behavior of the filter as a function of the input power has been tested up to 2 Watts limited by the amplified power supply.

Although many fundamental physics auestions are still unanswered, the technology of hightemperature superconductors (HTSs) has become mature for use in wireless Communications. In particular, superconducting filters utilizing HTS epitaxial films can provide better interference rejection, full use of the available freauency spectrum, decrease in the noise floor and size and weight reduction in receiver subsystems. A comparison of the microwave properties between films of high-T e superconductors YBa2Cu3O7-δ and Tl2Ba2CaCu2O8 and medium-T e superconductor Nb3Sn is reported. A first prototype of a superconducting bandpass filter designed to handle a high circulating power and spanning the freauency range from 1710 to 1785 MHz is presented. The implications of its insertion in cellular base stations are discussed. © 2000 Taylor & Francis Group, LLC.

Although the micronutrient deficiencies and the related neurological manifestations are widely reported after malabsorbitive weight loss surgery, little is known about cerebral dysfunction secondary to micronutrient impairment in subjects undergoing restrictive interventions (that is, sleeve gastrectomy). We describe a case of a 27-year-old woman with a late development of a Wernicke's encephalopathy (WE) and of severe polyneuropathy following a sleeve gastrectomy without any sleeve stenosis. The impact of WE after bariatric surgery is significantly underestimated. Such a risk should be taken into consideration also after restrictive weight loss surgery. Thus, surgeoun/clinicians involved in bariatric patients management must be aware of neurological sequelae related to this intervention.European Journal of Clinical Nutrition advance online publication, 8 February 2012; doi:10.1038/ejcn.2012.10.

The antenna pattern synthesis problem is of the utmost importance in almost every kind of antenna applications. Therefore, a very large number of contributions have appeared on this subject. But virtually all of them deal with simplified versions of the complete synthesis problem, wherein the degrees of freedom available in principle are strongly reduced, and/or idealized design criteria or requirements are considered. In this paper we present a formulation which allows us to overcome this fragmentation of the synthesis problem. A clear and direct description of the performance actually required by the antenna and a representation of the radiating properties of the antenna as a system allows us to formulate the synthesis problem as an intersections finding problem, i.e., to find a common element between a number of sets, each one containing elements fulfilling part of the requirements. This allows a completely general and flexible formulation of the problem, independent of the actual structure of the antenna. Then the practical implementation of this formulation is widely discussed, showing how an efficient solution procedure can be devised. The implications of the well-known ill-conditioning of the synthesis problem are also discussed. In order to show how the approach works and to assess its flexibility and power, a couple of significant examples are included, namely, a phase-only reconfigurable array and a shaped reflector synthesis. These examples are unconventional since no a priori choice of the intensity distribution (for the array case) or of the feed cluster (for the reflector case) is required. The method presented is able to exploit all the available degrees of freedom in order to fulfill the design requirements. >

The matrix method for array diagnosis is based on the reconstruction of the excitation from measured near-field data by solving the linear system relating the excitation coefficients to the field at the measurement points. In this paper the matrix method is applied to the diagnosis of element failures in high-performance conformal array radar. The results confirm the usefulness of this technique in the cases wherein the standard backward propagation technique cannot be applied.

A non-perturbing, fast, low-cost probe for near-field measurements is presented in this paper. The new sensing technique's capabilities in antenna fault diagnosis and direct measurement of field intensity distribution at subwavelength distance from the sources are demonstrated by test measurement on different microwave antennas and applicators. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 38: 95–98, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10981

In this paper we present an empirical procedure to design microwave slot array applicators for heating lossy dielectric slabs. To this end, a commercial simulation code has been used to characterize the behaviour of a slot radiating on a dielectric slab with a given complex permittivity. By using this characterization a waveguide slot linear array has been designed. Results show that this applicator is more efficient than a similar applicator designed by following a standard approximate analytical method.

In this works, a glow discharge cold plasma treatment was employed to treat organic and inorganic fibre (aramid , polyethylene and glass fibres) with the aim to improve the fibre-matrix interface properties. In order to quantitatively assess the effect of plasma treatment, treated and untreated fibres were used to fabricate specimens suitable for mechanical test characterisation. Peeling test and three-point bending tests were performed on untreated and treated specimens. Scanning electron microscopy was utilised to examine the plasma effects on the fibres surface and on the specimen fracture surfaces. The results obtained indicate that the interface strength depends of both the fibre type and the treatment time. In all cases, an increase in delamination energy was observed under appropriate treatment conditions. SEM analysis had shoved variation in the fibres roughens Although this last result, the measured Young’s modulus and flexural strength do not undergo any decrease, whichever the exposure time

Microstrip lines have been widely analysed in recent years, mainly by means of numerical methods or semianalytical approaches. In this paper, a new, and efficient solution, based on a dual approach, is proposed. The induced currents on the ground plane are evaluated and compared to the ones obtained by means of numerical methods.

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